diff options
Diffstat (limited to 'libc/string/x86_64/strlen.S')
| -rw-r--r-- | libc/string/x86_64/strlen.S | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/libc/string/x86_64/strlen.S b/libc/string/x86_64/strlen.S index 3b6f2ac86..4213f0ab6 100644 --- a/libc/string/x86_64/strlen.S +++ b/libc/string/x86_64/strlen.S @@ -40,8 +40,11 @@ ENTRY (strlen) 1: movq $0xfefefefefefefeff,%r8 /* Save magic. */ - .p2align 4 /* Align loop. */ -4: /* Main Loop is unrolled 4 times. */ + /* Align loop. */ + /* Next 3 insns are 10 bytes total, make sure we decode them in one go */ + .p2align 4,,10 +4: + /* Main Loop is unrolled 4 times. */ /* First unroll. */ movq (%rax), %rcx /* get double word (= 8 bytes) in question */ addq $8,%rax /* adjust pointer for next word */ @@ -98,8 +101,11 @@ ENTRY (strlen) the addition will not result in 0. */ jz 4b /* no NUL found => continue loop */ - .p2align 4 /* Align, it is a jump target. */ -3: subq $8,%rax /* correct pointer increment. */ + /* Align, it is a jump target. */ + /* Next 3 insns are 8 bytes total, make sure we decode them in one go */ + .p2align 3,,8 +3: + subq $8,%rax /* correct pointer increment. */ testb %cl, %cl /* is first byte NUL? */ jz 2f /* yes => return */ |