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authorH.J. Lu <hjl.tools@gmail.com>2018-05-23 11:25:20 -0700
committerH.J. Lu <hjl.tools@gmail.com>2018-05-23 11:25:42 -0700
commit727b38df054b26d7410c275930f72135061ab9e1 (patch)
treefb74b6f63c81f68de29c0438c0666719a556a6a2
parent2834fb46109a8a7c9161eb8d0d9ddc707a717144 (diff)
x86-64: Skip zero length in __mem[pcpy|move|set]_erms
This patch skips zero length in __mempcpy_erms, __memmove_erms and __memset_erms. Tested on x86-64. * sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S (__mempcpy_erms): Skip zero length. (__memmove_erms): Likewise. * sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S (__memset_erms): Likewise.
-rw-r--r--ChangeLog8
-rw-r--r--sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S6
-rw-r--r--sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S5
3 files changed, 19 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog
index 8cabe673ab..87c3f3df54 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2018-05-23 H.J. Lu <hongjiu.lu@intel.com>
+
+ * sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S
+ (__mempcpy_erms): Skip zero length.
+ (__memmove_erms): Likewise.
+ * sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
+ (__memset_erms): Likewise.
+
2018-05-23 Joseph Myers <joseph@codesourcery.com>
* sysdeps/alpha/Implies: Remove alpha/soft-fp.
diff --git a/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S b/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S
index 1404131bb7..e2ede45e9f 100644
--- a/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S
+++ b/sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S
@@ -156,6 +156,9 @@ END (__mempcpy_chk_erms)
/* Only used to measure performance of REP MOVSB. */
ENTRY (__mempcpy_erms)
movq %rdi, %rax
+ /* Skip zero length. */
+ testq %rdx, %rdx
+ jz 2f
addq %rdx, %rax
jmp L(start_movsb)
END (__mempcpy_erms)
@@ -167,6 +170,9 @@ END (__memmove_chk_erms)
ENTRY (__memmove_erms)
movq %rdi, %rax
+ /* Skip zero length. */
+ testq %rdx, %rdx
+ jz 2f
L(start_movsb):
movq %rdx, %rcx
cmpq %rsi, %rdi
diff --git a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
index 0a827f3e47..dc9cb88b37 100644
--- a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
+++ b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
@@ -128,6 +128,11 @@ END (__memset_chk_erms)
/* Only used to measure performance of REP STOSB. */
ENTRY (__memset_erms)
+ /* Skip zero length. */
+ testq %rdx, %rdx
+ jnz L(stosb)
+ movq %rdi, %rax
+ ret
# else
/* Provide a hidden symbol to debugger. */
.hidden MEMSET_SYMBOL (__memset, erms)