[llvm-bugs] [Bug 27145] New: IR for isfinite() could be improved?

[via llvm-bugs]

https://llvm.org/bugs/show_bug.cgi?id=27145

            Bug ID: 27145
           Summary: IR for isfinite() could be improved?
           Product: libraries
           Version: trunk
          Hardware: PC
                OS: All
            Status: NEW
          Severity: normal
          Priority: P
         Component: Transformation Utilities
          Assignee: unassignedbugs at nondot.org
          Reporter: spatel+llvm at rotateright.com
                CC: llvm-bugs at lists.llvm.org
    Classification: Unclassified

#include <math.h>
#include <stdbool.h>

bool foo(float x) { return isfinite(x); }

$ ./clang -O1 isnan.c -S -o -  -emit-llvm
...
define zeroext i1 @foo(float %x) #0 {
entry:
  %cmp.i = fcmp ord float %x, 0.000000e+00
  %0 = tail call float @llvm.fabs.f32(float %x) #2
  %cmp1.i = fcmp une float %0, 0x7FF0000000000000
  %1 = and i1 %cmp.i, %cmp1.i
  ret i1 %1
}


Can't we use 'fcmp one' here to eliminate the first compare?
"one: ordered and not equal"

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