[PATCH] D61806: [DAGCombiner] try to move bitcast after extract_subvector

[Sanjay Patel via Phabricator via llvm-commits]

spatel marked an inline comment as done.
spatel added inline comments.


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Comment at: llvm/test/CodeGen/X86/sad.ll:1452
 ; AVX2-NEXT:    vmovd %xmm0, %eax
 ; AVX2-NEXT:    vzeroupper
 ; AVX2-NEXT:    retq
----------------
RKSimon wrote:
> weird - if this is all xmm code now why hasn't the vzeroupper gone?
There seem to be several potential missed opportunities to squash this, but we have the following heading into isel:
          t142: v4i32 = scalar_to_vector Constant:i32<1>
        t143: v8i32 = insert_subvector undef:v8i32, t142, Constant:i64<0>
      t141: v8i32 = X86ISD::VZEXT_MOVL t143
    t178: v4i32 = extract_subvector t141, Constant:i64<0>



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  https://reviews.llvm.org/D61806/new/

https://reviews.llvm.org/D61806