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Correct prefetch hint in power7 memrchr
- From: Alan Modra <amodra at gmail dot com>
- To: libc-alpha at sourceware dot org
- Date: Tue, 25 Mar 2014 12:34:30 +1030
- Subject: Correct prefetch hint in power7 memrchr
- Authentication-results: sourceware.org; auth=none
Typo fix. Discovered when looking at some disassembly, and wondering
why this disassembled as dcbtt. My simple benchmark testing didn't
show any effect of using the wrong hint, but at a guess you'd only see
a difference on a very long memrchr with cold caches.
* sysdeps/powerpc/powerpc64/power7/memrchr.S: Correct stream hint.
diff --git a/sysdeps/powerpc/powerpc64/power7/memrchr.S b/sysdeps/powerpc/powerpc64/power7/memrchr.S
index 40e436f..0c01ca2 100644
--- a/sysdeps/powerpc/powerpc64/power7/memrchr.S
+++ b/sysdeps/powerpc/powerpc64/power7/memrchr.S
@@ -29,7 +29,7 @@ ENTRY (__memrchr)
mr r10,r3
clrrdi r6,r7,7
li r9,3<<5
- dcbt r9,r6,16 /* Stream hint, decreasing addresses. */
+ dcbt r9,r6,8 /* Stream hint, decreasing addresses. */
/* Replicate BYTE to doubleword. */
insrdi r4,r4,8,48
--
Alan Modra
Australia Development Lab, IBM