[PATCH] D90113: [DAGCombiner] Fold BinOp into Select containing identity constant

Wed Oct 28 11:06:11 PDT 2020

laytonio added inline comments.

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Comment at: llvm/test/CodeGen/X86/binop-identity.ll:2
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=x86_64-pc-linux -x86-cmov-converter=true -verify-machineinstrs < %s | FileCheck %s
+
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RKSimon wrote:
> Maybe pre-commit these tests to trunk and rebase this patch to show the delta?
> 
> I'm not sure you need -verify-machineinstrs
> 
> We're going to need a binop-identity-vector.ll set of tests as well.
> We're going to need a binop-identity-vector.ll set of tests as well.

What vector widths do you think would be best for testing here? Should I do a left and right for each binop at say <4 x i32>, <8 x i32>, and <16 x i32> with SSE, AVX, and AVX512, or is that overkill?

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D90113/new/

https://reviews.llvm.org/D90113