[Bug target/121591] x86 optimization: isless doesn't reuse EFLAGS result of other floating point comparisons with same operands

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121591

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2025-08-18
           Keywords|                            |missed-optimization

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Interesting LLVM does it do it either.

Simplified testcase:
```
int float_compare(double a, double b) {
    if (__builtin_isless(a, b))
        return 1;
    if (__builtin_isgreater(a, b))
        return 3;
  return 0;
}
```