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[PATCH 1/4] S390: Use mvcle for copies > 1MB on 32bit with default memcpy variant.
- From: Stefan Liebler <stli at linux dot vnet dot ibm dot com>
- To: libc-alpha at sourceware dot org
- Cc: carlos at redhat dot com, Wilco dot Dijkstra at arm dot com, neleai at seznam dot cz, Stefan Liebler <stli at linux dot vnet dot ibm dot com>
- Date: Tue, 26 Apr 2016 14:07:46 +0200
- Subject: [PATCH 1/4] S390: Use mvcle for copies > 1MB on 32bit with default memcpy variant.
- Authentication-results: sourceware.org; auth=none
If more than 255 bytes should be copied, the algorithm jumps away.
Before this patch, it jumps to the mvc-loop (.L_G5_12).
Now it jumps first to the "> 1MB" check, which jumps away to
__memcpy_mvcle. Otherwise, the mvc-loop (.L_G5_12) copies the bytes.
ChangeLog:
* sysdeps/s390/s390-32/memcpy.S (memcpy):
Jump to 1MB check before executing mvc-loop.
---
sysdeps/s390/s390-32/memcpy.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sysdeps/s390/s390-32/memcpy.S b/sysdeps/s390/s390-32/memcpy.S
index 62ecbbf..2ac51ab 100644
--- a/sysdeps/s390/s390-32/memcpy.S
+++ b/sysdeps/s390/s390-32/memcpy.S
@@ -42,7 +42,7 @@ ENTRY(memcpy)
srl %r5,8
ltr %r5,%r5
lr %r1,%r2
- jne .L_G5_12
+ jne .L_G5_13
ex %r4,.L_G5_17-.L_G5_16(%r13)
.L_G5_4:
l %r13,52(%r15)
--
2.3.0