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authorSebastian Pop <s.pop@samsung.com>2015-08-28 20:43:11 (GMT)
committerSebastian Pop <s.pop@samsung.com>2015-08-28 21:47:04 (GMT)
commitaa65e2d1e40e4dd0d936a275683c4aadfe8aa20f (patch)
tree9a059b4050b7d2694e159ffe09c3e5097f997886 /gcc-4.9/gcc
parentfa0139c9969e54f37f0add025af87cc21b46ffcb (diff)
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backport patch to fix PR65177
PR tree-optimization/65177 * tree-ssa-threadupdate.c (verify_seme): Renamed verify_jump_thread. (bb_in_bbs): New. (duplicate_seme_region): Renamed duplicate_thread_path. Redirect all edges not adjacent on the path to the original code. * gcc.dg/tree-ssa/ssa-dom-thread-10.c: New.
Diffstat (limited to 'gcc-4.9/gcc')
-rw-r--r--gcc-4.9/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-10.c24
-rw-r--r--gcc-4.9/gcc/tree-ssa-threadupdate.c93
2 files changed, 91 insertions, 26 deletions
diff --git a/gcc-4.9/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-10.c b/gcc-4.9/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-10.c
new file mode 100644
index 0000000..4acf580
--- /dev/null
+++ b/gcc-4.9/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-10.c
@@ -0,0 +1,24 @@
+/* PR 65177 */
+/* { dg-do compile } */
+/* { dg-options "-O3" } */
+
+typedef struct p7_profile_s {} P7_PROFILE;
+enum p7t_statetype_e {
+ p7T_S = 4, p7T_N = 5, p7T_E = 7, p7T_C = 8, p7T_J = 10, };
+typedef struct p7_trace_s {} P7_TRACE;
+typedef struct p7_gmx_s {
+ int L;
+} P7_GMX;
+static inline int select_c(const P7_PROFILE *gm, const P7_GMX *pp, const P7_GMX *gx, int i) {
+ float path[2];
+ return ((path[0] > path[1]) ? p7T_C : p7T_E);
+}
+void p7_GOATrace(const P7_PROFILE *gm, const P7_GMX *pp, const P7_GMX *gx, P7_TRACE *tr) {
+ int i = gx->L;
+ int sprv, scur;
+ while (sprv != p7T_S) {
+ switch (sprv) { case p7T_C: scur = select_c(gm, pp, gx, i); break; }
+ if ( (scur == p7T_N || scur == p7T_J || scur == p7T_C) && scur == sprv) i--;
+ sprv = scur;
+ }
+}
diff --git a/gcc-4.9/gcc/tree-ssa-threadupdate.c b/gcc-4.9/gcc/tree-ssa-threadupdate.c
index 3c7df9a..c2f02a6 100644
--- a/gcc-4.9/gcc/tree-ssa-threadupdate.c
+++ b/gcc-4.9/gcc/tree-ssa-threadupdate.c
@@ -1623,36 +1623,32 @@ bb_ends_with_multiway_branch (basic_block bb ATTRIBUTE_UNUSED)
return false;
}
-/* Verify that the REGION is a Single Entry Multiple Exits region: make sure no
- edge other than ENTRY is entering the REGION. */
+/* Verify that the REGION is a valid jump thread. A jump thread is a special
+ case of SEME Single Entry Multiple Exits region in which all nodes in the
+ REGION have exactly one incoming edge. The only exception is the first block
+ that may not have been connected to the rest of the cfg yet. */
DEBUG_FUNCTION void
-verify_seme (edge entry, basic_block *region, unsigned n_region)
+verify_jump_thread (basic_block *region, unsigned n_region)
{
- bitmap bbs = BITMAP_ALLOC (NULL);
-
for (unsigned i = 0; i < n_region; i++)
- bitmap_set_bit (bbs, region[i]->index);
+ gcc_assert (EDGE_COUNT (region[i]->preds) <= 1);
+}
- for (unsigned i = 0; i < n_region; i++)
- {
- edge e;
- edge_iterator ei;
- basic_block bb = region[i];
+/* Return true when BB is one of the first N items in BBS. */
- /* All predecessors other than ENTRY->src should be in the region. */
- for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei)); ei_next (&ei))
- if (e != entry)
- gcc_assert (bitmap_bit_p (bbs, e->src->index));
- }
+static inline bool
+bb_in_bbs (basic_block bb, basic_block *bbs, int n)
+{
+ for (int i = 0; i < n; i++)
+ if (bb == bbs[i])
+ return true;
- BITMAP_FREE (bbs);
+ return false;
}
-/* Duplicates a Single Entry Multiple Exit REGION (set of N_REGION basic
- blocks). The ENTRY edge is redirected to the duplicate of the region. If
- REGION is not a Single Entry region, ignore any incoming edges other than
- ENTRY: this makes the copied region a Single Entry region.
+/* Duplicates a jump-thread path of N_REGION basic blocks.
+ The ENTRY edge is redirected to the duplicate of the region.
Remove the last conditional statement in the last basic block in the REGION,
and create a single fallthru edge pointing to the same destination as the
@@ -1664,7 +1660,7 @@ verify_seme (edge entry, basic_block *region, unsigned n_region)
Returns false if it is unable to copy the region, true otherwise. */
static bool
-duplicate_seme_region (edge entry, edge exit,
+duplicate_thread_path (edge entry, edge exit,
basic_block *region, unsigned n_region,
basic_block *region_copy)
{
@@ -1726,7 +1722,53 @@ duplicate_seme_region (edge entry, edge exit,
}
copy_bbs (region, n_region, region_copy, &exit, 1, &exit_copy, loop,
- split_edge_bb_loc (entry), 0);
+ split_edge_bb_loc (entry), false);
+
+ /* Fix up: copy_bbs redirects all edges pointing to copied blocks. The
+ following code ensures that all the edges exiting the jump-thread path are
+ redirected back to the original code: these edges are exceptions
+ invalidating the property that is propagated by executing all the blocks of
+ the jump-thread path in order. */
+
+ for (i = 0; i < n_region; i++)
+ {
+ edge e;
+ edge_iterator ei;
+ basic_block bb = region_copy[i];
+
+ if (single_succ_p (bb))
+ {
+ /* Make sure the successor is the next node in the path. */
+ gcc_assert (i + 1 == n_region
+ || region_copy[i + 1] == single_succ_edge (bb)->dest);
+ continue;
+ }
+
+ /* Special case the last block on the path: make sure that it does not
+ jump back on the copied path. */
+ if (i + 1 == n_region)
+ {
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ if (bb_in_bbs (e->dest, region_copy, n_region - 1))
+ {
+ basic_block orig = get_bb_original (e->dest);
+ if (orig)
+ redirect_edge_and_branch_force (e, orig);
+ }
+ continue;
+ }
+
+ /* Redirect all other edges jumping to non-adjacent blocks back to the
+ original code. */
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ if (region_copy[i + 1] != e->dest)
+ {
+ basic_block orig = get_bb_original (e->dest);
+ if (orig)
+ redirect_edge_and_branch_force (e, orig);
+ }
+ }
+
if (total_count)
{
scale_bbs_frequencies_gcov_type (region, n_region,
@@ -1743,8 +1785,7 @@ duplicate_seme_region (edge entry, edge exit,
}
#ifdef ENABLE_CHECKING
- /* Make sure no edge other than ENTRY is entering the copied region. */
- verify_seme (entry, region_copy, n_region);
+ verify_jump_thread (region_copy, n_region);
#endif
/* Remove the last branch in the jump thread path. */
@@ -1849,7 +1890,7 @@ thread_through_all_blocks (bool may_peel_loop_headers)
for (unsigned int j = 0; j < len - 1; j++)
region[j] = (*path)[j]->e->dest;
- if (duplicate_seme_region (entry, exit, region, len - 1, NULL))
+ if (duplicate_thread_path (entry, exit, region, len - 1, NULL))
{
/* We do not update dominance info. */
free_dominance_info (CDI_DOMINATORS);