about summary refs log tree commit diff
diff options
context:
space:
mode:
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)
downloadglibc-727b38df054b26d7410c275930f72135061ab9e1.tar.gz
glibc-727b38df054b26d7410c275930f72135061ab9e1.tar.xz
glibc-727b38df054b26d7410c275930f72135061ab9e1.zip
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)