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-rw-r--r--sysdeps/x86_64/multiarch/strcmp-avx2.S15
1 files changed, 15 insertions, 0 deletions
diff --git a/sysdeps/x86_64/multiarch/strcmp-avx2.S b/sysdeps/x86_64/multiarch/strcmp-avx2.S
index 5f88a68262..d42b04b54f 100644
--- a/sysdeps/x86_64/multiarch/strcmp-avx2.S
+++ b/sysdeps/x86_64/multiarch/strcmp-avx2.S
@@ -591,7 +591,14 @@ L(loop_cross_page_2_vec):
movl $(PAGE_SIZE / (VEC_SIZE * 4) - 1), %esi
testq %rdi, %rdi
+# ifdef USE_AS_STRNCMP
+ /* At this point, if %rdi value is 0, it already tested
+ VEC_SIZE*4+%r10 byte starting from %rax. This label
+ checks whether strncmp maximum offset reached or not. */
+ je L(string_nbyte_offset_check)
+# else
je L(back_to_loop)
+# endif
tzcntq %rdi, %rcx
addq %r10, %rcx
/* Adjust for number of bytes skipped. */
@@ -627,6 +634,14 @@ L(loop_cross_page_2_vec):
VZEROUPPER
ret
+# ifdef USE_AS_STRNCMP
+L(string_nbyte_offset_check):
+ leaq (VEC_SIZE * 4)(%r10), %r10
+ cmpq %r10, %r11
+ jbe L(zero)
+ jmp L(back_to_loop)
+# endif
+
.p2align 4
L(cross_page_loop):
/* Check one byte/dword at a time. */