From 2fd1041a8d9684978546886d58fdf8add8c8d9f7 Mon Sep 17 00:00:00 2001
From: Rajalakshmi Srinivasaraghavan <raji@linux.vnet.ibm.com>
Date: Tue, 5 Jul 2016 21:20:41 +0530
Subject: [PATCH] powerpc: Fix return code of strcasecmp for unaligned inputs

If the input values are unaligned and if there are null characters in the
memory before the starting address of the input values, strcasecmp
gives incorrect return code. Fixed it by adding mask the bits that
are not part of the string.

(cherry picked from commit 30e4cc5413f72c2c728a544389da0c48500d9904)
---
 ChangeLog                                     |  6 ++++++
 sysdeps/powerpc/powerpc64/power8/strcasecmp.S | 17 ++++++++++++++---
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 9385bd0..af5f694 100644
diff --git a/sysdeps/powerpc/powerpc64/power8/strcasecmp.S b/sysdeps/powerpc/powerpc64/power8/strcasecmp.S
index 63f6217..c83dc52 100644
--- a/sysdeps/powerpc/powerpc64/power8/strcasecmp.S
+++ b/sysdeps/powerpc/powerpc64/power8/strcasecmp.S
@@ -40,11 +40,20 @@
 	vsel	v5, v7, v5, v8; \
 	vcmpequb.	v7, v5, v4;
 
-/* Get 16 bytes for unaligned case.  */
+/*
+ * Get 16 bytes for unaligned case.
+ * reg1: Vector to hold next 16 bytes.
+ * reg2: Address to read from.
+ * reg3: Permute control vector.
+ * v8: Tmp vector used to mask unwanted bytes.
+ * v9: Tmp vector,0 when null is found on first 16 bytes
+ */
 #ifdef __LITTLE_ENDIAN__
 #define GET16BYTES(reg1, reg2, reg3) \
 	lvx	reg1, 0, reg2; \
-	vcmpequb.	v8, v0, reg1; \
+	vspltisb	v8, -1; \
+	vperm	v8, v8, reg1, reg3; \
+	vcmpequb.	v8, v0, v8; \
 	beq	cr6, 1f; \
 	vspltisb	v9, 0; \
 	b	2f; \
@@ -57,7 +66,9 @@
 #else
 #define GET16BYTES(reg1, reg2, reg3) \
 	lvx	reg1, 0, reg2; \
-	vcmpequb.	v8, v0, reg1; \
+	vspltisb	 v8, -1; \
+	vperm	v8, reg1, v8,  reg3; \
+	vcmpequb.	v8, v0, v8; \
 	beq	cr6, 1f; \
 	vspltisb	v9, 0; \
 	b	2f; \
-- 
2.1.0