[PATCH] D118534: [X86] Introduce more common modern tunings into `generic`
Andrea Di Biagio via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Mon Jan 31 03:53:14 PST 2022
andreadb added inline comments.
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Comment at: llvm/lib/Target/X86/X86.td:1220
+ TuningFastScalarFSQRT,
+ TuningFastSHLDRotate,
+ TuningFast15ByteNOP,
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In my experience, SHLD is rarely fast on AMD processors.
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Comment at: llvm/lib/Target/X86/X86.td:1222-1223
+ TuningFast15ByteNOP,
+ TuningPOPCNTFalseDeps,
+ TuningLZCNTFalseDeps,
TuningInsertVZEROUPPER]>;
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These two tuning flags are very Intel specific.
I am not convinced that these should be added for "generic".
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Comment at: llvm/test/tools/llvm-mca/X86/cv_fpo_directive_no_segfault.s:2
# NOTE: Assertions have been autogenerated by utils/update_mca_test_checks.py
-# RUN: llvm-mca -mtriple=x86_64-unknown-unknown -mcpu=generic -resource-pressure=false -instruction-info=false < %s | FileCheck %s
+# RUN: llvm-mca -mtriple=x86_64-unknown-unknown -mcpu=x86-64 -resource-pressure=false -instruction-info=false < %s | FileCheck %s
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RKSimon wrote:
> @andreadb what test coverage do we need here?
I believe the test was just checking that llvm-mca didn't crash when parsing unknown asm directives.
So the output here is not really important. It is fine to change the mcpu to something else other than generic.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D118534/new/
https://reviews.llvm.org/D118534
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