Skip to content
Unverified Commit 5f78ba00 authored by Roman Lebedev's avatar Roman Lebedev
Browse files

[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
parent dc00cbb5
Loading
Loading
Loading
Loading
0% Loading or .
You are about to add 0 people to the discussion. Proceed with caution.
Please to comment