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| author | Richard Biener <rguenther@suse.de> | 2014-12-01 13:13:28 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2014-12-01 13:13:28 +0000 |
| commit | c306cfafefeb6e7b224cff163222c02f8def25f1 (patch) | |
| tree | d3ea17e09a1dfa1353724c654fefbb3c07efba1a /gcc/match.pd | |
| parent | e19740aef3f3c7c07c67e59560ef96e31e9bff96 (diff) | |
| download | gcc-c306cfafefeb6e7b224cff163222c02f8def25f1.zip gcc-c306cfafefeb6e7b224cff163222c02f8def25f1.tar.gz gcc-c306cfafefeb6e7b224cff163222c02f8def25f1.tar.bz2 | |
re PR tree-optimization/15346 ([tree-ssa] combine two successive divisions)
2014-12-01 Richard Biener <rguenther@suse.de>
PR tree-optimization/15346
* Makefile.in (gimple-match.o-warn): Remove -Wno-unused-parameter,
add -Wno-unused-but-set-variable.
* match.pd: Combine two successive divisions.
* gcc.dg/tree-ssa/forwprop-32.c: New testcase.
From-SVN: r218211
Diffstat (limited to 'gcc/match.pd')
| -rw-r--r-- | gcc/match.pd | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/gcc/match.pd b/gcc/match.pd index 42e7c62..ee9bbc6 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -129,6 +129,19 @@ along with GCC; see the file COPYING3. If not see && TYPE_UNSIGNED (type)) (trunc_div @0 @1))) +/* Combine two successive divisions. */ +(for div (trunc_div ceil_div floor_div round_div exact_div) + (simplify + (div (div @0 INTEGER_CST@1) INTEGER_CST@2) + (with { + bool overflow_p; + wide_int mul = wi::mul (@1, @2, TYPE_SIGN (type), &overflow_p); + } + (if (!overflow_p) + (div @0 { wide_int_to_tree (type, mul); })) + (if (overflow_p) + { build_zero_cst (type); })))) + /* Optimize A / A to 1.0 if we don't care about NaNs or Infinities. */ (simplify |