From da89496337b97e6a2aaf1e81d55cf998f6db1070 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Wed, 31 Jan 2024 19:17:27 +0100 Subject: Use gcc __builtin_stdc_* builtins in stdbit.h if possible The following patch uses the GCC 14 __builtin_stdc_* builtins in stdbit.h for the type-generic macros, so that when compiled with GCC 14 or later, it supports not just 8/16/32/64-bit unsigned integers, but also 128-bit (if target supports them) and unsigned _BitInt (any supported precision). And so that the macros don't expand arguments multiple times and can be evaluated in constant expressions. The new testcase is gcc's gcc/testsuite/gcc.dg/builtin-stdc-bit-1.c adjusted to test stdbit.h and the type-generic macros in there instead of the builtins and adjusted to use glibc test framework rather than gcc style tests with __builtin_abort (). Signed-off-by: Jakub Jelinek Reviewed-by: Joseph Myers --- manual/stdbit.texi | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'manual') diff --git a/manual/stdbit.texi b/manual/stdbit.texi index fe41c671d8..8688930f12 100644 --- a/manual/stdbit.texi +++ b/manual/stdbit.texi @@ -32,7 +32,13 @@ and @code{unsigned long long int}. In addition, there is a corresponding type-generic macro (not listed below), named the same as the functions but without any suffix such as @samp{_uc}. The type-generic macro can only be used with an argument of an unsigned -integer type with a width of 8, 16, 32 or 64 bits. +integer type with a width of 8, 16, 32 or 64 bits, or when using +a compiler with support for +@uref{https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html@code{__builtin_stdc_bit_ceil}}, +etc.@:, built-in functions such as GCC 14.1 or later +any unsigned integer type those built-in functions support. +In GCC 14.1 that includes support for @code{unsigned __int128} and +@code{unsigned _BitInt(@var{n})} if supported by the target. @deftypefun {unsigned int} stdc_leading_zeros_uc (unsigned char @var{x}) @deftypefunx {unsigned int} stdc_leading_zeros_us (unsigned short @var{x}) -- cgit 1.4.1