From b959822c94e6d32b36fad038e79c14f841e585c1 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Mon, 17 Oct 2022 09:17:20 +1000 Subject: include/qemu/int128: Use Int128 structure for TCI MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We are about to allow passing Int128 to/from tcg helper functions, but libffi doesn't support __int128_t, so use the structure. In order for atomic128.h to continue working, we must provide a mechanism to frob between real __int128_t and the structure. Provide a new union, Int128Alias, for this. We cannot modify Int128 itself, as any changed alignment would also break libffi. Reviewed-by: Alex Bennée Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson --- include/qemu/int128.h | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) (limited to 'include/qemu/int128.h') diff --git a/include/qemu/int128.h b/include/qemu/int128.h index d2b76ca6ac..f62a46b48c 100644 --- a/include/qemu/int128.h +++ b/include/qemu/int128.h @@ -3,7 +3,12 @@ #include "qemu/bswap.h" -#ifdef CONFIG_INT128 +/* + * With TCI, we need to use libffi for interfacing with TCG helpers. + * But libffi does not support __int128_t, and therefore cannot pass + * or return values of this type, force use of the Int128 struct. + */ +#if defined(CONFIG_INT128) && !defined(CONFIG_TCG_INTERPRETER) typedef __int128_t Int128; static inline Int128 int128_make64(uint64_t a) @@ -460,8 +465,7 @@ Int128 int128_divu(Int128, Int128); Int128 int128_remu(Int128, Int128); Int128 int128_divs(Int128, Int128); Int128 int128_rems(Int128, Int128); - -#endif /* CONFIG_INT128 */ +#endif /* CONFIG_INT128 && !CONFIG_TCG_INTERPRETER */ static inline void bswap128s(Int128 *s) { @@ -472,4 +476,19 @@ static inline void bswap128s(Int128 *s) #define INT128_MAX int128_make128(UINT64_MAX, INT64_MAX) #define INT128_MIN int128_make128(0, INT64_MIN) +/* + * When compiler supports a 128-bit type, define a combination of + * a possible structure and the native types. Ease parameter passing + * via use of the transparent union extension. + */ +#ifdef CONFIG_INT128 +typedef union { + Int128 s; + __int128_t i; + __uint128_t u; +} Int128Alias __attribute__((transparent_union)); +#else +typedef Int128 Int128Alias; +#endif /* CONFIG_INT128 */ + #endif /* INT128_H */ -- cgit 1.4.1