2014-10-08 Steve Ellcey <sellcey@mips.com>

	* newlib/libc/machine/mips/strcmp.c: Remove.
	* newlib/libc/machine/mips/strcmp.S: New.
	* newlib/libc/machine/mips/Makefile.am (lib_a_SOURCES):
	Replace strcmp.c with strcmp.S
	* newlib/libc/machine/mips/Makefile.in: Regenerate.

4 files changed, 269 insertions, 79 deletions

diff --git a/newlib/libc/machine/mips/Makefile.am b/newlib/libc/machine/mips/Makefile.am
index 46b4cc3b0..1695b18ff 100644
--- a/newlib/libc/machine/mips/Makefile.am
+++ b/newlib/libc/machine/mips/Makefile.am
@@ -8,7 +8,7 @@ AM_CCASFLAGS = $(INCLUDES)
 
 noinst_LIBRARIES = lib.a
 
-lib_a_SOURCES = setjmp.S strlen.c strcmp.c strncpy.c memset.S memcpy.S
+lib_a_SOURCES = setjmp.S strlen.c strcmp.S strncpy.c memset.S memcpy.S
 lib_a_CCASFLAGS=$(AM_CCASFLAGS) -D_COMPILING_NEWLIB
 lib_a_CFLAGS=$(AM_CFLAGS) -D_COMPILING_NEWLIB
 
diff --git a/newlib/libc/machine/mips/Makefile.in b/newlib/libc/machine/mips/Makefile.in
index 2bb7e1a0c..b2d729e9f 100644
--- a/newlib/libc/machine/mips/Makefile.in
+++ b/newlib/libc/machine/mips/Makefile.in
@@ -197,7 +197,7 @@ AUTOMAKE_OPTIONS = cygnus
 INCLUDES = $(NEWLIB_CFLAGS) $(CROSS_CFLAGS) $(TARGET_CFLAGS)
 AM_CCASFLAGS = $(INCLUDES)
 noinst_LIBRARIES = lib.a
-lib_a_SOURCES = setjmp.S strlen.c strcmp.c strncpy.c memset.S memcpy.S
+lib_a_SOURCES = setjmp.S strlen.c strcmp.S strncpy.c memset.S memcpy.S
 lib_a_CCASFLAGS = $(AM_CCASFLAGS) -D_COMPILING_NEWLIB
 lib_a_CFLAGS = $(AM_CFLAGS) -D_COMPILING_NEWLIB
 ACLOCAL_AMFLAGS = -I ../../.. -I ../../../..
@@ -266,6 +266,12 @@ lib_a-setjmp.o: setjmp.S
 lib_a-setjmp.obj: setjmp.S
 	$(CCAS) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CCASFLAGS) $(CCASFLAGS) -c -o lib_a-setjmp.obj `if test -f 'setjmp.S'; then $(CYGPATH_W) 'setjmp.S'; else $(CYGPATH_W) '$(srcdir)/setjmp.S'; fi`
 
+lib_a-strcmp.o: strcmp.S
+	$(CCAS) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CCASFLAGS) $(CCASFLAGS) -c -o lib_a-strcmp.o `test -f 'strcmp.S' || echo '$(srcdir)/'`strcmp.S
+
+lib_a-strcmp.obj: strcmp.S
+	$(CCAS) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CCASFLAGS) $(CCASFLAGS) -c -o lib_a-strcmp.obj `if test -f 'strcmp.S'; then $(CYGPATH_W) 'strcmp.S'; else $(CYGPATH_W) '$(srcdir)/strcmp.S'; fi`
+
 lib_a-memset.o: memset.S
 	$(CCAS) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CCASFLAGS) $(CCASFLAGS) -c -o lib_a-memset.o `test -f 'memset.S' || echo '$(srcdir)/'`memset.S
 
@@ -290,12 +296,6 @@ lib_a-strlen.o: strlen.c
 lib_a-strlen.obj: strlen.c
 	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-strlen.obj `if test -f 'strlen.c'; then $(CYGPATH_W) 'strlen.c'; else $(CYGPATH_W) '$(srcdir)/strlen.c'; fi`
 
-lib_a-strcmp.o: strcmp.c
-	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-strcmp.o `test -f 'strcmp.c' || echo '$(srcdir)/'`strcmp.c
-
-lib_a-strcmp.obj: strcmp.c
-	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-strcmp.obj `if test -f 'strcmp.c'; then $(CYGPATH_W) 'strcmp.c'; else $(CYGPATH_W) '$(srcdir)/strcmp.c'; fi`
-
 lib_a-strncpy.o: strncpy.c
 	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-strncpy.o `test -f 'strncpy.c' || echo '$(srcdir)/'`strncpy.c
 
diff --git a/newlib/libc/machine/mips/strcmp.S b/newlib/libc/machine/mips/strcmp.S
new file mode 100644
index 000000000..b1d757ee3
--- /dev/null
+++ b/newlib/libc/machine/mips/strcmp.S
@@ -0,0 +1,261 @@
+/*
+ * Copyright (c) 2014
+ *      Imagination Technologies Limited.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the MIPS Technologies, Inc., nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY IMAGINATION TECHNOLOGIES LIMITED ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL IMAGINATION TECHNOLOGIES LIMITED BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifdef ANDROID_CHANGES
+# include "machine/asm.h"
+# include "machine/regdef.h"
+#elif _LIBC
+# include <sysdep.h>
+# include <regdef.h>
+# include <sys/asm.h>
+#elif _COMPILING_NEWLIB
+# include "machine/asm.h"
+# include "machine/regdef.h"
+#else
+# include <regdef.h>
+# include <sys/asm.h>
+#endif
+
+/* Technically strcmp should not read past the end of the strings being
+   compared.  We will read a full word that may contain excess bits beyond
+   the NULL string terminator but unless ENABLE_READAHEAD is set, we will not
+   read the next word after the end of string.  Setting ENABLE_READAHEAD will
+   improve performance but is technically illegal based on the definition of
+   strcmp.  */
+#ifdef ENABLE_READAHEAD
+# define DELAY_READ
+#else
+# define DELAY_READ nop
+#endif
+
+/* Testing on a little endian machine showed using CLZ was a
+   performance loss, so we are not turning it on by default.  */
+#if defined(ENABLE_CLZ) && (__mips_isa_rev > 1)
+# define USE_CLZ
+#endif
+
+/* Some asm.h files do not have the L macro definition.  */
+#ifndef L
+# if _MIPS_SIM == _ABIO32
+#  define L(label) $L ## label
+# else
+#  define L(label) .L ## label
+# endif
+#endif
+
+/* Some asm.h files do not have the PTR_ADDIU macro definition.  */
+#ifndef PTR_ADDIU
+# ifdef USE_DOUBLE
+#  define PTR_ADDIU       daddiu
+# else
+#  define PTR_ADDIU       addiu
+# endif
+#endif
+
+/* Allow the routine to be named something else if desired.  */
+#ifndef STRCMP_NAME
+# define STRCMP_NAME strcmp
+#endif
+
+#ifdef ANDROID_CHANGES
+LEAF(STRCMP_NAME, 0)
+#else
+LEAF(STRCMP_NAME)
+#endif
+	.set	nomips16
+	.set	noreorder
+
+	or	t0, a0, a1
+	andi	t0,0x3
+	bne	t0, zero, L(byteloop)
+
+/* Both strings are 4 byte aligned at this point.  */
+
+	lui	t8, 0x0101
+	ori	t8, t8, 0x0101
+	lui	t9, 0x7f7f
+	ori	t9, 0x7f7f
+
+#define STRCMP32(OFFSET) \
+	lw	v0, OFFSET(a0); \
+	lw	v1, OFFSET(a1); \
+	subu	t0, v0, t8; \
+	bne	v0, v1, L(worddiff); \
+	nor	t1, v0, t9; \
+	and	t0, t0, t1; \
+	bne	t0, zero, L(returnzero)
+
+L(wordloop):
+	STRCMP32(0)
+	DELAY_READ
+	STRCMP32(4)
+	DELAY_READ
+	STRCMP32(8)
+	DELAY_READ
+	STRCMP32(12)
+	DELAY_READ
+	STRCMP32(16)
+	DELAY_READ
+	STRCMP32(20)
+	DELAY_READ
+	STRCMP32(24)
+	DELAY_READ
+	STRCMP32(28)
+	PTR_ADDIU a0, a0, 32
+	b	L(wordloop)
+	PTR_ADDIU a1, a1, 32
+
+L(returnzero):
+	j	ra
+	move	v0, zero
+
+L(worddiff):
+#ifdef USE_CLZ
+	subu	t0, v0, t8
+	nor	t1, v0, t9
+	and	t1, t0, t1
+	xor	t0, v0, v1
+	or	t0, t0, t1
+# if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	wsbh	t0, t0
+	rotr	t0, t0, 16
+# endif
+	clz	t1, t0
+	and	t1, 0xf8
+# if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+	neg	t1
+	addu	t1, 24
+# endif
+	rotrv	v0, v0, t1
+	rotrv	v1, v1, t1
+	and	v0, v0, 0xff
+	and	v1, v1, 0xff
+	j	ra
+	subu	v0, v0, v1
+#else /* USE_CLZ */
+# if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	andi	t0, v0, 0xff
+	beq	t0, zero, L(wexit01)
+	andi	t1, v1, 0xff
+	bne	t0, t1, L(wexit01)
+
+	srl	t8, v0, 8
+	srl	t9, v1, 8
+	andi	t8, t8, 0xff
+	beq	t8, zero, L(wexit89)
+	andi	t9, t9, 0xff
+	bne	t8, t9, L(wexit89)
+
+	srl	t0, v0, 16
+	srl	t1, v1, 16
+	andi	t0, t0, 0xff
+	beq	t0, zero, L(wexit01)
+	andi	t1, t1, 0xff
+	bne	t0, t1, L(wexit01)
+
+	srl	t8, v0, 24
+	srl	t9, v1, 24
+# else /* __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ */
+	srl	t0, v0, 24
+	beq	t0, zero, L(wexit01)
+	srl	t1, v1, 24
+	bne	t0, t1, L(wexit01)
+
+	srl	t8, v0, 16
+	srl	t9, v1, 16
+	andi	t8, t8, 0xff
+	beq	t8, zero, L(wexit89)
+	andi	t9, t9, 0xff
+	bne	t8, t9, L(wexit89)
+
+	srl	t0, v0, 8
+	srl	t1, v1, 8
+	andi	t0, t0, 0xff
+	beq	t0, zero, L(wexit01)
+	andi	t1, t1, 0xff
+	bne	t0, t1, L(wexit01)
+
+	andi	t8, v0, 0xff
+	andi	t9, v1, 0xff
+# endif /* __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ */
+
+L(wexit89):
+	j	ra
+	subu	v0, t8, t9
+L(wexit01):
+	j	ra
+	subu	v0, t0, t1
+#endif /* USE_CLZ */
+
+/* It might seem better to do the 'beq' instruction between the two 'lbu'
+   instructions so that the nop is not needed but testing showed that this
+   code is actually faster (based on glibc strcmp test).  */
+#define BYTECMP01(OFFSET) \
+	lbu	v0, OFFSET(a0); \
+	lbu	v1, OFFSET(a1); \
+	beq	v0, zero, L(bexit01); \
+	nop; \
+	bne	v0, v1, L(bexit01)
+
+#define BYTECMP89(OFFSET) \
+	lbu	t8, OFFSET(a0); \
+	lbu	t9, OFFSET(a1); \
+	beq	t8, zero, L(bexit89); \
+	nop;	\
+	bne	t8, t9, L(bexit89)
+
+L(byteloop):
+	BYTECMP01(0)
+	BYTECMP89(1)
+	BYTECMP01(2)
+	BYTECMP89(3)
+	BYTECMP01(4)
+	BYTECMP89(5)
+	BYTECMP01(6)
+	BYTECMP89(7)
+	PTR_ADDIU a0, a0, 8
+	b	L(byteloop)
+	PTR_ADDIU a1, a1, 8
+
+L(bexit01):
+	j	ra
+	subu	v0, v0, v1
+L(bexit89):
+	j	ra
+	subu	v0, t8, t9
+
+	.set	at
+	.set	reorder
+
+END(STRCMP_NAME)
+#ifndef ANDROID_CHANGES
+# ifdef _LIBC
+libc_hidden_builtin_def (STRCMP_NAME)
+# endif
+#endif
diff --git a/newlib/libc/machine/mips/strcmp.c b/newlib/libc/machine/mips/strcmp.c
deleted file mode 100644
index c9c1c6595..000000000
--- a/newlib/libc/machine/mips/strcmp.c
+++ /dev/null
@@ -1,71 +0,0 @@
-/*
- * strcmp.c -- strcmp function.  On at least some MIPS chips, a strcmp that is
- * unrolled twice is faster than the 'optimized' C version in newlib.
- *
- * Copyright (c) 2001 Red Hat, Inc.
- *
- * The authors hereby grant permission to use, copy, modify, distribute,
- * and license this software and its documentation for any purpose, provided
- * that existing copyright notices are retained in all copies and that this
- * notice is included verbatim in any distributions. No written agreement,
- * license, or royalty fee is required for any of the authorized uses.
- * Modifications to this software may be copyrighted by their authors
- * and need not follow the licensing terms described here, provided that
- * the new terms are clearly indicated on the first page of each file where
- * they apply.  */
-
-#include <stddef.h>
-#include <string.h>
-#include <stdlib.h>
-
-int
-strcmp (const char *s1, const char *s2)
-{ 
-  unsigned const char *us1 = (unsigned const char *)s1;
-  unsigned const char *us2 = (unsigned const char *)s2;
-  int c1a, c1b;
-  int c2a, c2b;
-
-  /* If the pointers aren't both aligned to a 16-byte boundary, do the
-     comparison byte by byte, so that we don't get an invalid page fault if we
-     are comparing a string whose null byte is at the last byte on the last
-     valid page.  */
-  if (((((long)us1) | ((long)us2)) & 1) == 0)
-    {
-      c1a = *us1;
-      for (;;)
-	{
-	  c1b = *us2;
-	  us1 += 2;
-	  if (c1a == '\0')
-	    goto ret1;
-
-	  c2a = us1[-1];
-	  if (c1a != c1b)
-	    goto ret1;
-
-	  c2b = us2[1];
-	  us2 += 2;
-	  if (c2a == '\0')
-	    break;
-
-	  c1a = *us1;
-	  if (c2a != c2b)
-	    break;
-	}
-
-      return c2a - c2b;
-    }
-  else
-    {
-      do
-	{
-	  c1a = *us1++;
-	  c1b = *us2++;
-	}
-      while (c1a != '\0' && c1a == c1b);
-    }
-
- ret1:
-  return c1a - c1b;
-}