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| author | Richard Biener <rguenther@suse.de> | 2018-04-20 10:31:23 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2018-04-20 10:31:23 +0000 |
| commit | b46ebc6c45d7a74ec18a0644f8b4e3c66ea84fb8 (patch) | |
| tree | 0a6e7898b15bef90b476597b6234e27d96c2db2b /gcc/match.pd | |
| parent | 2f1f3ac43828d7c9b8899f23683bf6b88066fc4a (diff) | |
| download | gcc-b46ebc6c45d7a74ec18a0644f8b4e3c66ea84fb8.zip gcc-b46ebc6c45d7a74ec18a0644f8b4e3c66ea84fb8.tar.gz gcc-b46ebc6c45d7a74ec18a0644f8b4e3c66ea84fb8.tar.bz2 | |
re PR tree-optimization/85475 (Compile time hog w/ -O1 -fpeel-loops)
2018-04-20 Richard Biener <rguenther@suse.de>
PR middle-end/85475
* match.pd ((X * CST) * Y -> (X * Y) * CST): Avoid exponential
complexity by forcing a single use of the multiply operand.
* gcc.dg/torture/pr85475.c: New testcase.
From-SVN: r259519
Diffstat (limited to 'gcc/match.pd')
| -rw-r--r-- | gcc/match.pd | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/gcc/match.pd b/gcc/match.pd index 442aad1..0de4432 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -2578,8 +2578,9 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) /* Reassociate (X * CST) * Y to (X * Y) * CST. This does not introduce signed overflow for CST != 0 && CST != -1. */ (simplify - (mult:c (mult:s @0 INTEGER_CST@1) @2) + (mult:c (mult:s@3 @0 INTEGER_CST@1) @2) (if (TREE_CODE (@2) != INTEGER_CST + && single_use (@3) && !integer_zerop (@1) && !integer_minus_onep (@1)) (mult (mult @0 @2) @1))) |