[PATCH] D118534: [X86] Introduce more common modern tunings into `generic`

[Andrea Di Biagio via Phabricator via llvm-commits]

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