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| author | Christoph Müllner <christoph.muellner@vrull.eu> | 2023-08-23 07:46:28 +0200 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2023-09-06 09:27:43 -0300 |
| commit | 3d6fcf1bd7f462d333c36a14efc0e03f2fdd3f9e (patch) | |
| tree | 773c257487ce30d630043e9a30f1894c15f1f65b /sysdeps | |
| parent | 3bf7bab88b0da01d4f5ef20afbbb45203185501e (diff) | |
| download | glibc-3d6fcf1bd7f462d333c36a14efc0e03f2fdd3f9e.zip glibc-3d6fcf1bd7f462d333c36a14efc0e03f2fdd3f9e.tar.gz glibc-3d6fcf1bd7f462d333c36a14efc0e03f2fdd3f9e.tar.bz2 | |
riscv: Add support for XTheadBb in string-fz[a,i].h
XTheadBb has similar instructions like Zbb, which allow optimized
string processing:
* th.ff0: find-first zero is a CLZ instruction.
* th.tstnbz: Similar like orc.b, but with a bit-inverted result.
The instructions are documented here:
https://github.com/T-head-Semi/thead-extension-spec/tree/master/xtheadbb
These instructions can be found in the T-Head C906 and the C910.
Tested with the string tests.
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/riscv/string-fza.h | 7 | ||||
| -rw-r--r-- | sysdeps/riscv/string-fzi.h | 2 |
2 files changed, 7 insertions, 2 deletions
diff --git a/sysdeps/riscv/string-fza.h b/sysdeps/riscv/string-fza.h index 4429653..4958d5d 100644 --- a/sysdeps/riscv/string-fza.h +++ b/sysdeps/riscv/string-fza.h @@ -19,7 +19,7 @@ #ifndef _RISCV_STRING_FZA_H #define _RISCV_STRING_FZA_H 1 -#ifdef __riscv_zbb +#if defined __riscv_zbb || defined __riscv_xtheadbb /* With bitmap extension we can use orc.b to find all zero bytes. */ # include <string-misc.h> # include <string-optype.h> @@ -32,8 +32,13 @@ static __always_inline find_t find_zero_all (op_t x) { find_t r; +#ifdef __riscv_xtheadbb + asm ("th.tstnbz %0, %1" : "=r" (r) : "r" (x)); + return r; +#else asm ("orc.b %0, %1" : "=r" (r) : "r" (x)); return ~r; +#endif } /* This function returns 0xff for each byte that is equal between X1 and diff --git a/sysdeps/riscv/string-fzi.h b/sysdeps/riscv/string-fzi.h index 8f56c37..45d6367 100644 --- a/sysdeps/riscv/string-fzi.h +++ b/sysdeps/riscv/string-fzi.h @@ -19,7 +19,7 @@ #ifndef _STRING_RISCV_FZI_H #define _STRING_RISCV_FZI_H 1 -#ifdef __riscv_zbb +#if defined __riscv_zbb || defined __riscv_xtheadbb # include <sysdeps/generic/string-fzi.h> #else /* Without bitmap clz/ctz extensions, it is faster to direct test the bits |