[PATCH 3/7] ldbl-128ibm-compat: Add tests for IBM long double functions

[Joseph Myers]

On Fri, 14 Feb 2020, Paul E. Murphy wrote:

> diff --git a/math/test-float128.h b/math/test-float128.h
> index 8f9eec14aa..07945a090b 100644
> --- a/math/test-float128.h
> +++ b/math/test-float128.h
> @@ -28,7 +28,7 @@
>  #define CFLOAT __CFLOAT128
>  #define BUILD_COMPLEX(real, imag) (CMPLXF128 ((real), (imag)))
>  #define PREFIX FLT128
> -#if FLT128_MANT_DIG == LDBL_MANT_DIG
> +#if __LONG_DOUBLE_USES_FLOAT128 == 0 && FLT128_MANT_DIG == LDBL_MANT_DIG
>  # define TYPE_STR "ldouble"
>  # define ULP_IDX ULP_LDBL
>  # define ULP_I_IDX ULP_I_LDBL

This condition doesn't make sense to me, but it may be because 
__LONG_DOUBLE_USES_FLOAT128 is a badly named macro.  Could you please post 
a patch that adds a comment to the top-level bits/long-double.h that 
documents the detailed semantics of the __LONG_DOUBLE_USES_FLOAT128, and 
then we can consider whether that macro needs to be given a better name?

-- 
Joseph S. Myers
joseph@codesourcery.com