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| author | Wilco Dijkstra <wilco.dijkstra@arm.com> | 2023-11-10 14:06:50 +0000 |
|---|---|---|
| committer | Wilco Dijkstra <wilco.dijkstra@arm.com> | 2023-11-10 14:19:59 +0000 |
| commit | f880bdc2716d59530949c9c03e4b759c6398c4e4 (patch) | |
| tree | ec78827c7a191576fe5d674fb5489482b086b7de /libatomic | |
| parent | 6aaf72ff533550dad68362e8da308b480a9e0f30 (diff) | |
| download | gcc-f880bdc2716d59530949c9c03e4b759c6398c4e4.zip gcc-f880bdc2716d59530949c9c03e4b759c6398c4e4.tar.gz gcc-f880bdc2716d59530949c9c03e4b759c6398c4e4.tar.bz2 | |
libatomic: Improve ifunc selection on AArch64
Add support for ifunc selection based on CPUID register. Neoverse N1 supports
atomic 128-bit load/store, so use the FEAT_USCAT ifunc like newer Neoverse
cores.
Reviewed-by: Kyrylo.Tkachov@arm.com
libatomic:
* config/linux/aarch64/host-config.h (ifunc1): Use CPUID in ifunc
selection.
Diffstat (limited to 'libatomic')
| -rw-r--r-- | libatomic/config/linux/aarch64/host-config.h | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/libatomic/config/linux/aarch64/host-config.h b/libatomic/config/linux/aarch64/host-config.h index bea2682..9747acc 100644 --- a/libatomic/config/linux/aarch64/host-config.h +++ b/libatomic/config/linux/aarch64/host-config.h @@ -26,7 +26,7 @@ #ifdef HWCAP_USCAT # if N == 16 -# define IFUNC_COND_1 (hwcap & HWCAP_USCAT) +# define IFUNC_COND_1 ifunc1 (hwcap) # else # define IFUNC_COND_1 (hwcap & HWCAP_ATOMICS) # endif @@ -41,4 +41,28 @@ #endif /* HAVE_IFUNC */ +#ifdef HWCAP_USCAT + +#define MIDR_IMPLEMENTOR(midr) (((midr) >> 24) & 255) +#define MIDR_PARTNUM(midr) (((midr) >> 4) & 0xfff) + +static inline bool +ifunc1 (unsigned long hwcap) +{ + if (hwcap & HWCAP_USCAT) + return true; + if (!(hwcap & HWCAP_CPUID)) + return false; + + unsigned long midr; + asm volatile ("mrs %0, midr_el1" : "=r" (midr)); + + /* Neoverse N1 supports atomic 128-bit load/store. */ + if (MIDR_IMPLEMENTOR (midr) == 'A' && MIDR_PARTNUM (midr) == 0xd0c) + return true; + + return false; +} +#endif + #include_next <host-config.h> |