[ARM] Adding strlen.S

The patch adds strlen.S to contain the complementary preprocessor
logic to strlen-stub.c intended to provide #inclusion of alternative
.S implementations.

Initially we just include the existing strlen-armv7.S implementation.

We rewrite _ISA_ARMV7 in both strlen.S and strlen-stub.c to use the
underlying existing underlying defintion from arm_asm.h in order to
avoide including that file, this is in effect the first step towards a
move to ACLE predefines only.

Tested by building newlib and comparing libc.a binaries before and
after for all permutations of:

      Architectures:
        armv4 armv4t armv5 armv5t armv5te armv6 armv6j armv6k
        armv6z armv6kz armv6t2 armv6-m armv6s-m armv7 armv7-a
        armv7ve armv7-r armv7-m armv7e-m armv8-a iwmmxt iwmmxt2

      ISAs:
        thumb arm

      Optimization Levels:
        Os O2

      Excluding:
        armv6s-m -mthumb
        armv6-m -mthumb

        armv6zk -mthumb
        armv6z -mthumb
        armv6k -mthumb
        armv6j -mthumb

newlib/ChangeLog

@@ -1,3 +1,11 @@
+2015-11-13  Marcus Shawcroft  <marcus.shawcroft@arm.com>
+
+	* libc/machine/arm/Makefile.am: Adding strlen.S.
+	* libc/machine/arm/Makefile.in: Regenerate.
+	* libc/machine/arm/strlen.S: New.
+	* libc/machine/arm/strlen-stub.c: Rewrite #if condition.
+	* libc/machine/arm/strlen-armv7.S: Remove surrounding #if.
+
 2015-11-13  Marcus Shawcroft  <marcus.shawcroft@arm.com>
 
 	* libc/machine/arm/Makefile.am: Rename strlen.c to strlen-stub.c

newlib/libc/machine/arm/Makefile.am

@@ -9,7 +9,7 @@ AM_CCASFLAGS = $(INCLUDES)
 noinst_LIBRARIES = lib.a
 
 lib_a_SOURCES = setjmp.S access.c strcmp.S strcpy.c \
-		strlen-armv7.S aeabi_memcpy.c aeabi_memcpy-armv7a.S \
+		aeabi_memcpy.c aeabi_memcpy-armv7a.S \
 		aeabi_memmove.c aeabi_memmove-soft.S \
 		aeabi_memset.c aeabi_memset-soft.S aeabi_memclr.c
 lib_a_SOURCES += memchr-stub.c
@@ -17,6 +17,7 @@ lib_a_SOURCES += memchr.S
 lib_a_SOURCES += memcpy-stub.c
 lib_a_SOURCES += memcpy.S
 lib_a_SOURCES += strlen-stub.c
+lib_a_SOURCES += strlen.S
 
 lib_a_CCASFLAGS=$(AM_CCASFLAGS)
 lib_a_CFLAGS = $(AM_CFLAGS)

newlib/libc/machine/arm/Makefile.in

@@ -71,14 +71,15 @@ lib_a_AR = $(AR) $(ARFLAGS)
 lib_a_LIBADD =
 am_lib_a_OBJECTS = lib_a-setjmp.$(OBJEXT) lib_a-access.$(OBJEXT) \
 	lib_a-strcmp.$(OBJEXT) lib_a-strcpy.$(OBJEXT) \
-	lib_a-strlen-armv7.$(OBJEXT) lib_a-aeabi_memcpy.$(OBJEXT) \
+	lib_a-aeabi_memcpy.$(OBJEXT) \
 	lib_a-aeabi_memcpy-armv7a.$(OBJEXT) \
 	lib_a-aeabi_memmove.$(OBJEXT) \
 	lib_a-aeabi_memmove-soft.$(OBJEXT) \
 	lib_a-aeabi_memset.$(OBJEXT) lib_a-aeabi_memset-soft.$(OBJEXT) \
 	lib_a-aeabi_memclr.$(OBJEXT) lib_a-memchr-stub.$(OBJEXT) \
 	lib_a-memchr.$(OBJEXT) lib_a-memcpy-stub.$(OBJEXT) \
-	lib_a-memcpy.$(OBJEXT) lib_a-strlen-stub.$(OBJEXT)
+	lib_a-memcpy.$(OBJEXT) lib_a-strlen-stub.$(OBJEXT) \
+	lib_a-strlen.$(OBJEXT)
 lib_a_OBJECTS = $(am_lib_a_OBJECTS)
 DEFAULT_INCLUDES = -I.@am__isrc@
 depcomp =
@@ -205,11 +206,11 @@ AUTOMAKE_OPTIONS = cygnus
 INCLUDES = $(NEWLIB_CFLAGS) $(CROSS_CFLAGS) $(TARGET_CFLAGS)
 AM_CCASFLAGS = $(INCLUDES)
 noinst_LIBRARIES = lib.a
-lib_a_SOURCES = setjmp.S access.c strcmp.S strcpy.c strlen-armv7.S \
+lib_a_SOURCES = setjmp.S access.c strcmp.S strcpy.c aeabi_memcpy.c \
-	aeabi_memcpy.c aeabi_memcpy-armv7a.S aeabi_memmove.c \
+	aeabi_memcpy-armv7a.S aeabi_memmove.c aeabi_memmove-soft.S \
-	aeabi_memmove-soft.S aeabi_memset.c aeabi_memset-soft.S \
+	aeabi_memset.c aeabi_memset-soft.S aeabi_memclr.c \
-	aeabi_memclr.c memchr-stub.c memchr.S memcpy-stub.c memcpy.S \
+	memchr-stub.c memchr.S memcpy-stub.c memcpy.S strlen-stub.c \
-	strlen-stub.c
+	strlen.S
 lib_a_CCASFLAGS = $(AM_CCASFLAGS)
 lib_a_CFLAGS = $(AM_CFLAGS)
 ACLOCAL_AMFLAGS = -I ../../.. -I ../../../..
@@ -295,12 +296,6 @@ lib_a-strcmp.o: 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-strlen-armv7.o: strlen-armv7.S
-	$(CCAS) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CCASFLAGS) $(CCASFLAGS) -c -o lib_a-strlen-armv7.o `test -f 'strlen-armv7.S' || echo '$(srcdir)/'`strlen-armv7.S
-
-lib_a-strlen-armv7.obj: strlen-armv7.S
-	$(CCAS) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CCASFLAGS) $(CCASFLAGS) -c -o lib_a-strlen-armv7.obj `if test -f 'strlen-armv7.S'; then $(CYGPATH_W) 'strlen-armv7.S'; else $(CYGPATH_W) '$(srcdir)/strlen-armv7.S'; fi`
-
 lib_a-aeabi_memcpy-armv7a.o: aeabi_memcpy-armv7a.S
 	$(CCAS) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CCASFLAGS) $(CCASFLAGS) -c -o lib_a-aeabi_memcpy-armv7a.o `test -f 'aeabi_memcpy-armv7a.S' || echo '$(srcdir)/'`aeabi_memcpy-armv7a.S
 
@@ -331,6 +326,12 @@ lib_a-memcpy.o: memcpy.S
 lib_a-memcpy.obj: memcpy.S
 	$(CCAS) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CCASFLAGS) $(CCASFLAGS) -c -o lib_a-memcpy.obj `if test -f 'memcpy.S'; then $(CYGPATH_W) 'memcpy.S'; else $(CYGPATH_W) '$(srcdir)/memcpy.S'; fi`
 
+lib_a-strlen.o: strlen.S
+	$(CCAS) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CCASFLAGS) $(CCASFLAGS) -c -o lib_a-strlen.o `test -f 'strlen.S' || echo '$(srcdir)/'`strlen.S
+
+lib_a-strlen.obj: strlen.S
+	$(CCAS) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CCASFLAGS) $(CCASFLAGS) -c -o lib_a-strlen.obj `if test -f 'strlen.S'; then $(CYGPATH_W) 'strlen.S'; else $(CYGPATH_W) '$(srcdir)/strlen.S'; fi`
+
 .c.o:
 	$(COMPILE) -c $<
 
@@ -385,11 +386,11 @@ lib_a-memcpy-stub.o: memcpy-stub.c
 lib_a-memcpy-stub.obj: memcpy-stub.c
 	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-memcpy-stub.obj `if test -f 'memcpy-stub.c'; then $(CYGPATH_W) 'memcpy-stub.c'; else $(CYGPATH_W) '$(srcdir)/memcpy-stub.c'; fi`
 
-lib_a-strlen.o: strlen.c
+lib_a-strlen-stub.o: strlen-stub.c
-	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-strlen.o `test -f 'strlen.c' || echo '$(srcdir)/'`strlen.c
+	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-strlen-stub.o `test -f 'strlen-stub.c' || echo '$(srcdir)/'`strlen-stub.c
 
-lib_a-strlen.obj: strlen.c
+lib_a-strlen-stub.obj: strlen-stub.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`
+	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-strlen-stub.obj `if test -f 'strlen-stub.c'; then $(CYGPATH_W) 'strlen-stub.c'; else $(CYGPATH_W) '$(srcdir)/strlen-stub.c'; fi`
 
 ID: $(HEADERS) $(SOURCES) $(LISP) $(TAGS_FILES)
 	list='$(SOURCES) $(HEADERS) $(LISP) $(TAGS_FILES)'; \

newlib/libc/machine/arm/strlen-armv7.S

@@ -34,13 +34,6 @@
 
 #include "arm_asm.h"
 
-/* NOTE: This ifdef MUST match the ones in arm/strlen.c
-   We fallback to the one in arm/strlen.c for size optimised or
-   for older architectures. */
-#if (defined(_ISA_ARM_7) || defined(__ARM_ARCH_6T2__)) && \
-    !(defined (__OPTIMIZE_SIZE__) || defined (PREFER_SIZE_OVER_SPEED) || \
-      (defined (__thumb__) && !defined (__thumb2__)))
-
 	.macro def_fn f p2align=0
 	.text
 	.p2align \p2align
@@ -153,5 +146,3 @@ def_fn	strlen p2align=6
 	mov	const_0, #0
 	b	.Lstart_realigned
 	.size	strlen, . - strlen
-
-#endif

newlib/libc/machine/arm/strlen-stub.c

@@ -67,8 +67,8 @@ strlen (const char* str)
 #if defined __thumb__ && ! defined __thumb2__
 #include "../../string/strlen.c"
 
-#elif defined _ISA_ARM_7 || defined __ARM_ARCH_6T2__
+#elif (__ARM_ARCH >= 7 && defined __ARM_ARCH_ISA_ARM) || defined __ARM_ARCH_6T2__
-  /* Implemented in strlen-armv7.S.  */
+  /* Implemented in strlen.S.  */
 
 #else
 size_t __attribute__((naked))

newlib/libc/machine/arm/strlen.S

@@ -0,0 +1,48 @@
+/* Copyright (c) 2015 ARM Ltd.
+   All rights reserved.
+
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions are met:
+       * Redistributions of source code must retain the above copyright
+	 notice, this list of conditions and the following disclaimer.
+       * 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.
+       * Neither the name of the Linaro 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 THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+   "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 THE COPYRIGHT
+   HOLDER OR CONTRIBUTORS 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.  */
+
+#include "acle-compat.h"
+
+#if defined __OPTIMIZE_SIZE__ || defined PREFER_SIZE_OVER_SPEED
+#if defined __thumb__ && !defined __thumb2__
+  /* Implemented in strlen-stub.c.  */
+
+#else
+  /* Implemented in strlen-stub.c.  */
+
+#endif
+
+#else /* defined __OPTIMIZE_SIZE__ || defined PREFER_SIZE_OVER_SPEED */
+#if defined __thumb__ && ! defined __thumb2__
+  /* Implemented in strlen-stub.c.  */
+
+#elif (__ARM_ARCH >= 7 && defined __ARM_ARCH_ISA_ARM) || defined __ARM_ARCH_6T2__
+#include "strlen-armv7.S"
+
+#else
+  /* Implemented in strlen-stub.c.  */
+#endif
+#endif