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| author | Sanjay Patel <spatel@rotateright.com> | 2021-08-17 07:31:05 -0400 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2021-08-17 08:10:42 -0400 |
| commit | d0975b7cb0e184e8e5f3975183c51937dfa4043a (patch) | |
| tree | a0497d4a1ad975d4618c57c41815a340f6123252 /llvm/lib/Bitcode/Writer/BitcodeWriter.cpp | |
| parent | 8fb269d94075c70b676ff8b7c8baf695cc66c74f (diff) | |
| download | llvm-d0975b7cb0e184e8e5f3975183c51937dfa4043a.zip llvm-d0975b7cb0e184e8e5f3975183c51937dfa4043a.tar.gz llvm-d0975b7cb0e184e8e5f3975183c51937dfa4043a.tar.bz2 | |
[InstCombine] fold signed min/max intrinsics with negated operands
If both operands are negated, we can invert the min/max and do
the negation after:
smax (neg nsw X), (neg nsw Y) --> neg nsw (smin X, Y)
smin (neg nsw X), (neg nsw Y) --> neg nsw (smax X, Y)
This is visible as a remaining regression in D98152. I don't see
a way to generalize this for 'unsigned' or adapt Negator to
handle it. This only appears to be safe with 'nsw':
https://alive2.llvm.org/ce/z/GUy1zJ
Differential Revision: https://reviews.llvm.org/D108165
Diffstat (limited to 'llvm/lib/Bitcode/Writer/BitcodeWriter.cpp')
0 files changed, 0 insertions, 0 deletions