diff options
Diffstat (limited to 'lib/libc/amd64/string/memchr.S')
| -rw-r--r-- | lib/libc/amd64/string/memchr.S | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/lib/libc/amd64/string/memchr.S b/lib/libc/amd64/string/memchr.S index e10bd6c22f90..cfab9b1302de 100644 --- a/lib/libc/amd64/string/memchr.S +++ b/lib/libc/amd64/string/memchr.S @@ -44,7 +44,9 @@ ARCHENTRY(__memchr, scalar) je .Lnomatch lea (, %rdi, 8), %ecx - add %rdi, %rdx # pointer to end of buffer + mov $-1, %rax + add %rdi, %rdx # pointer to end of buffer or to end of + cmovc %rax, %rdx # address space (whichever comes first) and $~7, %rdi # align to 8 bytes mov (%rdi), %rax # load first word movzbl %sil, %esi # clear stray high bits @@ -118,14 +120,15 @@ ARCHENTRY(__memchr, baseline) movd %esi, %xmm2 mov %edi, %ecx - add %rdi, %rdx # pointer to end of buffer + mov $-1, %r9 + add %rdi, %rdx # pointer to end of buffer or to end of + cmovc %r9, %rdx # address space (whichever comes first) and $~0x1f, %rdi # align to 32 bytes movdqa (%rdi), %xmm0 # load first 32 bytes movdqa 16(%rdi), %xmm1 punpcklbw %xmm2, %xmm2 # c -> cc - mov $-1, %r9d shl %cl, %r9d # mask with zeroes before the string punpcklwd %xmm2, %xmm2 # cc -> cccc |