[llvm-bugs] [Bug 39474] New: Failure to simplify abs(select(-x, +x, cond)) -> abs(x)

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=39474

            Bug ID: 39474
           Summary: Failure to simplify abs(select(-x,+x,cond)) -> abs(x)
           Product: libraries
           Version: trunk
          Hardware: PC
                OS: Windows NT
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: Common Code Generator Code
          Assignee: unassignedbugs at nondot.org
          Reporter: llvm-dev at redking.me.uk
                CC: filcab at gmail.com, llvm-bugs at lists.llvm.org,
                    spatel+llvm at rotateright.com, tilkax at gmail.com

https://godbolt.org/z/IiYvRv

#include <algorithm>

int abs_s32(bool b, int x)
{
    return std::abs(b ? -x : x);
}

float abs_f32(bool b, float x)
{
    return std::abs(b ? -x : x);
}

_Z7abs_s32bi: # @_Z7abs_s32bi
  movl %esi, %ecx
  negl %ecx
  testl %edi, %edi
  cmovel %esi, %ecx
  movl %ecx, %eax
  negl %eax
  cmovll %ecx, %eax
  retq


_Z7abs_f32bf: # @_Z7abs_f32bf
  testl %edi, %edi
  je .LBB1_2
  xorps .LCPI1_0(%rip), %xmm0
.LBB1_2:
  andps .LCPI1_1(%rip), %xmm0
  retq

gcc manages to optimize both:

_Z7abs_s32bi:
  movl %esi, %eax
  cltd
  xorl %edx, %eax
  subl %edx, %eax
  ret

_Z7abs_f32bf:
  andps .LC0(%rip), %xmm0
  ret

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