PowerPC: Optimized strcmp for PPC64/POWER7

Optimization is achieved on 8 byte aligned strings with double word
comparison using cmpb instruction. On unaligned strings loop unrolling
is applied for Power7 gain.

5 files changed, 122 insertions, 1 deletions

diff --git a/sysdeps/powerpc/powerpc64/multiarch/Makefile b/sysdeps/powerpc/powerpc64/multiarch/Makefile
index 35020a7b4c..05744e9081 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/multiarch/Makefile
@@ -17,7 +17,7 @@ sysdep_routines += memcpy-power7 memcpy-a2 memcpy-power6 memcpy-cell \
 		   strrchr-power7 strrchr-ppc64 strncat-power7 strncat-ppc64 \
 		   strspn-power7 strspn-ppc64 strcspn-power7 strcspn-ppc64 \
 		   strpbrk-power7 strpbrk-ppc64 strncpy-power7 strncpy-ppc64 \
-		   stpncpy-power7 stpncpy-ppc64
+		   stpncpy-power7 stpncpy-ppc64 strcmp-power7 strcmp-ppc64
 
 CFLAGS-strncase-power7.c += -mcpu=power7 -funroll-loops
 CFLAGS-strncase_l-power7.c += -mcpu=power7 -funroll-loops
diff --git a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
index d8578fb722..b3933a52d9 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
+++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c
@@ -294,5 +294,12 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
 	      IFUNC_IMPL_ADD (array, i, stpncpy, 1,
 			     __stpncpy_ppc))
 
+  /* Support sysdeps/powerpc/powerpc64/multiarch/strcmp.c.  */
+  IFUNC_IMPL (i, name, strcmp,
+	      IFUNC_IMPL_ADD (array, i, strcmp,
+			      hwcap & PPC_FEATURE_HAS_VSX,
+			      __strcmp_power7)
+	      IFUNC_IMPL_ADD (array, i, strcmp, 1,
+			     __strcmp_ppc))
   return i;
 }
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strcmp-power7.S b/sysdeps/powerpc/powerpc64/multiarch/strcmp-power7.S
new file mode 100644
index 0000000000..790ce8dbd5
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strcmp-power7.S
@@ -0,0 +1,40 @@
+/* Optimized strcmp implementation for POWER7.
+   Copyright (C) 2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   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 <sysdep.h>
+
+#undef EALIGN
+#define EALIGN(name, alignt, words)				\
+  .section ".text";						\
+  ENTRY_2(__strcmp_power7)					\
+  .align ALIGNARG(alignt);					\
+  EALIGN_W_##words;						\
+  BODY_LABEL(__strcmp_power7):					\
+  cfi_startproc;						\
+  LOCALENTRY(__strcmp_power7)
+
+#undef END
+#define END(name)						\
+  cfi_endproc;							\
+  TRACEBACK(__strcmp_power7)					\
+  END_2(__strcmp_power7)
+
+#undef libc_hidden_builtin_def
+#define libc_hidden_builtin_def(name)
+
+#include <sysdeps/powerpc/powerpc64/power7/strcmp.S>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strcmp-ppc64.S b/sysdeps/powerpc/powerpc64/multiarch/strcmp-ppc64.S
new file mode 100644
index 0000000000..93d12771f0
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strcmp-ppc64.S
@@ -0,0 +1,43 @@
+/* Default strcmp implementation for PowerPC64.
+   Copyright (C) 2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   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 <sysdep.h>
+
+#if defined SHARED && !defined NOT_IN_libc
+# undef EALIGN
+# define EALIGN(name, alignt, words)				\
+  .section ".text";						\
+  ENTRY_2(__strcmp_ppc)						\
+  .align ALIGNARG(alignt);					\
+  EALIGN_W_##words;						\
+  BODY_LABEL(__strcmp_ppc):					\
+  cfi_startproc;						\
+  LOCALENTRY(__strcmp_ppc)
+
+# undef END
+# define END(name)						\
+  cfi_endproc;							\
+  TRACEBACK(__strcmp_ppc)					\
+  END_2(__strcmp_ppc)
+
+# undef libc_hidden_builtin_def
+# define libc_hidden_builtin_def(name)				\
+    .globl __GI_strcmp; __GI_strcmp = __strcmp_ppc
+#endif
+
+#include <sysdeps/powerpc/powerpc64/strcmp.S>
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strcmp.c b/sysdeps/powerpc/powerpc64/multiarch/strcmp.c
new file mode 100644
index 0000000000..2013301aa1
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strcmp.c
@@ -0,0 +1,31 @@
+/* Multiple versions of strcmp. PowerPC64 version.
+   Copyright (C) 2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   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/>.  */
+
+#if defined SHARED && !defined NOT_IN_libc
+# include <string.h>
+# include <shlib-compat.h>
+# include "init-arch.h"
+
+extern __typeof (strcmp) __strcmp_ppc attribute_hidden;
+extern __typeof (strcmp) __strcmp_power7 attribute_hidden;
+
+libc_ifunc (strcmp,
+            (hwcap & PPC_FEATURE_HAS_VSX)
+            ? __strcmp_power7
+            : __strcmp_ppc);
+#endif