powerpc: Fix IFUNC for memrchr

Recent commit 59ba2d2b5421 missed to add __memrchr_power8 in
ifunc list.  Also handled discarding unwanted bytes for
unaligned inputs in power8 optimization.

2017-10-05  Rajalakshmi Srinivasaraghavan  <raji@linux.vnet.ibm.com>

	* sysdeps/powerpc/powerpc64/multiarch/memrchr-ppc64.c: Revert
	back to powerpc32 file.
	* sysdeps/powerpc/powerpc64/multiarch/memrchr.c
	(memrchr): Add __memrchr_power8 to ifunc list.
	* sysdeps/powerpc/powerpc64/power8/memrchr.S: Mask
	extra bytes for unaligned inputs.

diff --git a/sysdeps/powerpc/powerpc64/multiarch/memrchr-ppc64.c b/sysdeps/powerpc/powerpc64/multiarch/memrchr-ppc64.c
index be24689..e2d53ac 100644 (file)
--- a/sysdeps/powerpc/powerpc64/multiarch/memrchr-ppc64.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/memrchr-ppc64.c
@@ -15,17 +15,4 @@
    You should have received a copy of the GNU Lesser General Public
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
-
-#include <string.h>
-
-#define MEMRCHR  __memrchr_ppc
-
-#undef weak_alias
-#define weak_alias(a, b)
-
-#undef libc_hidden_builtin_def
-#define libc_hidden_builtin_def(name)
-
-extern __typeof (memrchr) __memrchr_ppc attribute_hidden;
-
-#include <string/memrchr.c>
+#include <sysdeps/powerpc/powerpc32/power4/multiarch/memrchr-ppc32.c>

diff --git a/sysdeps/powerpc/powerpc64/multiarch/memrchr.c b/sysdeps/powerpc/powerpc64/multiarch/memrchr.c
index fb09fdf..7d52af0 100644 (file)
--- a/sysdeps/powerpc/powerpc64/multiarch/memrchr.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/memrchr.c
@@ -23,13 +23,16 @@
 
 extern __typeof (__memrchr) __memrchr_ppc attribute_hidden;
 extern __typeof (__memrchr) __memrchr_power7 attribute_hidden;
+extern __typeof (__memrchr) __memrchr_power8 attribute_hidden;
 
 /* Avoid DWARF definition DIE on ifunc symbol so that GDB can handle
    ifunc symbol properly.  */
 libc_ifunc (__memrchr,
-           (hwcap & PPC_FEATURE_HAS_VSX)
-            ? __memrchr_power7
-            : __memrchr_ppc);
+           (hwcap2 & PPC_FEATURE2_ARCH_2_07)
+           ? __memrchr_power8 :
+             (hwcap & PPC_FEATURE_HAS_VSX)
+             ? __memrchr_power7
+           : __memrchr_ppc);
 
 weak_alias (__memrchr, memrchr)
 #else

diff --git a/sysdeps/powerpc/powerpc64/power8/memrchr.S b/sysdeps/powerpc/powerpc64/power8/memrchr.S
index 521b3c8..22b01ec 100644 (file)
--- a/sysdeps/powerpc/powerpc64/power8/memrchr.S
+++ b/sysdeps/powerpc/powerpc64/power8/memrchr.S
@@ -233,11 +233,35 @@ L(found):
 #endif
        addi    r8, r8, 63
        sub     r3, r8, r6      /* Compute final address.  */
+       cmpld   cr7, r3, r10
+       bgelr   cr7
+       li      r3, 0
        blr
 
        /* Found a match in last 16 bytes.  */
        .align  4
 L(found_16B):
+       cmpld   r8, r10         /* Are we on the last QW?  */
+       bge     L(last)
+       /* Now discard bytes before starting address.  */
+       sub     r9, r10, r8
+       MTVRD(v9, r9)
+       vspltisb        v8, 3
+       /* Mask unwanted bytes.  */
+#ifdef __LITTLE_ENDIAN__
+       lvsr    v7, 0, r10
+       vperm   v6, v0, v6, v7
+       vsldoi  v9, v0, v9, 8
+       vsl     v9, v9, v8
+       vslo    v6, v6, v9
+#else
+       lvsl    v7, 0, r10
+       vperm   v6, v6, v0, v7
+       vsldoi  v9, v0, v9, 8
+       vsl     v9, v9, v8
+       vsro    v6, v6, v9
+#endif
+L(last):
        /* Permute the first bit of each byte into bits 48-63.  */
        VBPERMQ(v6, v6, v10)
        /* Shift each component into its correct position for merging.  */