[libc-commits] [libc] [libc][math] Implement double precision acos correctly rounded for all rounding modes. (PR #138308)

[via libc-commits]

zimmermann6 wrote:

I still get failures:
```
zimmerma at biscotte:~/svn/core-math$ CORE_MATH_CHECK_STD=true LIBM=/localdisk/zimmerma/llvm-project/build/projects/libc/lib/libllvmlibc.a EXTRA_CFLAGS="-DCORE_MATH_SUPPORT_ERRNO -DCORE_MATH_CHECK_INEXACT" ./check.sh acos
Running worst cases check in --rndn mode...
FAIL x=-0x1.cb3b399d747f4p-55 ref=0x1.921fb54442d19p+0 z=0x1.921fb54442d18p+0
```


https://github.com/llvm/llvm-project/pull/138308