aboutsummaryrefslogtreecommitdiffstats
path: root/gcc-4.6/gcc/tree-vect-data-refs.c
diff options
context:
space:
mode:
authorJing Yu <jingyu@google.com>2011-12-19 16:56:54 -0800
committerJing Yu <jingyu@google.com>2011-12-19 16:56:54 -0800
commit40d7cd0fd78fe2004e2a53c4618c148339b02733 (patch)
tree5874557a6c86a1f564a03e5f28b266e31bc3759c /gcc-4.6/gcc/tree-vect-data-refs.c
parentfe2afdf3f3701489c05d2a7509752d6f0c7616f7 (diff)
downloadtoolchain_gcc-40d7cd0fd78fe2004e2a53c4618c148339b02733.tar.gz
toolchain_gcc-40d7cd0fd78fe2004e2a53c4618c148339b02733.tar.bz2
toolchain_gcc-40d7cd0fd78fe2004e2a53c4618c148339b02733.zip
Add gcc-4.6. Synced to @180989
Change-Id: Ie3676586e1d8e3c8cd9f07d022f450d05fa08439 svn://gcc.gnu.org/svn/gcc/branches/google/gcc-4_6-mobile
Diffstat (limited to 'gcc-4.6/gcc/tree-vect-data-refs.c')
-rw-r--r--gcc-4.6/gcc/tree-vect-data-refs.c4288
1 files changed, 4288 insertions, 0 deletions
diff --git a/gcc-4.6/gcc/tree-vect-data-refs.c b/gcc-4.6/gcc/tree-vect-data-refs.c
new file mode 100644
index 000000000..e0427c702
--- /dev/null
+++ b/gcc-4.6/gcc/tree-vect-data-refs.c
@@ -0,0 +1,4288 @@
+/* Data References Analysis and Manipulation Utilities for Vectorization.
+ Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
+ Free Software Foundation, Inc.
+ Contributed by Dorit Naishlos <dorit@il.ibm.com>
+ and Ira Rosen <irar@il.ibm.com>
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "ggc.h"
+#include "tree.h"
+#include "tm_p.h"
+#include "target.h"
+#include "basic-block.h"
+#include "tree-pretty-print.h"
+#include "gimple-pretty-print.h"
+#include "tree-flow.h"
+#include "tree-dump.h"
+#include "cfgloop.h"
+#include "tree-chrec.h"
+#include "tree-scalar-evolution.h"
+#include "tree-vectorizer.h"
+#include "diagnostic-core.h"
+
+/* Need to include rtl.h, expr.h, etc. for optabs. */
+#include "expr.h"
+#include "optabs.h"
+
+/* Return the smallest scalar part of STMT.
+ This is used to determine the vectype of the stmt. We generally set the
+ vectype according to the type of the result (lhs). For stmts whose
+ result-type is different than the type of the arguments (e.g., demotion,
+ promotion), vectype will be reset appropriately (later). Note that we have
+ to visit the smallest datatype in this function, because that determines the
+ VF. If the smallest datatype in the loop is present only as the rhs of a
+ promotion operation - we'd miss it.
+ Such a case, where a variable of this datatype does not appear in the lhs
+ anywhere in the loop, can only occur if it's an invariant: e.g.:
+ 'int_x = (int) short_inv', which we'd expect to have been optimized away by
+ invariant motion. However, we cannot rely on invariant motion to always
+ take invariants out of the loop, and so in the case of promotion we also
+ have to check the rhs.
+ LHS_SIZE_UNIT and RHS_SIZE_UNIT contain the sizes of the corresponding
+ types. */
+
+tree
+vect_get_smallest_scalar_type (gimple stmt, HOST_WIDE_INT *lhs_size_unit,
+ HOST_WIDE_INT *rhs_size_unit)
+{
+ tree scalar_type = gimple_expr_type (stmt);
+ HOST_WIDE_INT lhs, rhs;
+
+ lhs = rhs = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (scalar_type));
+
+ if (is_gimple_assign (stmt)
+ && (gimple_assign_cast_p (stmt)
+ || gimple_assign_rhs_code (stmt) == WIDEN_MULT_EXPR
+ || gimple_assign_rhs_code (stmt) == FLOAT_EXPR))
+ {
+ tree rhs_type = TREE_TYPE (gimple_assign_rhs1 (stmt));
+
+ rhs = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (rhs_type));
+ if (rhs < lhs)
+ scalar_type = rhs_type;
+ }
+
+ *lhs_size_unit = lhs;
+ *rhs_size_unit = rhs;
+ return scalar_type;
+}
+
+
+/* Find the place of the data-ref in STMT in the interleaving chain that starts
+ from FIRST_STMT. Return -1 if the data-ref is not a part of the chain. */
+
+int
+vect_get_place_in_interleaving_chain (gimple stmt, gimple first_stmt)
+{
+ gimple next_stmt = first_stmt;
+ int result = 0;
+
+ if (first_stmt != DR_GROUP_FIRST_DR (vinfo_for_stmt (stmt)))
+ return -1;
+
+ while (next_stmt && next_stmt != stmt)
+ {
+ result++;
+ next_stmt = DR_GROUP_NEXT_DR (vinfo_for_stmt (next_stmt));
+ }
+
+ if (next_stmt)
+ return result;
+ else
+ return -1;
+}
+
+
+/* Function vect_insert_into_interleaving_chain.
+
+ Insert DRA into the interleaving chain of DRB according to DRA's INIT. */
+
+static void
+vect_insert_into_interleaving_chain (struct data_reference *dra,
+ struct data_reference *drb)
+{
+ gimple prev, next;
+ tree next_init;
+ stmt_vec_info stmtinfo_a = vinfo_for_stmt (DR_STMT (dra));
+ stmt_vec_info stmtinfo_b = vinfo_for_stmt (DR_STMT (drb));
+
+ prev = DR_GROUP_FIRST_DR (stmtinfo_b);
+ next = DR_GROUP_NEXT_DR (vinfo_for_stmt (prev));
+ while (next)
+ {
+ next_init = DR_INIT (STMT_VINFO_DATA_REF (vinfo_for_stmt (next)));
+ if (tree_int_cst_compare (next_init, DR_INIT (dra)) > 0)
+ {
+ /* Insert here. */
+ DR_GROUP_NEXT_DR (vinfo_for_stmt (prev)) = DR_STMT (dra);
+ DR_GROUP_NEXT_DR (stmtinfo_a) = next;
+ return;
+ }
+ prev = next;
+ next = DR_GROUP_NEXT_DR (vinfo_for_stmt (prev));
+ }
+
+ /* We got to the end of the list. Insert here. */
+ DR_GROUP_NEXT_DR (vinfo_for_stmt (prev)) = DR_STMT (dra);
+ DR_GROUP_NEXT_DR (stmtinfo_a) = NULL;
+}
+
+
+/* Function vect_update_interleaving_chain.
+
+ For two data-refs DRA and DRB that are a part of a chain interleaved data
+ accesses, update the interleaving chain. DRB's INIT is smaller than DRA's.
+
+ There are four possible cases:
+ 1. New stmts - both DRA and DRB are not a part of any chain:
+ FIRST_DR = DRB
+ NEXT_DR (DRB) = DRA
+ 2. DRB is a part of a chain and DRA is not:
+ no need to update FIRST_DR
+ no need to insert DRB
+ insert DRA according to init
+ 3. DRA is a part of a chain and DRB is not:
+ if (init of FIRST_DR > init of DRB)
+ FIRST_DR = DRB
+ NEXT(FIRST_DR) = previous FIRST_DR
+ else
+ insert DRB according to its init
+ 4. both DRA and DRB are in some interleaving chains:
+ choose the chain with the smallest init of FIRST_DR
+ insert the nodes of the second chain into the first one. */
+
+static void
+vect_update_interleaving_chain (struct data_reference *drb,
+ struct data_reference *dra)
+{
+ stmt_vec_info stmtinfo_a = vinfo_for_stmt (DR_STMT (dra));
+ stmt_vec_info stmtinfo_b = vinfo_for_stmt (DR_STMT (drb));
+ tree next_init, init_dra_chain, init_drb_chain;
+ gimple first_a, first_b;
+ tree node_init;
+ gimple node, prev, next, first_stmt;
+
+ /* 1. New stmts - both DRA and DRB are not a part of any chain. */
+ if (!DR_GROUP_FIRST_DR (stmtinfo_a) && !DR_GROUP_FIRST_DR (stmtinfo_b))
+ {
+ DR_GROUP_FIRST_DR (stmtinfo_a) = DR_STMT (drb);
+ DR_GROUP_FIRST_DR (stmtinfo_b) = DR_STMT (drb);
+ DR_GROUP_NEXT_DR (stmtinfo_b) = DR_STMT (dra);
+ return;
+ }
+
+ /* 2. DRB is a part of a chain and DRA is not. */
+ if (!DR_GROUP_FIRST_DR (stmtinfo_a) && DR_GROUP_FIRST_DR (stmtinfo_b))
+ {
+ DR_GROUP_FIRST_DR (stmtinfo_a) = DR_GROUP_FIRST_DR (stmtinfo_b);
+ /* Insert DRA into the chain of DRB. */
+ vect_insert_into_interleaving_chain (dra, drb);
+ return;
+ }
+
+ /* 3. DRA is a part of a chain and DRB is not. */
+ if (DR_GROUP_FIRST_DR (stmtinfo_a) && !DR_GROUP_FIRST_DR (stmtinfo_b))
+ {
+ gimple old_first_stmt = DR_GROUP_FIRST_DR (stmtinfo_a);
+ tree init_old = DR_INIT (STMT_VINFO_DATA_REF (vinfo_for_stmt (
+ old_first_stmt)));
+ gimple tmp;
+
+ if (tree_int_cst_compare (init_old, DR_INIT (drb)) > 0)
+ {
+ /* DRB's init is smaller than the init of the stmt previously marked
+ as the first stmt of the interleaving chain of DRA. Therefore, we
+ update FIRST_STMT and put DRB in the head of the list. */
+ DR_GROUP_FIRST_DR (stmtinfo_b) = DR_STMT (drb);
+ DR_GROUP_NEXT_DR (stmtinfo_b) = old_first_stmt;
+
+ /* Update all the stmts in the list to point to the new FIRST_STMT. */
+ tmp = old_first_stmt;
+ while (tmp)
+ {
+ DR_GROUP_FIRST_DR (vinfo_for_stmt (tmp)) = DR_STMT (drb);
+ tmp = DR_GROUP_NEXT_DR (vinfo_for_stmt (tmp));
+ }
+ }
+ else
+ {
+ /* Insert DRB in the list of DRA. */
+ vect_insert_into_interleaving_chain (drb, dra);
+ DR_GROUP_FIRST_DR (stmtinfo_b) = DR_GROUP_FIRST_DR (stmtinfo_a);
+ }
+ return;
+ }
+
+ /* 4. both DRA and DRB are in some interleaving chains. */
+ first_a = DR_GROUP_FIRST_DR (stmtinfo_a);
+ first_b = DR_GROUP_FIRST_DR (stmtinfo_b);
+ if (first_a == first_b)
+ return;
+ init_dra_chain = DR_INIT (STMT_VINFO_DATA_REF (vinfo_for_stmt (first_a)));
+ init_drb_chain = DR_INIT (STMT_VINFO_DATA_REF (vinfo_for_stmt (first_b)));
+
+ if (tree_int_cst_compare (init_dra_chain, init_drb_chain) > 0)
+ {
+ /* Insert the nodes of DRA chain into the DRB chain.
+ After inserting a node, continue from this node of the DRB chain (don't
+ start from the beginning. */
+ node = DR_GROUP_FIRST_DR (stmtinfo_a);
+ prev = DR_GROUP_FIRST_DR (stmtinfo_b);
+ first_stmt = first_b;
+ }
+ else
+ {
+ /* Insert the nodes of DRB chain into the DRA chain.
+ After inserting a node, continue from this node of the DRA chain (don't
+ start from the beginning. */
+ node = DR_GROUP_FIRST_DR (stmtinfo_b);
+ prev = DR_GROUP_FIRST_DR (stmtinfo_a);
+ first_stmt = first_a;
+ }
+
+ while (node)
+ {
+ node_init = DR_INIT (STMT_VINFO_DATA_REF (vinfo_for_stmt (node)));
+ next = DR_GROUP_NEXT_DR (vinfo_for_stmt (prev));
+ while (next)
+ {
+ next_init = DR_INIT (STMT_VINFO_DATA_REF (vinfo_for_stmt (next)));
+ if (tree_int_cst_compare (next_init, node_init) > 0)
+ {
+ /* Insert here. */
+ DR_GROUP_NEXT_DR (vinfo_for_stmt (prev)) = node;
+ DR_GROUP_NEXT_DR (vinfo_for_stmt (node)) = next;
+ prev = node;
+ break;
+ }
+ prev = next;
+ next = DR_GROUP_NEXT_DR (vinfo_for_stmt (prev));
+ }
+ if (!next)
+ {
+ /* We got to the end of the list. Insert here. */
+ DR_GROUP_NEXT_DR (vinfo_for_stmt (prev)) = node;
+ DR_GROUP_NEXT_DR (vinfo_for_stmt (node)) = NULL;
+ prev = node;
+ }
+ DR_GROUP_FIRST_DR (vinfo_for_stmt (node)) = first_stmt;
+ node = DR_GROUP_NEXT_DR (vinfo_for_stmt (node));
+ }
+}
+
+
+/* Function vect_equal_offsets.
+
+ Check if OFFSET1 and OFFSET2 are identical expressions. */
+
+static bool
+vect_equal_offsets (tree offset1, tree offset2)
+{
+ bool res;
+
+ STRIP_NOPS (offset1);
+ STRIP_NOPS (offset2);
+
+ if (offset1 == offset2)
+ return true;
+
+ if (TREE_CODE (offset1) != TREE_CODE (offset2)
+ || (!BINARY_CLASS_P (offset1) && !UNARY_CLASS_P (offset1)))
+ return false;
+
+ res = vect_equal_offsets (TREE_OPERAND (offset1, 0),
+ TREE_OPERAND (offset2, 0));
+
+ if (!res || !BINARY_CLASS_P (offset1))
+ return res;
+
+ res = vect_equal_offsets (TREE_OPERAND (offset1, 1),
+ TREE_OPERAND (offset2, 1));
+
+ return res;
+}
+
+
+/* Check dependence between DRA and DRB for basic block vectorization.
+ If the accesses share same bases and offsets, we can compare their initial
+ constant offsets to decide whether they differ or not. In case of a read-
+ write dependence we check that the load is before the store to ensure that
+ vectorization will not change the order of the accesses. */
+
+static bool
+vect_drs_dependent_in_basic_block (struct data_reference *dra,
+ struct data_reference *drb)
+{
+ HOST_WIDE_INT type_size_a, type_size_b, init_a, init_b;
+ gimple earlier_stmt;
+
+ /* We only call this function for pairs of loads and stores, but we verify
+ it here. */
+ if (DR_IS_READ (dra) == DR_IS_READ (drb))
+ {
+ if (DR_IS_READ (dra))
+ return false;
+ else
+ return true;
+ }
+
+ /* Check that the data-refs have same bases and offsets. If not, we can't
+ determine if they are dependent. */
+ if ((DR_BASE_ADDRESS (dra) != DR_BASE_ADDRESS (drb)
+ && (TREE_CODE (DR_BASE_ADDRESS (dra)) != ADDR_EXPR
+ || TREE_CODE (DR_BASE_ADDRESS (drb)) != ADDR_EXPR
+ || TREE_OPERAND (DR_BASE_ADDRESS (dra), 0)
+ != TREE_OPERAND (DR_BASE_ADDRESS (drb),0)))
+ || !vect_equal_offsets (DR_OFFSET (dra), DR_OFFSET (drb)))
+ return true;
+
+ /* Check the types. */
+ type_size_a = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (dra))));
+ type_size_b = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (drb))));
+
+ if (type_size_a != type_size_b
+ || !types_compatible_p (TREE_TYPE (DR_REF (dra)),
+ TREE_TYPE (DR_REF (drb))))
+ return true;
+
+ init_a = TREE_INT_CST_LOW (DR_INIT (dra));
+ init_b = TREE_INT_CST_LOW (DR_INIT (drb));
+
+ /* Two different locations - no dependence. */
+ if (init_a != init_b)
+ return false;
+
+ /* We have a read-write dependence. Check that the load is before the store.
+ When we vectorize basic blocks, vector load can be only before
+ corresponding scalar load, and vector store can be only after its
+ corresponding scalar store. So the order of the acceses is preserved in
+ case the load is before the store. */
+ earlier_stmt = get_earlier_stmt (DR_STMT (dra), DR_STMT (drb));
+ if (DR_IS_READ (STMT_VINFO_DATA_REF (vinfo_for_stmt (earlier_stmt))))
+ return false;
+
+ return true;
+}
+
+
+/* Function vect_check_interleaving.
+
+ Check if DRA and DRB are a part of interleaving. In case they are, insert
+ DRA and DRB in an interleaving chain. */
+
+static bool
+vect_check_interleaving (struct data_reference *dra,
+ struct data_reference *drb)
+{
+ HOST_WIDE_INT type_size_a, type_size_b, diff_mod_size, step, init_a, init_b;
+
+ /* Check that the data-refs have same first location (except init) and they
+ are both either store or load (not load and store). */
+ if ((DR_BASE_ADDRESS (dra) != DR_BASE_ADDRESS (drb)
+ && (TREE_CODE (DR_BASE_ADDRESS (dra)) != ADDR_EXPR
+ || TREE_CODE (DR_BASE_ADDRESS (drb)) != ADDR_EXPR
+ || TREE_OPERAND (DR_BASE_ADDRESS (dra), 0)
+ != TREE_OPERAND (DR_BASE_ADDRESS (drb),0)))
+ || !vect_equal_offsets (DR_OFFSET (dra), DR_OFFSET (drb))
+ || !tree_int_cst_compare (DR_INIT (dra), DR_INIT (drb))
+ || DR_IS_READ (dra) != DR_IS_READ (drb))
+ return false;
+
+ /* Check:
+ 1. data-refs are of the same type
+ 2. their steps are equal
+ 3. the step (if greater than zero) is greater than the difference between
+ data-refs' inits. */
+ type_size_a = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (dra))));
+ type_size_b = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (drb))));
+
+ if (type_size_a != type_size_b
+ || tree_int_cst_compare (DR_STEP (dra), DR_STEP (drb))
+ || !types_compatible_p (TREE_TYPE (DR_REF (dra)),
+ TREE_TYPE (DR_REF (drb))))
+ return false;
+
+ init_a = TREE_INT_CST_LOW (DR_INIT (dra));
+ init_b = TREE_INT_CST_LOW (DR_INIT (drb));
+ step = TREE_INT_CST_LOW (DR_STEP (dra));
+
+ if (init_a > init_b)
+ {
+ /* If init_a == init_b + the size of the type * k, we have an interleaving,
+ and DRB is accessed before DRA. */
+ diff_mod_size = (init_a - init_b) % type_size_a;
+
+ if (step && (init_a - init_b) > step)
+ return false;
+
+ if (diff_mod_size == 0)
+ {
+ vect_update_interleaving_chain (drb, dra);
+ if (vect_print_dump_info (REPORT_DR_DETAILS))
+ {
+ fprintf (vect_dump, "Detected interleaving ");
+ print_generic_expr (vect_dump, DR_REF (dra), TDF_SLIM);
+ fprintf (vect_dump, " and ");
+ print_generic_expr (vect_dump, DR_REF (drb), TDF_SLIM);
+ }
+ return true;
+ }
+ }
+ else
+ {
+ /* If init_b == init_a + the size of the type * k, we have an
+ interleaving, and DRA is accessed before DRB. */
+ diff_mod_size = (init_b - init_a) % type_size_a;
+
+ if (step && (init_b - init_a) > step)
+ return false;
+
+ if (diff_mod_size == 0)
+ {
+ vect_update_interleaving_chain (dra, drb);
+ if (vect_print_dump_info (REPORT_DR_DETAILS))
+ {
+ fprintf (vect_dump, "Detected interleaving ");
+ print_generic_expr (vect_dump, DR_REF (dra), TDF_SLIM);
+ fprintf (vect_dump, " and ");
+ print_generic_expr (vect_dump, DR_REF (drb), TDF_SLIM);
+ }
+ return true;
+ }
+ }
+
+ return false;
+}
+
+/* Check if data references pointed by DR_I and DR_J are same or
+ belong to same interleaving group. Return FALSE if drs are
+ different, otherwise return TRUE. */
+
+static bool
+vect_same_range_drs (data_reference_p dr_i, data_reference_p dr_j)
+{
+ gimple stmt_i = DR_STMT (dr_i);
+ gimple stmt_j = DR_STMT (dr_j);
+
+ if (operand_equal_p (DR_REF (dr_i), DR_REF (dr_j), 0)
+ || (DR_GROUP_FIRST_DR (vinfo_for_stmt (stmt_i))
+ && DR_GROUP_FIRST_DR (vinfo_for_stmt (stmt_j))
+ && (DR_GROUP_FIRST_DR (vinfo_for_stmt (stmt_i))
+ == DR_GROUP_FIRST_DR (vinfo_for_stmt (stmt_j)))))
+ return true;
+ else
+ return false;
+}
+
+/* If address ranges represented by DDR_I and DDR_J are equal,
+ return TRUE, otherwise return FALSE. */
+
+static bool
+vect_vfa_range_equal (ddr_p ddr_i, ddr_p ddr_j)
+{
+ if ((vect_same_range_drs (DDR_A (ddr_i), DDR_A (ddr_j))
+ && vect_same_range_drs (DDR_B (ddr_i), DDR_B (ddr_j)))
+ || (vect_same_range_drs (DDR_A (ddr_i), DDR_B (ddr_j))
+ && vect_same_range_drs (DDR_B (ddr_i), DDR_A (ddr_j))))
+ return true;
+ else
+ return false;
+}
+
+/* Insert DDR into LOOP_VINFO list of ddrs that may alias and need to be
+ tested at run-time. Return TRUE if DDR was successfully inserted.
+ Return false if versioning is not supported. */
+
+static bool
+vect_mark_for_runtime_alias_test (ddr_p ddr, loop_vec_info loop_vinfo)
+{
+ struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
+
+ if ((unsigned) PARAM_VALUE (PARAM_VECT_MAX_VERSION_FOR_ALIAS_CHECKS) == 0)
+ return false;
+
+ if (vect_print_dump_info (REPORT_DR_DETAILS))
+ {
+ fprintf (vect_dump, "mark for run-time aliasing test between ");
+ print_generic_expr (vect_dump, DR_REF (DDR_A (ddr)), TDF_SLIM);
+ fprintf (vect_dump, " and ");
+ print_generic_expr (vect_dump, DR_REF (DDR_B (ddr)), TDF_SLIM);
+ }
+
+ if (optimize_loop_nest_for_size_p (loop))
+ {
+ if (vect_print_dump_info (REPORT_DR_DETAILS))
+ fprintf (vect_dump, "versioning not supported when optimizing for size.");
+ return false;
+ }
+
+ /* FORNOW: We don't support versioning with outer-loop vectorization. */
+ if (loop->inner)
+ {
+ if (vect_print_dump_info (REPORT_DR_DETAILS))
+ fprintf (vect_dump, "versioning not yet supported for outer-loops.");
+ return false;
+ }
+
+ VEC_safe_push (ddr_p, heap, LOOP_VINFO_MAY_ALIAS_DDRS (loop_vinfo), ddr);
+ return true;
+}
+
+
+/* Function vect_analyze_data_ref_dependence.
+
+ Return TRUE if there (might) exist a dependence between a memory-reference
+ DRA and a memory-reference DRB. When versioning for alias may check a
+ dependence at run-time, return FALSE. Adjust *MAX_VF according to
+ the data dependence. */
+
+static bool
+vect_analyze_data_ref_dependence (struct data_dependence_relation *ddr,
+ loop_vec_info loop_vinfo, int *max_vf,
+ bool *data_dependence_in_bb)
+{
+ unsigned int i;
+ struct loop *loop = NULL;
+ struct data_reference *dra = DDR_A (ddr);
+ struct data_reference *drb = DDR_B (ddr);
+ stmt_vec_info stmtinfo_a = vinfo_for_stmt (DR_STMT (dra));
+ stmt_vec_info stmtinfo_b = vinfo_for_stmt (DR_STMT (drb));
+ lambda_vector dist_v;
+ unsigned int loop_depth;
+
+ /* Don't bother to analyze statements marked as unvectorizable. */
+ if (!STMT_VINFO_VECTORIZABLE (stmtinfo_a)
+ || !STMT_VINFO_VECTORIZABLE (stmtinfo_b))
+ return false;
+
+ if (DDR_ARE_DEPENDENT (ddr) == chrec_known)
+ {
+ /* Independent data accesses. */
+ vect_check_interleaving (dra, drb);
+ return false;
+ }
+
+ if (loop_vinfo)
+ loop = LOOP_VINFO_LOOP (loop_vinfo);
+
+ if ((DR_IS_READ (dra) && DR_IS_READ (drb) && loop_vinfo) || dra == drb)
+ return false;
+
+ if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know)
+ {
+ if (loop_vinfo)
+ {
+ if (vect_print_dump_info (REPORT_DR_DETAILS))
+ {
+ fprintf (vect_dump, "versioning for alias required: "
+ "can't determine dependence between ");
+ print_generic_expr (vect_dump, DR_REF (dra), TDF_SLIM);
+ fprintf (vect_dump, " and ");
+ print_generic_expr (vect_dump, DR_REF (drb), TDF_SLIM);
+ }
+
+ /* Add to list of ddrs that need to be tested at run-time. */
+ return !vect_mark_for_runtime_alias_test (ddr, loop_vinfo);
+ }
+
+ /* When vectorizing a basic block unknown depnedence can still mean
+ strided access. */
+ if (vect_check_interleaving (dra, drb))
+ return false;
+
+ if (vect_print_dump_info (REPORT_DR_DETAILS))
+ {
+ fprintf (vect_dump, "can't determine dependence between ");
+ print_generic_expr (vect_dump, DR_REF (dra), TDF_SLIM);
+ fprintf (vect_dump, " and ");
+ print_generic_expr (vect_dump, DR_REF (drb), TDF_SLIM);
+ }
+
+ /* We do not vectorize basic blocks with write-write dependencies. */
+ if (DR_IS_WRITE (dra) && DR_IS_WRITE (drb))
+ return true;
+
+ /* We deal with read-write dependencies in basic blocks later (by
+ verifying that all the loads in the basic block are before all the
+ stores). */
+ *data_dependence_in_bb = true;
+ return false;
+ }
+
+ /* Versioning for alias is not yet supported for basic block SLP, and
+ dependence distance is unapplicable, hence, in case of known data
+ dependence, basic block vectorization is impossible for now. */
+ if (!loop_vinfo)
+ {
+ if (dra != drb && vect_check_interleaving (dra, drb))
+ return false;
+
+ if (vect_print_dump_info (REPORT_DR_DETAILS))
+ {
+ fprintf (vect_dump, "determined dependence between ");
+ print_generic_expr (vect_dump, DR_REF (dra), TDF_SLIM);
+ fprintf (vect_dump, " and ");
+ print_generic_expr (vect_dump, DR_REF (drb), TDF_SLIM);
+ }
+
+ /* Do not vectorize basic blcoks with write-write dependences. */
+ if (DR_IS_WRITE (dra) && DR_IS_WRITE (drb))
+ return true;
+
+ /* Check if this dependence is allowed in basic block vectorization. */
+ return vect_drs_dependent_in_basic_block (dra, drb);
+ }
+
+ /* Loop-based vectorization and known data dependence. */
+ if (DDR_NUM_DIST_VECTS (ddr) == 0)
+ {
+ if (vect_print_dump_info (REPORT_DR_DETAILS))
+ {
+ fprintf (vect_dump, "versioning for alias required: bad dist vector for ");
+ print_generic_expr (vect_dump, DR_REF (dra), TDF_SLIM);
+ fprintf (vect_dump, " and ");
+ print_generic_expr (vect_dump, DR_REF (drb), TDF_SLIM);
+ }
+ /* Add to list of ddrs that need to be tested at run-time. */
+ return !vect_mark_for_runtime_alias_test (ddr, loop_vinfo);
+ }
+
+ loop_depth = index_in_loop_nest (loop->num, DDR_LOOP_NEST (ddr));
+ FOR_EACH_VEC_ELT (lambda_vector, DDR_DIST_VECTS (ddr), i, dist_v)
+ {
+ int dist = dist_v[loop_depth];
+
+ if (vect_print_dump_info (REPORT_DR_DETAILS))
+ fprintf (vect_dump, "dependence distance = %d.", dist);
+
+ if (dist == 0)
+ {
+ if (vect_print_dump_info (REPORT_DR_DETAILS))
+ {
+ fprintf (vect_dump, "dependence distance == 0 between ");
+ print_generic_expr (vect_dump, DR_REF (dra), TDF_SLIM);
+ fprintf (vect_dump, " and ");
+ print_generic_expr (vect_dump, DR_REF (drb), TDF_SLIM);
+ }
+
+ /* For interleaving, mark that there is a read-write dependency if
+ necessary. We check before that one of the data-refs is store. */
+ if (DR_IS_READ (dra))
+ DR_GROUP_READ_WRITE_DEPENDENCE (stmtinfo_a) = true;
+ else
+ {
+ if (DR_IS_READ (drb))
+ DR_GROUP_READ_WRITE_DEPENDENCE (stmtinfo_b) = true;
+ }
+
+ continue;
+ }
+
+ if (dist > 0 && DDR_REVERSED_P (ddr))
+ {
+ /* If DDR_REVERSED_P the order of the data-refs in DDR was
+ reversed (to make distance vector positive), and the actual
+ distance is negative. */
+ if (vect_print_dump_info (REPORT_DR_DETAILS))
+ fprintf (vect_dump, "dependence distance negative.");
+ continue;
+ }
+
+ if (abs (dist) >= 2
+ && abs (dist) < *max_vf)
+ {
+ /* The dependence distance requires reduction of the maximal
+ vectorization factor. */
+ *max_vf = abs (dist);
+ if (vect_print_dump_info (REPORT_DR_DETAILS))
+ fprintf (vect_dump, "adjusting maximal vectorization factor to %i",
+ *max_vf);
+ }
+
+ if (abs (dist) >= *max_vf)
+ {
+ /* Dependence distance does not create dependence, as far as
+ vectorization is concerned, in this case. */
+ if (vect_print_dump_info (REPORT_DR_DETAILS))
+ fprintf (vect_dump, "dependence distance >= VF.");
+ continue;
+ }
+
+ if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
+ {
+ fprintf (vect_dump, "not vectorized, possible dependence "
+ "between data-refs ");
+ print_generic_expr (vect_dump, DR_REF (dra), TDF_SLIM);
+ fprintf (vect_dump, " and ");
+ print_generic_expr (vect_dump, DR_REF (drb), TDF_SLIM);
+ }
+
+ return true;
+ }
+
+ return false;
+}
+
+/* Function vect_analyze_data_ref_dependences.
+
+ Examine all the data references in the loop, and make sure there do not
+ exist any data dependences between them. Set *MAX_VF according to
+ the maximum vectorization factor the data dependences allow. */
+
+bool
+vect_analyze_data_ref_dependences (loop_vec_info loop_vinfo,
+ bb_vec_info bb_vinfo, int *max_vf,
+ bool *data_dependence_in_bb)
+{
+ unsigned int i;
+ VEC (ddr_p, heap) *ddrs = NULL;
+ struct data_dependence_relation *ddr;
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "=== vect_analyze_dependences ===");
+
+ if (loop_vinfo)
+ ddrs = LOOP_VINFO_DDRS (loop_vinfo);
+ else
+ ddrs = BB_VINFO_DDRS (bb_vinfo);
+
+ FOR_EACH_VEC_ELT (ddr_p, ddrs, i, ddr)
+ if (vect_analyze_data_ref_dependence (ddr, loop_vinfo, max_vf,
+ data_dependence_in_bb))
+ return false;
+
+ return true;
+}
+
+
+/* Function vect_compute_data_ref_alignment
+
+ Compute the misalignment of the data reference DR.
+
+ Output:
+ 1. If during the misalignment computation it is found that the data reference
+ cannot be vectorized then false is returned.
+ 2. DR_MISALIGNMENT (DR) is defined.
+
+ FOR NOW: No analysis is actually performed. Misalignment is calculated
+ only for trivial cases. TODO. */
+
+static bool
+vect_compute_data_ref_alignment (struct data_reference *dr)
+{
+ gimple stmt = DR_STMT (dr);
+ stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
+ loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
+ struct loop *loop = NULL;
+ tree ref = DR_REF (dr);
+ tree vectype;
+ tree base, base_addr;
+ bool base_aligned;
+ tree misalign;
+ tree aligned_to, alignment;
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "vect_compute_data_ref_alignment:");
+
+ if (loop_vinfo)
+ loop = LOOP_VINFO_LOOP (loop_vinfo);
+
+ /* Initialize misalignment to unknown. */
+ SET_DR_MISALIGNMENT (dr, -1);
+
+ misalign = DR_INIT (dr);
+ aligned_to = DR_ALIGNED_TO (dr);
+ base_addr = DR_BASE_ADDRESS (dr);
+ vectype = STMT_VINFO_VECTYPE (stmt_info);
+
+ /* In case the dataref is in an inner-loop of the loop that is being
+ vectorized (LOOP), we use the base and misalignment information
+ relative to the outer-loop (LOOP). This is ok only if the misalignment
+ stays the same throughout the execution of the inner-loop, which is why
+ we have to check that the stride of the dataref in the inner-loop evenly
+ divides by the vector size. */
+ if (loop && nested_in_vect_loop_p (loop, stmt))
+ {
+ tree step = DR_STEP (dr);
+ HOST_WIDE_INT dr_step = TREE_INT_CST_LOW (step);
+
+ if (dr_step % GET_MODE_SIZE (TYPE_MODE (vectype)) == 0)
+ {
+ if (vect_print_dump_info (REPORT_ALIGNMENT))
+ fprintf (vect_dump, "inner step divides the vector-size.");
+ misalign = STMT_VINFO_DR_INIT (stmt_info);
+ aligned_to = STMT_VINFO_DR_ALIGNED_TO (stmt_info);
+ base_addr = STMT_VINFO_DR_BASE_ADDRESS (stmt_info);
+ }
+ else
+ {
+ if (vect_print_dump_info (REPORT_ALIGNMENT))
+ fprintf (vect_dump, "inner step doesn't divide the vector-size.");
+ misalign = NULL_TREE;
+ }
+ }
+
+ base = build_fold_indirect_ref (base_addr);
+ alignment = ssize_int (TYPE_ALIGN (vectype)/BITS_PER_UNIT);
+
+ if ((aligned_to && tree_int_cst_compare (aligned_to, alignment) < 0)
+ || !misalign)
+ {
+ if (vect_print_dump_info (REPORT_ALIGNMENT))
+ {
+ fprintf (vect_dump, "Unknown alignment for access: ");
+ print_generic_expr (vect_dump, base, TDF_SLIM);
+ }
+ return true;
+ }
+
+ if ((DECL_P (base)
+ && tree_int_cst_compare (ssize_int (DECL_ALIGN_UNIT (base)),
+ alignment) >= 0)
+ || (TREE_CODE (base_addr) == SSA_NAME
+ && tree_int_cst_compare (ssize_int (TYPE_ALIGN_UNIT (TREE_TYPE (
+ TREE_TYPE (base_addr)))),
+ alignment) >= 0))
+ base_aligned = true;
+ else
+ base_aligned = false;
+
+ if (!base_aligned)
+ {
+ /* Do not change the alignment of global variables if
+ flag_section_anchors is enabled. */
+ if (!vect_can_force_dr_alignment_p (base, TYPE_ALIGN (vectype))
+ || (TREE_STATIC (base) && flag_section_anchors))
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ {
+ fprintf (vect_dump, "can't force alignment of ref: ");
+ print_generic_expr (vect_dump, ref, TDF_SLIM);
+ }
+ return true;
+ }
+
+ /* Force the alignment of the decl.
+ NOTE: This is the only change to the code we make during
+ the analysis phase, before deciding to vectorize the loop. */
+ if (vect_print_dump_info (REPORT_DETAILS))
+ {
+ fprintf (vect_dump, "force alignment of ");
+ print_generic_expr (vect_dump, ref, TDF_SLIM);
+ }
+
+ DECL_ALIGN (base) = TYPE_ALIGN (vectype);
+ DECL_USER_ALIGN (base) = 1;
+ }
+
+ /* At this point we assume that the base is aligned. */
+ gcc_assert (base_aligned
+ || (TREE_CODE (base) == VAR_DECL
+ && DECL_ALIGN (base) >= TYPE_ALIGN (vectype)));
+
+ /* If this is a backward running DR then first access in the larger
+ vectype actually is N-1 elements before the address in the DR.
+ Adjust misalign accordingly. */
+ if (tree_int_cst_compare (DR_STEP (dr), size_zero_node) < 0)
+ {
+ tree offset = ssize_int (TYPE_VECTOR_SUBPARTS (vectype) - 1);
+ /* DR_STEP(dr) is the same as -TYPE_SIZE of the scalar type,
+ otherwise we wouldn't be here. */
+ offset = fold_build2 (MULT_EXPR, ssizetype, offset, DR_STEP (dr));
+ /* PLUS because DR_STEP was negative. */
+ misalign = size_binop (PLUS_EXPR, misalign, offset);
+ }
+
+ /* Modulo alignment. */
+ misalign = size_binop (FLOOR_MOD_EXPR, misalign, alignment);
+
+ if (!host_integerp (misalign, 1))
+ {
+ /* Negative or overflowed misalignment value. */
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "unexpected misalign value");
+ return false;
+ }
+
+ SET_DR_MISALIGNMENT (dr, TREE_INT_CST_LOW (misalign));
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ {
+ fprintf (vect_dump, "misalign = %d bytes of ref ", DR_MISALIGNMENT (dr));
+ print_generic_expr (vect_dump, ref, TDF_SLIM);
+ }
+
+ return true;
+}
+
+
+/* Function vect_compute_data_refs_alignment
+
+ Compute the misalignment of data references in the loop.
+ Return FALSE if a data reference is found that cannot be vectorized. */
+
+static bool
+vect_compute_data_refs_alignment (loop_vec_info loop_vinfo,
+ bb_vec_info bb_vinfo)
+{
+ VEC (data_reference_p, heap) *datarefs;
+ struct data_reference *dr;
+ unsigned int i;
+
+ if (loop_vinfo)
+ datarefs = LOOP_VINFO_DATAREFS (loop_vinfo);
+ else
+ datarefs = BB_VINFO_DATAREFS (bb_vinfo);
+
+ FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, dr)
+ if (STMT_VINFO_VECTORIZABLE (vinfo_for_stmt (DR_STMT (dr)))
+ && !vect_compute_data_ref_alignment (dr))
+ {
+ if (bb_vinfo)
+ {
+ /* Mark unsupported statement as unvectorizable. */
+ STMT_VINFO_VECTORIZABLE (vinfo_for_stmt (DR_STMT (dr))) = false;
+ continue;
+ }
+ else
+ return false;
+ }
+
+ return true;
+}
+
+
+/* Function vect_update_misalignment_for_peel
+
+ DR - the data reference whose misalignment is to be adjusted.
+ DR_PEEL - the data reference whose misalignment is being made
+ zero in the vector loop by the peel.
+ NPEEL - the number of iterations in the peel loop if the misalignment
+ of DR_PEEL is known at compile time. */
+
+static void
+vect_update_misalignment_for_peel (struct data_reference *dr,
+ struct data_reference *dr_peel, int npeel)
+{
+ unsigned int i;
+ VEC(dr_p,heap) *same_align_drs;
+ struct data_reference *current_dr;
+ int dr_size = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (DR_REF (dr))));
+ int dr_peel_size = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (DR_REF (dr_peel))));
+ stmt_vec_info stmt_info = vinfo_for_stmt (DR_STMT (dr));
+ stmt_vec_info peel_stmt_info = vinfo_for_stmt (DR_STMT (dr_peel));
+
+ /* For interleaved data accesses the step in the loop must be multiplied by
+ the size of the interleaving group. */
+ if (STMT_VINFO_STRIDED_ACCESS (stmt_info))
+ dr_size *= DR_GROUP_SIZE (vinfo_for_stmt (DR_GROUP_FIRST_DR (stmt_info)));
+ if (STMT_VINFO_STRIDED_ACCESS (peel_stmt_info))
+ dr_peel_size *= DR_GROUP_SIZE (peel_stmt_info);
+
+ /* It can be assumed that the data refs with the same alignment as dr_peel
+ are aligned in the vector loop. */
+ same_align_drs
+ = STMT_VINFO_SAME_ALIGN_REFS (vinfo_for_stmt (DR_STMT (dr_peel)));
+ FOR_EACH_VEC_ELT (dr_p, same_align_drs, i, current_dr)
+ {
+ if (current_dr != dr)
+ continue;
+ gcc_assert (DR_MISALIGNMENT (dr) / dr_size ==
+ DR_MISALIGNMENT (dr_peel) / dr_peel_size);
+ SET_DR_MISALIGNMENT (dr, 0);
+ return;
+ }
+
+ if (known_alignment_for_access_p (dr)
+ && known_alignment_for_access_p (dr_peel))
+ {
+ bool negative = tree_int_cst_compare (DR_STEP (dr), size_zero_node) < 0;
+ int misal = DR_MISALIGNMENT (dr);
+ tree vectype = STMT_VINFO_VECTYPE (stmt_info);
+ misal += negative ? -npeel * dr_size : npeel * dr_size;
+ misal &= GET_MODE_SIZE (TYPE_MODE (vectype)) - 1;
+ SET_DR_MISALIGNMENT (dr, misal);
+ return;
+ }
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "Setting misalignment to -1.");
+ SET_DR_MISALIGNMENT (dr, -1);
+}
+
+
+/* Function vect_verify_datarefs_alignment
+
+ Return TRUE if all data references in the loop can be
+ handled with respect to alignment. */
+
+bool
+vect_verify_datarefs_alignment (loop_vec_info loop_vinfo, bb_vec_info bb_vinfo)
+{
+ VEC (data_reference_p, heap) *datarefs;
+ struct data_reference *dr;
+ enum dr_alignment_support supportable_dr_alignment;
+ unsigned int i;
+
+ if (loop_vinfo)
+ datarefs = LOOP_VINFO_DATAREFS (loop_vinfo);
+ else
+ datarefs = BB_VINFO_DATAREFS (bb_vinfo);
+
+ FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, dr)
+ {
+ gimple stmt = DR_STMT (dr);
+ stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
+
+ /* For interleaving, only the alignment of the first access matters.
+ Skip statements marked as not vectorizable. */
+ if ((STMT_VINFO_STRIDED_ACCESS (stmt_info)
+ && DR_GROUP_FIRST_DR (stmt_info) != stmt)
+ || !STMT_VINFO_VECTORIZABLE (stmt_info))
+ continue;
+
+ supportable_dr_alignment = vect_supportable_dr_alignment (dr, false);
+ if (!supportable_dr_alignment)
+ {
+ if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
+ {
+ if (DR_IS_READ (dr))
+ fprintf (vect_dump,
+ "not vectorized: unsupported unaligned load.");
+ else
+ fprintf (vect_dump,
+ "not vectorized: unsupported unaligned store.");
+
+ print_generic_expr (vect_dump, DR_REF (dr), TDF_SLIM);
+ }
+ return false;
+ }
+ if (supportable_dr_alignment != dr_aligned
+ && vect_print_dump_info (REPORT_ALIGNMENT))
+ fprintf (vect_dump, "Vectorizing an unaligned access.");
+ }
+ return true;
+}
+
+
+/* Function vector_alignment_reachable_p
+
+ Return true if vector alignment for DR is reachable by peeling
+ a few loop iterations. Return false otherwise. */
+
+static bool
+vector_alignment_reachable_p (struct data_reference *dr)
+{
+ gimple stmt = DR_STMT (dr);
+ stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
+ tree vectype = STMT_VINFO_VECTYPE (stmt_info);
+
+ if (STMT_VINFO_STRIDED_ACCESS (stmt_info))
+ {
+ /* For interleaved access we peel only if number of iterations in
+ the prolog loop ({VF - misalignment}), is a multiple of the
+ number of the interleaved accesses. */
+ int elem_size, mis_in_elements;
+ int nelements = TYPE_VECTOR_SUBPARTS (vectype);
+
+ /* FORNOW: handle only known alignment. */
+ if (!known_alignment_for_access_p (dr))
+ return false;
+
+ elem_size = GET_MODE_SIZE (TYPE_MODE (vectype)) / nelements;
+ mis_in_elements = DR_MISALIGNMENT (dr) / elem_size;
+
+ if ((nelements - mis_in_elements) % DR_GROUP_SIZE (stmt_info))
+ return false;
+ }
+
+ /* If misalignment is known at the compile time then allow peeling
+ only if natural alignment is reachable through peeling. */
+ if (known_alignment_for_access_p (dr) && !aligned_access_p (dr))
+ {
+ HOST_WIDE_INT elmsize =
+ int_cst_value (TYPE_SIZE_UNIT (TREE_TYPE (vectype)));
+ if (vect_print_dump_info (REPORT_DETAILS))
+ {
+ fprintf (vect_dump, "data size =" HOST_WIDE_INT_PRINT_DEC, elmsize);
+ fprintf (vect_dump, ". misalignment = %d. ", DR_MISALIGNMENT (dr));
+ }
+ if (DR_MISALIGNMENT (dr) % elmsize)
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "data size does not divide the misalignment.\n");
+ return false;
+ }
+ }
+
+ if (!known_alignment_for_access_p (dr))
+ {
+ tree type = (TREE_TYPE (DR_REF (dr)));
+ tree ba = DR_BASE_OBJECT (dr);
+ bool is_packed = false;
+
+ if (ba)
+ is_packed = contains_packed_reference (ba);
+
+ if (compare_tree_int (TYPE_SIZE (type), TYPE_ALIGN (type)) > 0)
+ is_packed = true;
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "Unknown misalignment, is_packed = %d",is_packed);
+ if (targetm.vectorize.vector_alignment_reachable (type, is_packed))
+ return true;
+ else
+ return false;
+ }
+
+ return true;
+}
+
+
+/* Calculate the cost of the memory access represented by DR. */
+
+static void
+vect_get_data_access_cost (struct data_reference *dr,
+ unsigned int *inside_cost,
+ unsigned int *outside_cost)
+{
+ gimple stmt = DR_STMT (dr);
+ stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
+ int nunits = TYPE_VECTOR_SUBPARTS (STMT_VINFO_VECTYPE (stmt_info));
+ loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
+ int vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo);
+ int ncopies = vf / nunits;
+ bool supportable_dr_alignment = vect_supportable_dr_alignment (dr, true);
+
+ if (!supportable_dr_alignment)
+ *inside_cost = VECT_MAX_COST;
+ else
+ {
+ if (DR_IS_READ (dr))
+ vect_get_load_cost (dr, ncopies, true, inside_cost, outside_cost);
+ else
+ vect_get_store_cost (dr, ncopies, inside_cost);
+ }
+
+ if (vect_print_dump_info (REPORT_COST))
+ fprintf (vect_dump, "vect_get_data_access_cost: inside_cost = %d, "
+ "outside_cost = %d.", *inside_cost, *outside_cost);
+}
+
+
+static hashval_t
+vect_peeling_hash (const void *elem)
+{
+ const struct _vect_peel_info *peel_info;
+
+ peel_info = (const struct _vect_peel_info *) elem;
+ return (hashval_t) peel_info->npeel;
+}
+
+
+static int
+vect_peeling_hash_eq (const void *elem1, const void *elem2)
+{
+ const struct _vect_peel_info *a, *b;
+
+ a = (const struct _vect_peel_info *) elem1;
+ b = (const struct _vect_peel_info *) elem2;
+ return (a->npeel == b->npeel);
+}
+
+
+/* Insert DR into peeling hash table with NPEEL as key. */
+
+static void
+vect_peeling_hash_insert (loop_vec_info loop_vinfo, struct data_reference *dr,
+ int npeel)
+{
+ struct _vect_peel_info elem, *slot;
+ void **new_slot;
+ bool supportable_dr_alignment = vect_supportable_dr_alignment (dr, true);
+
+ elem.npeel = npeel;
+ slot = (vect_peel_info) htab_find (LOOP_VINFO_PEELING_HTAB (loop_vinfo),
+ &elem);
+ if (slot)
+ slot->count++;
+ else
+ {
+ slot = XNEW (struct _vect_peel_info);
+ slot->npeel = npeel;
+ slot->dr = dr;
+ slot->count = 1;
+ new_slot = htab_find_slot (LOOP_VINFO_PEELING_HTAB (loop_vinfo), slot,
+ INSERT);
+ *new_slot = slot;
+ }
+
+ if (!supportable_dr_alignment && !flag_vect_cost_model)
+ slot->count += VECT_MAX_COST;
+}
+
+
+/* Traverse peeling hash table to find peeling option that aligns maximum
+ number of data accesses. */
+
+static int
+vect_peeling_hash_get_most_frequent (void **slot, void *data)
+{
+ vect_peel_info elem = (vect_peel_info) *slot;
+ vect_peel_extended_info max = (vect_peel_extended_info) data;
+
+ if (elem->count > max->peel_info.count
+ || (elem->count == max->peel_info.count
+ && max->peel_info.npeel > elem->npeel))
+ {
+ max->peel_info.npeel = elem->npeel;
+ max->peel_info.count = elem->count;
+ max->peel_info.dr = elem->dr;
+ }
+
+ return 1;
+}
+
+
+/* Traverse peeling hash table and calculate cost for each peeling option.
+ Find the one with the lowest cost. */
+
+static int
+vect_peeling_hash_get_lowest_cost (void **slot, void *data)
+{
+ vect_peel_info elem = (vect_peel_info) *slot;
+ vect_peel_extended_info min = (vect_peel_extended_info) data;
+ int save_misalignment, dummy;
+ unsigned int inside_cost = 0, outside_cost = 0, i;
+ gimple stmt = DR_STMT (elem->dr);
+ stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
+ loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
+ VEC (data_reference_p, heap) *datarefs = LOOP_VINFO_DATAREFS (loop_vinfo);
+ struct data_reference *dr;
+
+ FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, dr)
+ {
+ stmt = DR_STMT (dr);
+ stmt_info = vinfo_for_stmt (stmt);
+ /* For interleaving, only the alignment of the first access
+ matters. */
+ if (STMT_VINFO_STRIDED_ACCESS (stmt_info)
+ && DR_GROUP_FIRST_DR (stmt_info) != stmt)
+ continue;
+
+ save_misalignment = DR_MISALIGNMENT (dr);
+ vect_update_misalignment_for_peel (dr, elem->dr, elem->npeel);
+ vect_get_data_access_cost (dr, &inside_cost, &outside_cost);
+ SET_DR_MISALIGNMENT (dr, save_misalignment);
+ }
+
+ outside_cost += vect_get_known_peeling_cost (loop_vinfo, elem->npeel, &dummy,
+ vect_get_single_scalar_iteraion_cost (loop_vinfo));
+
+ if (inside_cost < min->inside_cost
+ || (inside_cost == min->inside_cost && outside_cost < min->outside_cost))
+ {
+ min->inside_cost = inside_cost;
+ min->outside_cost = outside_cost;
+ min->peel_info.dr = elem->dr;
+ min->peel_info.npeel = elem->npeel;
+ }
+
+ return 1;
+}
+
+
+/* Choose best peeling option by traversing peeling hash table and either
+ choosing an option with the lowest cost (if cost model is enabled) or the
+ option that aligns as many accesses as possible. */
+
+static struct data_reference *
+vect_peeling_hash_choose_best_peeling (loop_vec_info loop_vinfo,
+ unsigned int *npeel)
+{
+ struct _vect_peel_extended_info res;
+
+ res.peel_info.dr = NULL;
+
+ if (flag_vect_cost_model)
+ {
+ res.inside_cost = INT_MAX;
+ res.outside_cost = INT_MAX;
+ htab_traverse (LOOP_VINFO_PEELING_HTAB (loop_vinfo),
+ vect_peeling_hash_get_lowest_cost, &res);
+ }
+ else
+ {
+ res.peel_info.count = 0;
+ htab_traverse (LOOP_VINFO_PEELING_HTAB (loop_vinfo),
+ vect_peeling_hash_get_most_frequent, &res);
+ }
+
+ *npeel = res.peel_info.npeel;
+ return res.peel_info.dr;
+}
+
+
+/* Function vect_enhance_data_refs_alignment
+
+ This pass will use loop versioning and loop peeling in order to enhance
+ the alignment of data references in the loop.
+
+ FOR NOW: we assume that whatever versioning/peeling takes place, only the
+ original loop is to be vectorized. Any other loops that are created by
+ the transformations performed in this pass - are not supposed to be
+ vectorized. This restriction will be relaxed.
+
+ This pass will require a cost model to guide it whether to apply peeling
+ or versioning or a combination of the two. For example, the scheme that
+ intel uses when given a loop with several memory accesses, is as follows:
+ choose one memory access ('p') which alignment you want to force by doing
+ peeling. Then, either (1) generate a loop in which 'p' is aligned and all
+ other accesses are not necessarily aligned, or (2) use loop versioning to
+ generate one loop in which all accesses are aligned, and another loop in
+ which only 'p' is necessarily aligned.
+
+ ("Automatic Intra-Register Vectorization for the Intel Architecture",
+ Aart J.C. Bik, Milind Girkar, Paul M. Grey and Ximmin Tian, International
+ Journal of Parallel Programming, Vol. 30, No. 2, April 2002.)
+
+ Devising a cost model is the most critical aspect of this work. It will
+ guide us on which access to peel for, whether to use loop versioning, how
+ many versions to create, etc. The cost model will probably consist of
+ generic considerations as well as target specific considerations (on
+ powerpc for example, misaligned stores are more painful than misaligned
+ loads).
+
+ Here are the general steps involved in alignment enhancements:
+
+ -- original loop, before alignment analysis:
+ for (i=0; i<N; i++){
+ x = q[i]; # DR_MISALIGNMENT(q) = unknown
+ p[i] = y; # DR_MISALIGNMENT(p) = unknown
+ }
+
+ -- After vect_compute_data_refs_alignment:
+ for (i=0; i<N; i++){
+ x = q[i]; # DR_MISALIGNMENT(q) = 3
+ p[i] = y; # DR_MISALIGNMENT(p) = unknown
+ }
+
+ -- Possibility 1: we do loop versioning:
+ if (p is aligned) {
+ for (i=0; i<N; i++){ # loop 1A
+ x = q[i]; # DR_MISALIGNMENT(q) = 3
+ p[i] = y; # DR_MISALIGNMENT(p) = 0
+ }
+ }
+ else {
+ for (i=0; i<N; i++){ # loop 1B
+ x = q[i]; # DR_MISALIGNMENT(q) = 3
+ p[i] = y; # DR_MISALIGNMENT(p) = unaligned
+ }
+ }
+
+ -- Possibility 2: we do loop peeling:
+ for (i = 0; i < 3; i++){ # (scalar loop, not to be vectorized).
+ x = q[i];
+ p[i] = y;
+ }
+ for (i = 3; i < N; i++){ # loop 2A
+ x = q[i]; # DR_MISALIGNMENT(q) = 0
+ p[i] = y; # DR_MISALIGNMENT(p) = unknown
+ }
+
+ -- Possibility 3: combination of loop peeling and versioning:
+ for (i = 0; i < 3; i++){ # (scalar loop, not to be vectorized).
+ x = q[i];
+ p[i] = y;
+ }
+ if (p is aligned) {
+ for (i = 3; i<N; i++){ # loop 3A
+ x = q[i]; # DR_MISALIGNMENT(q) = 0
+ p[i] = y; # DR_MISALIGNMENT(p) = 0
+ }
+ }
+ else {
+ for (i = 3; i<N; i++){ # loop 3B
+ x = q[i]; # DR_MISALIGNMENT(q) = 0
+ p[i] = y; # DR_MISALIGNMENT(p) = unaligned
+ }
+ }
+
+ These loops are later passed to loop_transform to be vectorized. The
+ vectorizer will use the alignment information to guide the transformation
+ (whether to generate regular loads/stores, or with special handling for
+ misalignment). */
+
+bool
+vect_enhance_data_refs_alignment (loop_vec_info loop_vinfo)
+{
+ VEC (data_reference_p, heap) *datarefs = LOOP_VINFO_DATAREFS (loop_vinfo);
+ struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
+ enum dr_alignment_support supportable_dr_alignment;
+ struct data_reference *dr0 = NULL, *first_store = NULL;
+ struct data_reference *dr;
+ unsigned int i, j;
+ bool do_peeling = false;
+ bool do_versioning = false;
+ bool stat;
+ gimple stmt;
+ stmt_vec_info stmt_info;
+ int vect_versioning_for_alias_required;
+ unsigned int npeel = 0;
+ bool all_misalignments_unknown = true;
+ unsigned int vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo);
+ unsigned possible_npeel_number = 1;
+ tree vectype;
+ unsigned int nelements, mis, same_align_drs_max = 0;
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "=== vect_enhance_data_refs_alignment ===");
+
+ /* While cost model enhancements are expected in the future, the high level
+ view of the code at this time is as follows:
+
+ A) If there is a misaligned access then see if peeling to align
+ this access can make all data references satisfy
+ vect_supportable_dr_alignment. If so, update data structures
+ as needed and return true.
+
+ B) If peeling wasn't possible and there is a data reference with an
+ unknown misalignment that does not satisfy vect_supportable_dr_alignment
+ then see if loop versioning checks can be used to make all data
+ references satisfy vect_supportable_dr_alignment. If so, update
+ data structures as needed and return true.
+
+ C) If neither peeling nor versioning were successful then return false if
+ any data reference does not satisfy vect_supportable_dr_alignment.
+
+ D) Return true (all data references satisfy vect_supportable_dr_alignment).
+
+ Note, Possibility 3 above (which is peeling and versioning together) is not
+ being done at this time. */
+
+ /* (1) Peeling to force alignment. */
+
+ /* (1.1) Decide whether to perform peeling, and how many iterations to peel:
+ Considerations:
+ + How many accesses will become aligned due to the peeling
+ - How many accesses will become unaligned due to the peeling,
+ and the cost of misaligned accesses.
+ - The cost of peeling (the extra runtime checks, the increase
+ in code size). */
+
+ FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, dr)
+ {
+ stmt = DR_STMT (dr);
+ stmt_info = vinfo_for_stmt (stmt);
+
+ /* For interleaving, only the alignment of the first access
+ matters. */
+ if (STMT_VINFO_STRIDED_ACCESS (stmt_info)
+ && DR_GROUP_FIRST_DR (stmt_info) != stmt)
+ continue;
+
+ supportable_dr_alignment = vect_supportable_dr_alignment (dr, true);
+ do_peeling = vector_alignment_reachable_p (dr);
+ if (do_peeling)
+ {
+ if (known_alignment_for_access_p (dr))
+ {
+ unsigned int npeel_tmp;
+ bool negative = tree_int_cst_compare (DR_STEP (dr),
+ size_zero_node) < 0;
+
+ /* Save info about DR in the hash table. */
+ if (!LOOP_VINFO_PEELING_HTAB (loop_vinfo))
+ LOOP_VINFO_PEELING_HTAB (loop_vinfo) =
+ htab_create (1, vect_peeling_hash,
+ vect_peeling_hash_eq, free);
+
+ vectype = STMT_VINFO_VECTYPE (stmt_info);
+ nelements = TYPE_VECTOR_SUBPARTS (vectype);
+ mis = DR_MISALIGNMENT (dr) / GET_MODE_SIZE (TYPE_MODE (
+ TREE_TYPE (DR_REF (dr))));
+ npeel_tmp = (negative
+ ? (mis - nelements) : (nelements - mis))
+ & (nelements - 1);
+
+ /* For multiple types, it is possible that the bigger type access
+ will have more than one peeling option. E.g., a loop with two
+ types: one of size (vector size / 4), and the other one of
+ size (vector size / 8). Vectorization factor will 8. If both
+ access are misaligned by 3, the first one needs one scalar
+ iteration to be aligned, and the second one needs 5. But the
+ the first one will be aligned also by peeling 5 scalar
+ iterations, and in that case both accesses will be aligned.
+ Hence, except for the immediate peeling amount, we also want
+ to try to add full vector size, while we don't exceed
+ vectorization factor.
+ We do this automtically for cost model, since we calculate cost
+ for every peeling option. */
+ if (!flag_vect_cost_model)
+ possible_npeel_number = vf /nelements;
+
+ /* Handle the aligned case. We may decide to align some other
+ access, making DR unaligned. */
+ if (DR_MISALIGNMENT (dr) == 0)
+ {
+ npeel_tmp = 0;
+ if (!flag_vect_cost_model)
+ possible_npeel_number++;
+ }
+
+ for (j = 0; j < possible_npeel_number; j++)
+ {
+ gcc_assert (npeel_tmp <= vf);
+ vect_peeling_hash_insert (loop_vinfo, dr, npeel_tmp);
+ npeel_tmp += nelements;
+ }
+
+ all_misalignments_unknown = false;
+ /* Data-ref that was chosen for the case that all the
+ misalignments are unknown is not relevant anymore, since we
+ have a data-ref with known alignment. */
+ dr0 = NULL;
+ }
+ else
+ {
+ /* If we don't know all the misalignment values, we prefer
+ peeling for data-ref that has maximum number of data-refs
+ with the same alignment, unless the target prefers to align
+ stores over load. */
+ if (all_misalignments_unknown)
+ {
+ if (same_align_drs_max < VEC_length (dr_p,
+ STMT_VINFO_SAME_ALIGN_REFS (stmt_info))
+ || !dr0)
+ {
+ same_align_drs_max = VEC_length (dr_p,
+ STMT_VINFO_SAME_ALIGN_REFS (stmt_info));
+ dr0 = dr;
+ }
+
+ if (!first_store && DR_IS_WRITE (dr))
+ first_store = dr;
+ }
+
+ /* If there are both known and unknown misaligned accesses in the
+ loop, we choose peeling amount according to the known
+ accesses. */
+
+
+ if (!supportable_dr_alignment)
+ {
+ dr0 = dr;
+ if (!first_store && DR_IS_WRITE (dr))
+ first_store = dr;
+ }
+ }
+ }
+ else
+ {
+ if (!aligned_access_p (dr))
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "vector alignment may not be reachable");
+
+ break;
+ }
+ }
+ }
+
+ vect_versioning_for_alias_required
+ = LOOP_REQUIRES_VERSIONING_FOR_ALIAS (loop_vinfo);
+
+ /* Temporarily, if versioning for alias is required, we disable peeling
+ until we support peeling and versioning. Often peeling for alignment
+ will require peeling for loop-bound, which in turn requires that we
+ know how to adjust the loop ivs after the loop. */
+ if (vect_versioning_for_alias_required
+ || !vect_can_advance_ivs_p (loop_vinfo)
+ || !slpeel_can_duplicate_loop_p (loop, single_exit (loop)))
+ do_peeling = false;
+
+ if (do_peeling && all_misalignments_unknown
+ && vect_supportable_dr_alignment (dr0, false))
+ {
+
+ /* Check if the target requires to prefer stores over loads, i.e., if
+ misaligned stores are more expensive than misaligned loads (taking
+ drs with same alignment into account). */
+ if (first_store && DR_IS_READ (dr0))
+ {
+ unsigned int load_inside_cost = 0, load_outside_cost = 0;
+ unsigned int store_inside_cost = 0, store_outside_cost = 0;
+ unsigned int load_inside_penalty = 0, load_outside_penalty = 0;
+ unsigned int store_inside_penalty = 0, store_outside_penalty = 0;
+
+ vect_get_data_access_cost (dr0, &load_inside_cost,
+ &load_outside_cost);
+ vect_get_data_access_cost (first_store, &store_inside_cost,
+ &store_outside_cost);
+
+ /* Calculate the penalty for leaving FIRST_STORE unaligned (by
+ aligning the load DR0). */
+ load_inside_penalty = store_inside_cost;
+ load_outside_penalty = store_outside_cost;
+ for (i = 0; VEC_iterate (dr_p, STMT_VINFO_SAME_ALIGN_REFS
+ (vinfo_for_stmt (DR_STMT (first_store))),
+ i, dr);
+ i++)
+ if (DR_IS_READ (dr))
+ {
+ load_inside_penalty += load_inside_cost;
+ load_outside_penalty += load_outside_cost;
+ }
+ else
+ {
+ load_inside_penalty += store_inside_cost;
+ load_outside_penalty += store_outside_cost;
+ }
+
+ /* Calculate the penalty for leaving DR0 unaligned (by
+ aligning the FIRST_STORE). */
+ store_inside_penalty = load_inside_cost;
+ store_outside_penalty = load_outside_cost;
+ for (i = 0; VEC_iterate (dr_p, STMT_VINFO_SAME_ALIGN_REFS
+ (vinfo_for_stmt (DR_STMT (dr0))),
+ i, dr);
+ i++)
+ if (DR_IS_READ (dr))
+ {
+ store_inside_penalty += load_inside_cost;
+ store_outside_penalty += load_outside_cost;
+ }
+ else
+ {
+ store_inside_penalty += store_inside_cost;
+ store_outside_penalty += store_outside_cost;
+ }
+
+ if (load_inside_penalty > store_inside_penalty
+ || (load_inside_penalty == store_inside_penalty
+ && load_outside_penalty > store_outside_penalty))
+ dr0 = first_store;
+ }
+
+ /* In case there are only loads with different unknown misalignments, use
+ peeling only if it may help to align other accesses in the loop. */
+ if (!first_store && !VEC_length (dr_p, STMT_VINFO_SAME_ALIGN_REFS
+ (vinfo_for_stmt (DR_STMT (dr0))))
+ && vect_supportable_dr_alignment (dr0, false)
+ != dr_unaligned_supported)
+ do_peeling = false;
+ }
+
+ if (do_peeling && !dr0)
+ {
+ /* Peeling is possible, but there is no data access that is not supported
+ unless aligned. So we try to choose the best possible peeling. */
+
+ /* We should get here only if there are drs with known misalignment. */
+ gcc_assert (!all_misalignments_unknown);
+
+ /* Choose the best peeling from the hash table. */
+ dr0 = vect_peeling_hash_choose_best_peeling (loop_vinfo, &npeel);
+ if (!dr0 || !npeel)
+ do_peeling = false;
+ }
+
+ if (do_peeling)
+ {
+ stmt = DR_STMT (dr0);
+ stmt_info = vinfo_for_stmt (stmt);
+ vectype = STMT_VINFO_VECTYPE (stmt_info);
+ nelements = TYPE_VECTOR_SUBPARTS (vectype);
+
+ if (known_alignment_for_access_p (dr0))
+ {
+ bool negative = tree_int_cst_compare (DR_STEP (dr0),
+ size_zero_node) < 0;
+ if (!npeel)
+ {
+ /* Since it's known at compile time, compute the number of
+ iterations in the peeled loop (the peeling factor) for use in
+ updating DR_MISALIGNMENT values. The peeling factor is the
+ vectorization factor minus the misalignment as an element
+ count. */
+ mis = DR_MISALIGNMENT (dr0);
+ mis /= GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (DR_REF (dr0))));
+ npeel = ((negative ? mis - nelements : nelements - mis)
+ & (nelements - 1));
+ }
+
+ /* For interleaved data access every iteration accesses all the
+ members of the group, therefore we divide the number of iterations
+ by the group size. */
+ stmt_info = vinfo_for_stmt (DR_STMT (dr0));
+ if (STMT_VINFO_STRIDED_ACCESS (stmt_info))
+ npeel /= DR_GROUP_SIZE (stmt_info);
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "Try peeling by %d", npeel);
+ }
+
+ /* Ensure that all data refs can be vectorized after the peel. */
+ FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, dr)
+ {
+ int save_misalignment;
+
+ if (dr == dr0)
+ continue;
+
+ stmt = DR_STMT (dr);
+ stmt_info = vinfo_for_stmt (stmt);
+ /* For interleaving, only the alignment of the first access
+ matters. */
+ if (STMT_VINFO_STRIDED_ACCESS (stmt_info)
+ && DR_GROUP_FIRST_DR (stmt_info) != stmt)
+ continue;
+
+ save_misalignment = DR_MISALIGNMENT (dr);
+ vect_update_misalignment_for_peel (dr, dr0, npeel);
+ supportable_dr_alignment = vect_supportable_dr_alignment (dr, false);
+ SET_DR_MISALIGNMENT (dr, save_misalignment);
+
+ if (!supportable_dr_alignment)
+ {
+ do_peeling = false;
+ break;
+ }
+ }
+
+ if (do_peeling && known_alignment_for_access_p (dr0) && npeel == 0)
+ {
+ stat = vect_verify_datarefs_alignment (loop_vinfo, NULL);
+ if (!stat)
+ do_peeling = false;
+ else
+ return stat;
+ }
+
+ if (do_peeling)
+ {
+ /* (1.2) Update the DR_MISALIGNMENT of each data reference DR_i.
+ If the misalignment of DR_i is identical to that of dr0 then set
+ DR_MISALIGNMENT (DR_i) to zero. If the misalignment of DR_i and
+ dr0 are known at compile time then increment DR_MISALIGNMENT (DR_i)
+ by the peeling factor times the element size of DR_i (MOD the
+ vectorization factor times the size). Otherwise, the
+ misalignment of DR_i must be set to unknown. */
+ FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, dr)
+ if (dr != dr0)
+ vect_update_misalignment_for_peel (dr, dr0, npeel);
+
+ LOOP_VINFO_UNALIGNED_DR (loop_vinfo) = dr0;
+ if (npeel)
+ LOOP_PEELING_FOR_ALIGNMENT (loop_vinfo) = npeel;
+ else
+ LOOP_PEELING_FOR_ALIGNMENT (loop_vinfo) = DR_MISALIGNMENT (dr0);
+ SET_DR_MISALIGNMENT (dr0, 0);
+ if (vect_print_dump_info (REPORT_ALIGNMENT))
+ fprintf (vect_dump, "Alignment of access forced using peeling.");
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "Peeling for alignment will be applied.");
+
+ stat = vect_verify_datarefs_alignment (loop_vinfo, NULL);
+ gcc_assert (stat);
+ return stat;
+ }
+ }
+
+
+ /* (2) Versioning to force alignment. */
+
+ /* Try versioning if:
+ 1) flag_tree_vect_loop_version is TRUE
+ 2) optimize loop for speed
+ 3) there is at least one unsupported misaligned data ref with an unknown
+ misalignment, and
+ 4) all misaligned data refs with a known misalignment are supported, and
+ 5) the number of runtime alignment checks is within reason. */
+
+ do_versioning =
+ flag_tree_vect_loop_version
+ && optimize_loop_nest_for_speed_p (loop)
+ && (!loop->inner); /* FORNOW */
+
+ if (do_versioning)
+ {
+ FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, dr)
+ {
+ stmt = DR_STMT (dr);
+ stmt_info = vinfo_for_stmt (stmt);
+
+ /* For interleaving, only the alignment of the first access
+ matters. */
+ if (aligned_access_p (dr)
+ || (STMT_VINFO_STRIDED_ACCESS (stmt_info)
+ && DR_GROUP_FIRST_DR (stmt_info) != stmt))
+ continue;
+
+ supportable_dr_alignment = vect_supportable_dr_alignment (dr, false);
+
+ if (!supportable_dr_alignment)
+ {
+ gimple stmt;
+ int mask;
+ tree vectype;
+
+ if (known_alignment_for_access_p (dr)
+ || VEC_length (gimple,
+ LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo))
+ >= (unsigned) PARAM_VALUE (PARAM_VECT_MAX_VERSION_FOR_ALIGNMENT_CHECKS))
+ {
+ do_versioning = false;
+ break;
+ }
+
+ stmt = DR_STMT (dr);
+ vectype = STMT_VINFO_VECTYPE (vinfo_for_stmt (stmt));
+ gcc_assert (vectype);
+
+ /* The rightmost bits of an aligned address must be zeros.
+ Construct the mask needed for this test. For example,
+ GET_MODE_SIZE for the vector mode V4SI is 16 bytes so the
+ mask must be 15 = 0xf. */
+ mask = GET_MODE_SIZE (TYPE_MODE (vectype)) - 1;
+
+ /* FORNOW: use the same mask to test all potentially unaligned
+ references in the loop. The vectorizer currently supports
+ a single vector size, see the reference to
+ GET_MODE_NUNITS (TYPE_MODE (vectype)) where the
+ vectorization factor is computed. */
+ gcc_assert (!LOOP_VINFO_PTR_MASK (loop_vinfo)
+ || LOOP_VINFO_PTR_MASK (loop_vinfo) == mask);
+ LOOP_VINFO_PTR_MASK (loop_vinfo) = mask;
+ VEC_safe_push (gimple, heap,
+ LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo),
+ DR_STMT (dr));
+ }
+ }
+
+ /* Versioning requires at least one misaligned data reference. */
+ if (!LOOP_REQUIRES_VERSIONING_FOR_ALIGNMENT (loop_vinfo))
+ do_versioning = false;
+ else if (!do_versioning)
+ VEC_truncate (gimple, LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo), 0);
+ }
+
+ if (do_versioning)
+ {
+ VEC(gimple,heap) *may_misalign_stmts
+ = LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo);
+ gimple stmt;
+
+ /* It can now be assumed that the data references in the statements
+ in LOOP_VINFO_MAY_MISALIGN_STMTS will be aligned in the version
+ of the loop being vectorized. */
+ FOR_EACH_VEC_ELT (gimple, may_misalign_stmts, i, stmt)
+ {
+ stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
+ dr = STMT_VINFO_DATA_REF (stmt_info);
+ SET_DR_MISALIGNMENT (dr, 0);
+ if (vect_print_dump_info (REPORT_ALIGNMENT))
+ fprintf (vect_dump, "Alignment of access forced using versioning.");
+ }
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "Versioning for alignment will be applied.");
+
+ /* Peeling and versioning can't be done together at this time. */
+ gcc_assert (! (do_peeling && do_versioning));
+
+ stat = vect_verify_datarefs_alignment (loop_vinfo, NULL);
+ gcc_assert (stat);
+ return stat;
+ }
+
+ /* This point is reached if neither peeling nor versioning is being done. */
+ gcc_assert (! (do_peeling || do_versioning));
+
+ stat = vect_verify_datarefs_alignment (loop_vinfo, NULL);
+ return stat;
+}
+
+
+/* Function vect_find_same_alignment_drs.
+
+ Update group and alignment relations according to the chosen
+ vectorization factor. */
+
+static void
+vect_find_same_alignment_drs (struct data_dependence_relation *ddr,
+ loop_vec_info loop_vinfo)
+{
+ unsigned int i;
+ struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
+ int vectorization_factor = LOOP_VINFO_VECT_FACTOR (loop_vinfo);
+ struct data_reference *dra = DDR_A (ddr);
+ struct data_reference *drb = DDR_B (ddr);
+ stmt_vec_info stmtinfo_a = vinfo_for_stmt (DR_STMT (dra));
+ stmt_vec_info stmtinfo_b = vinfo_for_stmt (DR_STMT (drb));
+ int dra_size = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (DR_REF (dra))));
+ int drb_size = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (DR_REF (drb))));
+ lambda_vector dist_v;
+ unsigned int loop_depth;
+
+ if (DDR_ARE_DEPENDENT (ddr) == chrec_known)
+ return;
+
+ if (dra == drb)
+ return;
+
+ if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know)
+ return;
+
+ /* Loop-based vectorization and known data dependence. */
+ if (DDR_NUM_DIST_VECTS (ddr) == 0)
+ return;
+
+ /* Data-dependence analysis reports a distance vector of zero
+ for data-references that overlap only in the first iteration
+ but have different sign step (see PR45764).
+ So as a sanity check require equal DR_STEP. */
+ if (!operand_equal_p (DR_STEP (dra), DR_STEP (drb), 0))
+ return;
+
+ loop_depth = index_in_loop_nest (loop->num, DDR_LOOP_NEST (ddr));
+ FOR_EACH_VEC_ELT (lambda_vector, DDR_DIST_VECTS (ddr), i, dist_v)
+ {
+ int dist = dist_v[loop_depth];
+
+ if (vect_print_dump_info (REPORT_DR_DETAILS))
+ fprintf (vect_dump, "dependence distance = %d.", dist);
+
+ /* Same loop iteration. */
+ if (dist == 0
+ || (dist % vectorization_factor == 0 && dra_size == drb_size))
+ {
+ /* Two references with distance zero have the same alignment. */
+ VEC_safe_push (dr_p, heap, STMT_VINFO_SAME_ALIGN_REFS (stmtinfo_a), drb);
+ VEC_safe_push (dr_p, heap, STMT_VINFO_SAME_ALIGN_REFS (stmtinfo_b), dra);
+ if (vect_print_dump_info (REPORT_ALIGNMENT))
+ fprintf (vect_dump, "accesses have the same alignment.");
+ if (vect_print_dump_info (REPORT_DR_DETAILS))
+ {
+ fprintf (vect_dump, "dependence distance modulo vf == 0 between ");
+ print_generic_expr (vect_dump, DR_REF (dra), TDF_SLIM);
+ fprintf (vect_dump, " and ");
+ print_generic_expr (vect_dump, DR_REF (drb), TDF_SLIM);
+ }
+ }
+ }
+}
+
+
+/* Function vect_analyze_data_refs_alignment
+
+ Analyze the alignment of the data-references in the loop.
+ Return FALSE if a data reference is found that cannot be vectorized. */
+
+bool
+vect_analyze_data_refs_alignment (loop_vec_info loop_vinfo,
+ bb_vec_info bb_vinfo)
+{
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "=== vect_analyze_data_refs_alignment ===");
+
+ /* Mark groups of data references with same alignment using
+ data dependence information. */
+ if (loop_vinfo)
+ {
+ VEC (ddr_p, heap) *ddrs = LOOP_VINFO_DDRS (loop_vinfo);
+ struct data_dependence_relation *ddr;
+ unsigned int i;
+
+ FOR_EACH_VEC_ELT (ddr_p, ddrs, i, ddr)
+ vect_find_same_alignment_drs (ddr, loop_vinfo);
+ }
+
+ if (!vect_compute_data_refs_alignment (loop_vinfo, bb_vinfo))
+ {
+ if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
+ fprintf (vect_dump,
+ "not vectorized: can't calculate alignment for data ref.");
+ return false;
+ }
+
+ return true;
+}
+
+
+/* Analyze groups of strided accesses: check that DR belongs to a group of
+ strided accesses of legal size, step, etc. Detect gaps, single element
+ interleaving, and other special cases. Set strided access info.
+ Collect groups of strided stores for further use in SLP analysis. */
+
+static bool
+vect_analyze_group_access (struct data_reference *dr)
+{
+ tree step = DR_STEP (dr);
+ tree scalar_type = TREE_TYPE (DR_REF (dr));
+ HOST_WIDE_INT type_size = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (scalar_type));
+ gimple stmt = DR_STMT (dr);
+ stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
+ loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
+ bb_vec_info bb_vinfo = STMT_VINFO_BB_VINFO (stmt_info);
+ HOST_WIDE_INT dr_step = TREE_INT_CST_LOW (step);
+ HOST_WIDE_INT stride, last_accessed_element = 1;
+ bool slp_impossible = false;
+
+ /* For interleaving, STRIDE is STEP counted in elements, i.e., the size of the
+ interleaving group (including gaps). */
+ stride = dr_step / type_size;
+
+ /* Not consecutive access is possible only if it is a part of interleaving. */
+ if (!DR_GROUP_FIRST_DR (vinfo_for_stmt (stmt)))
+ {
+ /* Check if it this DR is a part of interleaving, and is a single
+ element of the group that is accessed in the loop. */
+
+ /* Gaps are supported only for loads. STEP must be a multiple of the type
+ size. The size of the group must be a power of 2. */
+ if (DR_IS_READ (dr)
+ && (dr_step % type_size) == 0
+ && stride > 0
+ && exact_log2 (stride) != -1)
+ {
+ DR_GROUP_FIRST_DR (vinfo_for_stmt (stmt)) = stmt;
+ DR_GROUP_SIZE (vinfo_for_stmt (stmt)) = stride;
+ if (vect_print_dump_info (REPORT_DR_DETAILS))
+ {
+ fprintf (vect_dump, "Detected single element interleaving ");
+ print_generic_expr (vect_dump, DR_REF (dr), TDF_SLIM);
+ fprintf (vect_dump, " step ");
+ print_generic_expr (vect_dump, step, TDF_SLIM);
+ }
+
+ if (loop_vinfo)
+ {
+ LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) = true;
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "Data access with gaps requires scalar "
+ "epilogue loop");
+ }
+
+ return true;
+ }
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ {
+ fprintf (vect_dump, "not consecutive access ");
+ print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM);
+ }
+
+ if (bb_vinfo)
+ {
+ /* Mark the statement as unvectorizable. */
+ STMT_VINFO_VECTORIZABLE (vinfo_for_stmt (DR_STMT (dr))) = false;
+ return true;
+ }
+
+ return false;
+ }
+
+ if (DR_GROUP_FIRST_DR (vinfo_for_stmt (stmt)) == stmt)
+ {
+ /* First stmt in the interleaving chain. Check the chain. */
+ gimple next = DR_GROUP_NEXT_DR (vinfo_for_stmt (stmt));
+ struct data_reference *data_ref = dr;
+ unsigned int count = 1;
+ tree next_step;
+ tree prev_init = DR_INIT (data_ref);
+ gimple prev = stmt;
+ HOST_WIDE_INT diff, count_in_bytes, gaps = 0;
+
+ while (next)
+ {
+ /* Skip same data-refs. In case that two or more stmts share
+ data-ref (supported only for loads), we vectorize only the first
+ stmt, and the rest get their vectorized loads from the first
+ one. */
+ if (!tree_int_cst_compare (DR_INIT (data_ref),
+ DR_INIT (STMT_VINFO_DATA_REF (
+ vinfo_for_stmt (next)))))
+ {
+ if (DR_IS_WRITE (data_ref))
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "Two store stmts share the same dr.");
+ return false;
+ }
+
+ /* Check that there is no load-store dependencies for this loads
+ to prevent a case of load-store-load to the same location. */
+ if (DR_GROUP_READ_WRITE_DEPENDENCE (vinfo_for_stmt (next))
+ || DR_GROUP_READ_WRITE_DEPENDENCE (vinfo_for_stmt (prev)))
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump,
+ "READ_WRITE dependence in interleaving.");
+ return false;
+ }
+
+ /* For load use the same data-ref load. */
+ DR_GROUP_SAME_DR_STMT (vinfo_for_stmt (next)) = prev;
+
+ prev = next;
+ next = DR_GROUP_NEXT_DR (vinfo_for_stmt (next));
+ continue;
+ }
+
+ prev = next;
+
+ /* Check that all the accesses have the same STEP. */
+ next_step = DR_STEP (STMT_VINFO_DATA_REF (vinfo_for_stmt (next)));
+ if (tree_int_cst_compare (step, next_step))
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "not consecutive access in interleaving");
+ return false;
+ }
+
+ data_ref = STMT_VINFO_DATA_REF (vinfo_for_stmt (next));
+ /* Check that the distance between two accesses is equal to the type
+ size. Otherwise, we have gaps. */
+ diff = (TREE_INT_CST_LOW (DR_INIT (data_ref))
+ - TREE_INT_CST_LOW (prev_init)) / type_size;
+ if (diff != 1)
+ {
+ /* FORNOW: SLP of accesses with gaps is not supported. */
+ slp_impossible = true;
+ if (DR_IS_WRITE (data_ref))
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "interleaved store with gaps");
+ return false;
+ }
+
+ gaps += diff - 1;
+ }
+
+ last_accessed_element += diff;
+
+ /* Store the gap from the previous member of the group. If there is no
+ gap in the access, DR_GROUP_GAP is always 1. */
+ DR_GROUP_GAP (vinfo_for_stmt (next)) = diff;
+
+ prev_init = DR_INIT (data_ref);
+ next = DR_GROUP_NEXT_DR (vinfo_for_stmt (next));
+ /* Count the number of data-refs in the chain. */
+ count++;
+ }
+
+ /* COUNT is the number of accesses found, we multiply it by the size of
+ the type to get COUNT_IN_BYTES. */
+ count_in_bytes = type_size * count;
+
+ /* Check that the size of the interleaving (including gaps) is not
+ greater than STEP. */
+ if (dr_step && dr_step < count_in_bytes + gaps * type_size)
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ {
+ fprintf (vect_dump, "interleaving size is greater than step for ");
+ print_generic_expr (vect_dump, DR_REF (dr), TDF_SLIM);
+ }
+ return false;
+ }
+
+ /* Check that the size of the interleaving is equal to STEP for stores,
+ i.e., that there are no gaps. */
+ if (dr_step && dr_step != count_in_bytes)
+ {
+ if (DR_IS_READ (dr))
+ {
+ slp_impossible = true;
+ /* There is a gap after the last load in the group. This gap is a
+ difference between the stride and the number of elements. When
+ there is no gap, this difference should be 0. */
+ DR_GROUP_GAP (vinfo_for_stmt (stmt)) = stride - count;
+ }
+ else
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "interleaved store with gaps");
+ return false;
+ }
+ }
+
+ /* Check that STEP is a multiple of type size. */
+ if (dr_step && (dr_step % type_size) != 0)
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ {
+ fprintf (vect_dump, "step is not a multiple of type size: step ");
+ print_generic_expr (vect_dump, step, TDF_SLIM);
+ fprintf (vect_dump, " size ");
+ print_generic_expr (vect_dump, TYPE_SIZE_UNIT (scalar_type),
+ TDF_SLIM);
+ }
+ return false;
+ }
+
+ /* FORNOW: we handle only interleaving that is a power of 2.
+ We don't fail here if it may be still possible to vectorize the
+ group using SLP. If not, the size of the group will be checked in
+ vect_analyze_operations, and the vectorization will fail. */
+ if (exact_log2 (stride) == -1)
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "interleaving is not a power of 2");
+
+ if (slp_impossible)
+ return false;
+ }
+
+ if (stride == 0)
+ stride = count;
+
+ DR_GROUP_SIZE (vinfo_for_stmt (stmt)) = stride;
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "Detected interleaving of size %d", (int)stride);
+
+ /* SLP: create an SLP data structure for every interleaving group of
+ stores for further analysis in vect_analyse_slp. */
+ if (DR_IS_WRITE (dr) && !slp_impossible)
+ {
+ if (loop_vinfo)
+ VEC_safe_push (gimple, heap, LOOP_VINFO_STRIDED_STORES (loop_vinfo),
+ stmt);
+ if (bb_vinfo)
+ VEC_safe_push (gimple, heap, BB_VINFO_STRIDED_STORES (bb_vinfo),
+ stmt);
+ }
+
+ /* There is a gap in the end of the group. */
+ if (stride - last_accessed_element > 0 && loop_vinfo)
+ {
+ LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) = true;
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "Data access with gaps requires scalar "
+ "epilogue loop");
+ }
+ }
+
+ return true;
+}
+
+
+/* Analyze the access pattern of the data-reference DR.
+ In case of non-consecutive accesses call vect_analyze_group_access() to
+ analyze groups of strided accesses. */
+
+static bool
+vect_analyze_data_ref_access (struct data_reference *dr)
+{
+ tree step = DR_STEP (dr);
+ tree scalar_type = TREE_TYPE (DR_REF (dr));
+ gimple stmt = DR_STMT (dr);
+ stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
+ loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
+ struct loop *loop = NULL;
+ HOST_WIDE_INT dr_step = TREE_INT_CST_LOW (step);
+
+ if (loop_vinfo)
+ loop = LOOP_VINFO_LOOP (loop_vinfo);
+
+ if (loop_vinfo && !step)
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "bad data-ref access in loop");
+ return false;
+ }
+
+ /* Don't allow invariant accesses in loops. */
+ if (loop_vinfo && dr_step == 0)
+ return false;
+
+ if (loop && nested_in_vect_loop_p (loop, stmt))
+ {
+ /* Interleaved accesses are not yet supported within outer-loop
+ vectorization for references in the inner-loop. */
+ DR_GROUP_FIRST_DR (vinfo_for_stmt (stmt)) = NULL;
+
+ /* For the rest of the analysis we use the outer-loop step. */
+ step = STMT_VINFO_DR_STEP (stmt_info);
+ dr_step = TREE_INT_CST_LOW (step);
+
+ if (dr_step == 0)
+ {
+ if (vect_print_dump_info (REPORT_ALIGNMENT))
+ fprintf (vect_dump, "zero step in outer loop.");
+ if (DR_IS_READ (dr))
+ return true;
+ else
+ return false;
+ }
+ }
+
+ /* Consecutive? */
+ if (!tree_int_cst_compare (step, TYPE_SIZE_UNIT (scalar_type))
+ || (dr_step < 0
+ && !compare_tree_int (TYPE_SIZE_UNIT (scalar_type), -dr_step)))
+ {
+ /* Mark that it is not interleaving. */
+ DR_GROUP_FIRST_DR (vinfo_for_stmt (stmt)) = NULL;
+ return true;
+ }
+
+ if (loop && nested_in_vect_loop_p (loop, stmt))
+ {
+ if (vect_print_dump_info (REPORT_ALIGNMENT))
+ fprintf (vect_dump, "strided access in outer loop.");
+ return false;
+ }
+
+ /* Not consecutive access - check if it's a part of interleaving group. */
+ return vect_analyze_group_access (dr);
+}
+
+
+/* Function vect_analyze_data_ref_accesses.
+
+ Analyze the access pattern of all the data references in the loop.
+
+ FORNOW: the only access pattern that is considered vectorizable is a
+ simple step 1 (consecutive) access.
+
+ FORNOW: handle only arrays and pointer accesses. */
+
+bool
+vect_analyze_data_ref_accesses (loop_vec_info loop_vinfo, bb_vec_info bb_vinfo)
+{
+ unsigned int i;
+ VEC (data_reference_p, heap) *datarefs;
+ struct data_reference *dr;
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "=== vect_analyze_data_ref_accesses ===");
+
+ if (loop_vinfo)
+ datarefs = LOOP_VINFO_DATAREFS (loop_vinfo);
+ else
+ datarefs = BB_VINFO_DATAREFS (bb_vinfo);
+
+ FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, dr)
+ if (STMT_VINFO_VECTORIZABLE (vinfo_for_stmt (DR_STMT (dr)))
+ && !vect_analyze_data_ref_access (dr))
+ {
+ if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
+ fprintf (vect_dump, "not vectorized: complicated access pattern.");
+
+ if (bb_vinfo)
+ {
+ /* Mark the statement as not vectorizable. */
+ STMT_VINFO_VECTORIZABLE (vinfo_for_stmt (DR_STMT (dr))) = false;
+ continue;
+ }
+ else
+ return false;
+ }
+
+ return true;
+}
+
+/* Function vect_prune_runtime_alias_test_list.
+
+ Prune a list of ddrs to be tested at run-time by versioning for alias.
+ Return FALSE if resulting list of ddrs is longer then allowed by
+ PARAM_VECT_MAX_VERSION_FOR_ALIAS_CHECKS, otherwise return TRUE. */
+
+bool
+vect_prune_runtime_alias_test_list (loop_vec_info loop_vinfo)
+{
+ VEC (ddr_p, heap) * ddrs =
+ LOOP_VINFO_MAY_ALIAS_DDRS (loop_vinfo);
+ unsigned i, j;
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "=== vect_prune_runtime_alias_test_list ===");
+
+ for (i = 0; i < VEC_length (ddr_p, ddrs); )
+ {
+ bool found;
+ ddr_p ddr_i;
+
+ ddr_i = VEC_index (ddr_p, ddrs, i);
+ found = false;
+
+ for (j = 0; j < i; j++)
+ {
+ ddr_p ddr_j = VEC_index (ddr_p, ddrs, j);
+
+ if (vect_vfa_range_equal (ddr_i, ddr_j))
+ {
+ if (vect_print_dump_info (REPORT_DR_DETAILS))
+ {
+ fprintf (vect_dump, "found equal ranges ");
+ print_generic_expr (vect_dump, DR_REF (DDR_A (ddr_i)), TDF_SLIM);
+ fprintf (vect_dump, ", ");
+ print_generic_expr (vect_dump, DR_REF (DDR_B (ddr_i)), TDF_SLIM);
+ fprintf (vect_dump, " and ");
+ print_generic_expr (vect_dump, DR_REF (DDR_A (ddr_j)), TDF_SLIM);
+ fprintf (vect_dump, ", ");
+ print_generic_expr (vect_dump, DR_REF (DDR_B (ddr_j)), TDF_SLIM);
+ }
+ found = true;
+ break;
+ }
+ }
+
+ if (found)
+ {
+ VEC_ordered_remove (ddr_p, ddrs, i);
+ continue;
+ }
+ i++;
+ }
+
+ if (VEC_length (ddr_p, ddrs) >
+ (unsigned) PARAM_VALUE (PARAM_VECT_MAX_VERSION_FOR_ALIAS_CHECKS))
+ {
+ if (vect_print_dump_info (REPORT_DR_DETAILS))
+ {
+ fprintf (vect_dump,
+ "disable versioning for alias - max number of generated "
+ "checks exceeded.");
+ }
+
+ VEC_truncate (ddr_p, LOOP_VINFO_MAY_ALIAS_DDRS (loop_vinfo), 0);
+
+ return false;
+ }
+
+ return true;
+}
+
+
+/* Function vect_analyze_data_refs.
+
+ Find all the data references in the loop or basic block.
+
+ The general structure of the analysis of data refs in the vectorizer is as
+ follows:
+ 1- vect_analyze_data_refs(loop/bb): call
+ compute_data_dependences_for_loop/bb to find and analyze all data-refs
+ in the loop/bb and their dependences.
+ 2- vect_analyze_dependences(): apply dependence testing using ddrs.
+ 3- vect_analyze_drs_alignment(): check that ref_stmt.alignment is ok.
+ 4- vect_analyze_drs_access(): check that ref_stmt.step is ok.
+
+*/
+
+bool
+vect_analyze_data_refs (loop_vec_info loop_vinfo,
+ bb_vec_info bb_vinfo,
+ int *min_vf)
+{
+ struct loop *loop = NULL;
+ basic_block bb = NULL;
+ unsigned int i;
+ VEC (data_reference_p, heap) *datarefs;
+ struct data_reference *dr;
+ tree scalar_type;
+ bool res;
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "=== vect_analyze_data_refs ===\n");
+
+ if (loop_vinfo)
+ {
+ loop = LOOP_VINFO_LOOP (loop_vinfo);
+ res = compute_data_dependences_for_loop
+ (loop, true,
+ &LOOP_VINFO_LOOP_NEST (loop_vinfo),
+ &LOOP_VINFO_DATAREFS (loop_vinfo),
+ &LOOP_VINFO_DDRS (loop_vinfo));
+
+ if (!res)
+ {
+ if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
+ fprintf (vect_dump, "not vectorized: loop contains function calls"
+ " or data references that cannot be analyzed");
+ return false;
+ }
+
+ datarefs = LOOP_VINFO_DATAREFS (loop_vinfo);
+ }
+ else
+ {
+ bb = BB_VINFO_BB (bb_vinfo);
+ res = compute_data_dependences_for_bb (bb, true,
+ &BB_VINFO_DATAREFS (bb_vinfo),
+ &BB_VINFO_DDRS (bb_vinfo));
+ if (!res)
+ {
+ if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
+ fprintf (vect_dump, "not vectorized: basic block contains function"
+ " calls or data references that cannot be analyzed");
+ return false;
+ }
+
+ datarefs = BB_VINFO_DATAREFS (bb_vinfo);
+ }
+
+ /* Go through the data-refs, check that the analysis succeeded. Update
+ pointer from stmt_vec_info struct to DR and vectype. */
+
+ FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, dr)
+ {
+ gimple stmt;
+ stmt_vec_info stmt_info;
+ tree base, offset, init;
+ int vf;
+
+ if (!dr || !DR_REF (dr))
+ {
+ if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
+ fprintf (vect_dump, "not vectorized: unhandled data-ref ");
+ return false;
+ }
+
+ stmt = DR_STMT (dr);
+ stmt_info = vinfo_for_stmt (stmt);
+
+ /* Check that analysis of the data-ref succeeded. */
+ if (!DR_BASE_ADDRESS (dr) || !DR_OFFSET (dr) || !DR_INIT (dr)
+ || !DR_STEP (dr))
+ {
+ if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
+ {
+ fprintf (vect_dump, "not vectorized: data ref analysis failed ");
+ print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM);
+ }
+
+ if (bb_vinfo)
+ {
+ /* Mark the statement as not vectorizable. */
+ STMT_VINFO_VECTORIZABLE (stmt_info) = false;
+ continue;
+ }
+ else
+ return false;
+ }
+
+ if (TREE_CODE (DR_BASE_ADDRESS (dr)) == INTEGER_CST)
+ {
+ if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
+ fprintf (vect_dump, "not vectorized: base addr of dr is a "
+ "constant");
+ if (bb_vinfo)
+ {
+ /* Mark the statement as not vectorizable. */
+ STMT_VINFO_VECTORIZABLE (stmt_info) = false;
+ continue;
+ }
+ else
+ return false;
+ }
+
+ if (TREE_THIS_VOLATILE (DR_REF (dr)))
+ {
+ if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
+ {
+ fprintf (vect_dump, "not vectorized: volatile type ");
+ print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM);
+ }
+ return false;
+ }
+
+ base = unshare_expr (DR_BASE_ADDRESS (dr));
+ offset = unshare_expr (DR_OFFSET (dr));
+ init = unshare_expr (DR_INIT (dr));
+
+ if (stmt_can_throw_internal (stmt))
+ {
+ if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
+ {
+ fprintf (vect_dump, "not vectorized: statement can throw an "
+ "exception ");
+ print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM);
+ }
+ return false;
+ }
+
+ /* Update DR field in stmt_vec_info struct. */
+
+ /* If the dataref is in an inner-loop of the loop that is considered for
+ for vectorization, we also want to analyze the access relative to
+ the outer-loop (DR contains information only relative to the
+ inner-most enclosing loop). We do that by building a reference to the
+ first location accessed by the inner-loop, and analyze it relative to
+ the outer-loop. */
+ if (loop && nested_in_vect_loop_p (loop, stmt))
+ {
+ tree outer_step, outer_base, outer_init;
+ HOST_WIDE_INT pbitsize, pbitpos;
+ tree poffset;
+ enum machine_mode pmode;
+ int punsignedp, pvolatilep;
+ affine_iv base_iv, offset_iv;
+ tree dinit;
+
+ /* Build a reference to the first location accessed by the
+ inner-loop: *(BASE+INIT). (The first location is actually
+ BASE+INIT+OFFSET, but we add OFFSET separately later). */
+ tree inner_base = build_fold_indirect_ref
+ (fold_build2 (POINTER_PLUS_EXPR,
+ TREE_TYPE (base), base,
+ fold_convert (sizetype, init)));
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ {
+ fprintf (vect_dump, "analyze in outer-loop: ");
+ print_generic_expr (vect_dump, inner_base, TDF_SLIM);
+ }
+
+ outer_base = get_inner_reference (inner_base, &pbitsize, &pbitpos,
+ &poffset, &pmode, &punsignedp, &pvolatilep, false);
+ gcc_assert (outer_base != NULL_TREE);
+
+ if (pbitpos % BITS_PER_UNIT != 0)
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "failed: bit offset alignment.\n");
+ return false;
+ }
+
+ outer_base = build_fold_addr_expr (outer_base);
+ if (!simple_iv (loop, loop_containing_stmt (stmt), outer_base,
+ &base_iv, false))
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "failed: evolution of base is not affine.\n");
+ return false;
+ }
+
+ if (offset)
+ {
+ if (poffset)
+ poffset = fold_build2 (PLUS_EXPR, TREE_TYPE (offset), offset,
+ poffset);
+ else
+ poffset = offset;
+ }
+
+ if (!poffset)
+ {
+ offset_iv.base = ssize_int (0);
+ offset_iv.step = ssize_int (0);
+ }
+ else if (!simple_iv (loop, loop_containing_stmt (stmt), poffset,
+ &offset_iv, false))
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "evolution of offset is not affine.\n");
+ return false;
+ }
+
+ outer_init = ssize_int (pbitpos / BITS_PER_UNIT);
+ split_constant_offset (base_iv.base, &base_iv.base, &dinit);
+ outer_init = size_binop (PLUS_EXPR, outer_init, dinit);
+ split_constant_offset (offset_iv.base, &offset_iv.base, &dinit);
+ outer_init = size_binop (PLUS_EXPR, outer_init, dinit);
+
+ outer_step = size_binop (PLUS_EXPR,
+ fold_convert (ssizetype, base_iv.step),
+ fold_convert (ssizetype, offset_iv.step));
+
+ STMT_VINFO_DR_STEP (stmt_info) = outer_step;
+ /* FIXME: Use canonicalize_base_object_address (base_iv.base); */
+ STMT_VINFO_DR_BASE_ADDRESS (stmt_info) = base_iv.base;
+ STMT_VINFO_DR_INIT (stmt_info) = outer_init;
+ STMT_VINFO_DR_OFFSET (stmt_info) =
+ fold_convert (ssizetype, offset_iv.base);
+ STMT_VINFO_DR_ALIGNED_TO (stmt_info) =
+ size_int (highest_pow2_factor (offset_iv.base));
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ {
+ fprintf (vect_dump, "\touter base_address: ");
+ print_generic_expr (vect_dump, STMT_VINFO_DR_BASE_ADDRESS (stmt_info), TDF_SLIM);
+ fprintf (vect_dump, "\n\touter offset from base address: ");
+ print_generic_expr (vect_dump, STMT_VINFO_DR_OFFSET (stmt_info), TDF_SLIM);
+ fprintf (vect_dump, "\n\touter constant offset from base address: ");
+ print_generic_expr (vect_dump, STMT_VINFO_DR_INIT (stmt_info), TDF_SLIM);
+ fprintf (vect_dump, "\n\touter step: ");
+ print_generic_expr (vect_dump, STMT_VINFO_DR_STEP (stmt_info), TDF_SLIM);
+ fprintf (vect_dump, "\n\touter aligned to: ");
+ print_generic_expr (vect_dump, STMT_VINFO_DR_ALIGNED_TO (stmt_info), TDF_SLIM);
+ }
+ }
+
+ if (STMT_VINFO_DATA_REF (stmt_info))
+ {
+ if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
+ {
+ fprintf (vect_dump,
+ "not vectorized: more than one data ref in stmt: ");
+ print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM);
+ }
+ return false;
+ }
+
+ STMT_VINFO_DATA_REF (stmt_info) = dr;
+
+ /* Set vectype for STMT. */
+ scalar_type = TREE_TYPE (DR_REF (dr));
+ STMT_VINFO_VECTYPE (stmt_info) =
+ get_vectype_for_scalar_type (scalar_type);
+ if (!STMT_VINFO_VECTYPE (stmt_info))
+ {
+ if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
+ {
+ fprintf (vect_dump,
+ "not vectorized: no vectype for stmt: ");
+ print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM);
+ fprintf (vect_dump, " scalar_type: ");
+ print_generic_expr (vect_dump, scalar_type, TDF_DETAILS);
+ }
+
+ if (bb_vinfo)
+ {
+ /* Mark the statement as not vectorizable. */
+ STMT_VINFO_VECTORIZABLE (stmt_info) = false;
+ continue;
+ }
+ else
+ return false;
+ }
+
+ /* Adjust the minimal vectorization factor according to the
+ vector type. */
+ vf = TYPE_VECTOR_SUBPARTS (STMT_VINFO_VECTYPE (stmt_info));
+ if (vf > *min_vf)
+ *min_vf = vf;
+ }
+
+ return true;
+}
+
+
+/* Function vect_get_new_vect_var.
+
+ Returns a name for a new variable. The current naming scheme appends the
+ prefix "vect_" or "vect_p" (depending on the value of VAR_KIND) to
+ the name of vectorizer generated variables, and appends that to NAME if
+ provided. */
+
+tree
+vect_get_new_vect_var (tree type, enum vect_var_kind var_kind, const char *name)
+{
+ const char *prefix;
+ tree new_vect_var;
+
+ switch (var_kind)
+ {
+ case vect_simple_var:
+ prefix = "vect_";
+ break;
+ case vect_scalar_var:
+ prefix = "stmp_";
+ break;
+ case vect_pointer_var:
+ prefix = "vect_p";
+ break;
+ default:
+ gcc_unreachable ();
+ }
+
+ if (name)
+ {
+ char* tmp = concat (prefix, name, NULL);
+ new_vect_var = create_tmp_var (type, tmp);
+ free (tmp);
+ }
+ else
+ new_vect_var = create_tmp_var (type, prefix);
+
+ /* Mark vector typed variable as a gimple register variable. */
+ if (TREE_CODE (type) == VECTOR_TYPE)
+ DECL_GIMPLE_REG_P (new_vect_var) = true;
+
+ return new_vect_var;
+}
+
+
+/* Function vect_create_addr_base_for_vector_ref.
+
+ Create an expression that computes the address of the first memory location
+ that will be accessed for a data reference.
+
+ Input:
+ STMT: The statement containing the data reference.
+ NEW_STMT_LIST: Must be initialized to NULL_TREE or a statement list.
+ OFFSET: Optional. If supplied, it is be added to the initial address.
+ LOOP: Specify relative to which loop-nest should the address be computed.
+ For example, when the dataref is in an inner-loop nested in an
+ outer-loop that is now being vectorized, LOOP can be either the
+ outer-loop, or the inner-loop. The first memory location accessed
+ by the following dataref ('in' points to short):
+
+ for (i=0; i<N; i++)
+ for (j=0; j<M; j++)
+ s += in[i+j]
+
+ is as follows:
+ if LOOP=i_loop: &in (relative to i_loop)
+ if LOOP=j_loop: &in+i*2B (relative to j_loop)
+
+ Output:
+ 1. Return an SSA_NAME whose value is the address of the memory location of
+ the first vector of the data reference.
+ 2. If new_stmt_list is not NULL_TREE after return then the caller must insert
+ these statement(s) which define the returned SSA_NAME.
+
+ FORNOW: We are only handling array accesses with step 1. */
+
+tree
+vect_create_addr_base_for_vector_ref (gimple stmt,
+ gimple_seq *new_stmt_list,
+ tree offset,
+ struct loop *loop)
+{
+ stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
+ struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info);
+ tree data_ref_base = unshare_expr (DR_BASE_ADDRESS (dr));
+ tree base_name;
+ tree data_ref_base_var;
+ tree vec_stmt;
+ tree addr_base, addr_expr;
+ tree dest;
+ gimple_seq seq = NULL;
+ tree base_offset = unshare_expr (DR_OFFSET (dr));
+ tree init = unshare_expr (DR_INIT (dr));
+ tree vect_ptr_type;
+ tree step = TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (dr)));
+ loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
+ tree base;
+
+ if (loop_vinfo && loop && loop != (gimple_bb (stmt))->loop_father)
+ {
+ struct loop *outer_loop = LOOP_VINFO_LOOP (loop_vinfo);
+
+ gcc_assert (nested_in_vect_loop_p (outer_loop, stmt));
+
+ data_ref_base = unshare_expr (STMT_VINFO_DR_BASE_ADDRESS (stmt_info));
+ base_offset = unshare_expr (STMT_VINFO_DR_OFFSET (stmt_info));
+ init = unshare_expr (STMT_VINFO_DR_INIT (stmt_info));
+ }
+
+ if (loop_vinfo)
+ base_name = build_fold_indirect_ref (data_ref_base);
+ else
+ {
+ base_offset = ssize_int (0);
+ init = ssize_int (0);
+ base_name = build_fold_indirect_ref (unshare_expr (DR_REF (dr)));
+ }
+
+ data_ref_base_var = create_tmp_var (TREE_TYPE (data_ref_base), "batmp");
+ add_referenced_var (data_ref_base_var);
+ data_ref_base = force_gimple_operand (data_ref_base, &seq, true,
+ data_ref_base_var);
+ gimple_seq_add_seq (new_stmt_list, seq);
+
+ /* Create base_offset */
+ base_offset = size_binop (PLUS_EXPR,
+ fold_convert (sizetype, base_offset),
+ fold_convert (sizetype, init));
+ dest = create_tmp_var (sizetype, "base_off");
+ add_referenced_var (dest);
+ base_offset = force_gimple_operand (base_offset, &seq, true, dest);
+ gimple_seq_add_seq (new_stmt_list, seq);
+
+ if (offset)
+ {
+ tree tmp = create_tmp_var (sizetype, "offset");
+
+ add_referenced_var (tmp);
+ offset = fold_build2 (MULT_EXPR, sizetype,
+ fold_convert (sizetype, offset), step);
+ base_offset = fold_build2 (PLUS_EXPR, sizetype,
+ base_offset, offset);
+ base_offset = force_gimple_operand (base_offset, &seq, false, tmp);
+ gimple_seq_add_seq (new_stmt_list, seq);
+ }
+
+ /* base + base_offset */
+ if (loop_vinfo)
+ addr_base = fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (data_ref_base),
+ data_ref_base, base_offset);
+ else
+ {
+ addr_base = build1 (ADDR_EXPR,
+ build_pointer_type (TREE_TYPE (DR_REF (dr))),
+ unshare_expr (DR_REF (dr)));
+ }
+
+ vect_ptr_type = build_pointer_type (STMT_VINFO_VECTYPE (stmt_info));
+ base = get_base_address (DR_REF (dr));
+ if (base
+ && TREE_CODE (base) == MEM_REF)
+ vect_ptr_type
+ = build_qualified_type (vect_ptr_type,
+ TYPE_QUALS (TREE_TYPE (TREE_OPERAND (base, 0))));
+
+ vec_stmt = fold_convert (vect_ptr_type, addr_base);
+ addr_expr = vect_get_new_vect_var (vect_ptr_type, vect_pointer_var,
+ get_name (base_name));
+ add_referenced_var (addr_expr);
+ vec_stmt = force_gimple_operand (vec_stmt, &seq, false, addr_expr);
+ gimple_seq_add_seq (new_stmt_list, seq);
+
+ if (DR_PTR_INFO (dr)
+ && TREE_CODE (vec_stmt) == SSA_NAME)
+ {
+ duplicate_ssa_name_ptr_info (vec_stmt, DR_PTR_INFO (dr));
+ if (offset)
+ {
+ SSA_NAME_PTR_INFO (vec_stmt)->align = 1;
+ SSA_NAME_PTR_INFO (vec_stmt)->misalign = 0;
+ }
+ }
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ {
+ fprintf (vect_dump, "created ");
+ print_generic_expr (vect_dump, vec_stmt, TDF_SLIM);
+ }
+
+ return vec_stmt;
+}
+
+
+/* Function vect_create_data_ref_ptr.
+
+ Create a new pointer to vector type (vp), that points to the first location
+ accessed in the loop by STMT, along with the def-use update chain to
+ appropriately advance the pointer through the loop iterations. Also set
+ aliasing information for the pointer. This vector pointer is used by the
+ callers to this function to create a memory reference expression for vector
+ load/store access.
+
+ Input:
+ 1. STMT: a stmt that references memory. Expected to be of the form
+ GIMPLE_ASSIGN <name, data-ref> or
+ GIMPLE_ASSIGN <data-ref, name>.
+ 2. AT_LOOP: the loop where the vector memref is to be created.
+ 3. OFFSET (optional): an offset to be added to the initial address accessed
+ by the data-ref in STMT.
+ 4. ONLY_INIT: indicate if vp is to be updated in the loop, or remain
+ pointing to the initial address.
+ 5. TYPE: if not NULL indicates the required type of the data-ref.
+
+ Output:
+ 1. Declare a new ptr to vector_type, and have it point to the base of the
+ data reference (initial addressed accessed by the data reference).
+ For example, for vector of type V8HI, the following code is generated:
+
+ v8hi *vp;
+ vp = (v8hi *)initial_address;
+
+ if OFFSET is not supplied:
+ initial_address = &a[init];
+ if OFFSET is supplied:
+ initial_address = &a[init + OFFSET];
+
+ Return the initial_address in INITIAL_ADDRESS.
+
+ 2. If ONLY_INIT is true, just return the initial pointer. Otherwise, also
+ update the pointer in each iteration of the loop.
+
+ Return the increment stmt that updates the pointer in PTR_INCR.
+
+ 3. Set INV_P to true if the access pattern of the data reference in the
+ vectorized loop is invariant. Set it to false otherwise.
+
+ 4. Return the pointer. */
+
+tree
+vect_create_data_ref_ptr (gimple stmt, struct loop *at_loop,
+ tree offset, tree *initial_address, gimple *ptr_incr,
+ bool only_init, bool *inv_p)
+{
+ tree base_name;
+ stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
+ loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
+ struct loop *loop = NULL;
+ bool nested_in_vect_loop = false;
+ struct loop *containing_loop = NULL;
+ tree vectype = STMT_VINFO_VECTYPE (stmt_info);
+ tree vect_ptr_type;
+ tree vect_ptr;
+ tree new_temp;
+ gimple vec_stmt;
+ gimple_seq new_stmt_list = NULL;
+ edge pe = NULL;
+ basic_block new_bb;
+ tree vect_ptr_init;
+ struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info);
+ tree vptr;
+ gimple_stmt_iterator incr_gsi;
+ bool insert_after;
+ bool negative;
+ tree indx_before_incr, indx_after_incr;
+ gimple incr;
+ tree step;
+ bb_vec_info bb_vinfo = STMT_VINFO_BB_VINFO (stmt_info);
+ gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
+ tree base;
+
+ if (loop_vinfo)
+ {
+ loop = LOOP_VINFO_LOOP (loop_vinfo);
+ nested_in_vect_loop = nested_in_vect_loop_p (loop, stmt);
+ containing_loop = (gimple_bb (stmt))->loop_father;
+ pe = loop_preheader_edge (loop);
+ }
+ else
+ {
+ gcc_assert (bb_vinfo);
+ only_init = true;
+ *ptr_incr = NULL;
+ }
+
+ /* Check the step (evolution) of the load in LOOP, and record
+ whether it's invariant. */
+ if (nested_in_vect_loop)
+ step = STMT_VINFO_DR_STEP (stmt_info);
+ else
+ step = DR_STEP (STMT_VINFO_DATA_REF (stmt_info));
+
+ if (tree_int_cst_compare (step, size_zero_node) == 0)
+ *inv_p = true;
+ else
+ *inv_p = false;
+ negative = tree_int_cst_compare (step, size_zero_node) < 0;
+
+ /* Create an expression for the first address accessed by this load
+ in LOOP. */
+ base_name = build_fold_indirect_ref (unshare_expr (DR_BASE_ADDRESS (dr)));
+
+ if (vect_print_dump_info (REPORT_DETAILS))
+ {
+ tree data_ref_base = base_name;
+ fprintf (vect_dump, "create vector-pointer variable to type: ");
+ print_generic_expr (vect_dump, vectype, TDF_SLIM);
+ if (TREE_CODE (data_ref_base) == VAR_DECL
+ || TREE_CODE (data_ref_base) == ARRAY_REF)
+ fprintf (vect_dump, " vectorizing an array ref: ");
+ else if (TREE_CODE (data_ref_base) == COMPONENT_REF)
+ fprintf (vect_dump, " vectorizing a record based array ref: ");
+ else if (TREE_CODE (data_ref_base) == SSA_NAME)
+ fprintf (vect_dump, " vectorizing a pointer ref: ");
+ print_generic_expr (vect_dump, base_name, TDF_SLIM);
+ }
+
+ /* (1) Create the new vector-pointer variable. */
+ vect_ptr_type = build_pointer_type (vectype);
+ base = get_base_address (DR_REF (dr));
+ if (base
+ && TREE_CODE (base) == MEM_REF)
+ vect_ptr_type
+ = build_qualified_type (vect_ptr_type,
+ TYPE_QUALS (TREE_TYPE (TREE_OPERAND (base, 0))));
+ vect_ptr = vect_get_new_vect_var (vect_ptr_type, vect_pointer_var,
+ get_name (base_name));
+
+ /* Vector types inherit the alias set of their component type by default so
+ we need to use a ref-all pointer if the data reference does not conflict
+ with the created vector data reference because it is not addressable. */
+ if (!alias_sets_conflict_p (get_deref_alias_set (vect_ptr),
+ get_alias_set (DR_REF (dr))))
+ {
+ vect_ptr_type
+ = build_pointer_type_for_mode (vectype,
+ TYPE_MODE (vect_ptr_type), true);
+ vect_ptr = vect_get_new_vect_var (vect_ptr_type, vect_pointer_var,
+ get_name (base_name));
+ }
+
+ /* Likewise for any of the data references in the stmt group. */
+ else if (STMT_VINFO_DR_GROUP_SIZE (stmt_info) > 1)
+ {
+ gimple orig_stmt = STMT_VINFO_DR_GROUP_FIRST_DR (stmt_info);
+ do
+ {
+ tree lhs = gimple_assign_lhs (orig_stmt);
+ if (!alias_sets_conflict_p (get_deref_alias_set (vect_ptr),
+ get_alias_set (lhs)))
+ {
+ vect_ptr_type
+ = build_pointer_type_for_mode (vectype,
+ TYPE_MODE (vect_ptr_type), true);
+ vect_ptr
+ = vect_get_new_vect_var (vect_ptr_type, vect_pointer_var,
+ get_name (base_name));
+ break;
+ }
+
+ orig_stmt = STMT_VINFO_DR_GROUP_NEXT_DR (vinfo_for_stmt (orig_stmt));
+ }
+ while (orig_stmt);
+ }
+
+ add_referenced_var (vect_ptr);
+
+ /* Note: If the dataref is in an inner-loop nested in LOOP, and we are
+ vectorizing LOOP (i.e., outer-loop vectorization), we need to create two
+ def-use update cycles for the pointer: one relative to the outer-loop
+ (LOOP), which is what steps (3) and (4) below do. The other is relative
+ to the inner-loop (which is the inner-most loop containing the dataref),
+ and this is done be step (5) below.
+
+ When vectorizing inner-most loops, the vectorized loop (LOOP) is also the
+ inner-most loop, and so steps (3),(4) work the same, and step (5) is
+ redundant. Steps (3),(4) create the following:
+
+ vp0 = &base_addr;
+ LOOP: vp1 = phi(vp0,vp2)
+ ...
+ ...
+ vp2 = vp1 + step
+ goto LOOP
+
+ If there is an inner-loop nested in loop, then step (5) will also be
+ applied, and an additional update in the inner-loop will be created:
+
+ vp0 = &base_addr;
+ LOOP: vp1 = phi(vp0,vp2)
+ ...
+ inner: vp3 = phi(vp1,vp4)
+ vp4 = vp3 + inner_step
+ if () goto inner
+ ...
+ vp2 = vp1 + step
+ if () goto LOOP */
+
+ /* (2) Calculate the initial address the vector-pointer, and set
+ the vector-pointer to point to it before the loop. */
+
+ /* Create: (&(base[init_val+offset]) in the loop preheader. */
+
+ new_temp = vect_create_addr_base_for_vector_ref (stmt, &new_stmt_list,
+ offset, loop);
+ if (new_stmt_list)
+ {
+ if (pe)
+ {
+ new_bb = gsi_insert_seq_on_edge_immediate (pe, new_stmt_list);
+ gcc_assert (!new_bb);
+ }
+ else
+ gsi_insert_seq_before (&gsi, new_stmt_list, GSI_SAME_STMT);
+ }
+
+ *initial_address = new_temp;
+
+ /* Create: p = (vectype *) initial_base */
+ if (TREE_CODE (new_temp) != SSA_NAME
+ || !useless_type_conversion_p (vect_ptr_type, TREE_TYPE (new_temp)))
+ {
+ vec_stmt = gimple_build_assign (vect_ptr,
+ fold_convert (vect_ptr_type, new_temp));
+ vect_ptr_init = make_ssa_name (vect_ptr, vec_stmt);
+ /* Copy the points-to information if it exists. */
+ if (DR_PTR_INFO (dr))
+ duplicate_ssa_name_ptr_info (vect_ptr_init, DR_PTR_INFO (dr));
+ gimple_assign_set_lhs (vec_stmt, vect_ptr_init);
+ if (pe)
+ {
+ new_bb = gsi_insert_on_edge_immediate (pe, vec_stmt);
+ gcc_assert (!new_bb);
+ }
+ else
+ gsi_insert_before (&gsi, vec_stmt, GSI_SAME_STMT);
+ }
+ else
+ vect_ptr_init = new_temp;
+
+ /* (3) Handle the updating of the vector-pointer inside the loop.
+ This is needed when ONLY_INIT is false, and also when AT_LOOP is the
+ inner-loop nested in LOOP (during outer-loop vectorization). */
+
+ /* No update in loop is required. */
+ if (only_init && (!loop_vinfo || at_loop == loop))
+ vptr = vect_ptr_init;
+ else
+ {
+ /* The step of the vector pointer is the Vector Size. */
+ tree step = TYPE_SIZE_UNIT (vectype);
+ /* One exception to the above is when the scalar step of the load in
+ LOOP is zero. In this case the step here is also zero. */
+ if (*inv_p)
+ step = size_zero_node;
+ else if (negative)
+ step = fold_build1 (NEGATE_EXPR, TREE_TYPE (step), step);
+
+ standard_iv_increment_position (loop, &incr_gsi, &insert_after);
+
+ create_iv (vect_ptr_init,
+ fold_convert (vect_ptr_type, step),
+ vect_ptr, loop, &incr_gsi, insert_after,
+ &indx_before_incr, &indx_after_incr);
+ incr = gsi_stmt (incr_gsi);
+ set_vinfo_for_stmt (incr, new_stmt_vec_info (incr, loop_vinfo, NULL));
+
+ /* Copy the points-to information if it exists. */
+ if (DR_PTR_INFO (dr))
+ {
+ duplicate_ssa_name_ptr_info (indx_before_incr, DR_PTR_INFO (dr));
+ duplicate_ssa_name_ptr_info (indx_after_incr, DR_PTR_INFO (dr));
+ }
+ if (ptr_incr)
+ *ptr_incr = incr;
+
+ vptr = indx_before_incr;
+ }
+
+ if (!nested_in_vect_loop || only_init)
+ return vptr;
+
+
+ /* (4) Handle the updating of the vector-pointer inside the inner-loop
+ nested in LOOP, if exists. */
+
+ gcc_assert (nested_in_vect_loop);
+ if (!only_init)
+ {
+ standard_iv_increment_position (containing_loop, &incr_gsi,
+ &insert_after);
+ create_iv (vptr, fold_convert (vect_ptr_type, DR_STEP (dr)), vect_ptr,
+ containing_loop, &incr_gsi, insert_after, &indx_before_incr,
+ &indx_after_incr);
+ incr = gsi_stmt (incr_gsi);
+ set_vinfo_for_stmt (incr, new_stmt_vec_info (incr, loop_vinfo, NULL));
+
+ /* Copy the points-to information if it exists. */
+ if (DR_PTR_INFO (dr))
+ {
+ duplicate_ssa_name_ptr_info (indx_before_incr, DR_PTR_INFO (dr));
+ duplicate_ssa_name_ptr_info (indx_after_incr, DR_PTR_INFO (dr));
+ }
+ if (ptr_incr)
+ *ptr_incr = incr;
+
+ return indx_before_incr;
+ }
+ else
+ gcc_unreachable ();
+}
+
+
+/* Function bump_vector_ptr
+
+ Increment a pointer (to a vector type) by vector-size. If requested,
+ i.e. if PTR-INCR is given, then also connect the new increment stmt
+ to the existing def-use update-chain of the pointer, by modifying
+ the PTR_INCR as illustrated below:
+
+ The pointer def-use update-chain before this function:
+ DATAREF_PTR = phi (p_0, p_2)
+ ....
+ PTR_INCR: p_2 = DATAREF_PTR + step
+
+ The pointer def-use update-chain after this function:
+ DATAREF_PTR = phi (p_0, p_2)
+ ....
+ NEW_DATAREF_PTR = DATAREF_PTR + BUMP
+ ....
+ PTR_INCR: p_2 = NEW_DATAREF_PTR + step
+
+ Input:
+ DATAREF_PTR - ssa_name of a pointer (to vector type) that is being updated
+ in the loop.
+ PTR_INCR - optional. The stmt that updates the pointer in each iteration of
+ the loop. The increment amount across iterations is expected
+ to be vector_size.
+ BSI - location where the new update stmt is to be placed.
+ STMT - the original scalar memory-access stmt that is being vectorized.
+ BUMP - optional. The offset by which to bump the pointer. If not given,
+ the offset is assumed to be vector_size.
+
+ Output: Return NEW_DATAREF_PTR as illustrated above.
+
+*/
+
+tree
+bump_vector_ptr (tree dataref_ptr, gimple ptr_incr, gimple_stmt_iterator *gsi,
+ gimple stmt, tree bump)
+{
+ stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
+ struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info);
+ tree vectype = STMT_VINFO_VECTYPE (stmt_info);
+ tree ptr_var = SSA_NAME_VAR (dataref_ptr);
+ tree update = TYPE_SIZE_UNIT (vectype);
+ gimple incr_stmt;
+ ssa_op_iter iter;
+ use_operand_p use_p;
+ tree new_dataref_ptr;
+
+ if (bump)
+ update = bump;
+
+ incr_stmt = gimple_build_assign_with_ops (POINTER_PLUS_EXPR, ptr_var,
+ dataref_ptr, update);
+ new_dataref_ptr = make_ssa_name (ptr_var, incr_stmt);
+ gimple_assign_set_lhs (incr_stmt, new_dataref_ptr);
+ vect_finish_stmt_generation (stmt, incr_stmt, gsi);
+
+ /* Copy the points-to information if it exists. */
+ if (DR_PTR_INFO (dr))
+ {
+ duplicate_ssa_name_ptr_info (new_dataref_ptr, DR_PTR_INFO (dr));
+ SSA_NAME_PTR_INFO (new_dataref_ptr)->align = 1;
+ SSA_NAME_PTR_INFO (new_dataref_ptr)->misalign = 0;
+ }
+
+ if (!ptr_incr)
+ return new_dataref_ptr;
+
+ /* Update the vector-pointer's cross-iteration increment. */
+ FOR_EACH_SSA_USE_OPERAND (use_p, ptr_incr, iter, SSA_OP_USE)
+ {
+ tree use = USE_FROM_PTR (use_p);
+
+ if (use == dataref_ptr)
+ SET_USE (use_p, new_dataref_ptr);
+ else
+ gcc_assert (tree_int_cst_compare (use, update) == 0);
+ }
+
+ return new_dataref_ptr;
+}
+
+
+/* Function vect_create_destination_var.
+
+ Create a new temporary of type VECTYPE. */
+
+tree
+vect_create_destination_var (tree scalar_dest, tree vectype)
+{
+ tree vec_dest;
+ const char *new_name;
+ tree type;
+ enum vect_var_kind kind;
+
+ kind = vectype ? vect_simple_var : vect_scalar_var;
+ type = vectype ? vectype : TREE_TYPE (scalar_dest);
+
+ gcc_assert (TREE_CODE (scalar_dest) == SSA_NAME);
+
+ new_name = get_name (scalar_dest);
+ if (!new_name)
+ new_name = "var_";
+ vec_dest = vect_get_new_vect_var (type, kind, new_name);
+ add_referenced_var (vec_dest);
+
+ return vec_dest;
+}
+
+/* Function vect_strided_store_supported.
+
+ Returns TRUE is INTERLEAVE_HIGH and INTERLEAVE_LOW operations are supported,
+ and FALSE otherwise. */
+
+bool
+vect_strided_store_supported (tree vectype)
+{
+ optab interleave_high_optab, interleave_low_optab;
+ enum machine_mode mode;
+
+ mode = TYPE_MODE (vectype);
+
+ /* Check that the operation is supported. */
+ interleave_high_optab = optab_for_tree_code (VEC_INTERLEAVE_HIGH_EXPR,
+ vectype, optab_default);
+ interleave_low_optab = optab_for_tree_code (VEC_INTERLEAVE_LOW_EXPR,
+ vectype, optab_default);
+ if (!interleave_high_optab || !interleave_low_optab)
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "no optab for interleave.");
+ return false;
+ }
+
+ if (optab_handler (interleave_high_optab, mode) == CODE_FOR_nothing
+ || optab_handler (interleave_low_optab, mode) == CODE_FOR_nothing)
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "interleave op not supported by target.");
+ return false;
+ }
+
+ return true;
+}
+
+
+/* Function vect_permute_store_chain.
+
+ Given a chain of interleaved stores in DR_CHAIN of LENGTH that must be
+ a power of 2, generate interleave_high/low stmts to reorder the data
+ correctly for the stores. Return the final references for stores in
+ RESULT_CHAIN.
+
+ E.g., LENGTH is 4 and the scalar type is short, i.e., VF is 8.
+ The input is 4 vectors each containing 8 elements. We assign a number to
+ each element, the input sequence is:
+
+ 1st vec: 0 1 2 3 4 5 6 7
+ 2nd vec: 8 9 10 11 12 13 14 15
+ 3rd vec: 16 17 18 19 20 21 22 23
+ 4th vec: 24 25 26 27 28 29 30 31
+
+ The output sequence should be:
+
+ 1st vec: 0 8 16 24 1 9 17 25
+ 2nd vec: 2 10 18 26 3 11 19 27
+ 3rd vec: 4 12 20 28 5 13 21 30
+ 4th vec: 6 14 22 30 7 15 23 31
+
+ i.e., we interleave the contents of the four vectors in their order.
+
+ We use interleave_high/low instructions to create such output. The input of
+ each interleave_high/low operation is two vectors:
+ 1st vec 2nd vec
+ 0 1 2 3 4 5 6 7
+ the even elements of the result vector are obtained left-to-right from the
+ high/low elements of the first vector. The odd elements of the result are
+ obtained left-to-right from the high/low elements of the second vector.
+ The output of interleave_high will be: 0 4 1 5
+ and of interleave_low: 2 6 3 7
+
+
+ The permutation is done in log LENGTH stages. In each stage interleave_high
+ and interleave_low stmts are created for each pair of vectors in DR_CHAIN,
+ where the first argument is taken from the first half of DR_CHAIN and the
+ second argument from it's second half.
+ In our example,
+
+ I1: interleave_high (1st vec, 3rd vec)
+ I2: interleave_low (1st vec, 3rd vec)
+ I3: interleave_high (2nd vec, 4th vec)
+ I4: interleave_low (2nd vec, 4th vec)
+
+ The output for the first stage is:
+
+ I1: 0 16 1 17 2 18 3 19
+ I2: 4 20 5 21 6 22 7 23
+ I3: 8 24 9 25 10 26 11 27
+ I4: 12 28 13 29 14 30 15 31
+
+ The output of the second stage, i.e. the final result is:
+
+ I1: 0 8 16 24 1 9 17 25
+ I2: 2 10 18 26 3 11 19 27
+ I3: 4 12 20 28 5 13 21 30
+ I4: 6 14 22 30 7 15 23 31. */
+
+bool
+vect_permute_store_chain (VEC(tree,heap) *dr_chain,
+ unsigned int length,
+ gimple stmt,
+ gimple_stmt_iterator *gsi,
+ VEC(tree,heap) **result_chain)
+{
+ tree perm_dest, vect1, vect2, high, low;
+ gimple perm_stmt;
+ tree vectype = STMT_VINFO_VECTYPE (vinfo_for_stmt (stmt));
+ int i;
+ unsigned int j;
+ enum tree_code high_code, low_code;
+
+ /* Check that the operation is supported. */
+ if (!vect_strided_store_supported (vectype))
+ return false;
+
+ *result_chain = VEC_copy (tree, heap, dr_chain);
+
+ for (i = 0; i < exact_log2 (length); i++)
+ {
+ for (j = 0; j < length/2; j++)
+ {
+ vect1 = VEC_index (tree, dr_chain, j);
+ vect2 = VEC_index (tree, dr_chain, j+length/2);
+
+ /* Create interleaving stmt:
+ in the case of big endian:
+ high = interleave_high (vect1, vect2)
+ and in the case of little endian:
+ high = interleave_low (vect1, vect2). */
+ perm_dest = create_tmp_var (vectype, "vect_inter_high");
+ DECL_GIMPLE_REG_P (perm_dest) = 1;
+ add_referenced_var (perm_dest);
+ if (BYTES_BIG_ENDIAN)
+ {
+ high_code = VEC_INTERLEAVE_HIGH_EXPR;
+ low_code = VEC_INTERLEAVE_LOW_EXPR;
+ }
+ else
+ {
+ low_code = VEC_INTERLEAVE_HIGH_EXPR;
+ high_code = VEC_INTERLEAVE_LOW_EXPR;
+ }
+ perm_stmt = gimple_build_assign_with_ops (high_code, perm_dest,
+ vect1, vect2);
+ high = make_ssa_name (perm_dest, perm_stmt);
+ gimple_assign_set_lhs (perm_stmt, high);
+ vect_finish_stmt_generation (stmt, perm_stmt, gsi);
+ VEC_replace (tree, *result_chain, 2*j, high);
+
+ /* Create interleaving stmt:
+ in the case of big endian:
+ low = interleave_low (vect1, vect2)
+ and in the case of little endian:
+ low = interleave_high (vect1, vect2). */
+ perm_dest = create_tmp_var (vectype, "vect_inter_low");
+ DECL_GIMPLE_REG_P (perm_dest) = 1;
+ add_referenced_var (perm_dest);
+ perm_stmt = gimple_build_assign_with_ops (low_code, perm_dest,
+ vect1, vect2);
+ low = make_ssa_name (perm_dest, perm_stmt);
+ gimple_assign_set_lhs (perm_stmt, low);
+ vect_finish_stmt_generation (stmt, perm_stmt, gsi);
+ VEC_replace (tree, *result_chain, 2*j+1, low);
+ }
+ dr_chain = VEC_copy (tree, heap, *result_chain);
+ }
+ return true;
+}
+
+/* Function vect_setup_realignment
+
+ This function is called when vectorizing an unaligned load using
+ the dr_explicit_realign[_optimized] scheme.
+ This function generates the following code at the loop prolog:
+
+ p = initial_addr;
+ x msq_init = *(floor(p)); # prolog load
+ realignment_token = call target_builtin;
+ loop:
+ x msq = phi (msq_init, ---)
+
+ The stmts marked with x are generated only for the case of
+ dr_explicit_realign_optimized.
+
+ The code above sets up a new (vector) pointer, pointing to the first
+ location accessed by STMT, and a "floor-aligned" load using that pointer.
+ It also generates code to compute the "realignment-token" (if the relevant
+ target hook was defined), and creates a phi-node at the loop-header bb
+ whose arguments are the result of the prolog-load (created by this
+ function) and the result of a load that takes place in the loop (to be
+ created by the caller to this function).
+
+ For the case of dr_explicit_realign_optimized:
+ The caller to this function uses the phi-result (msq) to create the
+ realignment code inside the loop, and sets up the missing phi argument,
+ as follows:
+ loop:
+ msq = phi (msq_init, lsq)
+ lsq = *(floor(p')); # load in loop
+ result = realign_load (msq, lsq, realignment_token);
+
+ For the case of dr_explicit_realign:
+ loop:
+ msq = *(floor(p)); # load in loop
+ p' = p + (VS-1);
+ lsq = *(floor(p')); # load in loop
+ result = realign_load (msq, lsq, realignment_token);
+
+ Input:
+ STMT - (scalar) load stmt to be vectorized. This load accesses
+ a memory location that may be unaligned.
+ BSI - place where new code is to be inserted.
+ ALIGNMENT_SUPPORT_SCHEME - which of the two misalignment handling schemes
+ is used.
+
+ Output:
+ REALIGNMENT_TOKEN - the result of a call to the builtin_mask_for_load
+ target hook, if defined.
+ Return value - the result of the loop-header phi node. */
+
+tree
+vect_setup_realignment (gimple stmt, gimple_stmt_iterator *gsi,
+ tree *realignment_token,
+ enum dr_alignment_support alignment_support_scheme,
+ tree init_addr,
+ struct loop **at_loop)
+{
+ stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
+ tree vectype = STMT_VINFO_VECTYPE (stmt_info);
+ loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
+ struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info);
+ struct loop *loop = NULL;
+ edge pe = NULL;
+ tree scalar_dest = gimple_assign_lhs (stmt);
+ tree vec_dest;
+ gimple inc;
+ tree ptr;
+ tree data_ref;
+ gimple new_stmt;
+ basic_block new_bb;
+ tree msq_init = NULL_TREE;
+ tree new_temp;
+ gimple phi_stmt;
+ tree msq = NULL_TREE;
+ gimple_seq stmts = NULL;
+ bool inv_p;
+ bool compute_in_loop = false;
+ bool nested_in_vect_loop = false;
+ struct loop *containing_loop = (gimple_bb (stmt))->loop_father;
+ struct loop *loop_for_initial_load = NULL;
+
+ if (loop_vinfo)
+ {
+ loop = LOOP_VINFO_LOOP (loop_vinfo);
+ nested_in_vect_loop = nested_in_vect_loop_p (loop, stmt);
+ }
+
+ gcc_assert (alignment_support_scheme == dr_explicit_realign
+ || alignment_support_scheme == dr_explicit_realign_optimized);
+
+ /* We need to generate three things:
+ 1. the misalignment computation
+ 2. the extra vector load (for the optimized realignment scheme).
+ 3. the phi node for the two vectors from which the realignment is
+ done (for the optimized realignment scheme). */
+
+ /* 1. Determine where to generate the misalignment computation.
+
+ If INIT_ADDR is NULL_TREE, this indicates that the misalignment
+ calculation will be generated by this function, outside the loop (in the
+ preheader). Otherwise, INIT_ADDR had already been computed for us by the
+ caller, inside the loop.
+
+ Background: If the misalignment remains fixed throughout the iterations of
+ the loop, then both realignment schemes are applicable, and also the
+ misalignment computation can be done outside LOOP. This is because we are
+ vectorizing LOOP, and so the memory accesses in LOOP advance in steps that
+ are a multiple of VS (the Vector Size), and therefore the misalignment in
+ different vectorized LOOP iterations is always the same.
+ The problem arises only if the memory access is in an inner-loop nested
+ inside LOOP, which is now being vectorized using outer-loop vectorization.
+ This is the only case when the misalignment of the memory access may not
+ remain fixed throughout the iterations of the inner-loop (as explained in
+ detail in vect_supportable_dr_alignment). In this case, not only is the
+ optimized realignment scheme not applicable, but also the misalignment
+ computation (and generation of the realignment token that is passed to
+ REALIGN_LOAD) have to be done inside the loop.
+
+ In short, INIT_ADDR indicates whether we are in a COMPUTE_IN_LOOP mode
+ or not, which in turn determines if the misalignment is computed inside
+ the inner-loop, or outside LOOP. */
+
+ if (init_addr != NULL_TREE || !loop_vinfo)
+ {
+ compute_in_loop = true;
+ gcc_assert (alignment_support_scheme == dr_explicit_realign);
+ }
+
+
+ /* 2. Determine where to generate the extra vector load.
+
+ For the optimized realignment scheme, instead of generating two vector
+ loads in each iteration, we generate a single extra vector load in the
+ preheader of the loop, and in each iteration reuse the result of the
+ vector load from the previous iteration. In case the memory access is in
+ an inner-loop nested inside LOOP, which is now being vectorized using
+ outer-loop vectorization, we need to determine whether this initial vector
+ load should be generated at the preheader of the inner-loop, or can be
+ generated at the preheader of LOOP. If the memory access has no evolution
+ in LOOP, it can be generated in the preheader of LOOP. Otherwise, it has
+ to be generated inside LOOP (in the preheader of the inner-loop). */
+
+ if (nested_in_vect_loop)
+ {
+ tree outerloop_step = STMT_VINFO_DR_STEP (stmt_info);
+ bool invariant_in_outerloop =
+ (tree_int_cst_compare (outerloop_step, size_zero_node) == 0);
+ loop_for_initial_load = (invariant_in_outerloop ? loop : loop->inner);
+ }
+ else
+ loop_for_initial_load = loop;
+ if (at_loop)
+ *at_loop = loop_for_initial_load;
+
+ if (loop_for_initial_load)
+ pe = loop_preheader_edge (loop_for_initial_load);
+
+ /* 3. For the case of the optimized realignment, create the first vector
+ load at the loop preheader. */
+
+ if (alignment_support_scheme == dr_explicit_realign_optimized)
+ {
+ /* Create msq_init = *(floor(p1)) in the loop preheader */
+
+ gcc_assert (!compute_in_loop);
+ vec_dest = vect_create_destination_var (scalar_dest, vectype);
+ ptr = vect_create_data_ref_ptr (stmt, loop_for_initial_load, NULL_TREE,
+ &init_addr, &inc, true, &inv_p);
+ new_stmt = gimple_build_assign_with_ops
+ (BIT_AND_EXPR, NULL_TREE, ptr,
+ build_int_cst (TREE_TYPE (ptr),
+ -(HOST_WIDE_INT)TYPE_ALIGN_UNIT (vectype)));
+ new_temp = make_ssa_name (SSA_NAME_VAR (ptr), new_stmt);
+ gimple_assign_set_lhs (new_stmt, new_temp);
+ new_bb = gsi_insert_on_edge_immediate (pe, new_stmt);
+ gcc_assert (!new_bb);
+ data_ref
+ = build2 (MEM_REF, TREE_TYPE (vec_dest), new_temp,
+ build_int_cst (reference_alias_ptr_type (DR_REF (dr)), 0));
+ new_stmt = gimple_build_assign (vec_dest, data_ref);
+ new_temp = make_ssa_name (vec_dest, new_stmt);
+ gimple_assign_set_lhs (new_stmt, new_temp);
+ mark_symbols_for_renaming (new_stmt);
+ if (pe)
+ {
+ new_bb = gsi_insert_on_edge_immediate (pe, new_stmt);
+ gcc_assert (!new_bb);
+ }
+ else
+ gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT);
+
+ msq_init = gimple_assign_lhs (new_stmt);
+ }
+
+ /* 4. Create realignment token using a target builtin, if available.
+ It is done either inside the containing loop, or before LOOP (as
+ determined above). */
+
+ if (targetm.vectorize.builtin_mask_for_load)
+ {
+ tree builtin_decl;
+
+ /* Compute INIT_ADDR - the initial addressed accessed by this memref. */
+ if (!init_addr)
+ {
+ /* Generate the INIT_ADDR computation outside LOOP. */
+ init_addr = vect_create_addr_base_for_vector_ref (stmt, &stmts,
+ NULL_TREE, loop);
+ if (loop)
+ {
+ pe = loop_preheader_edge (loop);
+ new_bb = gsi_insert_seq_on_edge_immediate (pe, stmts);
+ gcc_assert (!new_bb);
+ }
+ else
+ gsi_insert_seq_before (gsi, stmts, GSI_SAME_STMT);
+ }
+
+ builtin_decl = targetm.vectorize.builtin_mask_for_load ();
+ new_stmt = gimple_build_call (builtin_decl, 1, init_addr);
+ vec_dest =
+ vect_create_destination_var (scalar_dest,
+ gimple_call_return_type (new_stmt));
+ new_temp = make_ssa_name (vec_dest, new_stmt);
+ gimple_call_set_lhs (new_stmt, new_temp);
+
+ if (compute_in_loop)
+ gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT);
+ else
+ {
+ /* Generate the misalignment computation outside LOOP. */
+ pe = loop_preheader_edge (loop);
+ new_bb = gsi_insert_on_edge_immediate (pe, new_stmt);
+ gcc_assert (!new_bb);
+ }
+
+ *realignment_token = gimple_call_lhs (new_stmt);
+
+ /* The result of the CALL_EXPR to this builtin is determined from
+ the value of the parameter and no global variables are touched
+ which makes the builtin a "const" function. Requiring the
+ builtin to have the "const" attribute makes it unnecessary
+ to call mark_call_clobbered. */
+ gcc_assert (TREE_READONLY (builtin_decl));
+ }
+
+ if (alignment_support_scheme == dr_explicit_realign)
+ return msq;
+
+ gcc_assert (!compute_in_loop);
+ gcc_assert (alignment_support_scheme == dr_explicit_realign_optimized);
+
+
+ /* 5. Create msq = phi <msq_init, lsq> in loop */
+
+ pe = loop_preheader_edge (containing_loop);
+ vec_dest = vect_create_destination_var (scalar_dest, vectype);
+ msq = make_ssa_name (vec_dest, NULL);
+ phi_stmt = create_phi_node (msq, containing_loop->header);
+ SSA_NAME_DEF_STMT (msq) = phi_stmt;
+ add_phi_arg (phi_stmt, msq_init, pe, UNKNOWN_LOCATION);
+
+ return msq;
+}
+
+
+/* Function vect_strided_load_supported.
+
+ Returns TRUE is EXTRACT_EVEN and EXTRACT_ODD operations are supported,
+ and FALSE otherwise. */
+
+bool
+vect_strided_load_supported (tree vectype)
+{
+ optab perm_even_optab, perm_odd_optab;
+ enum machine_mode mode;
+
+ mode = TYPE_MODE (vectype);
+
+ perm_even_optab = optab_for_tree_code (VEC_EXTRACT_EVEN_EXPR, vectype,
+ optab_default);
+ if (!perm_even_optab)
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "no optab for perm_even.");
+ return false;
+ }
+
+ if (optab_handler (perm_even_optab, mode) == CODE_FOR_nothing)
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "perm_even op not supported by target.");
+ return false;
+ }
+
+ perm_odd_optab = optab_for_tree_code (VEC_EXTRACT_ODD_EXPR, vectype,
+ optab_default);
+ if (!perm_odd_optab)
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "no optab for perm_odd.");
+ return false;
+ }
+
+ if (optab_handler (perm_odd_optab, mode) == CODE_FOR_nothing)
+ {
+ if (vect_print_dump_info (REPORT_DETAILS))
+ fprintf (vect_dump, "perm_odd op not supported by target.");
+ return false;
+ }
+ return true;
+}
+
+
+/* Function vect_permute_load_chain.
+
+ Given a chain of interleaved loads in DR_CHAIN of LENGTH that must be
+ a power of 2, generate extract_even/odd stmts to reorder the input data
+ correctly. Return the final references for loads in RESULT_CHAIN.
+
+ E.g., LENGTH is 4 and the scalar type is short, i.e., VF is 8.
+ The input is 4 vectors each containing 8 elements. We assign a number to each
+ element, the input sequence is:
+
+ 1st vec: 0 1 2 3 4 5 6 7
+ 2nd vec: 8 9 10 11 12 13 14 15
+ 3rd vec: 16 17 18 19 20 21 22 23
+ 4th vec: 24 25 26 27 28 29 30 31
+
+ The output sequence should be:
+
+ 1st vec: 0 4 8 12 16 20 24 28
+ 2nd vec: 1 5 9 13 17 21 25 29
+ 3rd vec: 2 6 10 14 18 22 26 30
+ 4th vec: 3 7 11 15 19 23 27 31
+
+ i.e., the first output vector should contain the first elements of each
+ interleaving group, etc.
+
+ We use extract_even/odd instructions to create such output. The input of
+ each extract_even/odd operation is two vectors
+ 1st vec 2nd vec
+ 0 1 2 3 4 5 6 7
+
+ and the output is the vector of extracted even/odd elements. The output of
+ extract_even will be: 0 2 4 6
+ and of extract_odd: 1 3 5 7
+
+
+ The permutation is done in log LENGTH stages. In each stage extract_even
+ and extract_odd stmts are created for each pair of vectors in DR_CHAIN in
+ their order. In our example,
+
+ E1: extract_even (1st vec, 2nd vec)
+ E2: extract_odd (1st vec, 2nd vec)
+ E3: extract_even (3rd vec, 4th vec)
+ E4: extract_odd (3rd vec, 4th vec)
+
+ The output for the first stage will be:
+
+ E1: 0 2 4 6 8 10 12 14
+ E2: 1 3 5 7 9 11 13 15
+ E3: 16 18 20 22 24 26 28 30
+ E4: 17 19 21 23 25 27 29 31
+
+ In order to proceed and create the correct sequence for the next stage (or
+ for the correct output, if the second stage is the last one, as in our
+ example), we first put the output of extract_even operation and then the
+ output of extract_odd in RESULT_CHAIN (which is then copied to DR_CHAIN).
+ The input for the second stage is:
+
+ 1st vec (E1): 0 2 4 6 8 10 12 14
+ 2nd vec (E3): 16 18 20 22 24 26 28 30
+ 3rd vec (E2): 1 3 5 7 9 11 13 15
+ 4th vec (E4): 17 19 21 23 25 27 29 31
+
+ The output of the second stage:
+
+ E1: 0 4 8 12 16 20 24 28
+ E2: 2 6 10 14 18 22 26 30
+ E3: 1 5 9 13 17 21 25 29
+ E4: 3 7 11 15 19 23 27 31
+
+ And RESULT_CHAIN after reordering:
+
+ 1st vec (E1): 0 4 8 12 16 20 24 28
+ 2nd vec (E3): 1 5 9 13 17 21 25 29
+ 3rd vec (E2): 2 6 10 14 18 22 26 30
+ 4th vec (E4): 3 7 11 15 19 23 27 31. */
+
+bool
+vect_permute_load_chain (VEC(tree,heap) *dr_chain,
+ unsigned int length,
+ gimple stmt,
+ gimple_stmt_iterator *gsi,
+ VEC(tree,heap) **result_chain)
+{
+ tree perm_dest, data_ref, first_vect, second_vect;
+ gimple perm_stmt;
+ tree vectype = STMT_VINFO_VECTYPE (vinfo_for_stmt (stmt));
+ int i;
+ unsigned int j;
+
+ /* Check that the operation is supported. */
+ if (!vect_strided_load_supported (vectype))
+ return false;
+
+ *result_chain = VEC_copy (tree, heap, dr_chain);
+ for (i = 0; i < exact_log2 (length); i++)
+ {
+ for (j = 0; j < length; j +=2)
+ {
+ first_vect = VEC_index (tree, dr_chain, j);
+ second_vect = VEC_index (tree, dr_chain, j+1);
+
+ /* data_ref = permute_even (first_data_ref, second_data_ref); */
+ perm_dest = create_tmp_var (vectype, "vect_perm_even");
+ DECL_GIMPLE_REG_P (perm_dest) = 1;
+ add_referenced_var (perm_dest);
+
+ perm_stmt = gimple_build_assign_with_ops (VEC_EXTRACT_EVEN_EXPR,
+ perm_dest, first_vect,
+ second_vect);
+
+ data_ref = make_ssa_name (perm_dest, perm_stmt);
+ gimple_assign_set_lhs (perm_stmt, data_ref);
+ vect_finish_stmt_generation (stmt, perm_stmt, gsi);
+ mark_symbols_for_renaming (perm_stmt);
+
+ VEC_replace (tree, *result_chain, j/2, data_ref);
+
+ /* data_ref = permute_odd (first_data_ref, second_data_ref); */
+ perm_dest = create_tmp_var (vectype, "vect_perm_odd");
+ DECL_GIMPLE_REG_P (perm_dest) = 1;
+ add_referenced_var (perm_dest);
+
+ perm_stmt = gimple_build_assign_with_ops (VEC_EXTRACT_ODD_EXPR,
+ perm_dest, first_vect,
+ second_vect);
+ data_ref = make_ssa_name (perm_dest, perm_stmt);
+ gimple_assign_set_lhs (perm_stmt, data_ref);
+ vect_finish_stmt_generation (stmt, perm_stmt, gsi);
+ mark_symbols_for_renaming (perm_stmt);
+
+ VEC_replace (tree, *result_chain, j/2+length/2, data_ref);
+ }
+ dr_chain = VEC_copy (tree, heap, *result_chain);
+ }
+ return true;
+}
+
+
+/* Function vect_transform_strided_load.
+
+ Given a chain of input interleaved data-refs (in DR_CHAIN), build statements
+ to perform their permutation and ascribe the result vectorized statements to
+ the scalar statements.
+*/
+
+bool
+vect_transform_strided_load (gimple stmt, VEC(tree,heap) *dr_chain, int size,
+ gimple_stmt_iterator *gsi)
+{
+ stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
+ gimple first_stmt = DR_GROUP_FIRST_DR (stmt_info);
+ gimple next_stmt, new_stmt;
+ VEC(tree,heap) *result_chain = NULL;
+ unsigned int i, gap_count;
+ tree tmp_data_ref;
+
+ /* DR_CHAIN contains input data-refs that are a part of the interleaving.
+ RESULT_CHAIN is the output of vect_permute_load_chain, it contains permuted
+ vectors, that are ready for vector computation. */
+ result_chain = VEC_alloc (tree, heap, size);
+ /* Permute. */
+ if (!vect_permute_load_chain (dr_chain, size, stmt, gsi, &result_chain))
+ return false;
+
+ /* Put a permuted data-ref in the VECTORIZED_STMT field.
+ Since we scan the chain starting from it's first node, their order
+ corresponds the order of data-refs in RESULT_CHAIN. */
+ next_stmt = first_stmt;
+ gap_count = 1;
+ FOR_EACH_VEC_ELT (tree, result_chain, i, tmp_data_ref)
+ {
+ if (!next_stmt)
+ break;
+
+ /* Skip the gaps. Loads created for the gaps will be removed by dead
+ code elimination pass later. No need to check for the first stmt in
+ the group, since it always exists.
+ DR_GROUP_GAP is the number of steps in elements from the previous
+ access (if there is no gap DR_GROUP_GAP is 1). We skip loads that
+ correspond to the gaps. */
+ if (next_stmt != first_stmt
+ && gap_count < DR_GROUP_GAP (vinfo_for_stmt (next_stmt)))
+ {
+ gap_count++;
+ continue;
+ }
+
+ while (next_stmt)
+ {
+ new_stmt = SSA_NAME_DEF_STMT (tmp_data_ref);
+ /* We assume that if VEC_STMT is not NULL, this is a case of multiple
+ copies, and we put the new vector statement in the first available
+ RELATED_STMT. */
+ if (!STMT_VINFO_VEC_STMT (vinfo_for_stmt (next_stmt)))
+ STMT_VINFO_VEC_STMT (vinfo_for_stmt (next_stmt)) = new_stmt;
+ else
+ {
+ if (!DR_GROUP_SAME_DR_STMT (vinfo_for_stmt (next_stmt)))
+ {
+ gimple prev_stmt =
+ STMT_VINFO_VEC_STMT (vinfo_for_stmt (next_stmt));
+ gimple rel_stmt =
+ STMT_VINFO_RELATED_STMT (vinfo_for_stmt (prev_stmt));
+ while (rel_stmt)
+ {
+ prev_stmt = rel_stmt;
+ rel_stmt =
+ STMT_VINFO_RELATED_STMT (vinfo_for_stmt (rel_stmt));
+ }
+
+ STMT_VINFO_RELATED_STMT (vinfo_for_stmt (prev_stmt)) =
+ new_stmt;
+ }
+ }
+
+ next_stmt = DR_GROUP_NEXT_DR (vinfo_for_stmt (next_stmt));
+ gap_count = 1;
+ /* If NEXT_STMT accesses the same DR as the previous statement,
+ put the same TMP_DATA_REF as its vectorized statement; otherwise
+ get the next data-ref from RESULT_CHAIN. */
+ if (!next_stmt || !DR_GROUP_SAME_DR_STMT (vinfo_for_stmt (next_stmt)))
+ break;
+ }
+ }
+
+ VEC_free (tree, heap, result_chain);
+ return true;
+}
+
+/* Function vect_force_dr_alignment_p.
+
+ Returns whether the alignment of a DECL can be forced to be aligned
+ on ALIGNMENT bit boundary. */
+
+bool
+vect_can_force_dr_alignment_p (const_tree decl, unsigned int alignment)
+{
+ if (TREE_CODE (decl) != VAR_DECL)
+ return false;
+
+ if (DECL_EXTERNAL (decl))
+ return false;
+
+ if (TREE_ASM_WRITTEN (decl))
+ return false;
+
+ if (TREE_STATIC (decl))
+ return (alignment <= MAX_OFILE_ALIGNMENT);
+ else
+ return (alignment <= MAX_STACK_ALIGNMENT);
+}
+
+
+/* Return whether the data reference DR is supported with respect to its
+ alignment.
+ If CHECK_ALIGNED_ACCESSES is TRUE, check if the access is supported even
+ it is aligned, i.e., check if it is possible to vectorize it with different
+ alignment. */
+
+enum dr_alignment_support
+vect_supportable_dr_alignment (struct data_reference *dr,
+ bool check_aligned_accesses)
+{
+ gimple stmt = DR_STMT (dr);
+ stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
+ tree vectype = STMT_VINFO_VECTYPE (stmt_info);
+ enum machine_mode mode = TYPE_MODE (vectype);
+ loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
+ struct loop *vect_loop = NULL;
+ bool nested_in_vect_loop = false;
+
+ if (aligned_access_p (dr) && !check_aligned_accesses)
+ return dr_aligned;
+
+ if (loop_vinfo)
+ {
+ vect_loop = LOOP_VINFO_LOOP (loop_vinfo);
+ nested_in_vect_loop = nested_in_vect_loop_p (vect_loop, stmt);
+ }
+
+ /* Possibly unaligned access. */
+
+ /* We can choose between using the implicit realignment scheme (generating
+ a misaligned_move stmt) and the explicit realignment scheme (generating
+ aligned loads with a REALIGN_LOAD). There are two variants to the
+ explicit realignment scheme: optimized, and unoptimized.
+ We can optimize the realignment only if the step between consecutive
+ vector loads is equal to the vector size. Since the vector memory
+ accesses advance in steps of VS (Vector Size) in the vectorized loop, it
+ is guaranteed that the misalignment amount remains the same throughout the
+ execution of the vectorized loop. Therefore, we can create the
+ "realignment token" (the permutation mask that is passed to REALIGN_LOAD)
+ at the loop preheader.
+
+ However, in the case of outer-loop vectorization, when vectorizing a
+ memory access in the inner-loop nested within the LOOP that is now being
+ vectorized, while it is guaranteed that the misalignment of the
+ vectorized memory access will remain the same in different outer-loop
+ iterations, it is *not* guaranteed that is will remain the same throughout
+ the execution of the inner-loop. This is because the inner-loop advances
+ with the original scalar step (and not in steps of VS). If the inner-loop
+ step happens to be a multiple of VS, then the misalignment remains fixed
+ and we can use the optimized realignment scheme. For example:
+
+ for (i=0; i<N; i++)
+ for (j=0; j<M; j++)
+ s += a[i+j];
+
+ When vectorizing the i-loop in the above example, the step between
+ consecutive vector loads is 1, and so the misalignment does not remain
+ fixed across the execution of the inner-loop, and the realignment cannot
+ be optimized (as illustrated in the following pseudo vectorized loop):
+
+ for (i=0; i<N; i+=4)
+ for (j=0; j<M; j++){
+ vs += vp[i+j]; // misalignment of &vp[i+j] is {0,1,2,3,0,1,2,3,...}
+ // when j is {0,1,2,3,4,5,6,7,...} respectively.
+ // (assuming that we start from an aligned address).
+ }
+
+ We therefore have to use the unoptimized realignment scheme:
+
+ for (i=0; i<N; i+=4)
+ for (j=k; j<M; j+=4)
+ vs += vp[i+j]; // misalignment of &vp[i+j] is always k (assuming
+ // that the misalignment of the initial address is
+ // 0).
+
+ The loop can then be vectorized as follows:
+
+ for (k=0; k<4; k++){
+ rt = get_realignment_token (&vp[k]);
+ for (i=0; i<N; i+=4){
+ v1 = vp[i+k];
+ for (j=k; j<M; j+=4){
+ v2 = vp[i+j+VS-1];
+ va = REALIGN_LOAD <v1,v2,rt>;
+ vs += va;
+ v1 = v2;
+ }
+ }
+ } */
+
+ if (DR_IS_READ (dr))
+ {
+ bool is_packed = false;
+ tree type = (TREE_TYPE (DR_REF (dr)));
+
+ if (optab_handler (vec_realign_load_optab, mode) != CODE_FOR_nothing
+ && (!targetm.vectorize.builtin_mask_for_load
+ || targetm.vectorize.builtin_mask_for_load ()))
+ {
+ tree vectype = STMT_VINFO_VECTYPE (stmt_info);
+ if ((nested_in_vect_loop
+ && (TREE_INT_CST_LOW (DR_STEP (dr))
+ != GET_MODE_SIZE (TYPE_MODE (vectype))))
+ || !loop_vinfo)
+ return dr_explicit_realign;
+ else
+ return dr_explicit_realign_optimized;
+ }
+ if (!known_alignment_for_access_p (dr))
+ {
+ tree ba = DR_BASE_OBJECT (dr);
+
+ if (ba)
+ is_packed = contains_packed_reference (ba);
+ }
+
+ if (targetm.vectorize.
+ support_vector_misalignment (mode, type,
+ DR_MISALIGNMENT (dr), is_packed))
+ /* Can't software pipeline the loads, but can at least do them. */
+ return dr_unaligned_supported;
+ }
+ else
+ {
+ bool is_packed = false;
+ tree type = (TREE_TYPE (DR_REF (dr)));
+
+ if (!known_alignment_for_access_p (dr))
+ {
+ tree ba = DR_BASE_OBJECT (dr);
+
+ if (ba)
+ is_packed = contains_packed_reference (ba);
+ }
+
+ if (targetm.vectorize.
+ support_vector_misalignment (mode, type,
+ DR_MISALIGNMENT (dr), is_packed))
+ return dr_unaligned_supported;
+ }
+
+ /* Unsupported. */
+ return dr_unaligned_unsupported;
+}