From: Will Schmidt <will_schmidt@vnet.ibm.com>
Date: Thu, 18 Aug 2011 16:01:44 +0000 (-0500)
Subject: Provide a throughput boost to the 64-bit power7 strncmp code of approx
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=26c64647052d9e7f1c661bfa16d9b5cf1750f596;p=thirdparty%2Fglibc.git

Provide a throughput boost to the 64-bit power7 strncmp code of approx
15%.  The 32-bit throughput is not notably affected by this change, so
the change to the 32-bit code is done to keep the two files in sync
with each other.
---

diff --git a/ChangeLog b/ChangeLog
index afdd8833ffe..3c29d6ba1c8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2011-08-04  Will Schmidt  <will_schmidt@vnet.ibm.com>
+
+	* sysdeps/powerpc/powerpc32/power7/strncmp.S: Adjust the alignment
+	and add nop instructions for throughput optimization.
+	* sysdeps/powerpc/powerpc64/power7/strncmp.S: Adjust the alignment
+	and nop instructions for throughput optimization.
+
 2011-08-01  Adhemerval Zanella  <azanella@linux.vnet.ibm.com>
 
 	* sysdeps/powerpc/fpu/e_hypot.c: New file: hypot optimized for POWER.
diff --git a/sysdeps/powerpc/powerpc32/power7/strncmp.S b/sysdeps/powerpc/powerpc32/power7/strncmp.S
index ba72d0a029e..61b33c3c36d 100644
--- a/sysdeps/powerpc/powerpc32/power7/strncmp.S
+++ b/sysdeps/powerpc/powerpc32/power7/strncmp.S
@@ -27,7 +27,7 @@
 		     const char *s2 [r4],
 		     size_t size [r5])  */
 
-EALIGN (BP_SYM(strncmp),4,0)
+EALIGN (BP_SYM(strncmp),5,0)
 
 #define rTMP	r0
 #define rRTN	r3
@@ -47,9 +47,11 @@ EALIGN (BP_SYM(strncmp),4,0)
 #define rBITDIF	r11	/* bits that differ in s1 & s2 words */
 
 	dcbt	0,rSTR1
+	nop
 	or	rTMP,rSTR2,rSTR1
 	lis	r7F7F,0x7f7f
 	dcbt	0,rSTR2
+	nop
 	clrlwi.	rTMP,rTMP,30
 	cmplwi	cr1,rN,0
 	lis	rFEFE,-0x101
diff --git a/sysdeps/powerpc/powerpc64/power7/strncmp.S b/sysdeps/powerpc/powerpc64/power7/strncmp.S
index 34f1e52df96..bba44455c32 100644
--- a/sysdeps/powerpc/powerpc64/power7/strncmp.S
+++ b/sysdeps/powerpc/powerpc64/power7/strncmp.S
@@ -27,7 +27,7 @@
 		     const char *s2 [r4],
 		     size_t size [r5])  */
 
-EALIGN (BP_SYM(strncmp),4,0)
+EALIGN (BP_SYM(strncmp),5,0)
 	CALL_MCOUNT 3
 
 #define rTMP	r0
@@ -48,9 +48,11 @@ EALIGN (BP_SYM(strncmp),4,0)
 #define rBITDIF	r11	/* bits that differ in s1 & s2 words */
 
 	dcbt	0,rSTR1
+	nop
 	or	rTMP,rSTR2,rSTR1
 	lis	r7F7F,0x7f7f
 	dcbt	0,rSTR2
+	nop
 	clrldi.	rTMP,rTMP,61
 	cmpldi	cr1,rN,0
 	lis	rFEFE,-0x101