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| author | Wilco Dijkstra <wdijkstr@arm.com> | 2020-07-17 14:09:36 +0100 |
|---|---|---|
| committer | Wilco Dijkstra <wdijkstr@arm.com> | 2020-07-17 15:07:23 +0100 |
| commit | f46ef33ad134bec7ac992f28ee4b8b0614590e3e (patch) | |
| tree | f34fe31172e393172c15b2bb189382ad9c0b17e2 /sysdeps/aarch64/multiarch/strlen.c | |
| parent | 76b8442db51a8976de19934638a42532a3af607f (diff) | |
| download | glibc-f46ef33ad134bec7ac992f28ee4b8b0614590e3e.tar.gz glibc-f46ef33ad134bec7ac992f28ee4b8b0614590e3e.tar.xz glibc-f46ef33ad134bec7ac992f28ee4b8b0614590e3e.zip | |
AArch64: Improve strlen_asimd performance (bug 25824)
Optimize strlen using a mix of scalar and SIMD code. On modern micro architectures large strings are 2.6 times faster than existing strlen_asimd and 35% faster than the new MTE version of strlen. On a random strlen benchmark using small sizes the speedup is 7% vs strlen_asimd and 40% vs the MTE strlen. This fixes the main strlen regressions on Cortex-A53 and other cores with a simple Neon unit. Rename __strlen_generic to __strlen_mte, and select strlen_asimd when MTE is not enabled (this is waiting on support for a HWCAP_MTE bit). This fixes big-endian bug 25824. Passes GLIBC regression tests. Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Diffstat (limited to 'sysdeps/aarch64/multiarch/strlen.c')
| -rw-r--r-- | sysdeps/aarch64/multiarch/strlen.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/sysdeps/aarch64/multiarch/strlen.c b/sysdeps/aarch64/multiarch/strlen.c index 99f2cf2cde..7c0352dd87 100644 --- a/sysdeps/aarch64/multiarch/strlen.c +++ b/sysdeps/aarch64/multiarch/strlen.c @@ -26,17 +26,15 @@ # include <string.h> # include <init-arch.h> -#define USE_ASIMD_STRLEN() IS_FALKOR (midr) +/* This should check HWCAP_MTE when it is available. */ +#define MTE_ENABLED() (false) extern __typeof (__redirect_strlen) __strlen; -extern __typeof (__redirect_strlen) __strlen_generic attribute_hidden; +extern __typeof (__redirect_strlen) __strlen_mte attribute_hidden; extern __typeof (__redirect_strlen) __strlen_asimd attribute_hidden; -libc_ifunc (__strlen, - (USE_ASIMD_STRLEN () || IS_KUNPENG920 (midr) - ? __strlen_asimd - :__strlen_generic)); +libc_ifunc (__strlen, (MTE_ENABLED () ? __strlen_mte : __strlen_asimd)); # undef strlen strong_alias (__strlen, strlen); |