[PATCH v3 04/15] riscv: add vectorized strchrnul
Pincheng Wang <[email protected]>
| Newsgroups | gmane.comp.lib.newlib |
|---|---|
| Message-ID | <[email protected]> |
The vector implementation scans the string in vector-length chunks using fault-only-first loads (vle8ff.v), returning a pointer to the first match or to the terminating NUL without ever crossing into an unmapped page. This provides significant performance improvements on RVV-capable hardware. Use conditional compilation to fall back to the generic implementation when __riscv_vector is not available, maintaining compatibility with non-vector RISC-V systems. Signed-off-by: Pincheng Wang <[email protected]> --- newlib/libc/machine/riscv/Makefile.inc | 2 ++ newlib/libc/machine/riscv/strchrnul-asm.S | 27 +++++++++++++++++++++++ newlib/libc/machine/riscv/strchrnul.c | 5 +++++ 3 files changed, 34 insertions(+) create mode 100644 newlib/libc/machine/riscv/strchrnul-asm.S create mode 100644 newlib/libc/machine/riscv/strchrnul.c diff --git a/newlib/libc/machine/riscv/Makefile.inc b/newlib/libc/machine/riscv/Makefile.inc index 01a0aaf50..3c13fbc1a 100644 --- a/newlib/libc/machine/riscv/Makefile.inc +++ b/newlib/libc/machine/riscv/Makefile.inc @@ -22,6 +22,8 @@ libc_a_SOURCES += \ %D%/stpcpy.c \ %D%/strchr-asm.S \ %D%/strchr.c \ + %D%/strchrnul-asm.S \ + %D%/strchrnul.c \ %D%/strcmp.S \ %D%/strcpy.c \ %D%/strlen-asm.S \ diff --git a/newlib/libc/machine/riscv/strchrnul-asm.S b/newlib/libc/machine/riscv/strchrnul-asm.S new file mode 100644 index 000000000..dfe4bcd72 --- /dev/null +++ b/newlib/libc/machine/riscv/strchrnul-asm.S @@ -0,0 +1,27 @@ +#include <sys/asm.h> + +#if defined(__riscv_vector) && !defined(__OPTIMIZE_SIZE__) && !defined(PREFER_SIZE_OVER_SPEED) +ENTRY(strchrnul) +.Lloop: + vsetvli t0, zero, e8, m1, ta, ma + vle8ff.v v0, (a0) + vmseq.vx v8, v0, a1 + vmseq.vi v9, v0, 0 + vfirst.m a2, v8 + vfirst.m a3, v9 + bltz a2, .Lcheck_nul + bltz a3, .Lfound_char + bltu a2, a3, .Lfound_char +.Lfound_nul: + add a0, a0, a3 + ret +.Lfound_char: + add a0, a0, a2 + ret +.Lcheck_nul: + bgez a3, .Lfound_nul + csrr a4, vl + add a0, a0, a4 + j .Lloop +END(strchrnul) +#endif diff --git a/newlib/libc/machine/riscv/strchrnul.c b/newlib/libc/machine/riscv/strchrnul.c new file mode 100644 index 000000000..4a6d0e947 --- /dev/null +++ b/newlib/libc/machine/riscv/strchrnul.c @@ -0,0 +1,5 @@ +#if defined(__OPTIMIZE_SIZE__) || defined(PREFER_SIZE_OVER_SPEED) || !defined(__riscv_vector) || defined(__riscv_e) +# include "../../string/strchrnul.c" +#else +/* strchrnul defined in strchrnul-asm.S */ +#endif -- 2.39.5