diff options
| author | Bin Cheng <bin.cheng@arm.com> | 2016-08-09 15:08:02 +0000 |
|---|---|---|
| committer | Bin Cheng <amker@gcc.gnu.org> | 2016-08-09 15:08:02 +0000 |
| commit | 42970a179d71e59c317440d0567b003681e915ba (patch) | |
| tree | e2dec7e06bcb0dea52cd1cba64b1dc05f6b884da /gcc/tree-ssa-loop-niter.c | |
| parent | 8aa46dd2d5808a951afee6c6322615225f298d6a (diff) | |
re PR tree-optimization/72772 (Missed SCEV after pass reordering@236440)
PR tree-optimization/72772
* tree-ssa-loop-niter.c (loop_exits_before_overflow): Check equality
for expanded base.
gcc/testsuite
PR tree-optimization/pr72772
* gcc.dg/tree-ssa/pr72772.c: New test.
From-SVN: r239291
Diffstat (limited to 'gcc/tree-ssa-loop-niter.c')
| -rw-r--r-- | gcc/tree-ssa-loop-niter.c | 23 |
1 files changed, 15 insertions, 8 deletions
diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c index a34672afd24..a50d2b4b43e 100644 --- a/gcc/tree-ssa-loop-niter.c +++ b/gcc/tree-ssa-loop-niter.c @@ -4214,7 +4214,7 @@ loop_exits_before_overflow (tree base, tree step, for (civ = loop->control_ivs; civ; civ = civ->next) { enum tree_code code; - tree stepped, extreme, civ_type = TREE_TYPE (civ->step); + tree civ_type = TREE_TYPE (civ->step); /* Have to consider type difference because operand_equal_p ignores that for constants. */ @@ -4227,11 +4227,13 @@ loop_exits_before_overflow (tree base, tree step, continue; /* Done proving if this is a no-overflow control IV. */ - if (operand_equal_p (base, civ->base, 0) - /* Control IV is recorded after expanding simple operations, - Here we compare it against expanded base too. */ - || operand_equal_p (expand_simple_operations (base), - civ->base, 0)) + if (operand_equal_p (base, civ->base, 0)) + return true; + + /* Control IV is recorded after expanding simple operations, + Here we expand base and compare it too. */ + tree expanded_base = expand_simple_operations (base); + if (operand_equal_p (expanded_base, civ->base, 0)) return true; /* If this is a before stepping control IV, in other words, we have @@ -4253,9 +4255,14 @@ loop_exits_before_overflow (tree base, tree step, else code = PLUS_EXPR; - stepped = fold_build2 (code, TREE_TYPE (base), base, step); - if (operand_equal_p (stepped, civ->base, 0)) + tree stepped = fold_build2 (code, TREE_TYPE (base), base, step); + tree expanded_stepped = fold_build2 (code, TREE_TYPE (base), + expanded_base, step); + if (operand_equal_p (stepped, civ->base, 0) + || operand_equal_p (expanded_stepped, civ->base, 0)) { + tree extreme; + if (tree_int_cst_sign_bit (step)) { code = LT_EXPR; |