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| author | H.J. Lu <hjl.tools@gmail.com> | 2017-06-05 07:58:11 -0700 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2017-06-05 07:58:23 -0700 |
| commit | 30cb625a21bc7ad450fdc45d1f682e2b27c353de (patch) | |
| tree | e104957e2f5bf150b00ad8cb31dbb19e1275dc0f | |
| parent | 7395928b957ebb35afb696c3278d14122aa97b51 (diff) | |
| download | glibc-30cb625a21bc7ad450fdc45d1f682e2b27c353de.tar.gz | |
x86-64: Update strlen.S to support wcslen/wcsnlen
The difference between strlen and wcslen is byte vs int. We can
replace pminub and pcmpeqb with pminud and pcmpeqd to turn strlen
into wcslen.
* sysdeps/x86_64/strlen.S (PMINU): New.
(PCMPEQ): Likewise.
(SHIFT_RETURN): Likewise.
(FIND_ZERO): Replace pcmpeqb with PCMPEQ.
(strlen): Add SHIFT_RETURN before ret. Replace pcmpeqb and
pminub with PCMPEQ and PMINU.
* sysdeps/x86_64/wcsnlen.S: New file.
| -rw-r--r-- | ChangeLog | 10 | ||||
| -rw-r--r-- | sysdeps/x86_64/strlen.S | 61 | ||||
| -rw-r--r-- | sysdeps/x86_64/wcsnlen.S | 7 |
3 files changed, 57 insertions, 21 deletions
@@ -1,5 +1,15 @@ 2017-06-05 H.J. Lu <hongjiu.lu@intel.com> + * sysdeps/x86_64/strlen.S (PMINU): New. + (PCMPEQ): Likewise. + (SHIFT_RETURN): Likewise. + (FIND_ZERO): Replace pcmpeqb with PCMPEQ. + (strlen): Add SHIFT_RETURN before ret. Replace pcmpeqb and + pminub with PCMPEQ and PMINU. + * sysdeps/x86_64/wcsnlen.S: New file. + +2017-06-05 H.J. Lu <hongjiu.lu@intel.com> + * sysdeps/x86_64/memrchr.S (__memrchr): Use 32-bit registers for the lower 32 bits. Remove redundant instructions. diff --git a/sysdeps/x86_64/strlen.S b/sysdeps/x86_64/strlen.S index 5896e6b9ee..b5ab117c79 100644 --- a/sysdeps/x86_64/strlen.S +++ b/sysdeps/x86_64/strlen.S @@ -1,4 +1,4 @@ -/* SSE2 version of strlen. +/* SSE2 version of strlen/wcslen. Copyright (C) 2012-2017 Free Software Foundation, Inc. This file is part of the GNU C Library. @@ -18,6 +18,16 @@ #include <sysdep.h> +#ifdef AS_WCSLEN +# define PMINU pminud +# define PCMPEQ pcmpeqd +# define SHIFT_RETURN shrq $2, %rax +#else +# define PMINU pminub +# define PCMPEQ pcmpeqb +# define SHIFT_RETURN +#endif + /* Long lived register in strlen(s), strnlen(s, n) are: %xmm3 - zero @@ -32,10 +42,10 @@ ENTRY(strlen) /* Test 64 bytes from %rax for zero. Save result as bitmask in %rdx. */ #define FIND_ZERO \ - pcmpeqb (%rax), %xmm0; \ - pcmpeqb 16(%rax), %xmm1; \ - pcmpeqb 32(%rax), %xmm2; \ - pcmpeqb 48(%rax), %xmm3; \ + PCMPEQ (%rax), %xmm0; \ + PCMPEQ 16(%rax), %xmm1; \ + PCMPEQ 32(%rax), %xmm2; \ + PCMPEQ 48(%rax), %xmm3; \ pmovmskb %xmm0, %esi; \ pmovmskb %xmm1, %edx; \ pmovmskb %xmm2, %r8d; \ @@ -54,6 +64,9 @@ ENTRY(strlen) xor %rax, %rax ret L(n_nonzero): +# ifdef AS_WCSLEN + shlq $2, %rsi +# endif /* Initialize long lived registers. */ @@ -96,6 +109,7 @@ L(n_nonzero): test %rdx, %rdx; \ je L(lab); \ bsfq %rdx, %rax; \ + SHIFT_RETURN; \ ret #ifdef AS_STRNLEN @@ -104,19 +118,20 @@ L(n_nonzero): #else /* Test first 16 bytes unaligned. */ movdqu (%rax), %xmm4 - pcmpeqb %xmm0, %xmm4 + PCMPEQ %xmm0, %xmm4 pmovmskb %xmm4, %edx test %edx, %edx je L(next48_bytes) bsf %edx, %eax /* If eax is zeroed 16bit bsf can be used. */ + SHIFT_RETURN ret L(next48_bytes): /* Same as FIND_ZERO except we do not check first 16 bytes. */ andq $-16, %rax - pcmpeqb 16(%rax), %xmm1 - pcmpeqb 32(%rax), %xmm2 - pcmpeqb 48(%rax), %xmm3 + PCMPEQ 16(%rax), %xmm1 + PCMPEQ 32(%rax), %xmm2 + PCMPEQ 48(%rax), %xmm3 pmovmskb %xmm1, %edx pmovmskb %xmm2, %r8d pmovmskb %xmm3, %ecx @@ -145,6 +160,7 @@ L(strnlen_ret): test %rdx, %rdx je L(loop_init) bsfq %rdx, %rax + SHIFT_RETURN ret #endif .p2align 4 @@ -161,10 +177,10 @@ L(loop): je L(exit_end) movdqa (%rax), %xmm0 - pminub 16(%rax), %xmm0 - pminub 32(%rax), %xmm0 - pminub 48(%rax), %xmm0 - pcmpeqb %xmm3, %xmm0 + PMINU 16(%rax), %xmm0 + PMINU 32(%rax), %xmm0 + PMINU 48(%rax), %xmm0 + PCMPEQ %xmm3, %xmm0 pmovmskb %xmm0, %edx testl %edx, %edx jne L(exit) @@ -182,6 +198,7 @@ L(first): bsfq %rdx, %rdx addq %rdx, %rax subq %rdi, %rax + SHIFT_RETURN ret .p2align 4 @@ -192,6 +209,7 @@ L(exit): bsfq %rdx, %rdx addq %rdx, %rax subq %rdi, %rax + SHIFT_RETURN ret #else @@ -201,10 +219,10 @@ L(exit): L(loop): movdqa 64(%rax), %xmm0 - pminub 80(%rax), %xmm0 - pminub 96(%rax), %xmm0 - pminub 112(%rax), %xmm0 - pcmpeqb %xmm3, %xmm0 + PMINU 80(%rax), %xmm0 + PMINU 96(%rax), %xmm0 + PMINU 112(%rax), %xmm0 + PCMPEQ %xmm3, %xmm0 pmovmskb %xmm0, %edx testl %edx, %edx jne L(exit64) @@ -212,10 +230,10 @@ L(loop): subq $-128, %rax movdqa (%rax), %xmm0 - pminub 16(%rax), %xmm0 - pminub 32(%rax), %xmm0 - pminub 48(%rax), %xmm0 - pcmpeqb %xmm3, %xmm0 + PMINU 16(%rax), %xmm0 + PMINU 32(%rax), %xmm0 + PMINU 48(%rax), %xmm0 + PCMPEQ %xmm3, %xmm0 pmovmskb %xmm0, %edx testl %edx, %edx jne L(exit0) @@ -231,6 +249,7 @@ L(exit0): bsfq %rdx, %rdx addq %rdx, %rax subq %rdi, %rax + SHIFT_RETURN ret #endif diff --git a/sysdeps/x86_64/wcsnlen.S b/sysdeps/x86_64/wcsnlen.S new file mode 100644 index 0000000000..968bb693b4 --- /dev/null +++ b/sysdeps/x86_64/wcsnlen.S @@ -0,0 +1,7 @@ +#define AS_WCSLEN +#define AS_STRNLEN +#define strlen __wcsnlen + +#include "strlen.S" + +weak_alias(__wcsnlen, wcsnlen) |