Re: [PATCH 3/6] ldbl-128ibm-compat: Redirect long double functions to f128/ieee128 functions

[Paul E Murphy <murphyp at linux dot ibm dot com>]

On 2/3/20 3:10 PM, Paul E. Murphy wrote:
> From: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
>
> Modify the headers to redirect long double functions to global __*f128
> symbols or to __*ieee128 otherwise.
>
> Most of the functions in math.h benefit from the infrastructure already
> available for __LDBL_COMPAT.  The only exceptions are nexttowardf and
> nexttoward that need especial treatment.
>
> Both math/bits/mathcalls-helper-functions.h and math/bits/mathcalls.h
> were modified in order to provide alternative redirection destinations
> that are essential to support functions that should not be redirected to
> the same name pattern of the rest of the functions, i.e.: __fpclassify,
> __signbit, __iseqsig, __issignaling, isinf, finite and isnan, which will
> be redirected to __*f128 instead of __*ieee128 used for the rest.
> ---
>   include/math.h                                |  9 ++-
>   math/bits/mathcalls-helper-functions.h        | 18 +++---
>   math/bits/mathcalls.h                         |  9 ++-
>   math/math.h                                   | 59 ++++++++++++++++++-
>   .../ieee754/ldbl-128ibm/bits/iscanonical.h    |  8 ++-
>   5 files changed, 85 insertions(+), 18 deletions(-)

I think the majority of this patch is OK.  My only contribution was to 
fixup against the deprecation of the finite entry points.

The naming of the nexttoward ABI is a bit awkward, but I proffer no 
better solutions.

If there are no requests for improvement, or objections, I will commit 
this and the following patch 4, the equivalent support for complex.h, on 
Friday.

> diff --git a/math/math.h b/math/math.h
> index e13b3f3a29..1692ff4a45 100644
> --- a/math/math.h
> +++ b/math/math.h
> @@ -283,6 +283,10 @@ enum
>     extern type __MATH_PRECNAME(function,suffix) args __THROW
>   #define __MATHDECL_1(type, function, suffix, args) \
>     __MATHDECL_1_IMPL(type, function, suffix, args)
> +/* Ignore the alias by default.  The alias is only useful with
> +   redirections.  */
> +#define __MATHDECL_ALIAS(type, function, suffix, args, alias) \
> +  __MATHDECL_1(type, function, suffix, args)
>
>   #define __MATHREDIR(type, function, suffix, args, to) \
>     extern type __REDIRECT_NTH (__MATH_PRECNAME (function, suffix), args, to)
> @@ -338,6 +342,35 @@ extern long double __REDIRECT_NTH (nexttowardl,
>   #   undef __MATHDECL_1
>   #   define __MATHDECL_1(type, function,suffix, args) \
>     __MATHREDIR(type, function, suffix, args, __CONCAT(function,suffix))
> +
> +#  elif __LONG_DOUBLE_USES_FLOAT128 == 1
> +#   ifdef __REDIRECT_NTH
> +#    ifdef __USE_ISOC99
> +extern float __REDIRECT_NTH (nexttowardf, (float __x, long double __y),
> +			    __nexttowardf_to_ieee128)
> +  __attribute__ ((__const__));
> +extern double __REDIRECT_NTH (nexttoward, (double __x, long double __y),
> +			     __nexttoward_to_ieee128)
> +  __attribute__ ((__const__));