[llvm-bugs] [Bug 27340] New: [X86] AVX1 targets failure to use PABS* instructions with 256-bit inputs

[via llvm-bugs]

https://llvm.org/bugs/show_bug.cgi?id=27340

            Bug ID: 27340
           Summary: [X86] AVX1 targets failure to use PABS* instructions
                    with 256-bit inputs
           Product: libraries
           Version: trunk
          Hardware: PC
                OS: Windows NT
            Status: NEW
          Severity: normal
          Priority: P
         Component: Backend: X86
          Assignee: unassignedbugs at nondot.org
          Reporter: llvm-dev at redking.me.uk
                CC: llvm-bugs at lists.llvm.org, spatel+llvm at rotateright.com
    Classification: Unclassified

llvm\test\CodeGen\X86\viabs.ll

define <8 x i32> @test6(<8 x i32> %a) nounwind {
; AVX1-LABEL: test6:
; AVX1:       # BB#0:
; AVX1-NEXT:    vextractf128 $1, %ymm0, %xmm1
; AVX1-NEXT:    vpsrad $31, %xmm1, %xmm2
; AVX1-NEXT:    vpaddd %xmm2, %xmm1, %xmm1
; AVX1-NEXT:    vpsrad $31, %xmm0, %xmm3
; AVX1-NEXT:    vpaddd %xmm3, %xmm0, %xmm0
; AVX1-NEXT:    vinsertf128 $1, %xmm1, %ymm0, %ymm0
; AVX1-NEXT:    vinsertf128 $1, %xmm2, %ymm3, %ymm1
; AVX1-NEXT:    vxorps %ymm1, %ymm0, %ymm0
; AVX1-NEXT:    retq
;
; AVX2-LABEL: test6:
; AVX2:       # BB#0:
; AVX2-NEXT:    vpabsd %ymm0, %ymm0
; AVX2-NEXT:    retq
  %tmp1neg = sub <8 x i32> zeroinitializer, %a
  %b = icmp sgt <8 x i32> %a, <i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1,
i32 -1, i32 -1>
  %abs = select <8 x i1> %b, <8 x i32> %a, <8 x i32> %tmp1neg
  ret <8 x i32> %abs
}

I'd expect the AVX1 target to be something like:
; AVX1-NEXT:    vextractf128 $1, %ymm0, %xmm1
; AVX1-NEXT:    vpabsd %xmm0, %xmm0
; AVX1-NEXT:    vpabsd %xmm1, %xmm1
; AVX1-NEXT:    vinsertf128 $1, %xmm1, %ymm0, %ymm0
; AVX1-NEXT:    retq

Same for 32i8 / 16i16 cases.

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