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PR for llvm/llvm-project#53592 #5

Merged
merged 2 commits into from
Feb 7, 2022
Merged

PR for llvm/llvm-project#53592 #5

merged 2 commits into from
Feb 7, 2022

Commits on Feb 5, 2022

  1. [x86] add test coverage for AMD Ryzen fast sqrt codegen; NFC 

    (cherry picked from commit 1eb4f88)
    @rotateright @llvmbot
    rotateright authored and llvmbot committed Feb 5, 2022
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  2. [x86] enable fast sqrtss/sqrtps tuning for AMD Zen cores 

    As discussed in D118534, all of the recent AMD CPUs have
relatively fast (<14 cycle latency) "sqrtss" and "sqrtps"
instructions:
https://uops.info/table.html?search=sqrtps&cb_lat=on&cb_tp=on&cb_SNB=on&cb_SKL=on&cb_ZENp=on&cb_ZEN2=on&cb_ZEN3=on&cb_measurements=on&cb_avx=on&cb_sse=on

So we should set this tuning flag to alter codegen of plain
"sqrt(X)" expansion (as opposed to reciprocal-sqrt - there
is other test coverage for that pattern). The expansion is
both slower and less accurate than the hardware instruction.

Differential Revision: https://reviews.llvm.org/D119001

(cherry picked from commit fff3e1d)
    @rotateright @llvmbot
    rotateright authored and llvmbot committed Feb 5, 2022
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