[Bug middle-end/116891] invalid optimization of -fma(-x,y,-z) when -03 and -frounding-math are used

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116891

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING
          Component|c++                         |middle-end
   Last reconfirmed|                            |2024-09-30
     Ever confirmed|0                           |1

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I tried:
```
#include <cmath>

double bad_fma( double y, double z, double w) { 
   return std::fma( -y, z, -w );
}
```

and it produces with `-O3 -frounding-math -mfma`:
```
_Z7bad_fmaddd:
        .cfi_startproc
        vfnmsub132sd    %xmm1, %xmm2, %xmm0     # tmp104, tmp105, <retval>
        ret     
```

https://godbolt.org/z/fzs1cso3P


Can you provide the preprocessed source you are using and/or even the full
testcase including what headers you are using and what exact options you used?