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authorBen Cheng <bccheng@google.com>2013-03-28 11:14:20 -0700
committerBen Cheng <bccheng@google.com>2013-03-28 12:40:33 -0700
commitaf0c51ac87ab2a87caa03fa108f0d164987a2764 (patch)
tree4b8b470f7c5b69642fdab8d0aa1fbc148d02196b /gcc-4.8/gcc/stmt.c
parentd87cae247d39ebf4f5a6bf25c932a14d2fdb9384 (diff)
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[GCC 4.8] Initial check-in of GCC 4.8.0
Change-Id: I0719d8a6d0f69b367a6ab6f10eb75622dbf12771
Diffstat (limited to 'gcc-4.8/gcc/stmt.c')
-rw-r--r--gcc-4.8/gcc/stmt.c2998
1 files changed, 2998 insertions, 0 deletions
diff --git a/gcc-4.8/gcc/stmt.c b/gcc-4.8/gcc/stmt.c
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+/* Expands front end tree to back end RTL for GCC
+ Copyright (C) 1987-2013 Free Software Foundation, Inc.
+
+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/>. */
+
+/* This file handles the generation of rtl code from tree structure
+ above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
+ The functions whose names start with `expand_' are called by the
+ expander to generate RTL instructions for various kinds of constructs. */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+
+#include "rtl.h"
+#include "hard-reg-set.h"
+#include "tree.h"
+#include "tm_p.h"
+#include "flags.h"
+#include "except.h"
+#include "function.h"
+#include "insn-config.h"
+#include "expr.h"
+#include "libfuncs.h"
+#include "recog.h"
+#include "machmode.h"
+#include "diagnostic-core.h"
+#include "output.h"
+#include "ggc.h"
+#include "langhooks.h"
+#include "predict.h"
+#include "optabs.h"
+#include "target.h"
+#include "gimple.h"
+#include "regs.h"
+#include "alloc-pool.h"
+#include "pretty-print.h"
+#include "pointer-set.h"
+#include "params.h"
+#include "dumpfile.h"
+
+
+/* Functions and data structures for expanding case statements. */
+
+/* Case label structure, used to hold info on labels within case
+ statements. We handle "range" labels; for a single-value label
+ as in C, the high and low limits are the same.
+
+ We start with a vector of case nodes sorted in ascending order, and
+ the default label as the last element in the vector. Before expanding
+ to RTL, we transform this vector into a list linked via the RIGHT
+ fields in the case_node struct. Nodes with higher case values are
+ later in the list.
+
+ Switch statements can be output in three forms. A branch table is
+ used if there are more than a few labels and the labels are dense
+ within the range between the smallest and largest case value. If a
+ branch table is used, no further manipulations are done with the case
+ node chain.
+
+ The alternative to the use of a branch table is to generate a series
+ of compare and jump insns. When that is done, we use the LEFT, RIGHT,
+ and PARENT fields to hold a binary tree. Initially the tree is
+ totally unbalanced, with everything on the right. We balance the tree
+ with nodes on the left having lower case values than the parent
+ and nodes on the right having higher values. We then output the tree
+ in order.
+
+ For very small, suitable switch statements, we can generate a series
+ of simple bit test and branches instead. */
+
+struct case_node
+{
+ struct case_node *left; /* Left son in binary tree */
+ struct case_node *right; /* Right son in binary tree; also node chain */
+ struct case_node *parent; /* Parent of node in binary tree */
+ tree low; /* Lowest index value for this label */
+ tree high; /* Highest index value for this label */
+ tree code_label; /* Label to jump to when node matches */
+ int prob; /* Probability of taking this case. */
+ /* Probability of reaching subtree rooted at this node */
+ int subtree_prob;
+};
+
+typedef struct case_node case_node;
+typedef struct case_node *case_node_ptr;
+
+extern basic_block label_to_block_fn (struct function *, tree);
+
+static int n_occurrences (int, const char *);
+static bool tree_conflicts_with_clobbers_p (tree, HARD_REG_SET *);
+static void expand_nl_goto_receiver (void);
+static bool check_operand_nalternatives (tree, tree);
+static bool check_unique_operand_names (tree, tree, tree);
+static char *resolve_operand_name_1 (char *, tree, tree, tree);
+static void expand_null_return_1 (void);
+static void expand_value_return (rtx);
+static void balance_case_nodes (case_node_ptr *, case_node_ptr);
+static int node_has_low_bound (case_node_ptr, tree);
+static int node_has_high_bound (case_node_ptr, tree);
+static int node_is_bounded (case_node_ptr, tree);
+static void emit_case_nodes (rtx, case_node_ptr, rtx, int, tree);
+
+/* Return the rtx-label that corresponds to a LABEL_DECL,
+ creating it if necessary. */
+
+rtx
+label_rtx (tree label)
+{
+ gcc_assert (TREE_CODE (label) == LABEL_DECL);
+
+ if (!DECL_RTL_SET_P (label))
+ {
+ rtx r = gen_label_rtx ();
+ SET_DECL_RTL (label, r);
+ if (FORCED_LABEL (label) || DECL_NONLOCAL (label))
+ LABEL_PRESERVE_P (r) = 1;
+ }
+
+ return DECL_RTL (label);
+}
+
+/* As above, but also put it on the forced-reference list of the
+ function that contains it. */
+rtx
+force_label_rtx (tree label)
+{
+ rtx ref = label_rtx (label);
+ tree function = decl_function_context (label);
+
+ gcc_assert (function);
+
+ forced_labels = gen_rtx_EXPR_LIST (VOIDmode, ref, forced_labels);
+ return ref;
+}
+
+/* Add an unconditional jump to LABEL as the next sequential instruction. */
+
+void
+emit_jump (rtx label)
+{
+ do_pending_stack_adjust ();
+ emit_jump_insn (gen_jump (label));
+ emit_barrier ();
+}
+
+/* Emit code to jump to the address
+ specified by the pointer expression EXP. */
+
+void
+expand_computed_goto (tree exp)
+{
+ rtx x = expand_normal (exp);
+
+ x = convert_memory_address (Pmode, x);
+
+ do_pending_stack_adjust ();
+ emit_indirect_jump (x);
+}
+
+/* Handle goto statements and the labels that they can go to. */
+
+/* Specify the location in the RTL code of a label LABEL,
+ which is a LABEL_DECL tree node.
+
+ This is used for the kind of label that the user can jump to with a
+ goto statement, and for alternatives of a switch or case statement.
+ RTL labels generated for loops and conditionals don't go through here;
+ they are generated directly at the RTL level, by other functions below.
+
+ Note that this has nothing to do with defining label *names*.
+ Languages vary in how they do that and what that even means. */
+
+void
+expand_label (tree label)
+{
+ rtx label_r = label_rtx (label);
+
+ do_pending_stack_adjust ();
+ emit_label (label_r);
+ if (DECL_NAME (label))
+ LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
+
+ if (DECL_NONLOCAL (label))
+ {
+ expand_nl_goto_receiver ();
+ nonlocal_goto_handler_labels
+ = gen_rtx_EXPR_LIST (VOIDmode, label_r,
+ nonlocal_goto_handler_labels);
+ }
+
+ if (FORCED_LABEL (label))
+ forced_labels = gen_rtx_EXPR_LIST (VOIDmode, label_r, forced_labels);
+
+ if (DECL_NONLOCAL (label) || FORCED_LABEL (label))
+ maybe_set_first_label_num (label_r);
+}
+
+/* Generate RTL code for a `goto' statement with target label LABEL.
+ LABEL should be a LABEL_DECL tree node that was or will later be
+ defined with `expand_label'. */
+
+void
+expand_goto (tree label)
+{
+#ifdef ENABLE_CHECKING
+ /* Check for a nonlocal goto to a containing function. Should have
+ gotten translated to __builtin_nonlocal_goto. */
+ tree context = decl_function_context (label);
+ gcc_assert (!context || context == current_function_decl);
+#endif
+
+ emit_jump (label_rtx (label));
+}
+
+/* Return the number of times character C occurs in string S. */
+static int
+n_occurrences (int c, const char *s)
+{
+ int n = 0;
+ while (*s)
+ n += (*s++ == c);
+ return n;
+}
+
+/* Generate RTL for an asm statement (explicit assembler code).
+ STRING is a STRING_CST node containing the assembler code text,
+ or an ADDR_EXPR containing a STRING_CST. VOL nonzero means the
+ insn is volatile; don't optimize it. */
+
+static void
+expand_asm_loc (tree string, int vol, location_t locus)
+{
+ rtx body;
+
+ if (TREE_CODE (string) == ADDR_EXPR)
+ string = TREE_OPERAND (string, 0);
+
+ body = gen_rtx_ASM_INPUT_loc (VOIDmode,
+ ggc_strdup (TREE_STRING_POINTER (string)),
+ locus);
+
+ MEM_VOLATILE_P (body) = vol;
+
+ emit_insn (body);
+}
+
+/* Parse the output constraint pointed to by *CONSTRAINT_P. It is the
+ OPERAND_NUMth output operand, indexed from zero. There are NINPUTS
+ inputs and NOUTPUTS outputs to this extended-asm. Upon return,
+ *ALLOWS_MEM will be TRUE iff the constraint allows the use of a
+ memory operand. Similarly, *ALLOWS_REG will be TRUE iff the
+ constraint allows the use of a register operand. And, *IS_INOUT
+ will be true if the operand is read-write, i.e., if it is used as
+ an input as well as an output. If *CONSTRAINT_P is not in
+ canonical form, it will be made canonical. (Note that `+' will be
+ replaced with `=' as part of this process.)
+
+ Returns TRUE if all went well; FALSE if an error occurred. */
+
+bool
+parse_output_constraint (const char **constraint_p, int operand_num,
+ int ninputs, int noutputs, bool *allows_mem,
+ bool *allows_reg, bool *is_inout)
+{
+ const char *constraint = *constraint_p;
+ const char *p;
+
+ /* Assume the constraint doesn't allow the use of either a register
+ or memory. */
+ *allows_mem = false;
+ *allows_reg = false;
+
+ /* Allow the `=' or `+' to not be at the beginning of the string,
+ since it wasn't explicitly documented that way, and there is a
+ large body of code that puts it last. Swap the character to
+ the front, so as not to uglify any place else. */
+ p = strchr (constraint, '=');
+ if (!p)
+ p = strchr (constraint, '+');
+
+ /* If the string doesn't contain an `=', issue an error
+ message. */
+ if (!p)
+ {
+ error ("output operand constraint lacks %<=%>");
+ return false;
+ }
+
+ /* If the constraint begins with `+', then the operand is both read
+ from and written to. */
+ *is_inout = (*p == '+');
+
+ /* Canonicalize the output constraint so that it begins with `='. */
+ if (p != constraint || *is_inout)
+ {
+ char *buf;
+ size_t c_len = strlen (constraint);
+
+ if (p != constraint)
+ warning (0, "output constraint %qc for operand %d "
+ "is not at the beginning",
+ *p, operand_num);
+
+ /* Make a copy of the constraint. */
+ buf = XALLOCAVEC (char, c_len + 1);
+ strcpy (buf, constraint);
+ /* Swap the first character and the `=' or `+'. */
+ buf[p - constraint] = buf[0];
+ /* Make sure the first character is an `='. (Until we do this,
+ it might be a `+'.) */
+ buf[0] = '=';
+ /* Replace the constraint with the canonicalized string. */
+ *constraint_p = ggc_alloc_string (buf, c_len);
+ constraint = *constraint_p;
+ }
+
+ /* Loop through the constraint string. */
+ for (p = constraint + 1; *p; p += CONSTRAINT_LEN (*p, p))
+ switch (*p)
+ {
+ case '+':
+ case '=':
+ error ("operand constraint contains incorrectly positioned "
+ "%<+%> or %<=%>");
+ return false;
+
+ case '%':
+ if (operand_num + 1 == ninputs + noutputs)
+ {
+ error ("%<%%%> constraint used with last operand");
+ return false;
+ }
+ break;
+
+ case 'V': case TARGET_MEM_CONSTRAINT: case 'o':
+ *allows_mem = true;
+ break;
+
+ case '?': case '!': case '*': case '&': case '#':
+ case 'E': case 'F': case 'G': case 'H':
+ case 's': case 'i': case 'n':
+ case 'I': case 'J': case 'K': case 'L': case 'M':
+ case 'N': case 'O': case 'P': case ',':
+ break;
+
+ case '0': case '1': case '2': case '3': case '4':
+ case '5': case '6': case '7': case '8': case '9':
+ case '[':
+ error ("matching constraint not valid in output operand");
+ return false;
+
+ case '<': case '>':
+ /* ??? Before flow, auto inc/dec insns are not supposed to exist,
+ excepting those that expand_call created. So match memory
+ and hope. */
+ *allows_mem = true;
+ break;
+
+ case 'g': case 'X':
+ *allows_reg = true;
+ *allows_mem = true;
+ break;
+
+ case 'p': case 'r':
+ *allows_reg = true;
+ break;
+
+ default:
+ if (!ISALPHA (*p))
+ break;
+ if (REG_CLASS_FROM_CONSTRAINT (*p, p) != NO_REGS)
+ *allows_reg = true;
+#ifdef EXTRA_CONSTRAINT_STR
+ else if (EXTRA_ADDRESS_CONSTRAINT (*p, p))
+ *allows_reg = true;
+ else if (EXTRA_MEMORY_CONSTRAINT (*p, p))
+ *allows_mem = true;
+ else
+ {
+ /* Otherwise we can't assume anything about the nature of
+ the constraint except that it isn't purely registers.
+ Treat it like "g" and hope for the best. */
+ *allows_reg = true;
+ *allows_mem = true;
+ }
+#endif
+ break;
+ }
+
+ return true;
+}
+
+/* Similar, but for input constraints. */
+
+bool
+parse_input_constraint (const char **constraint_p, int input_num,
+ int ninputs, int noutputs, int ninout,
+ const char * const * constraints,
+ bool *allows_mem, bool *allows_reg)
+{
+ const char *constraint = *constraint_p;
+ const char *orig_constraint = constraint;
+ size_t c_len = strlen (constraint);
+ size_t j;
+ bool saw_match = false;
+
+ /* Assume the constraint doesn't allow the use of either
+ a register or memory. */
+ *allows_mem = false;
+ *allows_reg = false;
+
+ /* Make sure constraint has neither `=', `+', nor '&'. */
+
+ for (j = 0; j < c_len; j += CONSTRAINT_LEN (constraint[j], constraint+j))
+ switch (constraint[j])
+ {
+ case '+': case '=': case '&':
+ if (constraint == orig_constraint)
+ {
+ error ("input operand constraint contains %qc", constraint[j]);
+ return false;
+ }
+ break;
+
+ case '%':
+ if (constraint == orig_constraint
+ && input_num + 1 == ninputs - ninout)
+ {
+ error ("%<%%%> constraint used with last operand");
+ return false;
+ }
+ break;
+
+ case 'V': case TARGET_MEM_CONSTRAINT: case 'o':
+ *allows_mem = true;
+ break;
+
+ case '<': case '>':
+ case '?': case '!': case '*': case '#':
+ case 'E': case 'F': case 'G': case 'H':
+ case 's': case 'i': case 'n':
+ case 'I': case 'J': case 'K': case 'L': case 'M':
+ case 'N': case 'O': case 'P': case ',':
+ break;
+
+ /* Whether or not a numeric constraint allows a register is
+ decided by the matching constraint, and so there is no need
+ to do anything special with them. We must handle them in
+ the default case, so that we don't unnecessarily force
+ operands to memory. */
+ case '0': case '1': case '2': case '3': case '4':
+ case '5': case '6': case '7': case '8': case '9':
+ {
+ char *end;
+ unsigned long match;
+
+ saw_match = true;
+
+ match = strtoul (constraint + j, &end, 10);
+ if (match >= (unsigned long) noutputs)
+ {
+ error ("matching constraint references invalid operand number");
+ return false;
+ }
+
+ /* Try and find the real constraint for this dup. Only do this
+ if the matching constraint is the only alternative. */
+ if (*end == '\0'
+ && (j == 0 || (j == 1 && constraint[0] == '%')))
+ {
+ constraint = constraints[match];
+ *constraint_p = constraint;
+ c_len = strlen (constraint);
+ j = 0;
+ /* ??? At the end of the loop, we will skip the first part of
+ the matched constraint. This assumes not only that the
+ other constraint is an output constraint, but also that
+ the '=' or '+' come first. */
+ break;
+ }
+ else
+ j = end - constraint;
+ /* Anticipate increment at end of loop. */
+ j--;
+ }
+ /* Fall through. */
+
+ case 'p': case 'r':
+ *allows_reg = true;
+ break;
+
+ case 'g': case 'X':
+ *allows_reg = true;
+ *allows_mem = true;
+ break;
+
+ default:
+ if (! ISALPHA (constraint[j]))
+ {
+ error ("invalid punctuation %qc in constraint", constraint[j]);
+ return false;
+ }
+ if (REG_CLASS_FROM_CONSTRAINT (constraint[j], constraint + j)
+ != NO_REGS)
+ *allows_reg = true;
+#ifdef EXTRA_CONSTRAINT_STR
+ else if (EXTRA_ADDRESS_CONSTRAINT (constraint[j], constraint + j))
+ *allows_reg = true;
+ else if (EXTRA_MEMORY_CONSTRAINT (constraint[j], constraint + j))
+ *allows_mem = true;
+ else
+ {
+ /* Otherwise we can't assume anything about the nature of
+ the constraint except that it isn't purely registers.
+ Treat it like "g" and hope for the best. */
+ *allows_reg = true;
+ *allows_mem = true;
+ }
+#endif
+ break;
+ }
+
+ if (saw_match && !*allows_reg)
+ warning (0, "matching constraint does not allow a register");
+
+ return true;
+}
+
+/* Return DECL iff there's an overlap between *REGS and DECL, where DECL
+ can be an asm-declared register. Called via walk_tree. */
+
+static tree
+decl_overlaps_hard_reg_set_p (tree *declp, int *walk_subtrees ATTRIBUTE_UNUSED,
+ void *data)
+{
+ tree decl = *declp;
+ const HARD_REG_SET *const regs = (const HARD_REG_SET *) data;
+
+ if (TREE_CODE (decl) == VAR_DECL)
+ {
+ if (DECL_HARD_REGISTER (decl)
+ && REG_P (DECL_RTL (decl))
+ && REGNO (DECL_RTL (decl)) < FIRST_PSEUDO_REGISTER)
+ {
+ rtx reg = DECL_RTL (decl);
+
+ if (overlaps_hard_reg_set_p (*regs, GET_MODE (reg), REGNO (reg)))
+ return decl;
+ }
+ walk_subtrees = 0;
+ }
+ else if (TYPE_P (decl) || TREE_CODE (decl) == PARM_DECL)
+ walk_subtrees = 0;
+ return NULL_TREE;
+}
+
+/* If there is an overlap between *REGS and DECL, return the first overlap
+ found. */
+tree
+tree_overlaps_hard_reg_set (tree decl, HARD_REG_SET *regs)
+{
+ return walk_tree (&decl, decl_overlaps_hard_reg_set_p, regs, NULL);
+}
+
+/* Check for overlap between registers marked in CLOBBERED_REGS and
+ anything inappropriate in T. Emit error and return the register
+ variable definition for error, NULL_TREE for ok. */
+
+static bool
+tree_conflicts_with_clobbers_p (tree t, HARD_REG_SET *clobbered_regs)
+{
+ /* Conflicts between asm-declared register variables and the clobber
+ list are not allowed. */
+ tree overlap = tree_overlaps_hard_reg_set (t, clobbered_regs);
+
+ if (overlap)
+ {
+ error ("asm-specifier for variable %qE conflicts with asm clobber list",
+ DECL_NAME (overlap));
+
+ /* Reset registerness to stop multiple errors emitted for a single
+ variable. */
+ DECL_REGISTER (overlap) = 0;
+ return true;
+ }
+
+ return false;
+}
+
+/* Generate RTL for an asm statement with arguments.
+ STRING is the instruction template.
+ OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
+ Each output or input has an expression in the TREE_VALUE and
+ a tree list in TREE_PURPOSE which in turn contains a constraint
+ name in TREE_VALUE (or NULL_TREE) and a constraint string
+ in TREE_PURPOSE.
+ CLOBBERS is a list of STRING_CST nodes each naming a hard register
+ that is clobbered by this insn.
+
+ Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
+ Some elements of OUTPUTS may be replaced with trees representing temporary
+ values. The caller should copy those temporary values to the originally
+ specified lvalues.
+
+ VOL nonzero means the insn is volatile; don't optimize it. */
+
+static void
+expand_asm_operands (tree string, tree outputs, tree inputs,
+ tree clobbers, tree labels, int vol, location_t locus)
+{
+ rtvec argvec, constraintvec, labelvec;
+ rtx body;
+ int ninputs = list_length (inputs);
+ int noutputs = list_length (outputs);
+ int nlabels = list_length (labels);
+ int ninout;
+ int nclobbers;
+ HARD_REG_SET clobbered_regs;
+ int clobber_conflict_found = 0;
+ tree tail;
+ tree t;
+ int i;
+ /* Vector of RTX's of evaluated output operands. */
+ rtx *output_rtx = XALLOCAVEC (rtx, noutputs);
+ int *inout_opnum = XALLOCAVEC (int, noutputs);
+ rtx *real_output_rtx = XALLOCAVEC (rtx, noutputs);
+ enum machine_mode *inout_mode = XALLOCAVEC (enum machine_mode, noutputs);
+ const char **constraints = XALLOCAVEC (const char *, noutputs + ninputs);
+ int old_generating_concat_p = generating_concat_p;
+
+ /* An ASM with no outputs needs to be treated as volatile, for now. */
+ if (noutputs == 0)
+ vol = 1;
+
+ if (! check_operand_nalternatives (outputs, inputs))
+ return;
+
+ string = resolve_asm_operand_names (string, outputs, inputs, labels);
+
+ /* Collect constraints. */
+ i = 0;
+ for (t = outputs; t ; t = TREE_CHAIN (t), i++)
+ constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
+ for (t = inputs; t ; t = TREE_CHAIN (t), i++)
+ constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
+
+ /* Sometimes we wish to automatically clobber registers across an asm.
+ Case in point is when the i386 backend moved from cc0 to a hard reg --
+ maintaining source-level compatibility means automatically clobbering
+ the flags register. */
+ clobbers = targetm.md_asm_clobbers (outputs, inputs, clobbers);
+
+ /* Count the number of meaningful clobbered registers, ignoring what
+ we would ignore later. */
+ nclobbers = 0;
+ CLEAR_HARD_REG_SET (clobbered_regs);
+ for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
+ {
+ const char *regname;
+ int nregs;
+
+ if (TREE_VALUE (tail) == error_mark_node)
+ return;
+ regname = TREE_STRING_POINTER (TREE_VALUE (tail));
+
+ i = decode_reg_name_and_count (regname, &nregs);
+ if (i == -4)
+ ++nclobbers;
+ else if (i == -2)
+ error ("unknown register name %qs in %<asm%>", regname);
+
+ /* Mark clobbered registers. */
+ if (i >= 0)
+ {
+ int reg;
+
+ for (reg = i; reg < i + nregs; reg++)
+ {
+ ++nclobbers;
+
+ /* Clobbering the PIC register is an error. */
+ if (reg == (int) PIC_OFFSET_TABLE_REGNUM)
+ {
+ error ("PIC register clobbered by %qs in %<asm%>", regname);
+ return;
+ }
+
+ SET_HARD_REG_BIT (clobbered_regs, reg);
+ }
+ }
+ }
+
+ /* First pass over inputs and outputs checks validity and sets
+ mark_addressable if needed. */
+
+ ninout = 0;
+ for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
+ {
+ tree val = TREE_VALUE (tail);
+ tree type = TREE_TYPE (val);
+ const char *constraint;
+ bool is_inout;
+ bool allows_reg;
+ bool allows_mem;
+
+ /* If there's an erroneous arg, emit no insn. */
+ if (type == error_mark_node)
+ return;
+
+ /* Try to parse the output constraint. If that fails, there's
+ no point in going further. */
+ constraint = constraints[i];
+ if (!parse_output_constraint (&constraint, i, ninputs, noutputs,
+ &allows_mem, &allows_reg, &is_inout))
+ return;
+
+ if (! allows_reg
+ && (allows_mem
+ || is_inout
+ || (DECL_P (val)
+ && REG_P (DECL_RTL (val))
+ && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type))))
+ mark_addressable (val);
+
+ if (is_inout)
+ ninout++;
+ }
+
+ ninputs += ninout;
+ if (ninputs + noutputs > MAX_RECOG_OPERANDS)
+ {
+ error ("more than %d operands in %<asm%>", MAX_RECOG_OPERANDS);
+ return;
+ }
+
+ for (i = 0, tail = inputs; tail; i++, tail = TREE_CHAIN (tail))
+ {
+ bool allows_reg, allows_mem;
+ const char *constraint;
+
+ /* If there's an erroneous arg, emit no insn, because the ASM_INPUT
+ would get VOIDmode and that could cause a crash in reload. */
+ if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
+ return;
+
+ constraint = constraints[i + noutputs];
+ if (! parse_input_constraint (&constraint, i, ninputs, noutputs, ninout,
+ constraints, &allows_mem, &allows_reg))
+ return;
+
+ if (! allows_reg && allows_mem)
+ mark_addressable (TREE_VALUE (tail));
+ }
+
+ /* Second pass evaluates arguments. */
+
+ /* Make sure stack is consistent for asm goto. */
+ if (nlabels > 0)
+ do_pending_stack_adjust ();
+
+ ninout = 0;
+ for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
+ {
+ tree val = TREE_VALUE (tail);
+ tree type = TREE_TYPE (val);
+ bool is_inout;
+ bool allows_reg;
+ bool allows_mem;
+ rtx op;
+ bool ok;
+
+ ok = parse_output_constraint (&constraints[i], i, ninputs,
+ noutputs, &allows_mem, &allows_reg,
+ &is_inout);
+ gcc_assert (ok);
+
+ /* If an output operand is not a decl or indirect ref and our constraint
+ allows a register, make a temporary to act as an intermediate.
+ Make the asm insn write into that, then our caller will copy it to
+ the real output operand. Likewise for promoted variables. */
+
+ generating_concat_p = 0;
+
+ real_output_rtx[i] = NULL_RTX;
+ if ((TREE_CODE (val) == INDIRECT_REF
+ && allows_mem)
+ || (DECL_P (val)
+ && (allows_mem || REG_P (DECL_RTL (val)))
+ && ! (REG_P (DECL_RTL (val))
+ && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
+ || ! allows_reg
+ || is_inout)
+ {
+ op = expand_expr (val, NULL_RTX, VOIDmode, EXPAND_WRITE);
+ if (MEM_P (op))
+ op = validize_mem (op);
+
+ if (! allows_reg && !MEM_P (op))
+ error ("output number %d not directly addressable", i);
+ if ((! allows_mem && MEM_P (op))
+ || GET_CODE (op) == CONCAT)
+ {
+ real_output_rtx[i] = op;
+ op = gen_reg_rtx (GET_MODE (op));
+ if (is_inout)
+ emit_move_insn (op, real_output_rtx[i]);
+ }
+ }
+ else
+ {
+ op = assign_temp (type, 0, 1);
+ op = validize_mem (op);
+ if (!MEM_P (op) && TREE_CODE (TREE_VALUE (tail)) == SSA_NAME)
+ set_reg_attrs_for_decl_rtl (SSA_NAME_VAR (TREE_VALUE (tail)), op);
+ TREE_VALUE (tail) = make_tree (type, op);
+ }
+ output_rtx[i] = op;
+
+ generating_concat_p = old_generating_concat_p;
+
+ if (is_inout)
+ {
+ inout_mode[ninout] = TYPE_MODE (type);
+ inout_opnum[ninout++] = i;
+ }
+
+ if (tree_conflicts_with_clobbers_p (val, &clobbered_regs))
+ clobber_conflict_found = 1;
+ }
+
+ /* Make vectors for the expression-rtx, constraint strings,
+ and named operands. */
+
+ argvec = rtvec_alloc (ninputs);
+ constraintvec = rtvec_alloc (ninputs);
+ labelvec = rtvec_alloc (nlabels);
+
+ body = gen_rtx_ASM_OPERANDS ((noutputs == 0 ? VOIDmode
+ : GET_MODE (output_rtx[0])),
+ ggc_strdup (TREE_STRING_POINTER (string)),
+ empty_string, 0, argvec, constraintvec,
+ labelvec, locus);
+
+ MEM_VOLATILE_P (body) = vol;
+
+ /* Eval the inputs and put them into ARGVEC.
+ Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
+
+ for (i = 0, tail = inputs; tail; tail = TREE_CHAIN (tail), ++i)
+ {
+ bool allows_reg, allows_mem;
+ const char *constraint;
+ tree val, type;
+ rtx op;
+ bool ok;
+
+ constraint = constraints[i + noutputs];
+ ok = parse_input_constraint (&constraint, i, ninputs, noutputs, ninout,
+ constraints, &allows_mem, &allows_reg);
+ gcc_assert (ok);
+
+ generating_concat_p = 0;
+
+ val = TREE_VALUE (tail);
+ type = TREE_TYPE (val);
+ /* EXPAND_INITIALIZER will not generate code for valid initializer
+ constants, but will still generate code for other types of operand.
+ This is the behavior we want for constant constraints. */
+ op = expand_expr (val, NULL_RTX, VOIDmode,
+ allows_reg ? EXPAND_NORMAL
+ : allows_mem ? EXPAND_MEMORY
+ : EXPAND_INITIALIZER);
+
+ /* Never pass a CONCAT to an ASM. */
+ if (GET_CODE (op) == CONCAT)
+ op = force_reg (GET_MODE (op), op);
+ else if (MEM_P (op))
+ op = validize_mem (op);
+
+ if (asm_operand_ok (op, constraint, NULL) <= 0)
+ {
+ if (allows_reg && TYPE_MODE (type) != BLKmode)
+ op = force_reg (TYPE_MODE (type), op);
+ else if (!allows_mem)
+ warning (0, "asm operand %d probably doesn%'t match constraints",
+ i + noutputs);
+ else if (MEM_P (op))
+ {
+ /* We won't recognize either volatile memory or memory
+ with a queued address as available a memory_operand
+ at this point. Ignore it: clearly this *is* a memory. */
+ }
+ else
+ gcc_unreachable ();
+ }
+
+ generating_concat_p = old_generating_concat_p;
+ ASM_OPERANDS_INPUT (body, i) = op;
+
+ ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, i)
+ = gen_rtx_ASM_INPUT (TYPE_MODE (type),
+ ggc_strdup (constraints[i + noutputs]));
+
+ if (tree_conflicts_with_clobbers_p (val, &clobbered_regs))
+ clobber_conflict_found = 1;
+ }
+
+ /* Protect all the operands from the queue now that they have all been
+ evaluated. */
+
+ generating_concat_p = 0;
+
+ /* For in-out operands, copy output rtx to input rtx. */
+ for (i = 0; i < ninout; i++)
+ {
+ int j = inout_opnum[i];
+ char buffer[16];
+
+ ASM_OPERANDS_INPUT (body, ninputs - ninout + i)
+ = output_rtx[j];
+
+ sprintf (buffer, "%d", j);
+ ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, ninputs - ninout + i)
+ = gen_rtx_ASM_INPUT (inout_mode[i], ggc_strdup (buffer));
+ }
+
+ /* Copy labels to the vector. */
+ for (i = 0, tail = labels; i < nlabels; ++i, tail = TREE_CHAIN (tail))
+ ASM_OPERANDS_LABEL (body, i)
+ = gen_rtx_LABEL_REF (Pmode, label_rtx (TREE_VALUE (tail)));
+
+ generating_concat_p = old_generating_concat_p;
+
+ /* Now, for each output, construct an rtx
+ (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER
+ ARGVEC CONSTRAINTS OPNAMES))
+ If there is more than one, put them inside a PARALLEL. */
+
+ if (nlabels > 0 && nclobbers == 0)
+ {
+ gcc_assert (noutputs == 0);
+ emit_jump_insn (body);
+ }
+ else if (noutputs == 0 && nclobbers == 0)
+ {
+ /* No output operands: put in a raw ASM_OPERANDS rtx. */
+ emit_insn (body);
+ }
+ else if (noutputs == 1 && nclobbers == 0)
+ {
+ ASM_OPERANDS_OUTPUT_CONSTRAINT (body) = ggc_strdup (constraints[0]);
+ emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
+ }
+ else
+ {
+ rtx obody = body;
+ int num = noutputs;
+
+ if (num == 0)
+ num = 1;
+
+ body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
+
+ /* For each output operand, store a SET. */
+ for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
+ {
+ XVECEXP (body, 0, i)
+ = gen_rtx_SET (VOIDmode,
+ output_rtx[i],
+ gen_rtx_ASM_OPERANDS
+ (GET_MODE (output_rtx[i]),
+ ggc_strdup (TREE_STRING_POINTER (string)),
+ ggc_strdup (constraints[i]),
+ i, argvec, constraintvec, labelvec, locus));
+
+ MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
+ }
+
+ /* If there are no outputs (but there are some clobbers)
+ store the bare ASM_OPERANDS into the PARALLEL. */
+
+ if (i == 0)
+ XVECEXP (body, 0, i++) = obody;
+
+ /* Store (clobber REG) for each clobbered register specified. */
+
+ for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
+ {
+ const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
+ int reg, nregs;
+ int j = decode_reg_name_and_count (regname, &nregs);
+ rtx clobbered_reg;
+
+ if (j < 0)
+ {
+ if (j == -3) /* `cc', which is not a register */
+ continue;
+
+ if (j == -4) /* `memory', don't cache memory across asm */
+ {
+ XVECEXP (body, 0, i++)
+ = gen_rtx_CLOBBER (VOIDmode,
+ gen_rtx_MEM
+ (BLKmode,
+ gen_rtx_SCRATCH (VOIDmode)));
+ continue;
+ }
+
+ /* Ignore unknown register, error already signaled. */
+ continue;
+ }
+
+ for (reg = j; reg < j + nregs; reg++)
+ {
+ /* Use QImode since that's guaranteed to clobber just
+ * one reg. */
+ clobbered_reg = gen_rtx_REG (QImode, reg);
+
+ /* Do sanity check for overlap between clobbers and
+ respectively input and outputs that hasn't been
+ handled. Such overlap should have been detected and
+ reported above. */
+ if (!clobber_conflict_found)
+ {
+ int opno;
+
+ /* We test the old body (obody) contents to avoid
+ tripping over the under-construction body. */
+ for (opno = 0; opno < noutputs; opno++)
+ if (reg_overlap_mentioned_p (clobbered_reg,
+ output_rtx[opno]))
+ internal_error
+ ("asm clobber conflict with output operand");
+
+ for (opno = 0; opno < ninputs - ninout; opno++)
+ if (reg_overlap_mentioned_p (clobbered_reg,
+ ASM_OPERANDS_INPUT (obody,
+ opno)))
+ internal_error
+ ("asm clobber conflict with input operand");
+ }
+
+ XVECEXP (body, 0, i++)
+ = gen_rtx_CLOBBER (VOIDmode, clobbered_reg);
+ }
+ }
+
+ if (nlabels > 0)
+ emit_jump_insn (body);
+ else
+ emit_insn (body);
+ }
+
+ /* For any outputs that needed reloading into registers, spill them
+ back to where they belong. */
+ for (i = 0; i < noutputs; ++i)
+ if (real_output_rtx[i])
+ emit_move_insn (real_output_rtx[i], output_rtx[i]);
+
+ crtl->has_asm_statement = 1;
+ free_temp_slots ();
+}
+
+void
+expand_asm_stmt (gimple stmt)
+{
+ int noutputs;
+ tree outputs, tail, t;
+ tree *o;
+ size_t i, n;
+ const char *s;
+ tree str, out, in, cl, labels;
+ location_t locus = gimple_location (stmt);
+
+ /* Meh... convert the gimple asm operands into real tree lists.
+ Eventually we should make all routines work on the vectors instead
+ of relying on TREE_CHAIN. */
+ out = NULL_TREE;
+ n = gimple_asm_noutputs (stmt);
+ if (n > 0)
+ {
+ t = out = gimple_asm_output_op (stmt, 0);
+ for (i = 1; i < n; i++)
+ t = TREE_CHAIN (t) = gimple_asm_output_op (stmt, i);
+ }
+
+ in = NULL_TREE;
+ n = gimple_asm_ninputs (stmt);
+ if (n > 0)
+ {
+ t = in = gimple_asm_input_op (stmt, 0);
+ for (i = 1; i < n; i++)
+ t = TREE_CHAIN (t) = gimple_asm_input_op (stmt, i);
+ }
+
+ cl = NULL_TREE;
+ n = gimple_asm_nclobbers (stmt);
+ if (n > 0)
+ {
+ t = cl = gimple_asm_clobber_op (stmt, 0);
+ for (i = 1; i < n; i++)
+ t = TREE_CHAIN (t) = gimple_asm_clobber_op (stmt, i);
+ }
+
+ labels = NULL_TREE;
+ n = gimple_asm_nlabels (stmt);
+ if (n > 0)
+ {
+ t = labels = gimple_asm_label_op (stmt, 0);
+ for (i = 1; i < n; i++)
+ t = TREE_CHAIN (t) = gimple_asm_label_op (stmt, i);
+ }
+
+ s = gimple_asm_string (stmt);
+ str = build_string (strlen (s), s);
+
+ if (gimple_asm_input_p (stmt))
+ {
+ expand_asm_loc (str, gimple_asm_volatile_p (stmt), locus);
+ return;
+ }
+
+ outputs = out;
+ noutputs = gimple_asm_noutputs (stmt);
+ /* o[I] is the place that output number I should be written. */
+ o = (tree *) alloca (noutputs * sizeof (tree));
+
+ /* Record the contents of OUTPUTS before it is modified. */
+ for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
+ o[i] = TREE_VALUE (tail);
+
+ /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
+ OUTPUTS some trees for where the values were actually stored. */
+ expand_asm_operands (str, outputs, in, cl, labels,
+ gimple_asm_volatile_p (stmt), locus);
+
+ /* Copy all the intermediate outputs into the specified outputs. */
+ for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
+ {
+ if (o[i] != TREE_VALUE (tail))
+ {
+ expand_assignment (o[i], TREE_VALUE (tail), false);
+ free_temp_slots ();
+
+ /* Restore the original value so that it's correct the next
+ time we expand this function. */
+ TREE_VALUE (tail) = o[i];
+ }
+ }
+}
+
+/* A subroutine of expand_asm_operands. Check that all operands have
+ the same number of alternatives. Return true if so. */
+
+static bool
+check_operand_nalternatives (tree outputs, tree inputs)
+{
+ if (outputs || inputs)
+ {
+ tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
+ int nalternatives
+ = n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp)));
+ tree next = inputs;
+
+ if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
+ {
+ error ("too many alternatives in %<asm%>");
+ return false;
+ }
+
+ tmp = outputs;
+ while (tmp)
+ {
+ const char *constraint
+ = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp)));
+
+ if (n_occurrences (',', constraint) != nalternatives)
+ {
+ error ("operand constraints for %<asm%> differ "
+ "in number of alternatives");
+ return false;
+ }
+
+ if (TREE_CHAIN (tmp))
+ tmp = TREE_CHAIN (tmp);
+ else
+ tmp = next, next = 0;
+ }
+ }
+
+ return true;
+}
+
+/* A subroutine of expand_asm_operands. Check that all operand names
+ are unique. Return true if so. We rely on the fact that these names
+ are identifiers, and so have been canonicalized by get_identifier,
+ so all we need are pointer comparisons. */
+
+static bool
+check_unique_operand_names (tree outputs, tree inputs, tree labels)
+{
+ tree i, j, i_name = NULL_TREE;
+
+ for (i = outputs; i ; i = TREE_CHAIN (i))
+ {
+ i_name = TREE_PURPOSE (TREE_PURPOSE (i));
+ if (! i_name)
+ continue;
+
+ for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
+ if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
+ goto failure;
+ }
+
+ for (i = inputs; i ; i = TREE_CHAIN (i))
+ {
+ i_name = TREE_PURPOSE (TREE_PURPOSE (i));
+ if (! i_name)
+ continue;
+
+ for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
+ if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
+ goto failure;
+ for (j = outputs; j ; j = TREE_CHAIN (j))
+ if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
+ goto failure;
+ }
+
+ for (i = labels; i ; i = TREE_CHAIN (i))
+ {
+ i_name = TREE_PURPOSE (i);
+ if (! i_name)
+ continue;
+
+ for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
+ if (simple_cst_equal (i_name, TREE_PURPOSE (j)))
+ goto failure;
+ for (j = inputs; j ; j = TREE_CHAIN (j))
+ if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
+ goto failure;
+ }
+
+ return true;
+
+ failure:
+ error ("duplicate asm operand name %qs", TREE_STRING_POINTER (i_name));
+ return false;
+}
+
+/* A subroutine of expand_asm_operands. Resolve the names of the operands
+ in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in
+ STRING and in the constraints to those numbers. */
+
+tree
+resolve_asm_operand_names (tree string, tree outputs, tree inputs, tree labels)
+{
+ char *buffer;
+ char *p;
+ const char *c;
+ tree t;
+
+ check_unique_operand_names (outputs, inputs, labels);
+
+ /* Substitute [<name>] in input constraint strings. There should be no
+ named operands in output constraints. */
+ for (t = inputs; t ; t = TREE_CHAIN (t))
+ {
+ c = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
+ if (strchr (c, '[') != NULL)
+ {
+ p = buffer = xstrdup (c);
+ while ((p = strchr (p, '[')) != NULL)
+ p = resolve_operand_name_1 (p, outputs, inputs, NULL);
+ TREE_VALUE (TREE_PURPOSE (t))
+ = build_string (strlen (buffer), buffer);
+ free (buffer);
+ }
+ }
+
+ /* Now check for any needed substitutions in the template. */
+ c = TREE_STRING_POINTER (string);
+ while ((c = strchr (c, '%')) != NULL)
+ {
+ if (c[1] == '[')
+ break;
+ else if (ISALPHA (c[1]) && c[2] == '[')
+ break;
+ else
+ {
+ c += 1 + (c[1] == '%');
+ continue;
+ }
+ }
+
+ if (c)
+ {
+ /* OK, we need to make a copy so we can perform the substitutions.
+ Assume that we will not need extra space--we get to remove '['
+ and ']', which means we cannot have a problem until we have more
+ than 999 operands. */
+ buffer = xstrdup (TREE_STRING_POINTER (string));
+ p = buffer + (c - TREE_STRING_POINTER (string));
+
+ while ((p = strchr (p, '%')) != NULL)
+ {
+ if (p[1] == '[')
+ p += 1;
+ else if (ISALPHA (p[1]) && p[2] == '[')
+ p += 2;
+ else
+ {
+ p += 1 + (p[1] == '%');
+ continue;
+ }
+
+ p = resolve_operand_name_1 (p, outputs, inputs, labels);
+ }
+
+ string = build_string (strlen (buffer), buffer);
+ free (buffer);
+ }
+
+ return string;
+}
+
+/* A subroutine of resolve_operand_names. P points to the '[' for a
+ potential named operand of the form [<name>]. In place, replace
+ the name and brackets with a number. Return a pointer to the
+ balance of the string after substitution. */
+
+static char *
+resolve_operand_name_1 (char *p, tree outputs, tree inputs, tree labels)
+{
+ char *q;
+ int op;
+ tree t;
+
+ /* Collect the operand name. */
+ q = strchr (++p, ']');
+ if (!q)
+ {
+ error ("missing close brace for named operand");
+ return strchr (p, '\0');
+ }
+ *q = '\0';
+
+ /* Resolve the name to a number. */
+ for (op = 0, t = outputs; t ; t = TREE_CHAIN (t), op++)
+ {
+ tree name = TREE_PURPOSE (TREE_PURPOSE (t));
+ if (name && strcmp (TREE_STRING_POINTER (name), p) == 0)
+ goto found;
+ }
+ for (t = inputs; t ; t = TREE_CHAIN (t), op++)
+ {
+ tree name = TREE_PURPOSE (TREE_PURPOSE (t));
+ if (name && strcmp (TREE_STRING_POINTER (name), p) == 0)
+ goto found;
+ }
+ for (t = labels; t ; t = TREE_CHAIN (t), op++)
+ {
+ tree name = TREE_PURPOSE (t);
+ if (name && strcmp (TREE_STRING_POINTER (name), p) == 0)
+ goto found;
+ }
+
+ error ("undefined named operand %qs", identifier_to_locale (p));
+ op = 0;
+
+ found:
+ /* Replace the name with the number. Unfortunately, not all libraries
+ get the return value of sprintf correct, so search for the end of the
+ generated string by hand. */
+ sprintf (--p, "%d", op);
+ p = strchr (p, '\0');
+
+ /* Verify the no extra buffer space assumption. */
+ gcc_assert (p <= q);
+
+ /* Shift the rest of the buffer down to fill the gap. */
+ memmove (p, q + 1, strlen (q + 1) + 1);
+
+ return p;
+}
+
+/* Generate RTL to return from the current function, with no value.
+ (That is, we do not do anything about returning any value.) */
+
+void
+expand_null_return (void)
+{
+ /* If this function was declared to return a value, but we
+ didn't, clobber the return registers so that they are not
+ propagated live to the rest of the function. */
+ clobber_return_register ();
+
+ expand_null_return_1 ();
+}
+
+/* Generate RTL to return directly from the current function.
+ (That is, we bypass any return value.) */
+
+void
+expand_naked_return (void)
+{
+ rtx end_label;
+
+ clear_pending_stack_adjust ();
+ do_pending_stack_adjust ();
+
+ end_label = naked_return_label;
+ if (end_label == 0)
+ end_label = naked_return_label = gen_label_rtx ();
+
+ emit_jump (end_label);
+}
+
+/* Generate RTL to return from the current function, with value VAL. */
+
+static void
+expand_value_return (rtx val)
+{
+ /* Copy the value to the return location unless it's already there. */
+
+ tree decl = DECL_RESULT (current_function_decl);
+ rtx return_reg = DECL_RTL (decl);
+ if (return_reg != val)
+ {
+ tree funtype = TREE_TYPE (current_function_decl);
+ tree type = TREE_TYPE (decl);
+ int unsignedp = TYPE_UNSIGNED (type);
+ enum machine_mode old_mode = DECL_MODE (decl);
+ enum machine_mode mode;
+ if (DECL_BY_REFERENCE (decl))
+ mode = promote_function_mode (type, old_mode, &unsignedp, funtype, 2);
+ else
+ mode = promote_function_mode (type, old_mode, &unsignedp, funtype, 1);
+
+ if (mode != old_mode)
+ val = convert_modes (mode, old_mode, val, unsignedp);
+
+ if (GET_CODE (return_reg) == PARALLEL)
+ emit_group_load (return_reg, val, type, int_size_in_bytes (type));
+ else
+ emit_move_insn (return_reg, val);
+ }
+
+ expand_null_return_1 ();
+}
+
+/* Output a return with no value. */
+
+static void
+expand_null_return_1 (void)
+{
+ clear_pending_stack_adjust ();
+ do_pending_stack_adjust ();
+ emit_jump (return_label);
+}
+
+/* Generate RTL to evaluate the expression RETVAL and return it
+ from the current function. */
+
+void
+expand_return (tree retval)
+{
+ rtx result_rtl;
+ rtx val = 0;
+ tree retval_rhs;
+
+ /* If function wants no value, give it none. */
+ if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
+ {
+ expand_normal (retval);
+ expand_null_return ();
+ return;
+ }
+
+ if (retval == error_mark_node)
+ {
+ /* Treat this like a return of no value from a function that
+ returns a value. */
+ expand_null_return ();
+ return;
+ }
+ else if ((TREE_CODE (retval) == MODIFY_EXPR
+ || TREE_CODE (retval) == INIT_EXPR)
+ && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
+ retval_rhs = TREE_OPERAND (retval, 1);
+ else
+ retval_rhs = retval;
+
+ result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
+
+ /* If we are returning the RESULT_DECL, then the value has already
+ been stored into it, so we don't have to do anything special. */
+ if (TREE_CODE (retval_rhs) == RESULT_DECL)
+ expand_value_return (result_rtl);
+
+ /* If the result is an aggregate that is being returned in one (or more)
+ registers, load the registers here. */
+
+ else if (retval_rhs != 0
+ && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
+ && REG_P (result_rtl))
+ {
+ val = copy_blkmode_to_reg (GET_MODE (result_rtl), retval_rhs);
+ if (val)
+ {
+ /* Use the mode of the result value on the return register. */
+ PUT_MODE (result_rtl, GET_MODE (val));
+ expand_value_return (val);
+ }
+ else
+ expand_null_return ();
+ }
+ else if (retval_rhs != 0
+ && !VOID_TYPE_P (TREE_TYPE (retval_rhs))
+ && (REG_P (result_rtl)
+ || (GET_CODE (result_rtl) == PARALLEL)))
+ {
+ /* Calculate the return value into a temporary (usually a pseudo
+ reg). */
+ tree ot = TREE_TYPE (DECL_RESULT (current_function_decl));
+ tree nt = build_qualified_type (ot, TYPE_QUALS (ot) | TYPE_QUAL_CONST);
+
+ val = assign_temp (nt, 0, 1);
+ val = expand_expr (retval_rhs, val, GET_MODE (val), EXPAND_NORMAL);
+ val = force_not_mem (val);
+ /* Return the calculated value. */
+ expand_value_return (val);
+ }
+ else
+ {
+ /* No hard reg used; calculate value into hard return reg. */
+ expand_expr (retval, const0_rtx, VOIDmode, EXPAND_NORMAL);
+ expand_value_return (result_rtl);
+ }
+}
+
+/* Emit code to restore vital registers at the beginning of a nonlocal goto
+ handler. */
+static void
+expand_nl_goto_receiver (void)
+{
+ rtx chain;
+
+ /* Clobber the FP when we get here, so we have to make sure it's
+ marked as used by this function. */
+ emit_use (hard_frame_pointer_rtx);
+
+ /* Mark the static chain as clobbered here so life information
+ doesn't get messed up for it. */
+ chain = targetm.calls.static_chain (current_function_decl, true);
+ if (chain && REG_P (chain))
+ emit_clobber (chain);
+
+#ifdef HAVE_nonlocal_goto
+ if (! HAVE_nonlocal_goto)
+#endif
+ /* First adjust our frame pointer to its actual value. It was
+ previously set to the start of the virtual area corresponding to
+ the stacked variables when we branched here and now needs to be
+ adjusted to the actual hardware fp value.
+
+ Assignments are to virtual registers are converted by
+ instantiate_virtual_regs into the corresponding assignment
+ to the underlying register (fp in this case) that makes
+ the original assignment true.
+ So the following insn will actually be
+ decrementing fp by STARTING_FRAME_OFFSET. */
+ emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
+
+#if !HARD_FRAME_POINTER_IS_ARG_POINTER
+ if (fixed_regs[ARG_POINTER_REGNUM])
+ {
+#ifdef ELIMINABLE_REGS
+ /* If the argument pointer can be eliminated in favor of the
+ frame pointer, we don't need to restore it. We assume here
+ that if such an elimination is present, it can always be used.
+ This is the case on all known machines; if we don't make this
+ assumption, we do unnecessary saving on many machines. */
+ static const struct elims {const int from, to;} elim_regs[] = ELIMINABLE_REGS;
+ size_t i;
+
+ for (i = 0; i < ARRAY_SIZE (elim_regs); i++)
+ if (elim_regs[i].from == ARG_POINTER_REGNUM
+ && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
+ break;
+
+ if (i == ARRAY_SIZE (elim_regs))
+#endif
+ {
+ /* Now restore our arg pointer from the address at which it
+ was saved in our stack frame. */
+ emit_move_insn (crtl->args.internal_arg_pointer,
+ copy_to_reg (get_arg_pointer_save_area ()));
+ }
+ }
+#endif
+
+#ifdef HAVE_nonlocal_goto_receiver
+ if (HAVE_nonlocal_goto_receiver)
+ emit_insn (gen_nonlocal_goto_receiver ());
+#endif
+
+ /* We must not allow the code we just generated to be reordered by
+ scheduling. Specifically, the update of the frame pointer must
+ happen immediately, not later. */
+ emit_insn (gen_blockage ());
+}
+
+/* Emit code to save the current value of stack. */
+rtx
+expand_stack_save (void)
+{
+ rtx ret = NULL_RTX;
+
+ do_pending_stack_adjust ();
+ emit_stack_save (SAVE_BLOCK, &ret);
+ return ret;
+}
+
+/* Emit code to restore the current value of stack. */
+void
+expand_stack_restore (tree var)
+{
+ rtx prev, sa = expand_normal (var);
+
+ sa = convert_memory_address (Pmode, sa);
+
+ prev = get_last_insn ();
+ emit_stack_restore (SAVE_BLOCK, sa);
+ fixup_args_size_notes (prev, get_last_insn (), 0);
+}
+
+/* Generate code to jump to LABEL if OP0 and OP1 are equal in mode MODE. PROB
+ is the probability of jumping to LABEL. */
+static void
+do_jump_if_equal (enum machine_mode mode, rtx op0, rtx op1, rtx label,
+ int unsignedp, int prob)
+{
+ gcc_assert (prob <= REG_BR_PROB_BASE);
+ do_compare_rtx_and_jump (op0, op1, EQ, unsignedp, mode,
+ NULL_RTX, NULL_RTX, label, prob);
+}
+
+/* Do the insertion of a case label into case_list. The labels are
+ fed to us in descending order from the sorted vector of case labels used
+ in the tree part of the middle end. So the list we construct is
+ sorted in ascending order.
+
+ LABEL is the case label to be inserted. LOW and HIGH are the bounds
+ against which the index is compared to jump to LABEL and PROB is the
+ estimated probability LABEL is reached from the switch statement. */
+
+static struct case_node *
+add_case_node (struct case_node *head, tree low, tree high,
+ tree label, int prob, alloc_pool case_node_pool)
+{
+ struct case_node *r;
+
+ gcc_checking_assert (low);
+ gcc_checking_assert (high && (TREE_TYPE (low) == TREE_TYPE (high)));
+
+ /* Add this label to the chain. */
+ r = (struct case_node *) pool_alloc (case_node_pool);
+ r->low = low;
+ r->high = high;
+ r->code_label = label;
+ r->parent = r->left = NULL;
+ r->prob = prob;
+ r->subtree_prob = prob;
+ r->right = head;
+ return r;
+}
+
+/* Dump ROOT, a list or tree of case nodes, to file. */
+
+static void
+dump_case_nodes (FILE *f, struct case_node *root,
+ int indent_step, int indent_level)
+{
+ HOST_WIDE_INT low, high;
+
+ if (root == 0)
+ return;
+ indent_level++;
+
+ dump_case_nodes (f, root->left, indent_step, indent_level);
+
+ low = tree_low_cst (root->low, 0);
+ high = tree_low_cst (root->high, 0);
+
+ fputs (";; ", f);
+ if (high == low)
+ fprintf(f, "%*s" HOST_WIDE_INT_PRINT_DEC,
+ indent_step * indent_level, "", low);
+ else
+ fprintf(f, "%*s" HOST_WIDE_INT_PRINT_DEC " ... " HOST_WIDE_INT_PRINT_DEC,
+ indent_step * indent_level, "", low, high);
+ fputs ("\n", f);
+
+ dump_case_nodes (f, root->right, indent_step, indent_level);
+}
+
+#ifndef HAVE_casesi
+#define HAVE_casesi 0
+#endif
+
+#ifndef HAVE_tablejump
+#define HAVE_tablejump 0
+#endif
+
+/* Return the smallest number of different values for which it is best to use a
+ jump-table instead of a tree of conditional branches. */
+
+static unsigned int
+case_values_threshold (void)
+{
+ unsigned int threshold = PARAM_VALUE (PARAM_CASE_VALUES_THRESHOLD);
+
+ if (threshold == 0)
+ threshold = targetm.case_values_threshold ();
+
+ return threshold;
+}
+
+/* Return true if a switch should be expanded as a decision tree.
+ RANGE is the difference between highest and lowest case.
+ UNIQ is number of unique case node targets, not counting the default case.
+ COUNT is the number of comparisons needed, not counting the default case. */
+
+static bool
+expand_switch_as_decision_tree_p (tree range,
+ unsigned int uniq ATTRIBUTE_UNUSED,
+ unsigned int count)
+{
+ int max_ratio;
+
+ /* If neither casesi or tablejump is available, or flag_jump_tables
+ over-ruled us, we really have no choice. */
+ if (!HAVE_casesi && !HAVE_tablejump)
+ return true;
+ if (!flag_jump_tables)
+ return true;
+#ifndef ASM_OUTPUT_ADDR_DIFF_ELT
+ if (flag_pic)
+ return true;
+#endif
+
+ /* If the switch is relatively small such that the cost of one
+ indirect jump on the target are higher than the cost of a
+ decision tree, go with the decision tree.
+
+ If range of values is much bigger than number of values,
+ or if it is too large to represent in a HOST_WIDE_INT,
+ make a sequence of conditional branches instead of a dispatch.
+
+ The definition of "much bigger" depends on whether we are
+ optimizing for size or for speed. If the former, the maximum
+ ratio range/count = 3, because this was found to be the optimal
+ ratio for size on i686-pc-linux-gnu, see PR11823. The ratio
+ 10 is much older, and was probably selected after an extensive
+ benchmarking investigation on numerous platforms. Or maybe it
+ just made sense to someone at some point in the history of GCC,
+ who knows... */
+ max_ratio = optimize_insn_for_size_p () ? 3 : 10;
+ if (count < case_values_threshold ()
+ || ! host_integerp (range, /*pos=*/1)
+ || compare_tree_int (range, max_ratio * count) > 0)
+ return true;
+
+ return false;
+}
+
+/* Generate a decision tree, switching on INDEX_EXPR and jumping to
+ one of the labels in CASE_LIST or to the DEFAULT_LABEL.
+ DEFAULT_PROB is the estimated probability that it jumps to
+ DEFAULT_LABEL.
+
+ We generate a binary decision tree to select the appropriate target
+ code. This is done as follows:
+
+ If the index is a short or char that we do not have
+ an insn to handle comparisons directly, convert it to
+ a full integer now, rather than letting each comparison
+ generate the conversion.
+
+ Load the index into a register.
+
+ The list of cases is rearranged into a binary tree,
+ nearly optimal assuming equal probability for each case.
+
+ The tree is transformed into RTL, eliminating redundant
+ test conditions at the same time.
+
+ If program flow could reach the end of the decision tree
+ an unconditional jump to the default code is emitted.
+
+ The above process is unaware of the CFG. The caller has to fix up
+ the CFG itself. This is done in cfgexpand.c. */
+
+static void
+emit_case_decision_tree (tree index_expr, tree index_type,
+ struct case_node *case_list, rtx default_label,
+ int default_prob)
+{
+ rtx index = expand_normal (index_expr);
+
+ if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
+ && ! have_insn_for (COMPARE, GET_MODE (index)))
+ {
+ int unsignedp = TYPE_UNSIGNED (index_type);
+ enum machine_mode wider_mode;
+ for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
+ wider_mode = GET_MODE_WIDER_MODE (wider_mode))
+ if (have_insn_for (COMPARE, wider_mode))
+ {
+ index = convert_to_mode (wider_mode, index, unsignedp);
+ break;
+ }
+ }
+
+ do_pending_stack_adjust ();
+
+ if (MEM_P (index))
+ {
+ index = copy_to_reg (index);
+ if (TREE_CODE (index_expr) == SSA_NAME)
+ set_reg_attrs_for_decl_rtl (SSA_NAME_VAR (index_expr), index);
+ }
+
+ balance_case_nodes (&case_list, NULL);
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ int indent_step = ceil_log2 (TYPE_PRECISION (index_type)) + 2;
+ fprintf (dump_file, ";; Expanding GIMPLE switch as decision tree:\n");
+ dump_case_nodes (dump_file, case_list, indent_step, 0);
+ }
+
+ emit_case_nodes (index, case_list, default_label, default_prob, index_type);
+ if (default_label)
+ emit_jump (default_label);
+}
+
+/* Return the sum of probabilities of outgoing edges of basic block BB. */
+
+static int
+get_outgoing_edge_probs (basic_block bb)
+{
+ edge e;
+ edge_iterator ei;
+ int prob_sum = 0;
+ if (!bb)
+ return 0;
+ FOR_EACH_EDGE(e, ei, bb->succs)
+ prob_sum += e->probability;
+ return prob_sum;
+}
+
+/* Computes the conditional probability of jumping to a target if the branch
+ instruction is executed.
+ TARGET_PROB is the estimated probability of jumping to a target relative
+ to some basic block BB.
+ BASE_PROB is the probability of reaching the branch instruction relative
+ to the same basic block BB. */
+
+static inline int
+conditional_probability (int target_prob, int base_prob)
+{
+ if (base_prob > 0)
+ {
+ gcc_assert (target_prob >= 0);
+ gcc_assert (target_prob <= base_prob);
+ return RDIV (target_prob * REG_BR_PROB_BASE, base_prob);
+ }
+ return -1;
+}
+
+/* Generate a dispatch tabler, switching on INDEX_EXPR and jumping to
+ one of the labels in CASE_LIST or to the DEFAULT_LABEL.
+ MINVAL, MAXVAL, and RANGE are the extrema and range of the case
+ labels in CASE_LIST. STMT_BB is the basic block containing the statement.
+
+ First, a jump insn is emitted. First we try "casesi". If that
+ fails, try "tablejump". A target *must* have one of them (or both).
+
+ Then, a table with the target labels is emitted.
+
+ The process is unaware of the CFG. The caller has to fix up
+ the CFG itself. This is done in cfgexpand.c. */
+
+static void
+emit_case_dispatch_table (tree index_expr, tree index_type,
+ struct case_node *case_list, rtx default_label,
+ tree minval, tree maxval, tree range,
+ basic_block stmt_bb)
+{
+ int i, ncases;
+ struct case_node *n;
+ rtx *labelvec;
+ rtx fallback_label = label_rtx (case_list->code_label);
+ rtx table_label = gen_label_rtx ();
+ bool has_gaps = false;
+ edge default_edge = stmt_bb ? EDGE_SUCC(stmt_bb, 0) : NULL;
+ int default_prob = default_edge ? default_edge->probability : 0;
+ int base = get_outgoing_edge_probs (stmt_bb);
+ bool try_with_tablejump = false;
+
+ int new_default_prob = conditional_probability (default_prob,
+ base);
+
+ if (! try_casesi (index_type, index_expr, minval, range,
+ table_label, default_label, fallback_label,
+ new_default_prob))
+ {
+ /* Index jumptables from zero for suitable values of minval to avoid
+ a subtraction. For the rationale see:
+ "http://gcc.gnu.org/ml/gcc-patches/2001-10/msg01234.html". */
+ if (optimize_insn_for_speed_p ()
+ && compare_tree_int (minval, 0) > 0
+ && compare_tree_int (minval, 3) < 0)
+ {
+ minval = build_int_cst (index_type, 0);
+ range = maxval;
+ has_gaps = true;
+ }
+ try_with_tablejump = true;
+ }
+
+ /* Get table of labels to jump to, in order of case index. */
+
+ ncases = tree_low_cst (range, 0) + 1;
+ labelvec = XALLOCAVEC (rtx, ncases);
+ memset (labelvec, 0, ncases * sizeof (rtx));
+
+ for (n = case_list; n; n = n->right)
+ {
+ /* Compute the low and high bounds relative to the minimum
+ value since that should fit in a HOST_WIDE_INT while the
+ actual values may not. */
+ HOST_WIDE_INT i_low
+ = tree_low_cst (fold_build2 (MINUS_EXPR, index_type,
+ n->low, minval), 1);
+ HOST_WIDE_INT i_high
+ = tree_low_cst (fold_build2 (MINUS_EXPR, index_type,
+ n->high, minval), 1);
+ HOST_WIDE_INT i;
+
+ for (i = i_low; i <= i_high; i ++)
+ labelvec[i]
+ = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
+ }
+
+ /* Fill in the gaps with the default. We may have gaps at
+ the beginning if we tried to avoid the minval subtraction,
+ so substitute some label even if the default label was
+ deemed unreachable. */
+ if (!default_label)
+ default_label = fallback_label;
+ for (i = 0; i < ncases; i++)
+ if (labelvec[i] == 0)
+ {
+ has_gaps = true;
+ labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
+ }
+
+ if (has_gaps)
+ {
+ /* There is at least one entry in the jump table that jumps
+ to default label. The default label can either be reached
+ through the indirect jump or the direct conditional jump
+ before that. Split the probability of reaching the
+ default label among these two jumps. */
+ new_default_prob = conditional_probability (default_prob/2,
+ base);
+ default_prob /= 2;
+ base -= default_prob;
+ }
+ else
+ {
+ base -= default_prob;
+ default_prob = 0;
+ }
+
+ if (default_edge)
+ default_edge->probability = default_prob;
+
+ /* We have altered the probability of the default edge. So the probabilities
+ of all other edges need to be adjusted so that it sums up to
+ REG_BR_PROB_BASE. */
+ if (base)
+ {
+ edge e;
+ edge_iterator ei;
+ FOR_EACH_EDGE (e, ei, stmt_bb->succs)
+ e->probability = RDIV (e->probability * REG_BR_PROB_BASE, base);
+ }
+
+ if (try_with_tablejump)
+ {
+ bool ok = try_tablejump (index_type, index_expr, minval, range,
+ table_label, default_label, new_default_prob);
+ gcc_assert (ok);
+ }
+ /* Output the table. */
+ emit_label (table_label);
+
+ if (CASE_VECTOR_PC_RELATIVE || flag_pic)
+ emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
+ gen_rtx_LABEL_REF (Pmode, table_label),
+ gen_rtvec_v (ncases, labelvec),
+ const0_rtx, const0_rtx));
+ else
+ emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
+ gen_rtvec_v (ncases, labelvec)));
+
+ /* Record no drop-through after the table. */
+ emit_barrier ();
+}
+
+/* Reset the aux field of all outgoing edges of basic block BB. */
+
+static inline void
+reset_out_edges_aux (basic_block bb)
+{
+ edge e;
+ edge_iterator ei;
+ FOR_EACH_EDGE(e, ei, bb->succs)
+ e->aux = (void *)0;
+}
+
+/* Compute the number of case labels that correspond to each outgoing edge of
+ STMT. Record this information in the aux field of the edge. */
+
+static inline void
+compute_cases_per_edge (gimple stmt)
+{
+ basic_block bb = gimple_bb (stmt);
+ reset_out_edges_aux (bb);
+ int ncases = gimple_switch_num_labels (stmt);
+ for (int i = ncases - 1; i >= 1; --i)
+ {
+ tree elt = gimple_switch_label (stmt, i);
+ tree lab = CASE_LABEL (elt);
+ basic_block case_bb = label_to_block_fn (cfun, lab);
+ edge case_edge = find_edge (bb, case_bb);
+ case_edge->aux = (void *)((intptr_t)(case_edge->aux) + 1);
+ }
+}
+
+/* Terminate a case (Pascal/Ada) or switch (C) statement
+ in which ORIG_INDEX is the expression to be tested.
+ If ORIG_TYPE is not NULL, it is the original ORIG_INDEX
+ type as given in the source before any compiler conversions.
+ Generate the code to test it and jump to the right place. */
+
+void
+expand_case (gimple stmt)
+{
+ tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE;
+ rtx default_label = NULL_RTX;
+ unsigned int count, uniq;
+ int i;
+ int ncases = gimple_switch_num_labels (stmt);
+ tree index_expr = gimple_switch_index (stmt);
+ tree index_type = TREE_TYPE (index_expr);
+ tree elt;
+ basic_block bb = gimple_bb (stmt);
+
+ /* A list of case labels; it is first built as a list and it may then
+ be rearranged into a nearly balanced binary tree. */
+ struct case_node *case_list = 0;
+
+ /* A pool for case nodes. */
+ alloc_pool case_node_pool;
+
+ /* An ERROR_MARK occurs for various reasons including invalid data type.
+ ??? Can this still happen, with GIMPLE and all? */
+ if (index_type == error_mark_node)
+ return;
+
+ /* cleanup_tree_cfg removes all SWITCH_EXPR with their index
+ expressions being INTEGER_CST. */
+ gcc_assert (TREE_CODE (index_expr) != INTEGER_CST);
+
+ case_node_pool = create_alloc_pool ("struct case_node pool",
+ sizeof (struct case_node),
+ 100);
+
+ do_pending_stack_adjust ();
+
+ /* Find the default case target label. */
+ default_label = label_rtx (CASE_LABEL (gimple_switch_default_label (stmt)));
+ edge default_edge = EDGE_SUCC(bb, 0);
+ int default_prob = default_edge->probability;
+
+ /* Get upper and lower bounds of case values. */
+ elt = gimple_switch_label (stmt, 1);
+ minval = fold_convert (index_type, CASE_LOW (elt));
+ elt = gimple_switch_label (stmt, ncases - 1);
+ if (CASE_HIGH (elt))
+ maxval = fold_convert (index_type, CASE_HIGH (elt));
+ else
+ maxval = fold_convert (index_type, CASE_LOW (elt));
+
+ /* Compute span of values. */
+ range = fold_build2 (MINUS_EXPR, index_type, maxval, minval);
+
+ /* Listify the labels queue and gather some numbers to decide
+ how to expand this switch(). */
+ uniq = 0;
+ count = 0;
+ struct pointer_set_t *seen_labels = pointer_set_create ();
+ compute_cases_per_edge (stmt);
+
+ for (i = ncases - 1; i >= 1; --i)
+ {
+ elt = gimple_switch_label (stmt, i);
+ tree low = CASE_LOW (elt);
+ gcc_assert (low);
+ tree high = CASE_HIGH (elt);
+ gcc_assert (! high || tree_int_cst_lt (low, high));
+ tree lab = CASE_LABEL (elt);
+
+ /* Count the elements.
+ A range counts double, since it requires two compares. */
+ count++;
+ if (high)
+ count++;
+
+ /* If we have not seen this label yet, then increase the
+ number of unique case node targets seen. */
+ if (!pointer_set_insert (seen_labels, lab))
+ uniq++;
+
+ /* The bounds on the case range, LOW and HIGH, have to be converted
+ to case's index type TYPE. Note that the original type of the
+ case index in the source code is usually "lost" during
+ gimplification due to type promotion, but the case labels retain the
+ original type. Make sure to drop overflow flags. */
+ low = fold_convert (index_type, low);
+ if (TREE_OVERFLOW (low))
+ low = build_int_cst_wide (index_type,
+ TREE_INT_CST_LOW (low),
+ TREE_INT_CST_HIGH (low));
+
+ /* The canonical from of a case label in GIMPLE is that a simple case
+ has an empty CASE_HIGH. For the casesi and tablejump expanders,
+ the back ends want simple cases to have high == low. */
+ if (! high)
+ high = low;
+ high = fold_convert (index_type, high);
+ if (TREE_OVERFLOW (high))
+ high = build_int_cst_wide (index_type,
+ TREE_INT_CST_LOW (high),
+ TREE_INT_CST_HIGH (high));
+
+ basic_block case_bb = label_to_block_fn (cfun, lab);
+ edge case_edge = find_edge (bb, case_bb);
+ case_list = add_case_node (
+ case_list, low, high, lab,
+ case_edge->probability / (intptr_t)(case_edge->aux),
+ case_node_pool);
+ }
+ pointer_set_destroy (seen_labels);
+ reset_out_edges_aux (bb);
+
+ /* cleanup_tree_cfg removes all SWITCH_EXPR with a single
+ destination, such as one with a default case only.
+ It also removes cases that are out of range for the switch
+ type, so we should never get a zero here. */
+ gcc_assert (count > 0);
+
+ rtx before_case = get_last_insn ();
+
+ /* Decide how to expand this switch.
+ The two options at this point are a dispatch table (casesi or
+ tablejump) or a decision tree. */
+
+ if (expand_switch_as_decision_tree_p (range, uniq, count))
+ emit_case_decision_tree (index_expr, index_type,
+ case_list, default_label,
+ default_prob);
+ else
+ emit_case_dispatch_table (index_expr, index_type,
+ case_list, default_label,
+ minval, maxval, range, bb);
+
+ reorder_insns (NEXT_INSN (before_case), get_last_insn (), before_case);
+
+ free_temp_slots ();
+ free_alloc_pool (case_node_pool);
+}
+
+/* Expand the dispatch to a short decrement chain if there are few cases
+ to dispatch to. Likewise if neither casesi nor tablejump is available,
+ or if flag_jump_tables is set. Otherwise, expand as a casesi or a
+ tablejump. The index mode is always the mode of integer_type_node.
+ Trap if no case matches the index.
+
+ DISPATCH_INDEX is the index expression to switch on. It should be a
+ memory or register operand.
+
+ DISPATCH_TABLE is a set of case labels. The set should be sorted in
+ ascending order, be contiguous, starting with value 0, and contain only
+ single-valued case labels. */
+
+void
+expand_sjlj_dispatch_table (rtx dispatch_index,
+ vec<tree> dispatch_table)
+{
+ tree index_type = integer_type_node;
+ enum machine_mode index_mode = TYPE_MODE (index_type);
+
+ int ncases = dispatch_table.length ();
+
+ do_pending_stack_adjust ();
+ rtx before_case = get_last_insn ();
+
+ /* Expand as a decrement-chain if there are 5 or fewer dispatch
+ labels. This covers more than 98% of the cases in libjava,
+ and seems to be a reasonable compromise between the "old way"
+ of expanding as a decision tree or dispatch table vs. the "new
+ way" with decrement chain or dispatch table. */
+ if (dispatch_table.length () <= 5
+ || (!HAVE_casesi && !HAVE_tablejump)
+ || !flag_jump_tables)
+ {
+ /* Expand the dispatch as a decrement chain:
+
+ "switch(index) {case 0: do_0; case 1: do_1; ...; case N: do_N;}"
+
+ ==>
+
+ if (index == 0) do_0; else index--;
+ if (index == 0) do_1; else index--;
+ ...
+ if (index == 0) do_N; else index--;
+
+ This is more efficient than a dispatch table on most machines.
+ The last "index--" is redundant but the code is trivially dead
+ and will be cleaned up by later passes. */
+ rtx index = copy_to_mode_reg (index_mode, dispatch_index);
+ rtx zero = CONST0_RTX (index_mode);
+ for (int i = 0; i < ncases; i++)
+ {
+ tree elt = dispatch_table[i];
+ rtx lab = label_rtx (CASE_LABEL (elt));
+ do_jump_if_equal (index_mode, index, zero, lab, 0, -1);
+ force_expand_binop (index_mode, sub_optab,
+ index, CONST1_RTX (index_mode),
+ index, 0, OPTAB_DIRECT);
+ }
+ }
+ else
+ {
+ /* Similar to expand_case, but much simpler. */
+ struct case_node *case_list = 0;
+ alloc_pool case_node_pool = create_alloc_pool ("struct sjlj_case pool",
+ sizeof (struct case_node),
+ ncases);
+ tree index_expr = make_tree (index_type, dispatch_index);
+ tree minval = build_int_cst (index_type, 0);
+ tree maxval = CASE_LOW (dispatch_table.last ());
+ tree range = maxval;
+ rtx default_label = gen_label_rtx ();
+
+ for (int i = ncases - 1; i >= 0; --i)
+ {
+ tree elt = dispatch_table[i];
+ tree low = CASE_LOW (elt);
+ tree lab = CASE_LABEL (elt);
+ case_list = add_case_node (case_list, low, low, lab, 0, case_node_pool);
+ }
+
+ emit_case_dispatch_table (index_expr, index_type,
+ case_list, default_label,
+ minval, maxval, range,
+ BLOCK_FOR_INSN (before_case));
+ emit_label (default_label);
+ free_alloc_pool (case_node_pool);
+ }
+
+ /* Dispatching something not handled? Trap! */
+ expand_builtin_trap ();
+
+ reorder_insns (NEXT_INSN (before_case), get_last_insn (), before_case);
+
+ free_temp_slots ();
+}
+
+
+/* Take an ordered list of case nodes
+ and transform them into a near optimal binary tree,
+ on the assumption that any target code selection value is as
+ likely as any other.
+
+ The transformation is performed by splitting the ordered
+ list into two equal sections plus a pivot. The parts are
+ then attached to the pivot as left and right branches. Each
+ branch is then transformed recursively. */
+
+static void
+balance_case_nodes (case_node_ptr *head, case_node_ptr parent)
+{
+ case_node_ptr np;
+
+ np = *head;
+ if (np)
+ {
+ int i = 0;
+ int ranges = 0;
+ case_node_ptr *npp;
+ case_node_ptr left;
+
+ /* Count the number of entries on branch. Also count the ranges. */
+
+ while (np)
+ {
+ if (!tree_int_cst_equal (np->low, np->high))
+ ranges++;
+
+ i++;
+ np = np->right;
+ }
+
+ if (i > 2)
+ {
+ /* Split this list if it is long enough for that to help. */
+ npp = head;
+ left = *npp;
+
+ /* If there are just three nodes, split at the middle one. */
+ if (i == 3)
+ npp = &(*npp)->right;
+ else
+ {
+ /* Find the place in the list that bisects the list's total cost,
+ where ranges count as 2.
+ Here I gets half the total cost. */
+ i = (i + ranges + 1) / 2;
+ while (1)
+ {
+ /* Skip nodes while their cost does not reach that amount. */
+ if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
+ i--;
+ i--;
+ if (i <= 0)
+ break;
+ npp = &(*npp)->right;
+ }
+ }
+ *head = np = *npp;
+ *npp = 0;
+ np->parent = parent;
+ np->left = left;
+
+ /* Optimize each of the two split parts. */
+ balance_case_nodes (&np->left, np);
+ balance_case_nodes (&np->right, np);
+ np->subtree_prob = np->prob;
+ np->subtree_prob += np->left->subtree_prob;
+ np->subtree_prob += np->right->subtree_prob;
+ }
+ else
+ {
+ /* Else leave this branch as one level,
+ but fill in `parent' fields. */
+ np = *head;
+ np->parent = parent;
+ np->subtree_prob = np->prob;
+ for (; np->right; np = np->right)
+ {
+ np->right->parent = np;
+ (*head)->subtree_prob += np->right->subtree_prob;
+ }
+ }
+ }
+}
+
+/* Search the parent sections of the case node tree
+ to see if a test for the lower bound of NODE would be redundant.
+ INDEX_TYPE is the type of the index expression.
+
+ The instructions to generate the case decision tree are
+ output in the same order as nodes are processed so it is
+ known that if a parent node checks the range of the current
+ node minus one that the current node is bounded at its lower
+ span. Thus the test would be redundant. */
+
+static int
+node_has_low_bound (case_node_ptr node, tree index_type)
+{
+ tree low_minus_one;
+ case_node_ptr pnode;
+
+ /* If the lower bound of this node is the lowest value in the index type,
+ we need not test it. */
+
+ if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
+ return 1;
+
+ /* If this node has a left branch, the value at the left must be less
+ than that at this node, so it cannot be bounded at the bottom and
+ we need not bother testing any further. */
+
+ if (node->left)
+ return 0;
+
+ low_minus_one = fold_build2 (MINUS_EXPR, TREE_TYPE (node->low),
+ node->low,
+ build_int_cst (TREE_TYPE (node->low), 1));
+
+ /* If the subtraction above overflowed, we can't verify anything.
+ Otherwise, look for a parent that tests our value - 1. */
+
+ if (! tree_int_cst_lt (low_minus_one, node->low))
+ return 0;
+
+ for (pnode = node->parent; pnode; pnode = pnode->parent)
+ if (tree_int_cst_equal (low_minus_one, pnode->high))
+ return 1;
+
+ return 0;
+}
+
+/* Search the parent sections of the case node tree
+ to see if a test for the upper bound of NODE would be redundant.
+ INDEX_TYPE is the type of the index expression.
+
+ The instructions to generate the case decision tree are
+ output in the same order as nodes are processed so it is
+ known that if a parent node checks the range of the current
+ node plus one that the current node is bounded at its upper
+ span. Thus the test would be redundant. */
+
+static int
+node_has_high_bound (case_node_ptr node, tree index_type)
+{
+ tree high_plus_one;
+ case_node_ptr pnode;
+
+ /* If there is no upper bound, obviously no test is needed. */
+
+ if (TYPE_MAX_VALUE (index_type) == NULL)
+ return 1;
+
+ /* If the upper bound of this node is the highest value in the type
+ of the index expression, we need not test against it. */
+
+ if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
+ return 1;
+
+ /* If this node has a right branch, the value at the right must be greater
+ than that at this node, so it cannot be bounded at the top and
+ we need not bother testing any further. */
+
+ if (node->right)
+ return 0;
+
+ high_plus_one = fold_build2 (PLUS_EXPR, TREE_TYPE (node->high),
+ node->high,
+ build_int_cst (TREE_TYPE (node->high), 1));
+
+ /* If the addition above overflowed, we can't verify anything.
+ Otherwise, look for a parent that tests our value + 1. */
+
+ if (! tree_int_cst_lt (node->high, high_plus_one))
+ return 0;
+
+ for (pnode = node->parent; pnode; pnode = pnode->parent)
+ if (tree_int_cst_equal (high_plus_one, pnode->low))
+ return 1;
+
+ return 0;
+}
+
+/* Search the parent sections of the
+ case node tree to see if both tests for the upper and lower
+ bounds of NODE would be redundant. */
+
+static int
+node_is_bounded (case_node_ptr node, tree index_type)
+{
+ return (node_has_low_bound (node, index_type)
+ && node_has_high_bound (node, index_type));
+}
+
+
+/* Emit step-by-step code to select a case for the value of INDEX.
+ The thus generated decision tree follows the form of the
+ case-node binary tree NODE, whose nodes represent test conditions.
+ INDEX_TYPE is the type of the index of the switch.
+
+ Care is taken to prune redundant tests from the decision tree
+ by detecting any boundary conditions already checked by
+ emitted rtx. (See node_has_high_bound, node_has_low_bound
+ and node_is_bounded, above.)
+
+ Where the test conditions can be shown to be redundant we emit
+ an unconditional jump to the target code. As a further
+ optimization, the subordinates of a tree node are examined to
+ check for bounded nodes. In this case conditional and/or
+ unconditional jumps as a result of the boundary check for the
+ current node are arranged to target the subordinates associated
+ code for out of bound conditions on the current node.
+
+ We can assume that when control reaches the code generated here,
+ the index value has already been compared with the parents
+ of this node, and determined to be on the same side of each parent
+ as this node is. Thus, if this node tests for the value 51,
+ and a parent tested for 52, we don't need to consider
+ the possibility of a value greater than 51. If another parent
+ tests for the value 50, then this node need not test anything. */
+
+static void
+emit_case_nodes (rtx index, case_node_ptr node, rtx default_label,
+ int default_prob, tree index_type)
+{
+ /* If INDEX has an unsigned type, we must make unsigned branches. */
+ int unsignedp = TYPE_UNSIGNED (index_type);
+ int probability;
+ int prob = node->prob, subtree_prob = node->subtree_prob;
+ enum machine_mode mode = GET_MODE (index);
+ enum machine_mode imode = TYPE_MODE (index_type);
+
+ /* Handle indices detected as constant during RTL expansion. */
+ if (mode == VOIDmode)
+ mode = imode;
+
+ /* See if our parents have already tested everything for us.
+ If they have, emit an unconditional jump for this node. */
+ if (node_is_bounded (node, index_type))
+ emit_jump (label_rtx (node->code_label));
+
+ else if (tree_int_cst_equal (node->low, node->high))
+ {
+ probability = conditional_probability (prob, subtree_prob + default_prob);
+ /* Node is single valued. First see if the index expression matches
+ this node and then check our children, if any. */
+ do_jump_if_equal (mode, index,
+ convert_modes (mode, imode,
+ expand_normal (node->low),
+ unsignedp),
+ label_rtx (node->code_label), unsignedp, probability);
+ /* Since this case is taken at this point, reduce its weight from
+ subtree_weight. */
+ subtree_prob -= prob;
+ if (node->right != 0 && node->left != 0)
+ {
+ /* This node has children on both sides.
+ Dispatch to one side or the other
+ by comparing the index value with this node's value.
+ If one subtree is bounded, check that one first,
+ so we can avoid real branches in the tree. */
+
+ if (node_is_bounded (node->right, index_type))
+ {
+ probability = conditional_probability (
+ node->right->prob,
+ subtree_prob + default_prob);
+ emit_cmp_and_jump_insns (index,
+ convert_modes
+ (mode, imode,
+ expand_normal (node->high),
+ unsignedp),
+ GT, NULL_RTX, mode, unsignedp,
+ label_rtx (node->right->code_label),
+ probability);
+ emit_case_nodes (index, node->left, default_label, default_prob,
+ index_type);
+ }
+
+ else if (node_is_bounded (node->left, index_type))
+ {
+ probability = conditional_probability (
+ node->left->prob,
+ subtree_prob + default_prob);
+ emit_cmp_and_jump_insns (index,
+ convert_modes
+ (mode, imode,
+ expand_normal (node->high),
+ unsignedp),
+ LT, NULL_RTX, mode, unsignedp,
+ label_rtx (node->left->code_label),
+ probability);
+ emit_case_nodes (index, node->right, default_label, default_prob, index_type);
+ }
+
+ /* If both children are single-valued cases with no
+ children, finish up all the work. This way, we can save
+ one ordered comparison. */
+ else if (tree_int_cst_equal (node->right->low, node->right->high)
+ && node->right->left == 0
+ && node->right->right == 0
+ && tree_int_cst_equal (node->left->low, node->left->high)
+ && node->left->left == 0
+ && node->left->right == 0)
+ {
+ /* Neither node is bounded. First distinguish the two sides;
+ then emit the code for one side at a time. */
+
+ /* See if the value matches what the right hand side
+ wants. */
+ probability = conditional_probability (
+ node->right->prob,
+ subtree_prob + default_prob);
+ do_jump_if_equal (mode, index,
+ convert_modes (mode, imode,
+ expand_normal (node->right->low),
+ unsignedp),
+ label_rtx (node->right->code_label),
+ unsignedp, probability);
+
+ /* See if the value matches what the left hand side
+ wants. */
+ probability = conditional_probability (
+ node->left->prob,
+ subtree_prob + default_prob);
+ do_jump_if_equal (mode, index,
+ convert_modes (mode, imode,
+ expand_normal (node->left->low),
+ unsignedp),
+ label_rtx (node->left->code_label),
+ unsignedp, probability);
+ }
+
+ else
+ {
+ /* Neither node is bounded. First distinguish the two sides;
+ then emit the code for one side at a time. */
+
+ tree test_label
+ = build_decl (curr_insn_location (),
+ LABEL_DECL, NULL_TREE, NULL_TREE);
+
+ /* The default label could be reached either through the right
+ subtree or the left subtree. Divide the probability
+ equally. */
+ probability = conditional_probability (
+ node->right->subtree_prob + default_prob/2,
+ subtree_prob + default_prob);
+ /* See if the value is on the right. */
+ emit_cmp_and_jump_insns (index,
+ convert_modes
+ (mode, imode,
+ expand_normal (node->high),
+ unsignedp),
+ GT, NULL_RTX, mode, unsignedp,
+ label_rtx (test_label),
+ probability);
+ default_prob /= 2;
+
+ /* Value must be on the left.
+ Handle the left-hand subtree. */
+ emit_case_nodes (index, node->left, default_label, default_prob, index_type);
+ /* If left-hand subtree does nothing,
+ go to default. */
+ if (default_label)
+ emit_jump (default_label);
+
+ /* Code branches here for the right-hand subtree. */
+ expand_label (test_label);
+ emit_case_nodes (index, node->right, default_label, default_prob, index_type);
+ }
+ }
+
+ else if (node->right != 0 && node->left == 0)
+ {
+ /* Here we have a right child but no left so we issue a conditional
+ branch to default and process the right child.
+
+ Omit the conditional branch to default if the right child
+ does not have any children and is single valued; it would
+ cost too much space to save so little time. */
+
+ if (node->right->right || node->right->left
+ || !tree_int_cst_equal (node->right->low, node->right->high))
+ {
+ if (!node_has_low_bound (node, index_type))
+ {
+ probability = conditional_probability (
+ default_prob/2,
+ subtree_prob + default_prob);
+ emit_cmp_and_jump_insns (index,
+ convert_modes
+ (mode, imode,
+ expand_normal (node->high),
+ unsignedp),
+ LT, NULL_RTX, mode, unsignedp,
+ default_label,
+ probability);
+ default_prob /= 2;
+ }
+
+ emit_case_nodes (index, node->right, default_label, default_prob, index_type);
+ }
+ else
+ {
+ probability = conditional_probability (
+ node->right->subtree_prob,
+ subtree_prob + default_prob);
+ /* We cannot process node->right normally
+ since we haven't ruled out the numbers less than
+ this node's value. So handle node->right explicitly. */
+ do_jump_if_equal (mode, index,
+ convert_modes
+ (mode, imode,
+ expand_normal (node->right->low),
+ unsignedp),
+ label_rtx (node->right->code_label), unsignedp, probability);
+ }
+ }
+
+ else if (node->right == 0 && node->left != 0)
+ {
+ /* Just one subtree, on the left. */
+ if (node->left->left || node->left->right
+ || !tree_int_cst_equal (node->left->low, node->left->high))
+ {
+ if (!node_has_high_bound (node, index_type))
+ {
+ probability = conditional_probability (
+ default_prob/2,
+ subtree_prob + default_prob);
+ emit_cmp_and_jump_insns (index,
+ convert_modes
+ (mode, imode,
+ expand_normal (node->high),
+ unsignedp),
+ GT, NULL_RTX, mode, unsignedp,
+ default_label,
+ probability);
+ default_prob /= 2;
+ }
+
+ emit_case_nodes (index, node->left, default_label,
+ default_prob, index_type);
+ }
+ else
+ {
+ probability = conditional_probability (
+ node->left->subtree_prob,
+ subtree_prob + default_prob);
+ /* We cannot process node->left normally
+ since we haven't ruled out the numbers less than
+ this node's value. So handle node->left explicitly. */
+ do_jump_if_equal (mode, index,
+ convert_modes
+ (mode, imode,
+ expand_normal (node->left->low),
+ unsignedp),
+ label_rtx (node->left->code_label), unsignedp, probability);
+ }
+ }
+ }
+ else
+ {
+ /* Node is a range. These cases are very similar to those for a single
+ value, except that we do not start by testing whether this node
+ is the one to branch to. */
+
+ if (node->right != 0 && node->left != 0)
+ {
+ /* Node has subtrees on both sides.
+ If the right-hand subtree is bounded,
+ test for it first, since we can go straight there.
+ Otherwise, we need to make a branch in the control structure,
+ then handle the two subtrees. */
+ tree test_label = 0;
+
+ if (node_is_bounded (node->right, index_type))
+ {
+ /* Right hand node is fully bounded so we can eliminate any
+ testing and branch directly to the target code. */
+ probability = conditional_probability (
+ node->right->subtree_prob,
+ subtree_prob + default_prob);
+ emit_cmp_and_jump_insns (index,
+ convert_modes
+ (mode, imode,
+ expand_normal (node->high),
+ unsignedp),
+ GT, NULL_RTX, mode, unsignedp,
+ label_rtx (node->right->code_label),
+ probability);
+ }
+ else
+ {
+ /* Right hand node requires testing.
+ Branch to a label where we will handle it later. */
+
+ test_label = build_decl (curr_insn_location (),
+ LABEL_DECL, NULL_TREE, NULL_TREE);
+ probability = conditional_probability (
+ node->right->subtree_prob + default_prob/2,
+ subtree_prob + default_prob);
+ emit_cmp_and_jump_insns (index,
+ convert_modes
+ (mode, imode,
+ expand_normal (node->high),
+ unsignedp),
+ GT, NULL_RTX, mode, unsignedp,
+ label_rtx (test_label),
+ probability);
+ default_prob /= 2;
+ }
+
+ /* Value belongs to this node or to the left-hand subtree. */
+
+ probability = conditional_probability (
+ prob,
+ subtree_prob + default_prob);
+ emit_cmp_and_jump_insns (index,
+ convert_modes
+ (mode, imode,
+ expand_normal (node->low),
+ unsignedp),
+ GE, NULL_RTX, mode, unsignedp,
+ label_rtx (node->code_label),
+ probability);
+
+ /* Handle the left-hand subtree. */
+ emit_case_nodes (index, node->left, default_label, default_prob, index_type);
+
+ /* If right node had to be handled later, do that now. */
+
+ if (test_label)
+ {
+ /* If the left-hand subtree fell through,
+ don't let it fall into the right-hand subtree. */
+ if (default_label)
+ emit_jump (default_label);
+
+ expand_label (test_label);
+ emit_case_nodes (index, node->right, default_label, default_prob, index_type);
+ }
+ }
+
+ else if (node->right != 0 && node->left == 0)
+ {
+ /* Deal with values to the left of this node,
+ if they are possible. */
+ if (!node_has_low_bound (node, index_type))
+ {
+ probability = conditional_probability (
+ default_prob/2,
+ subtree_prob + default_prob);
+ emit_cmp_and_jump_insns (index,
+ convert_modes
+ (mode, imode,
+ expand_normal (node->low),
+ unsignedp),
+ LT, NULL_RTX, mode, unsignedp,
+ default_label,
+ probability);
+ default_prob /= 2;
+ }
+
+ /* Value belongs to this node or to the right-hand subtree. */
+
+ probability = conditional_probability (
+ prob,
+ subtree_prob + default_prob);
+ emit_cmp_and_jump_insns (index,
+ convert_modes
+ (mode, imode,
+ expand_normal (node->high),
+ unsignedp),
+ LE, NULL_RTX, mode, unsignedp,
+ label_rtx (node->code_label),
+ probability);
+
+ emit_case_nodes (index, node->right, default_label, default_prob, index_type);
+ }
+
+ else if (node->right == 0 && node->left != 0)
+ {
+ /* Deal with values to the right of this node,
+ if they are possible. */
+ if (!node_has_high_bound (node, index_type))
+ {
+ probability = conditional_probability (
+ default_prob/2,
+ subtree_prob + default_prob);
+ emit_cmp_and_jump_insns (index,
+ convert_modes
+ (mode, imode,
+ expand_normal (node->high),
+ unsignedp),
+ GT, NULL_RTX, mode, unsignedp,
+ default_label,
+ probability);
+ default_prob /= 2;
+ }
+
+ /* Value belongs to this node or to the left-hand subtree. */
+
+ probability = conditional_probability (
+ prob,
+ subtree_prob + default_prob);
+ emit_cmp_and_jump_insns (index,
+ convert_modes
+ (mode, imode,
+ expand_normal (node->low),
+ unsignedp),
+ GE, NULL_RTX, mode, unsignedp,
+ label_rtx (node->code_label),
+ probability);
+
+ emit_case_nodes (index, node->left, default_label, default_prob, index_type);
+ }
+
+ else
+ {
+ /* Node has no children so we check low and high bounds to remove
+ redundant tests. Only one of the bounds can exist,
+ since otherwise this node is bounded--a case tested already. */
+ int high_bound = node_has_high_bound (node, index_type);
+ int low_bound = node_has_low_bound (node, index_type);
+
+ if (!high_bound && low_bound)
+ {
+ probability = conditional_probability (
+ default_prob,
+ subtree_prob + default_prob);
+ emit_cmp_and_jump_insns (index,
+ convert_modes
+ (mode, imode,
+ expand_normal (node->high),
+ unsignedp),
+ GT, NULL_RTX, mode, unsignedp,
+ default_label,
+ probability);
+ }
+
+ else if (!low_bound && high_bound)
+ {
+ probability = conditional_probability (
+ default_prob,
+ subtree_prob + default_prob);
+ emit_cmp_and_jump_insns (index,
+ convert_modes
+ (mode, imode,
+ expand_normal (node->low),
+ unsignedp),
+ LT, NULL_RTX, mode, unsignedp,
+ default_label,
+ probability);
+ }
+ else if (!low_bound && !high_bound)
+ {
+ /* Widen LOW and HIGH to the same width as INDEX. */
+ tree type = lang_hooks.types.type_for_mode (mode, unsignedp);
+ tree low = build1 (CONVERT_EXPR, type, node->low);
+ tree high = build1 (CONVERT_EXPR, type, node->high);
+ rtx low_rtx, new_index, new_bound;
+
+ /* Instead of doing two branches, emit one unsigned branch for
+ (index-low) > (high-low). */
+ low_rtx = expand_expr (low, NULL_RTX, mode, EXPAND_NORMAL);
+ new_index = expand_simple_binop (mode, MINUS, index, low_rtx,
+ NULL_RTX, unsignedp,
+ OPTAB_WIDEN);
+ new_bound = expand_expr (fold_build2 (MINUS_EXPR, type,
+ high, low),
+ NULL_RTX, mode, EXPAND_NORMAL);
+
+ probability = conditional_probability (
+ default_prob,
+ subtree_prob + default_prob);
+ emit_cmp_and_jump_insns (new_index, new_bound, GT, NULL_RTX,
+ mode, 1, default_label, probability);
+ }
+
+ emit_jump (label_rtx (node->code_label));
+ }
+ }
+}