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diamonds are not valid execution threads for jump threading

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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.

From-SVN: r221675
This commit is contained in:
Sebastian Pop 2015-03-25 22:49:47 +00:00 • committed by Sebastian Pop
parent 9c8129f563
commit 71e3f77e8c
4 changed files with 107 additions and 29 deletions
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8
gcc/ChangeLog
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@ -1,3 +1,11 @@
2015-03-25 Sebastian Pop <s.pop@samsung.com>
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.
2015-03-25 Uros Bizjak <ubizjak@gmail.com>
PR bootstrap/65537

5
gcc/testsuite/ChangeLog
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@ -1,3 +1,8 @@
2015-03-25 Sebastian Pop <s.pop@samsung.com>
PR tree-optimization/65177
* gcc.dg/tree-ssa/ssa-dom-thread-10.c: New.
2015-03-25 Uros Bizjak <ubizjak@gmail.com>
* gcc.target/i386/sse-13.c: Include x86intrin.h and adjust #defines.

24
gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-10.c Normal file
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@ -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;
}
}

99
gcc/tree-ssa-threadupdate.c
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@ -2328,36 +2328,32 @@ 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);
for (unsigned i = 0; i < n_region; i++)
{
edge e;
edge_iterator ei;
basic_block bb = region[i];
/* 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));
}
BITMAP_FREE (bbs);
gcc_assert (EDGE_COUNT (region[i]->preds) <= 1);
}
/* 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.
/* Return true when BB is one of the first N items in BBS. */
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;
return false;
}
/* 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
@ -2369,7 +2365,7 @@ 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)
{
@ -2428,7 +2424,53 @@ 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,
@ -2445,8 +2487,7 @@ 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. */
@ -2550,7 +2591,7 @@ 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);