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| author | Sanjay Patel <spatel@rotateright.com> | 2018-11-04 14:28:48 +0000 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2018-11-04 14:28:48 +0000 |
| commit | e7c94ef1debe790ab90833cf72e21b584651db16 (patch) | |
| tree | 4dd1c912d2c692254888d07117d0c2730d214894 /clang/lib/Lex/ModuleMap.cpp | |
| parent | d96bdd2402d5f1477a92b679909d99c37172f868 (diff) | |
| download | llvm-e7c94ef1debe790ab90833cf72e21b584651db16.zip llvm-e7c94ef1debe790ab90833cf72e21b584651db16.tar.gz llvm-e7c94ef1debe790ab90833cf72e21b584651db16.tar.bz2 | |
[ValueTracking] determine sign of 0.0 from select when matching min/max FP
In PR39475:
https://bugs.llvm.org/show_bug.cgi?id=39475
..we may fail to recognize/simplify fabs() in some cases because we do not
canonicalize fcmp with a -0.0 operand.
Adding that canonicalization can cause regressions on min/max FP tests, so
that's this patch: for the purpose of determining whether something is min/max,
let the value returned by the select determine how we treat a 0.0 operand in the fcmp.
This patch doesn't actually change the -0.0 to +0.0. It just changes the analysis, so
we don't fail to recognize equivalent min/max patterns that only differ in the
signbit of 0.0.
Differential Revision: https://reviews.llvm.org/D54001
llvm-svn: 346097
Diffstat (limited to 'clang/lib/Lex/ModuleMap.cpp')
0 files changed, 0 insertions, 0 deletions