[llvm-bugs] [Bug 47406] New: [X86][SSE] Incorrect domain register move to XMM0 for BLENDV instructons

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=47406

            Bug ID: 47406
           Summary: [X86][SSE] Incorrect domain register move to XMM0 for
                    BLENDV instructons
           Product: libraries
           Version: trunk
          Hardware: PC
                OS: Windows NT
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: Backend: X86
          Assignee: unassignedbugs at nondot.org
          Reporter: llvm-dev at redking.me.uk
                CC: craig.topper at gmail.com, llvm-bugs at lists.llvm.org,
                    llvm-dev at redking.me.uk, spatel+llvm at rotateright.com

The SSE variants of PBLENDVB/BLENDVPD must move the condition mask to XMM0, but
the move instruction that is used is always MOVAPS, not MOVDQA/MOVAPD.

https://simd.godbolt.org/z/Tdx169

define <16 x i8> @blend_slt_v16i8(<16 x i8> %0, <16 x i8> %1, <16 x i8> %2) {
  %4 = icmp slt <16 x i8> %2, zeroinitializer
  %5 = select <16 x i1> %4, <16 x i8> %1, <16 x i8> %0
  ret <16 x i8> %5
}

define <4 x float> @blend_slt_v4f32(<4 x float> %0, <4 x float> %1, <4 x i32>
%2) {
  %4 = icmp slt <4 x i32> %2, zeroinitializer
  %5 = select <4 x i1> %4, <4 x float> %1, <4 x float> %0
  ret <4 x float> %5
}

define <2 x double> @blend_slt_v2f64(<2 x double> %0, <2 x double> %1, <2 x
i64> %2) {
  %4 = icmp slt <2 x i64> %2, zeroinitializer
  %5 = select <2 x i1> %4, <2 x double> %1, <2 x double> %0
  ret <2 x double> %5
}

llc -mattr=+sse4.1

blend_slt_v16i8:                        # @blend_slt_v16i8
        movdqa  %xmm0, %xmm3
        movaps  %xmm2, %xmm0
        pblendvb        %xmm0, %xmm1, %xmm3
        movdqa  %xmm3, %xmm0
        retq
blend_slt_v4f32:                        # @blend_slt_v4f32
        movaps  %xmm0, %xmm3
        movaps  %xmm2, %xmm0
        blendvps        %xmm0, %xmm1, %xmm3
        movaps  %xmm3, %xmm0
        retq
blend_slt_v2f64:                        # @blend_slt_v2f64
        movapd  %xmm0, %xmm3
        movaps  %xmm2, %xmm0
        blendvpd        %xmm0, %xmm1, %xmm3
        movapd  %xmm3, %xmm0
        retq

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