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| author | Richard Biener <rguenther@suse.de> | 2016-02-24 12:03:27 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2016-02-24 12:03:27 +0000 |
| commit | e53d562a36ead2279b98bc7cde3abe9606b44ee2 (patch) | |
| tree | 5cd461c7bd1554cfa9a6aa0662f753d76e4bb68a /gcc/tree-ssa-loop-niter.c | |
| parent | debc68edb4df2357589427fe90ea894467c7b2e2 (diff) | |
| download | gcc-e53d562a36ead2279b98bc7cde3abe9606b44ee2.zip gcc-e53d562a36ead2279b98bc7cde3abe9606b44ee2.tar.gz gcc-e53d562a36ead2279b98bc7cde3abe9606b44ee2.tar.bz2 | |
re PR tree-optimization/68963 (O3 vs. O2 discards part of loop and terminates early)
2016-02-24 Richard Biener <rguenther@suse.de>
PR middle-end/68963
* tree-ssa-loop-niter.c (derive_constant_upper_bound_ops): Fix
bogus check.
(record_nonwrapping_iv): Do not fall back to the low/high bound
for non-constant IV bases if the stmt is not always executed.
* gcc.dg/torture/pr68963.c: New testcase.
From-SVN: r233660
Diffstat (limited to 'gcc/tree-ssa-loop-niter.c')
| -rw-r--r-- | gcc/tree-ssa-loop-niter.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c index fbeeb9d..43632ed 100644 --- a/gcc/tree-ssa-loop-niter.c +++ b/gcc/tree-ssa-loop-niter.c @@ -2757,7 +2757,7 @@ derive_constant_upper_bound_ops (tree type, tree op0, enum tree_code code, tree op1) { tree subtype, maxt; - widest_int bnd, max, mmax, cst; + widest_int bnd, max, cst; gimple *stmt; if (INTEGRAL_TYPE_P (type)) @@ -2823,8 +2823,8 @@ derive_constant_upper_bound_ops (tree type, tree op0, /* OP0 + CST. We need to check that BND <= MAX (type) - CST. */ - mmax -= cst; - if (wi::ltu_p (bnd, max)) + widest_int mmax = max - cst; + if (wi::leu_p (bnd, mmax)) return max; return bnd + cst; @@ -3065,7 +3065,9 @@ record_nonwrapping_iv (struct loop *loop, tree base, tree step, gimple *stmt, && get_range_info (orig_base, &min, &max) == VR_RANGE && wi::gts_p (high, max)) base = wide_int_to_tree (unsigned_type, max); - else if (TREE_CODE (base) != INTEGER_CST) + else if (TREE_CODE (base) != INTEGER_CST + && dominated_by_p (CDI_DOMINATORS, + loop->latch, gimple_bb (stmt))) base = fold_convert (unsigned_type, high); delta = fold_build2 (MINUS_EXPR, unsigned_type, base, extreme); step = fold_build1 (NEGATE_EXPR, unsigned_type, step); @@ -3080,7 +3082,9 @@ record_nonwrapping_iv (struct loop *loop, tree base, tree step, gimple *stmt, && get_range_info (orig_base, &min, &max) == VR_RANGE && wi::gts_p (min, low)) base = wide_int_to_tree (unsigned_type, min); - else if (TREE_CODE (base) != INTEGER_CST) + else if (TREE_CODE (base) != INTEGER_CST + && dominated_by_p (CDI_DOMINATORS, + loop->latch, gimple_bb (stmt))) base = fold_convert (unsigned_type, low); delta = fold_build2 (MINUS_EXPR, unsigned_type, extreme, base); } |