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author | Richard Henderson <richard.henderson@linaro.org> | 2022-11-05 11:34:58 +0000 |
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committer | Richard Henderson <richard.henderson@linaro.org> | 2023-05-16 15:21:39 -0700 |
commit | e61f1efeb730fd64441131ea721086065904ff67 (patch) | |
tree | c1c902b988700c06782fb573239a6cff0c0d3646 /accel/tcg | |
parent | 35c653c4029794f67a523191941104fe12f2b22d (diff) | |
download | qemu-e61f1efeb730fd64441131ea721086065904ff67.zip qemu-e61f1efeb730fd64441131ea721086065904ff67.tar.gz qemu-e61f1efeb730fd64441131ea721086065904ff67.tar.bz2 |
meson: Detect atomic128 support with optimization
There is an edge condition prior to gcc13 for which optimization
is required to generate 16-byte atomic sequences. Detect this.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'accel/tcg')
-rw-r--r-- | accel/tcg/ldst_atomicity.c.inc | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/accel/tcg/ldst_atomicity.c.inc b/accel/tcg/ldst_atomicity.c.inc index ce73b32..ba5db7c 100644 --- a/accel/tcg/ldst_atomicity.c.inc +++ b/accel/tcg/ldst_atomicity.c.inc @@ -16,6 +16,23 @@ #endif #define HAVE_al8_fast (ATOMIC_REG_SIZE >= 8) +/* + * If __alignof(unsigned __int128) < 16, GCC may refuse to inline atomics + * that are supported by the host, e.g. s390x. We can force the pointer to + * have our known alignment with __builtin_assume_aligned, however prior to + * GCC 13 that was only reliable with optimization enabled. See + * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107389 + */ +#if defined(CONFIG_ATOMIC128_OPT) +# if !defined(__OPTIMIZE__) +# define ATTRIBUTE_ATOMIC128_OPT __attribute__((optimize("O1"))) +# endif +# define CONFIG_ATOMIC128 +#endif +#ifndef ATTRIBUTE_ATOMIC128_OPT +# define ATTRIBUTE_ATOMIC128_OPT +#endif + #if defined(CONFIG_ATOMIC128) # define HAVE_al16_fast true #else @@ -152,7 +169,8 @@ static inline uint64_t load_atomic8(void *pv) * * Atomically load 16 aligned bytes from @pv. */ -static inline Int128 load_atomic16(void *pv) +static inline Int128 ATTRIBUTE_ATOMIC128_OPT +load_atomic16(void *pv) { #ifdef CONFIG_ATOMIC128 __uint128_t *p = __builtin_assume_aligned(pv, 16); @@ -356,7 +374,8 @@ static uint64_t load_atom_extract_al16_or_exit(CPUArchState *env, uintptr_t ra, * cross an 16-byte boundary then the access must be 16-byte atomic, * otherwise the access must be 8-byte atomic. */ -static inline uint64_t load_atom_extract_al16_or_al8(void *pv, int s) +static inline uint64_t ATTRIBUTE_ATOMIC128_OPT +load_atom_extract_al16_or_al8(void *pv, int s) { #if defined(CONFIG_ATOMIC128) uintptr_t pi = (uintptr_t)pv; @@ -692,7 +711,8 @@ static inline void store_atomic8(void *pv, uint64_t val) * * Atomically store 16 aligned bytes to @pv. */ -static inline void store_atomic16(void *pv, Int128Alias val) +static inline void ATTRIBUTE_ATOMIC128_OPT +store_atomic16(void *pv, Int128Alias val) { #if defined(CONFIG_ATOMIC128) __uint128_t *pu = __builtin_assume_aligned(pv, 16); @@ -790,7 +810,8 @@ static void store_atom_insert_al8(uint64_t *p, uint64_t val, uint64_t msk) * * Atomically store @val to @p masked by @msk. */ -static void store_atom_insert_al16(Int128 *ps, Int128Alias val, Int128Alias msk) +static void ATTRIBUTE_ATOMIC128_OPT +store_atom_insert_al16(Int128 *ps, Int128Alias val, Int128Alias msk) { #if defined(CONFIG_ATOMIC128) __uint128_t *pu, old, new; |