Re: [PATCH v6] Added Redirects to longdouble error functions [BZ #29033]

[Paul E Murphy <murphyp@linux.ibm.com>]

On 4/17/23 6:04 AM, Sachin Monga via Libc-alpha wrote:
> This patch redirects the error functions to the appropriate
> longdouble variants which enables the compiler to optimize
> for the abi ieeelongdouble.
> 
> Signed-off-by: Sachin Monga <smonga@linux.ibm.com>


> diff --git a/misc/tst-ldbl-errorfptr.c b/misc/tst-ldbl-errorfptr.c
> new file mode 100644
> index 0000000000..e11575b6a5
> --- /dev/null
> +++ b/misc/tst-ldbl-errorfptr.c
...
> +#define NLDBL_SYMBOL2(alias) __ASMNAME (#alias)
> +#define NLDBL_SYMBOL(alias) NLDBL_SYMBOL2 (__nldbl_##alias)
> +#define IEEE_LONG_DOUBLE(alias) __ASMNAME ("__" #alias "ieee128")
> +#define NO_LONG_DOUBLE(alias) NLDBL_SYMBOL (alias)
> +#define DEFAULT_SYMBOL(alias) NLDBL_SYMBOL2 (alias)

I think the above can be further simplified (see comment below).


> +#if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1
> +  error_sym = (char *) IEEE_LONG_DOUBLE(error);
> +  error_sym_at_line = (char *) IEEE_LONG_DOUBLE(error_at_line);
> +#elif defined __LONG_DOUBLE_MATH_OPTIONAL && defined __NO_LONG_DOUBLE_MATH
> +  error_sym = (char *) NO_LONG_DOUBLE(error);
> +  error_sym_at_line = (char *) NO_LONG_DOUBLE(error_at_line);
> +#else
> +  error_sym = (char *) DEFAULT_SYMBOL(error);
> +  error_sym_at_line = (char *) DEFAULT_SYMBOL(error_at_line);
> +#endif

Can the if/elif/else be consolidated into one? I think a more simple 
macro can be used to configure the expected names of the potentially 
redirected function. e.x

#if redirect_to_f128
# define LDBL_NAME(x) "__" #x "ieee128"
#else redirect_to_double
# define LDBL_NAME(x) "__nldbl_" #x
#else
# define LDBL_NAME(x) #x
#endif

Otherwise, this LGTM.