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| author | Roman Lebedev <lebedev.ri@gmail.com> | 2021-05-11 19:35:41 +0300 |
|---|---|---|
| committer | Roman Lebedev <lebedev.ri@gmail.com> | 2021-05-11 19:39:41 +0300 |
| commit | 5f78ba001ca23ab826b9be823fc8ac0a0e5d2237 (patch) | |
| tree | af01c9b5cc0c673d6e478f0b296843003113bc9d /llvm/lib/TextAPI/Platform.cpp | |
| parent | dc00cbb5053895356955a6dc03632d4fa05048e3 (diff) | |
| download | llvm-5f78ba001ca23ab826b9be823fc8ac0a0e5d2237.zip llvm-5f78ba001ca23ab826b9be823fc8ac0a0e5d2237.tar.gz llvm-5f78ba001ca23ab826b9be823fc8ac0a0e5d2237.tar.bz2 | |
[X86][Codegen] Shift amount mod: sh? i64 x, (32-y) --> sh? i64 x, -(y+32)
I've seen this in the RawSpeed's BitPumpMSB*::push() hotpath,
after fixing the buffer abstraction to a more sane one,
when looking into a +5% runtime regression.
I was hoping that this would fix it, but it does not look it does.
This seems to be at least not worse than the original pattern.
But i'm actually mainly interested in the case where we already
compute `(y+32)` (see last test),
https://alive2.llvm.org/ce/z/ZCzJio
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D101944
Diffstat (limited to 'llvm/lib/TextAPI/Platform.cpp')
0 files changed, 0 insertions, 0 deletions