svn commit: r210665 - head/sys/amd64/amd64
Xin LI
delphij at FreeBSD.org
Fri Jul 30 21:39:29 UTC 2010
Author: delphij
Date: Fri Jul 30 21:39:28 2010
New Revision: 210665
URL: http://svn.freebsd.org/changeset/base/210665
Log:
In rdmsr_safe, use zero extend (by doing a 32-bit movl over
eax to itself) instead of a sign extend.
Discussed with: stas
MFC after: 1 month
Modified:
head/sys/amd64/amd64/support.S
Modified: head/sys/amd64/amd64/support.S
==============================================================================
--- head/sys/amd64/amd64/support.S Fri Jul 30 21:28:25 2010 (r210664)
+++ head/sys/amd64/amd64/support.S Fri Jul 30 21:39:28 2010 (r210665)
@@ -729,7 +729,7 @@ ENTRY(rdmsr_safe)
rdmsr /* Read MSR pointed by %ecx. Returns
hi byte in edx, lo in %eax */
salq $32,%rdx /* sign-shift %rdx left */
- cltq /* sign-extend %eax -> %rax */
+ movl %eax,%eax /* zero-extend %eax -> %rax */
orq %rdx,%rax
movq %rax,(%rsi)
xorq %rax,%rax
More information about the svn-src-head
mailing list