* libc/machine/arm/strcmp.S: New File.
* libc/machine/arm/strcmp.c: Deleted. * libc/machine/arm/Makefile.am: Replaces strcmp.c with strcmp.S * libc/machine/arm/Makefile.in: Regenerated. * testsuite/newlib.string/strcmp-1.c: New file.
This commit is contained in:
Corinna Vinschen
parent
a442c9cddc
commit
3543a40d5c
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@ -1,3 +1,11 @@
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2012-02-08 Greta Yorsh <Greta.Yorsh@arm.com>
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* libc/machine/arm/strcmp.S: New File.
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* libc/machine/arm/strcmp.c: Deleted.
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* libc/machine/arm/Makefile.am: Replaces strcmp.c with strcmp.S
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* libc/machine/arm/Makefile.in: Regenerated.
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* testsuite/newlib.string/strcmp-1.c: New file.
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2012-02-07 Corinna Vinschen <vinschen@redhat.com>
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2012-02-07 Corinna Vinschen <vinschen@redhat.com>
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* libc/include/inttypes.h: Redefine pointer type macros.
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* libc/include/inttypes.h: Redefine pointer type macros.
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@ -8,7 +8,7 @@ AM_CCASFLAGS = $(INCLUDES)
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noinst_LIBRARIES = lib.a
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noinst_LIBRARIES = lib.a
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lib_a_SOURCES = setjmp.S access.c strlen.c strcmp.c strcpy.c \
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lib_a_SOURCES = setjmp.S access.c strlen.c strcmp.S strcpy.c \
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memcpy.S memcpy-stub.c memchr-stub.c memchr.S \
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memcpy.S memcpy-stub.c memchr-stub.c memchr.S \
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strlen.c strlen-armv7.S
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strlen.c strlen-armv7.S
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lib_a_CCASFLAGS=$(AM_CCASFLAGS)
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lib_a_CCASFLAGS=$(AM_CCASFLAGS)
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@ -178,7 +178,7 @@ AUTOMAKE_OPTIONS = cygnus
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INCLUDES = $(NEWLIB_CFLAGS) $(CROSS_CFLAGS) $(TARGET_CFLAGS)
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INCLUDES = $(NEWLIB_CFLAGS) $(CROSS_CFLAGS) $(TARGET_CFLAGS)
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AM_CCASFLAGS = $(INCLUDES)
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AM_CCASFLAGS = $(INCLUDES)
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noinst_LIBRARIES = lib.a
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noinst_LIBRARIES = lib.a
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lib_a_SOURCES = setjmp.S access.c strlen.c strcmp.c strcpy.c \
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lib_a_SOURCES = setjmp.S access.c strlen.c strcmp.S strcpy.c \
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memcpy.S memcpy-stub.c memchr-stub.c memchr.S \
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memcpy.S memcpy-stub.c memchr-stub.c memchr.S \
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strlen.c strlen-armv7.S
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strlen.c strlen-armv7.S
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@ -250,6 +250,12 @@ lib_a-setjmp.o: setjmp.S
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lib_a-setjmp.obj: setjmp.S
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lib_a-setjmp.obj: setjmp.S
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$(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`
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$(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`
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lib_a-strcmp.o: strcmp.S
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$(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
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lib_a-strcmp.obj: strcmp.S
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$(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`
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lib_a-memcpy.o: memcpy.S
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lib_a-memcpy.o: memcpy.S
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$(CCAS) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CCASFLAGS) $(CCASFLAGS) -c -o lib_a-memcpy.o `test -f 'memcpy.S' || echo '$(srcdir)/'`memcpy.S
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$(CCAS) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CCASFLAGS) $(CCASFLAGS) -c -o lib_a-memcpy.o `test -f 'memcpy.S' || echo '$(srcdir)/'`memcpy.S
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@ -286,12 +292,6 @@ lib_a-strlen.o: strlen.c
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lib_a-strlen.obj: strlen.c
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lib_a-strlen.obj: strlen.c
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$(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`
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$(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`
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lib_a-strcmp.o: strcmp.c
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$(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
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lib_a-strcmp.obj: strcmp.c
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$(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`
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lib_a-strcpy.o: strcpy.c
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lib_a-strcpy.o: strcpy.c
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$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-strcpy.o `test -f 'strcpy.c' || echo '$(srcdir)/'`strcpy.c
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$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-strcpy.o `test -f 'strcpy.c' || echo '$(srcdir)/'`strcpy.c
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@ -0,0 +1,777 @@
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/*
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* Copyright (c) 2012 ARM Ltd
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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|
* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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|
* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the company may not be used to endorse or promote
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* products derived from this software without specific prior written
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* permission.
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*
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* THIS SOFTWARE IS PROVIDED BY ARM LTD ``AS IS'' AND ANY EXPRESS OR IMPLIED
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|
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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|
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL ARM LTD BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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|
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
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|
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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|
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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|
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "arm_asm.h"
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#ifdef __ARMEB__
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#define S2LOMEM lsl
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#define S2LOMEMEQ lsleq
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#define S2HIMEM lsr
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#define MSB 0x000000ff
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#define LSB 0xff000000
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#define BYTE0_OFFSET 24
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#define BYTE1_OFFSET 16
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#define BYTE2_OFFSET 8
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#define BYTE3_OFFSET 0
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#else /* not __ARMEB__ */
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#define S2LOMEM lsr
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#define S2LOMEMEQ lsreq
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#define S2HIMEM lsl
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#define BYTE0_OFFSET 0
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#define BYTE1_OFFSET 8
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#define BYTE2_OFFSET 16
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#define BYTE3_OFFSET 24
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#define MSB 0xff000000
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#define LSB 0x000000ff
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#endif /* not __ARMEB__ */
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.syntax unified
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#if defined (__thumb__)
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.thumb
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.thumb_func
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#endif
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.global strcmp
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.type strcmp, %function
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strcmp:
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#if (defined (__thumb__) && !defined (__thumb2__))
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1:
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ldrb r2, [r0]
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ldrb r3, [r1]
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adds r0, r0, #1
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adds r1, r1, #1
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cmp r2, #0
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beq 2f
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cmp r2, r3
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beq 1b
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2:
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subs r0, r2, r3
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bx lr
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#elif (defined (__OPTIMIZE_SIZE__) || defined (PREFER_SIZE_OVER_SPEED))
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1:
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ldrb r2, [r0], #1
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ldrb r3, [r1], #1
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cmp r2, #1
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it cs
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cmpcs r2, r3
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beq 1b
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subs r0, r2, r3
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RETURN
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#elif (defined (_ISA_THUMB_2) || defined (_ISA_ARM_6))
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/* Use LDRD whenever possible. */
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/* The main thing to look out for when comparing large blocks is that
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the loads do not cross a page boundary when loading past the index
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of the byte with the first difference or the first string-terminator.
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For example, if the strings are identical and the string-terminator
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is at index k, byte by byte comparison will not load beyond address
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s1+k and s2+k; word by word comparison may load up to 3 bytes beyond
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|
k; double word - up to 7 bytes. If the load of these bytes crosses
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a page boundary, it might cause a memory fault (if the page is not mapped)
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that would not have happened in byte by byte comparison.
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If an address is (double) word aligned, then a load of a (double) word
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from that address will not cross a page boundary.
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Therefore, the algorithm below considers word and double-word alignment
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of strings separately. */
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/* High-level description of the algorithm.
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* The fast path: if both strings are double-word aligned,
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use LDRD to load two words from each string in every loop iteration.
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* If the strings have the same offset from a word boundary,
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use LDRB to load and compare byte by byte until
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the first string is aligned to a word boundary (at most 3 bytes).
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|
This is optimized for quick return on short unaligned strings.
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* If the strings have the same offset from a double-word boundary,
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|
use LDRD to load two words from each string in every loop iteration, as in the fast path.
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* If the strings do not have the same offset from a double-word boundary,
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||||||
|
load a word from the second string before the loop to initialize the queue.
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||||||
|
Use LDRD to load two words from every string in every loop iteration.
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||||||
|
Inside the loop, load the second word from the second string only after comparing
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||||||
|
the first word, using the queued value, to guarantee safety across page boundaries.
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||||||
|
* If the strings do not have the same offset from a word boundary,
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|
use LDR and a shift queue. Order of loads and comparisons matters,
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||||||
|
similarly to the previous case.
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||||||
|
|
||||||
|
* Use UADD8 and SEL to compare words, and use REV and CLZ to compute the return value.
|
||||||
|
* The only difference between ARM and Thumb modes is the use of CBZ instruction.
|
||||||
|
* The only difference between big and little endian is the use of REV in little endian
|
||||||
|
to compute the return value, instead of MOV.
|
||||||
|
* No preload. [TODO.]
|
||||||
|
*/
|
||||||
|
|
||||||
|
.macro m_cbz reg label
|
||||||
|
#ifdef __thumb2__
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||||||
|
cbz \reg, \label
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||||||
|
#else /* not defined __thumb2__ */
|
||||||
|
cmp \reg, #0
|
||||||
|
beq \label
|
||||||
|
#endif /* not defined __thumb2__ */
|
||||||
|
.endm /* m_cbz */
|
||||||
|
|
||||||
|
.macro m_cbnz reg label
|
||||||
|
#ifdef __thumb2__
|
||||||
|
cbnz \reg, \label
|
||||||
|
#else /* not defined __thumb2__ */
|
||||||
|
cmp \reg, #0
|
||||||
|
bne \label
|
||||||
|
#endif /* not defined __thumb2__ */
|
||||||
|
.endm /* m_cbnz */
|
||||||
|
|
||||||
|
.macro init
|
||||||
|
/* Macro to save temporary registers and prepare magic values. */
|
||||||
|
subs sp, sp, #16
|
||||||
|
strd r4, r5, [sp, #8]
|
||||||
|
strd r6, r7, [sp]
|
||||||
|
mvn r6, #0 /* all F */
|
||||||
|
mov r7, #0 /* all 0 */
|
||||||
|
.endm /* init */
|
||||||
|
|
||||||
|
.macro magic_compare_and_branch w1 w2 label
|
||||||
|
/* Macro to compare registers w1 and w2 and conditionally branch to label. */
|
||||||
|
cmp \w1, \w2 /* Are w1 and w2 the same? */
|
||||||
|
magic_find_zero_bytes \w1
|
||||||
|
it eq
|
||||||
|
cmpeq ip, #0 /* Is there a zero byte in w1? */
|
||||||
|
bne \label
|
||||||
|
.endm /* magic_compare_and_branch */
|
||||||
|
|
||||||
|
.macro magic_find_zero_bytes w1
|
||||||
|
/* Macro to find all-zero bytes in w1, result is in ip. */
|
||||||
|
#if (defined (__ARM_FEATURE_DSP))
|
||||||
|
uadd8 ip, \w1, r6
|
||||||
|
sel ip, r7, r6
|
||||||
|
#else /* not defined (__ARM_FEATURE_DSP) */
|
||||||
|
/* __ARM_FEATURE_DSP is not defined for some Cortex-M processors.
|
||||||
|
Coincidently, these processors only have Thumb-2 mode, where we can use the
|
||||||
|
the (large) magic constant available directly as an immediate in instructions.
|
||||||
|
Note that we cannot use the magic constant in ARM mode, where we need
|
||||||
|
to create the constant in a register. */
|
||||||
|
sub ip, \w1, #0x01010101
|
||||||
|
bic ip, ip, \w1
|
||||||
|
and ip, ip, #0x80808080
|
||||||
|
#endif /* not defined (__ARM_FEATURE_DSP) */
|
||||||
|
.endm /* magic_find_zero_bytes */
|
||||||
|
|
||||||
|
.macro setup_return w1 w2
|
||||||
|
#ifdef __ARMEB__
|
||||||
|
mov r1, \w1
|
||||||
|
mov r2, \w2
|
||||||
|
#else /* not __ARMEB__ */
|
||||||
|
rev r1, \w1
|
||||||
|
rev r2, \w2
|
||||||
|
#endif /* not __ARMEB__ */
|
||||||
|
.endm /* setup_return */
|
||||||
|
|
||||||
|
/*
|
||||||
|
optpld r0, #0
|
||||||
|
optpld r1, #0
|
||||||
|
*/
|
||||||
|
|
||||||
|
/* Are both strings double-word aligned? */
|
||||||
|
orr ip, r0, r1
|
||||||
|
tst ip, #7
|
||||||
|
bne do_align
|
||||||
|
|
||||||
|
/* Fast path. */
|
||||||
|
init
|
||||||
|
|
||||||
|
doubleword_aligned:
|
||||||
|
|
||||||
|
/* Get here when the strings to compare are double-word aligned. */
|
||||||
|
/* Compare two words in every iteration. */
|
||||||
|
.p2align 2
|
||||||
|
2:
|
||||||
|
/*
|
||||||
|
optpld r0, #16
|
||||||
|
optpld r1, #16
|
||||||
|
*/
|
||||||
|
|
||||||
|
/* Load the next double-word from each string. */
|
||||||
|
ldrd r2, r3, [r0], #8
|
||||||
|
ldrd r4, r5, [r1], #8
|
||||||
|
|
||||||
|
magic_compare_and_branch w1=r2, w2=r4, label=return_24
|
||||||
|
magic_compare_and_branch w1=r3, w2=r5, label=return_35
|
||||||
|
b 2b
|
||||||
|
|
||||||
|
do_align:
|
||||||
|
/* Is the first string word-aligned? */
|
||||||
|
ands ip, r0, #3
|
||||||
|
beq word_aligned_r0
|
||||||
|
|
||||||
|
/* Fast compare byte by byte until the first string is word-aligned. */
|
||||||
|
/* The offset of r0 from a word boundary is in ip. Thus, the number of bytes
|
||||||
|
to read until the next word boudnary is 4-ip. */
|
||||||
|
bic r0, r0, #3
|
||||||
|
ldr r2, [r0], #4
|
||||||
|
lsls ip, ip, #31
|
||||||
|
beq byte2
|
||||||
|
bcs byte3
|
||||||
|
|
||||||
|
byte1:
|
||||||
|
ldrb ip, [r1], #1
|
||||||
|
uxtb r3, r2, ror #BYTE1_OFFSET
|
||||||
|
subs ip, r3, ip
|
||||||
|
bne fast_return
|
||||||
|
m_cbz reg=r3, label=fast_return
|
||||||
|
|
||||||
|
byte2:
|
||||||
|
ldrb ip, [r1], #1
|
||||||
|
uxtb r3, r2, ror #BYTE2_OFFSET
|
||||||
|
subs ip, r3, ip
|
||||||
|
bne fast_return
|
||||||
|
m_cbz reg=r3, label=fast_return
|
||||||
|
|
||||||
|
byte3:
|
||||||
|
ldrb ip, [r1], #1
|
||||||
|
uxtb r3, r2, ror #BYTE3_OFFSET
|
||||||
|
subs ip, r3, ip
|
||||||
|
bne fast_return
|
||||||
|
m_cbnz reg=r3, label=word_aligned_r0
|
||||||
|
|
||||||
|
fast_return:
|
||||||
|
mov r0, ip
|
||||||
|
bx lr
|
||||||
|
|
||||||
|
word_aligned_r0:
|
||||||
|
init
|
||||||
|
/* The first string is word-aligned. */
|
||||||
|
/* Is the second string word-aligned? */
|
||||||
|
ands ip, r1, #3
|
||||||
|
bne strcmp_unaligned
|
||||||
|
|
||||||
|
word_aligned:
|
||||||
|
/* The strings are word-aligned. */
|
||||||
|
/* Is the first string double-word aligned? */
|
||||||
|
tst r0, #4
|
||||||
|
beq doubleword_aligned_r0
|
||||||
|
|
||||||
|
/* If r0 is not double-word aligned yet, align it by loading
|
||||||
|
and comparing the next word from each string. */
|
||||||
|
ldr r2, [r0], #4
|
||||||
|
ldr r4, [r1], #4
|
||||||
|
magic_compare_and_branch w1=r2 w2=r4 label=return_24
|
||||||
|
|
||||||
|
doubleword_aligned_r0:
|
||||||
|
/* Get here when r0 is double-word aligned. */
|
||||||
|
/* Is r1 doubleword_aligned? */
|
||||||
|
tst r1, #4
|
||||||
|
beq doubleword_aligned
|
||||||
|
|
||||||
|
/* Get here when the strings to compare are word-aligned,
|
||||||
|
r0 is double-word aligned, but r1 is not double-word aligned. */
|
||||||
|
|
||||||
|
/* Initialize the queue. */
|
||||||
|
ldr r5, [r1], #4
|
||||||
|
|
||||||
|
/* Compare two words in every iteration. */
|
||||||
|
.p2align 2
|
||||||
|
3:
|
||||||
|
/*
|
||||||
|
optpld r0, #16
|
||||||
|
optpld r1, #16
|
||||||
|
*/
|
||||||
|
|
||||||
|
/* Load the next double-word from each string and compare. */
|
||||||
|
ldrd r2, r3, [r0], #8
|
||||||
|
magic_compare_and_branch w1=r2 w2=r5 label=return_25
|
||||||
|
ldrd r4, r5, [r1], #8
|
||||||
|
magic_compare_and_branch w1=r3 w2=r4 label=return_34
|
||||||
|
b 3b
|
||||||
|
|
||||||
|
.macro miscmp_word offsetlo offsethi
|
||||||
|
/* Macro to compare misaligned strings. */
|
||||||
|
/* r0, r1 are word-aligned, and at least one of the strings
|
||||||
|
is not double-word aligned. */
|
||||||
|
/* Compare one word in every loop iteration. */
|
||||||
|
/* OFFSETLO is the original bit-offset of r1 from a word-boundary,
|
||||||
|
OFFSETHI is 32 - OFFSETLO (i.e., offset from the next word). */
|
||||||
|
|
||||||
|
/* Initialize the shift queue. */
|
||||||
|
ldr r5, [r1], #4
|
||||||
|
|
||||||
|
/* Compare one word from each string in every loop iteration. */
|
||||||
|
.p2align 2
|
||||||
|
7:
|
||||||
|
ldr r3, [r0], #4
|
||||||
|
S2LOMEM r5, r5, #\offsetlo
|
||||||
|
magic_find_zero_bytes w1=r3
|
||||||
|
cmp r7, ip, S2HIMEM #\offsetlo
|
||||||
|
and r2, r3, r6, S2LOMEM #\offsetlo
|
||||||
|
it eq
|
||||||
|
cmpeq r2, r5
|
||||||
|
bne return_25
|
||||||
|
ldr r5, [r1], #4
|
||||||
|
cmp ip, #0
|
||||||
|
eor r3, r2, r3
|
||||||
|
S2HIMEM r2, r5, #\offsethi
|
||||||
|
it eq
|
||||||
|
cmpeq r3, r2
|
||||||
|
bne return_32
|
||||||
|
b 7b
|
||||||
|
.endm /* miscmp_word */
|
||||||
|
|
||||||
|
strcmp_unaligned:
|
||||||
|
/* r0 is word-aligned, r1 is at offset ip from a word. */
|
||||||
|
/* Align r1 to the (previous) word-boundary. */
|
||||||
|
bic r1, r1, #3
|
||||||
|
|
||||||
|
/* Unaligned comparison word by word using LDRs. */
|
||||||
|
cmp ip, #2
|
||||||
|
beq miscmp_word_16 /* If ip == 2. */
|
||||||
|
bge miscmp_word_24 /* If ip == 3. */
|
||||||
|
miscmp_word offsetlo=8 offsethi=24 /* If ip == 1. */
|
||||||
|
miscmp_word_16: miscmp_word offsetlo=16 offsethi=16
|
||||||
|
miscmp_word_24: miscmp_word offsetlo=24 offsethi=8
|
||||||
|
|
||||||
|
|
||||||
|
return_32:
|
||||||
|
setup_return w1=r3, w2=r2
|
||||||
|
b do_return
|
||||||
|
return_34:
|
||||||
|
setup_return w1=r3, w2=r4
|
||||||
|
b do_return
|
||||||
|
return_25:
|
||||||
|
setup_return w1=r2, w2=r5
|
||||||
|
b do_return
|
||||||
|
return_35:
|
||||||
|
setup_return w1=r3, w2=r5
|
||||||
|
b do_return
|
||||||
|
return_24:
|
||||||
|
setup_return w1=r2, w2=r4
|
||||||
|
|
||||||
|
do_return:
|
||||||
|
|
||||||
|
#ifdef __ARMEB__
|
||||||
|
mov r0, ip
|
||||||
|
#else /* not __ARMEB__ */
|
||||||
|
rev r0, ip
|
||||||
|
#endif /* not __ARMEB__ */
|
||||||
|
|
||||||
|
/* Restore temporaries early, before computing the return value. */
|
||||||
|
ldrd r6, r7, [sp]
|
||||||
|
ldrd r4, r5, [sp, #8]
|
||||||
|
adds sp, sp, #16
|
||||||
|
|
||||||
|
/* There is a zero or a different byte between r1 and r2. */
|
||||||
|
/* r0 contains a mask of all-zero bytes in r1. */
|
||||||
|
/* Using r0 and not ip here because cbz requires low register. */
|
||||||
|
m_cbz reg=r0, label=compute_return_value
|
||||||
|
clz r0, r0
|
||||||
|
/* r0 contains the number of bits on the left of the first all-zero byte in r1. */
|
||||||
|
rsb r0, r0, #24
|
||||||
|
/* Here, r0 contains the number of bits on the right of the first all-zero byte in r1. */
|
||||||
|
lsr r1, r1, r0
|
||||||
|
lsr r2, r2, r0
|
||||||
|
|
||||||
|
compute_return_value:
|
||||||
|
subs r0, r1, r2
|
||||||
|
bx lr
|
||||||
|
|
||||||
|
|
||||||
|
#else /* !(defined (_ISA_THUMB_2) || defined (_ISA_ARM_6)
|
||||||
|
defined (__OPTIMIZE_SIZE__) || defined (PREFER_SIZE_OVER_SPEED) ||
|
||||||
|
(defined (__thumb__) && !defined (__thumb2__))) */
|
||||||
|
|
||||||
|
/* Use LDR whenever possible. */
|
||||||
|
|
||||||
|
#ifdef __thumb2__
|
||||||
|
#define magic1(REG) 0x01010101
|
||||||
|
#define magic2(REG) 0x80808080
|
||||||
|
#else
|
||||||
|
#define magic1(REG) REG
|
||||||
|
#define magic2(REG) REG, lsl #7
|
||||||
|
#endif
|
||||||
|
|
||||||
|
optpld r0
|
||||||
|
optpld r1
|
||||||
|
eor r2, r0, r1
|
||||||
|
tst r2, #3
|
||||||
|
/* Strings not at same byte offset from a word boundary. */
|
||||||
|
bne strcmp_unaligned
|
||||||
|
ands r2, r0, #3
|
||||||
|
bic r0, r0, #3
|
||||||
|
bic r1, r1, #3
|
||||||
|
ldr ip, [r0], #4
|
||||||
|
it eq
|
||||||
|
ldreq r3, [r1], #4
|
||||||
|
beq 1f
|
||||||
|
/* Although s1 and s2 have identical initial alignment, they are
|
||||||
|
not currently word aligned. Rather than comparing bytes,
|
||||||
|
make sure that any bytes fetched from before the addressed
|
||||||
|
bytes are forced to 0xff. Then they will always compare
|
||||||
|
equal. */
|
||||||
|
eor r2, r2, #3
|
||||||
|
lsl r2, r2, #3
|
||||||
|
mvn r3, MSB
|
||||||
|
S2LOMEM r2, r3, r2
|
||||||
|
ldr r3, [r1], #4
|
||||||
|
orr ip, ip, r2
|
||||||
|
orr r3, r3, r2
|
||||||
|
1:
|
||||||
|
#ifndef __thumb2__
|
||||||
|
/* Load the 'magic' constant 0x01010101. */
|
||||||
|
str r4, [sp, #-4]!
|
||||||
|
mov r4, #1
|
||||||
|
orr r4, r4, r4, lsl #8
|
||||||
|
orr r4, r4, r4, lsl #16
|
||||||
|
#endif
|
||||||
|
.p2align 2
|
||||||
|
4:
|
||||||
|
optpld r0, #8
|
||||||
|
optpld r1, #8
|
||||||
|
sub r2, ip, magic1(r4)
|
||||||
|
cmp ip, r3
|
||||||
|
itttt eq
|
||||||
|
/* check for any zero bytes in first word */
|
||||||
|
biceq r2, r2, ip
|
||||||
|
tsteq r2, magic2(r4)
|
||||||
|
ldreq ip, [r0], #4
|
||||||
|
ldreq r3, [r1], #4
|
||||||
|
beq 4b
|
||||||
|
2:
|
||||||
|
/* There's a zero or a different byte in the word */
|
||||||
|
S2HIMEM r0, ip, #24
|
||||||
|
S2LOMEM ip, ip, #8
|
||||||
|
cmp r0, #1
|
||||||
|
it cs
|
||||||
|
cmpcs r0, r3, S2HIMEM #24
|
||||||
|
it eq
|
||||||
|
S2LOMEMEQ r3, r3, #8
|
||||||
|
beq 2b
|
||||||
|
/* On a big-endian machine, r0 contains the desired byte in bits
|
||||||
|
0-7; on a little-endian machine they are in bits 24-31. In
|
||||||
|
both cases the other bits in r0 are all zero. For r3 the
|
||||||
|
interesting byte is at the other end of the word, but the
|
||||||
|
other bits are not necessarily zero. We need a signed result
|
||||||
|
representing the differnece in the unsigned bytes, so for the
|
||||||
|
little-endian case we can't just shift the interesting bits
|
||||||
|
up. */
|
||||||
|
#ifdef __ARMEB__
|
||||||
|
sub r0, r0, r3, lsr #24
|
||||||
|
#else
|
||||||
|
and r3, r3, #255
|
||||||
|
#ifdef __thumb2__
|
||||||
|
/* No RSB instruction in Thumb2 */
|
||||||
|
lsr r0, r0, #24
|
||||||
|
sub r0, r0, r3
|
||||||
|
#else
|
||||||
|
rsb r0, r3, r0, lsr #24
|
||||||
|
#endif
|
||||||
|
#endif
|
||||||
|
#ifndef __thumb2__
|
||||||
|
ldr r4, [sp], #4
|
||||||
|
#endif
|
||||||
|
RETURN
|
||||||
|
|
||||||
|
|
||||||
|
strcmp_unaligned:
|
||||||
|
|
||||||
|
#if 0
|
||||||
|
/* The assembly code below is based on the following alogrithm. */
|
||||||
|
#ifdef __ARMEB__
|
||||||
|
#define RSHIFT <<
|
||||||
|
#define LSHIFT >>
|
||||||
|
#else
|
||||||
|
#define RSHIFT >>
|
||||||
|
#define LSHIFT <<
|
||||||
|
#endif
|
||||||
|
|
||||||
|
#define body(shift) \
|
||||||
|
mask = 0xffffffffU RSHIFT shift; \
|
||||||
|
w1 = *wp1++; \
|
||||||
|
w2 = *wp2++; \
|
||||||
|
do \
|
||||||
|
{ \
|
||||||
|
t1 = w1 & mask; \
|
||||||
|
if (__builtin_expect(t1 != w2 RSHIFT shift, 0)) \
|
||||||
|
{ \
|
||||||
|
w2 RSHIFT= shift; \
|
||||||
|
break; \
|
||||||
|
} \
|
||||||
|
if (__builtin_expect(((w1 - b1) & ~w1) & (b1 << 7), 0)) \
|
||||||
|
{ \
|
||||||
|
/* See comment in assembler below re syndrome on big-endian */\
|
||||||
|
if ((((w1 - b1) & ~w1) & (b1 << 7)) & mask) \
|
||||||
|
w2 RSHIFT= shift; \
|
||||||
|
else \
|
||||||
|
{ \
|
||||||
|
w2 = *wp2; \
|
||||||
|
t1 = w1 RSHIFT (32 - shift); \
|
||||||
|
w2 = (w2 LSHIFT (32 - shift)) RSHIFT (32 - shift); \
|
||||||
|
} \
|
||||||
|
break; \
|
||||||
|
} \
|
||||||
|
w2 = *wp2++; \
|
||||||
|
t1 ^= w1; \
|
||||||
|
if (__builtin_expect(t1 != w2 LSHIFT (32 - shift), 0)) \
|
||||||
|
{ \
|
||||||
|
t1 = w1 >> (32 - shift); \
|
||||||
|
w2 = (w2 << (32 - shift)) RSHIFT (32 - shift); \
|
||||||
|
break; \
|
||||||
|
} \
|
||||||
|
w1 = *wp1++; \
|
||||||
|
} while (1)
|
||||||
|
|
||||||
|
const unsigned* wp1;
|
||||||
|
const unsigned* wp2;
|
||||||
|
unsigned w1, w2;
|
||||||
|
unsigned mask;
|
||||||
|
unsigned shift;
|
||||||
|
unsigned b1 = 0x01010101;
|
||||||
|
char c1, c2;
|
||||||
|
unsigned t1;
|
||||||
|
|
||||||
|
while (((unsigned) s1) & 3)
|
||||||
|
{
|
||||||
|
c1 = *s1++;
|
||||||
|
c2 = *s2++;
|
||||||
|
if (c1 == 0 || c1 != c2)
|
||||||
|
return c1 - (int)c2;
|
||||||
|
}
|
||||||
|
wp1 = (unsigned*) (((unsigned)s1) & ~3);
|
||||||
|
wp2 = (unsigned*) (((unsigned)s2) & ~3);
|
||||||
|
t1 = ((unsigned) s2) & 3;
|
||||||
|
if (t1 == 1)
|
||||||
|
{
|
||||||
|
body(8);
|
||||||
|
}
|
||||||
|
else if (t1 == 2)
|
||||||
|
{
|
||||||
|
body(16);
|
||||||
|
}
|
||||||
|
else
|
||||||
|
{
|
||||||
|
body (24);
|
||||||
|
}
|
||||||
|
|
||||||
|
do
|
||||||
|
{
|
||||||
|
#ifdef __ARMEB__
|
||||||
|
c1 = (char) t1 >> 24;
|
||||||
|
c2 = (char) w2 >> 24;
|
||||||
|
#else /* not __ARMEB__ */
|
||||||
|
c1 = (char) t1;
|
||||||
|
c2 = (char) w2;
|
||||||
|
#endif /* not __ARMEB__ */
|
||||||
|
t1 RSHIFT= 8;
|
||||||
|
w2 RSHIFT= 8;
|
||||||
|
} while (c1 != 0 && c1 == c2);
|
||||||
|
return c1 - c2;
|
||||||
|
#endif /* 0 */
|
||||||
|
|
||||||
|
|
||||||
|
wp1 .req r0
|
||||||
|
wp2 .req r1
|
||||||
|
b1 .req r2
|
||||||
|
w1 .req r4
|
||||||
|
w2 .req r5
|
||||||
|
t1 .req ip
|
||||||
|
@ r3 is scratch
|
||||||
|
|
||||||
|
/* First of all, compare bytes until wp1(sp1) is word-aligned. */
|
||||||
|
1:
|
||||||
|
tst wp1, #3
|
||||||
|
beq 2f
|
||||||
|
ldrb r2, [wp1], #1
|
||||||
|
ldrb r3, [wp2], #1
|
||||||
|
cmp r2, #1
|
||||||
|
it cs
|
||||||
|
cmpcs r2, r3
|
||||||
|
beq 1b
|
||||||
|
sub r0, r2, r3
|
||||||
|
RETURN
|
||||||
|
|
||||||
|
2:
|
||||||
|
str r5, [sp, #-4]!
|
||||||
|
str r4, [sp, #-4]!
|
||||||
|
//stmfd sp!, {r4, r5}
|
||||||
|
mov b1, #1
|
||||||
|
orr b1, b1, b1, lsl #8
|
||||||
|
orr b1, b1, b1, lsl #16
|
||||||
|
|
||||||
|
and t1, wp2, #3
|
||||||
|
bic wp2, wp2, #3
|
||||||
|
ldr w1, [wp1], #4
|
||||||
|
ldr w2, [wp2], #4
|
||||||
|
cmp t1, #2
|
||||||
|
beq 2f
|
||||||
|
bhi 3f
|
||||||
|
|
||||||
|
/* Critical inner Loop: Block with 3 bytes initial overlap */
|
||||||
|
.p2align 2
|
||||||
|
1:
|
||||||
|
bic t1, w1, MSB
|
||||||
|
cmp t1, w2, S2LOMEM #8
|
||||||
|
sub r3, w1, b1
|
||||||
|
bic r3, r3, w1
|
||||||
|
bne 4f
|
||||||
|
ands r3, r3, b1, lsl #7
|
||||||
|
it eq
|
||||||
|
ldreq w2, [wp2], #4
|
||||||
|
bne 5f
|
||||||
|
eor t1, t1, w1
|
||||||
|
cmp t1, w2, S2HIMEM #24
|
||||||
|
bne 6f
|
||||||
|
ldr w1, [wp1], #4
|
||||||
|
b 1b
|
||||||
|
4:
|
||||||
|
S2LOMEM w2, w2, #8
|
||||||
|
b 8f
|
||||||
|
|
||||||
|
5:
|
||||||
|
#ifdef __ARMEB__
|
||||||
|
/* The syndrome value may contain false ones if the string ends
|
||||||
|
with the bytes 0x01 0x00 */
|
||||||
|
tst w1, #0xff000000
|
||||||
|
itt ne
|
||||||
|
tstne w1, #0x00ff0000
|
||||||
|
tstne w1, #0x0000ff00
|
||||||
|
beq 7f
|
||||||
|
#else
|
||||||
|
bics r3, r3, #0xff000000
|
||||||
|
bne 7f
|
||||||
|
#endif
|
||||||
|
ldrb w2, [wp2]
|
||||||
|
S2LOMEM t1, w1, #24
|
||||||
|
#ifdef __ARMEB__
|
||||||
|
lsl w2, w2, #24
|
||||||
|
#endif
|
||||||
|
b 8f
|
||||||
|
|
||||||
|
6:
|
||||||
|
S2LOMEM t1, w1, #24
|
||||||
|
and w2, w2, LSB
|
||||||
|
b 8f
|
||||||
|
|
||||||
|
/* Critical inner Loop: Block with 2 bytes initial overlap */
|
||||||
|
.p2align 2
|
||||||
|
2:
|
||||||
|
S2HIMEM t1, w1, #16
|
||||||
|
sub r3, w1, b1
|
||||||
|
S2LOMEM t1, t1, #16
|
||||||
|
bic r3, r3, w1
|
||||||
|
cmp t1, w2, S2LOMEM #16
|
||||||
|
bne 4f
|
||||||
|
ands r3, r3, b1, lsl #7
|
||||||
|
it eq
|
||||||
|
ldreq w2, [wp2], #4
|
||||||
|
bne 5f
|
||||||
|
eor t1, t1, w1
|
||||||
|
cmp t1, w2, S2HIMEM #16
|
||||||
|
bne 6f
|
||||||
|
ldr w1, [wp1], #4
|
||||||
|
b 2b
|
||||||
|
|
||||||
|
5:
|
||||||
|
#ifdef __ARMEB__
|
||||||
|
/* The syndrome value may contain false ones if the string ends
|
||||||
|
with the bytes 0x01 0x00 */
|
||||||
|
tst w1, #0xff000000
|
||||||
|
it ne
|
||||||
|
tstne w1, #0x00ff0000
|
||||||
|
beq 7f
|
||||||
|
#else
|
||||||
|
lsls r3, r3, #16
|
||||||
|
bne 7f
|
||||||
|
#endif
|
||||||
|
ldrh w2, [wp2]
|
||||||
|
S2LOMEM t1, w1, #16
|
||||||
|
#ifdef __ARMEB__
|
||||||
|
lsl w2, w2, #16
|
||||||
|
#endif
|
||||||
|
b 8f
|
||||||
|
|
||||||
|
6:
|
||||||
|
S2HIMEM w2, w2, #16
|
||||||
|
S2LOMEM t1, w1, #16
|
||||||
|
4:
|
||||||
|
S2LOMEM w2, w2, #16
|
||||||
|
b 8f
|
||||||
|
|
||||||
|
/* Critical inner Loop: Block with 1 byte initial overlap */
|
||||||
|
.p2align 2
|
||||||
|
3:
|
||||||
|
and t1, w1, LSB
|
||||||
|
cmp t1, w2, S2LOMEM #24
|
||||||
|
sub r3, w1, b1
|
||||||
|
bic r3, r3, w1
|
||||||
|
bne 4f
|
||||||
|
ands r3, r3, b1, lsl #7
|
||||||
|
it eq
|
||||||
|
ldreq w2, [wp2], #4
|
||||||
|
bne 5f
|
||||||
|
eor t1, t1, w1
|
||||||
|
cmp t1, w2, S2HIMEM #8
|
||||||
|
bne 6f
|
||||||
|
ldr w1, [wp1], #4
|
||||||
|
b 3b
|
||||||
|
4:
|
||||||
|
S2LOMEM w2, w2, #24
|
||||||
|
b 8f
|
||||||
|
5:
|
||||||
|
/* The syndrome value may contain false ones if the string ends
|
||||||
|
with the bytes 0x01 0x00 */
|
||||||
|
tst w1, LSB
|
||||||
|
beq 7f
|
||||||
|
ldr w2, [wp2], #4
|
||||||
|
6:
|
||||||
|
S2LOMEM t1, w1, #8
|
||||||
|
bic w2, w2, MSB
|
||||||
|
b 8f
|
||||||
|
7:
|
||||||
|
mov r0, #0
|
||||||
|
//ldmfd sp!, {r4, r5}
|
||||||
|
ldr r4, [sp], #4
|
||||||
|
ldr r5, [sp], #4
|
||||||
|
RETURN
|
||||||
|
8:
|
||||||
|
and r2, t1, LSB
|
||||||
|
and r0, w2, LSB
|
||||||
|
cmp r0, #1
|
||||||
|
it cs
|
||||||
|
cmpcs r0, r2
|
||||||
|
itt eq
|
||||||
|
S2LOMEMEQ t1, t1, #8
|
||||||
|
S2LOMEMEQ w2, w2, #8
|
||||||
|
beq 8b
|
||||||
|
sub r0, r2, r0
|
||||||
|
//ldmfd sp!, {r4, r5}
|
||||||
|
ldr r4, [sp], #4
|
||||||
|
ldr r5, [sp], #4
|
||||||
|
RETURN
|
||||||
|
|
||||||
|
#endif /* !(defined (_ISA_THUMB_2) || defined (_ISA_ARM_6)
|
||||||
|
defined (__OPTIMIZE_SIZE__) || defined (PREFER_SIZE_OVER_SPEED) ||
|
||||||
|
(defined (__thumb__) && !defined (__thumb2__))) */
|
||||||
|
|
@ -1,445 +0,0 @@
|
||||||
/*
|
|
||||||
* Copyright (c) 2008 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:
|
|
||||||
* 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. The name of the company may not be used to endorse or promote
|
|
||||||
* products derived from this software without specific prior written
|
|
||||||
* permission.
|
|
||||||
*
|
|
||||||
* THIS SOFTWARE IS PROVIDED BY ARM LTD ``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 ARM LTD 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 "arm_asm.h"
|
|
||||||
#include <_ansi.h>
|
|
||||||
#include <string.h>
|
|
||||||
|
|
||||||
#ifdef __ARMEB__
|
|
||||||
#define SHFT2LSB "lsl"
|
|
||||||
#define SHFT2MSB "lsr"
|
|
||||||
#define MSB "0x000000ff"
|
|
||||||
#define LSB "0xff000000"
|
|
||||||
#else
|
|
||||||
#define SHFT2LSB "lsr"
|
|
||||||
#define SHFT2MSB "lsl"
|
|
||||||
#define MSB "0xff000000"
|
|
||||||
#define LSB "0x000000ff"
|
|
||||||
#endif
|
|
||||||
|
|
||||||
#ifdef __thumb2__
|
|
||||||
#define magic1(REG) "#0x01010101"
|
|
||||||
#define magic2(REG) "#0x80808080"
|
|
||||||
#else
|
|
||||||
#define magic1(REG) #REG
|
|
||||||
#define magic2(REG) #REG ", lsl #7"
|
|
||||||
#endif
|
|
||||||
|
|
||||||
int
|
|
||||||
__attribute__((naked)) strcmp (const char* s1, const char* s2)
|
|
||||||
{
|
|
||||||
asm(
|
|
||||||
#if !(defined(__OPTIMIZE_SIZE__) || defined (PREFER_SIZE_OVER_SPEED) || \
|
|
||||||
(defined (__thumb__) && !defined (__thumb2__)))
|
|
||||||
"optpld r0\n\t"
|
|
||||||
"optpld r1\n\t"
|
|
||||||
"eor r2, r0, r1\n\t"
|
|
||||||
"tst r2, #3\n\t"
|
|
||||||
/* Strings not at same byte offset from a word boundary. */
|
|
||||||
"bne strcmp_unaligned\n\t"
|
|
||||||
"ands r2, r0, #3\n\t"
|
|
||||||
"bic r0, r0, #3\n\t"
|
|
||||||
"bic r1, r1, #3\n\t"
|
|
||||||
"ldr ip, [r0], #4\n\t"
|
|
||||||
"it eq\n\t"
|
|
||||||
"ldreq r3, [r1], #4\n\t"
|
|
||||||
"beq 1f\n\t"
|
|
||||||
/* Although s1 and s2 have identical initial alignment, they are
|
|
||||||
not currently word aligned. Rather than comparing bytes,
|
|
||||||
make sure that any bytes fetched from before the addressed
|
|
||||||
bytes are forced to 0xff. Then they will always compare
|
|
||||||
equal. */
|
|
||||||
"eor r2, r2, #3\n\t"
|
|
||||||
"lsl r2, r2, #3\n\t"
|
|
||||||
"mvn r3, #"MSB"\n\t"
|
|
||||||
SHFT2LSB" r2, r3, r2\n\t"
|
|
||||||
"ldr r3, [r1], #4\n\t"
|
|
||||||
"orr ip, ip, r2\n\t"
|
|
||||||
"orr r3, r3, r2\n"
|
|
||||||
"1:\n\t"
|
|
||||||
#ifndef __thumb2__
|
|
||||||
/* Load the 'magic' constant 0x01010101. */
|
|
||||||
"str r4, [sp, #-4]!\n\t"
|
|
||||||
"mov r4, #1\n\t"
|
|
||||||
"orr r4, r4, r4, lsl #8\n\t"
|
|
||||||
"orr r4, r4, r4, lsl #16\n"
|
|
||||||
#endif
|
|
||||||
".p2align 2\n"
|
|
||||||
"4:\n\t"
|
|
||||||
"optpld r0, #8\n\t"
|
|
||||||
"optpld r1, #8\n\t"
|
|
||||||
"sub r2, ip, "magic1(r4)"\n\t"
|
|
||||||
"cmp ip, r3\n\t"
|
|
||||||
"itttt eq\n\t"
|
|
||||||
/* check for any zero bytes in first word */
|
|
||||||
"biceq r2, r2, ip\n\t"
|
|
||||||
"tsteq r2, "magic2(r4)"\n\t"
|
|
||||||
"ldreq ip, [r0], #4\n\t"
|
|
||||||
"ldreq r3, [r1], #4\n\t"
|
|
||||||
"beq 4b\n"
|
|
||||||
"2:\n\t"
|
|
||||||
/* There's a zero or a different byte in the word */
|
|
||||||
SHFT2MSB" r0, ip, #24\n\t"
|
|
||||||
SHFT2LSB" ip, ip, #8\n\t"
|
|
||||||
"cmp r0, #1\n\t"
|
|
||||||
"it cs\n\t"
|
|
||||||
"cmpcs r0, r3, "SHFT2MSB" #24\n\t"
|
|
||||||
"it eq\n\t"
|
|
||||||
SHFT2LSB"eq r3, r3, #8\n\t"
|
|
||||||
"beq 2b\n\t"
|
|
||||||
/* On a big-endian machine, r0 contains the desired byte in bits
|
|
||||||
0-7; on a little-endian machine they are in bits 24-31. In
|
|
||||||
both cases the other bits in r0 are all zero. For r3 the
|
|
||||||
interesting byte is at the other end of the word, but the
|
|
||||||
other bits are not necessarily zero. We need a signed result
|
|
||||||
representing the differnece in the unsigned bytes, so for the
|
|
||||||
little-endian case we can't just shift the interesting bits
|
|
||||||
up. */
|
|
||||||
#ifdef __ARMEB__
|
|
||||||
"sub r0, r0, r3, lsr #24\n\t"
|
|
||||||
#else
|
|
||||||
"and r3, r3, #255\n\t"
|
|
||||||
#ifdef __thumb2__
|
|
||||||
/* No RSB instruction in Thumb2 */
|
|
||||||
"lsr r0, r0, #24\n\t"
|
|
||||||
"sub r0, r0, r3\n\t"
|
|
||||||
#else
|
|
||||||
"rsb r0, r3, r0, lsr #24\n\t"
|
|
||||||
#endif
|
|
||||||
#endif
|
|
||||||
#ifndef __thumb2__
|
|
||||||
"ldr r4, [sp], #4\n\t"
|
|
||||||
#endif
|
|
||||||
"RETURN"
|
|
||||||
#elif (defined (__thumb__) && !defined (__thumb2__))
|
|
||||||
"1:\n\t"
|
|
||||||
"ldrb r2, [r0]\n\t"
|
|
||||||
"ldrb r3, [r1]\n\t"
|
|
||||||
"add r0, r0, #1\n\t"
|
|
||||||
"add r1, r1, #1\n\t"
|
|
||||||
"cmp r2, #0\n\t"
|
|
||||||
"beq 2f\n\t"
|
|
||||||
"cmp r2, r3\n\t"
|
|
||||||
"beq 1b\n\t"
|
|
||||||
"2:\n\t"
|
|
||||||
"sub r0, r2, r3\n\t"
|
|
||||||
"bx lr"
|
|
||||||
#else
|
|
||||||
"3:\n\t"
|
|
||||||
"ldrb r2, [r0], #1\n\t"
|
|
||||||
"ldrb r3, [r1], #1\n\t"
|
|
||||||
"cmp r2, #1\n\t"
|
|
||||||
"it cs\n\t"
|
|
||||||
"cmpcs r2, r3\n\t"
|
|
||||||
"beq 3b\n\t"
|
|
||||||
"sub r0, r2, r3\n\t"
|
|
||||||
"RETURN"
|
|
||||||
#endif
|
|
||||||
);
|
|
||||||
}
|
|
||||||
|
|
||||||
#if !(defined(__OPTIMIZE_SIZE__) || defined (PREFER_SIZE_OVER_SPEED) || \
|
|
||||||
(defined (__thumb__) && !defined (__thumb2__)))
|
|
||||||
static int __attribute__((naked, used))
|
|
||||||
strcmp_unaligned(const char* s1, const char* s2)
|
|
||||||
{
|
|
||||||
#if 0
|
|
||||||
/* The assembly code below is based on the following alogrithm. */
|
|
||||||
#ifdef __ARMEB__
|
|
||||||
#define RSHIFT <<
|
|
||||||
#define LSHIFT >>
|
|
||||||
#else
|
|
||||||
#define RSHIFT >>
|
|
||||||
#define LSHIFT <<
|
|
||||||
#endif
|
|
||||||
|
|
||||||
#define body(shift) \
|
|
||||||
mask = 0xffffffffU RSHIFT shift; \
|
|
||||||
w1 = *wp1++; \
|
|
||||||
w2 = *wp2++; \
|
|
||||||
do \
|
|
||||||
{ \
|
|
||||||
t1 = w1 & mask; \
|
|
||||||
if (__builtin_expect(t1 != w2 RSHIFT shift, 0)) \
|
|
||||||
{ \
|
|
||||||
w2 RSHIFT= shift; \
|
|
||||||
break; \
|
|
||||||
} \
|
|
||||||
if (__builtin_expect(((w1 - b1) & ~w1) & (b1 << 7), 0)) \
|
|
||||||
{ \
|
|
||||||
/* See comment in assembler below re syndrome on big-endian */\
|
|
||||||
if ((((w1 - b1) & ~w1) & (b1 << 7)) & mask) \
|
|
||||||
w2 RSHIFT= shift; \
|
|
||||||
else \
|
|
||||||
{ \
|
|
||||||
w2 = *wp2; \
|
|
||||||
t1 = w1 RSHIFT (32 - shift); \
|
|
||||||
w2 = (w2 LSHIFT (32 - shift)) RSHIFT (32 - shift); \
|
|
||||||
} \
|
|
||||||
break; \
|
|
||||||
} \
|
|
||||||
w2 = *wp2++; \
|
|
||||||
t1 ^= w1; \
|
|
||||||
if (__builtin_expect(t1 != w2 LSHIFT (32 - shift), 0)) \
|
|
||||||
{ \
|
|
||||||
t1 = w1 >> (32 - shift); \
|
|
||||||
w2 = (w2 << (32 - shift)) RSHIFT (32 - shift); \
|
|
||||||
break; \
|
|
||||||
} \
|
|
||||||
w1 = *wp1++; \
|
|
||||||
} while (1)
|
|
||||||
|
|
||||||
const unsigned* wp1;
|
|
||||||
const unsigned* wp2;
|
|
||||||
unsigned w1, w2;
|
|
||||||
unsigned mask;
|
|
||||||
unsigned shift;
|
|
||||||
unsigned b1 = 0x01010101;
|
|
||||||
char c1, c2;
|
|
||||||
unsigned t1;
|
|
||||||
|
|
||||||
while (((unsigned) s1) & 3)
|
|
||||||
{
|
|
||||||
c1 = *s1++;
|
|
||||||
c2 = *s2++;
|
|
||||||
if (c1 == 0 || c1 != c2)
|
|
||||||
return c1 - (int)c2;
|
|
||||||
}
|
|
||||||
wp1 = (unsigned*) (((unsigned)s1) & ~3);
|
|
||||||
wp2 = (unsigned*) (((unsigned)s2) & ~3);
|
|
||||||
t1 = ((unsigned) s2) & 3;
|
|
||||||
if (t1 == 1)
|
|
||||||
{
|
|
||||||
body(8);
|
|
||||||
}
|
|
||||||
else if (t1 == 2)
|
|
||||||
{
|
|
||||||
body(16);
|
|
||||||
}
|
|
||||||
else
|
|
||||||
{
|
|
||||||
body (24);
|
|
||||||
}
|
|
||||||
|
|
||||||
do
|
|
||||||
{
|
|
||||||
#ifdef __ARMEB__
|
|
||||||
c1 = (char) t1 >> 24;
|
|
||||||
c2 = (char) w2 >> 24;
|
|
||||||
#else
|
|
||||||
c1 = (char) t1;
|
|
||||||
c2 = (char) w2;
|
|
||||||
#endif
|
|
||||||
t1 RSHIFT= 8;
|
|
||||||
w2 RSHIFT= 8;
|
|
||||||
} while (c1 != 0 && c1 == c2);
|
|
||||||
return c1 - c2;
|
|
||||||
#endif
|
|
||||||
|
|
||||||
asm("wp1 .req r0\n\t"
|
|
||||||
"wp2 .req r1\n\t"
|
|
||||||
"b1 .req r2\n\t"
|
|
||||||
"w1 .req r4\n\t"
|
|
||||||
"w2 .req r5\n\t"
|
|
||||||
"t1 .req ip\n\t"
|
|
||||||
"@ r3 is scratch\n"
|
|
||||||
|
|
||||||
/* First of all, compare bytes until wp1(sp1) is word-aligned. */
|
|
||||||
"1:\n\t"
|
|
||||||
"tst wp1, #3\n\t"
|
|
||||||
"beq 2f\n\t"
|
|
||||||
"ldrb r2, [wp1], #1\n\t"
|
|
||||||
"ldrb r3, [wp2], #1\n\t"
|
|
||||||
"cmp r2, #1\n\t"
|
|
||||||
"it cs\n\t"
|
|
||||||
"cmpcs r2, r3\n\t"
|
|
||||||
"beq 1b\n\t"
|
|
||||||
"sub r0, r2, r3\n\t"
|
|
||||||
"RETURN\n"
|
|
||||||
|
|
||||||
"2:\n\t"
|
|
||||||
"str r5, [sp, #-4]!\n\t"
|
|
||||||
"str r4, [sp, #-4]!\n\t"
|
|
||||||
// "stmfd sp!, {r4, r5}\n\t"
|
|
||||||
"mov b1, #1\n\t"
|
|
||||||
"orr b1, b1, b1, lsl #8\n\t"
|
|
||||||
"orr b1, b1, b1, lsl #16\n\t"
|
|
||||||
|
|
||||||
"and t1, wp2, #3\n\t"
|
|
||||||
"bic wp2, wp2, #3\n\t"
|
|
||||||
"ldr w1, [wp1], #4\n\t"
|
|
||||||
"ldr w2, [wp2], #4\n\t"
|
|
||||||
"cmp t1, #2\n\t"
|
|
||||||
"beq 2f\n\t"
|
|
||||||
"bhi 3f\n"
|
|
||||||
|
|
||||||
/* Critical inner Loop: Block with 3 bytes initial overlap */
|
|
||||||
".p2align 2\n"
|
|
||||||
"1:\n\t"
|
|
||||||
"bic t1, w1, #"MSB"\n\t"
|
|
||||||
"cmp t1, w2, "SHFT2LSB" #8\n\t"
|
|
||||||
"sub r3, w1, b1\n\t"
|
|
||||||
"bic r3, r3, w1\n\t"
|
|
||||||
"bne 4f\n\t"
|
|
||||||
"ands r3, r3, b1, lsl #7\n\t"
|
|
||||||
"it eq\n\t"
|
|
||||||
"ldreq w2, [wp2], #4\n\t"
|
|
||||||
"bne 5f\n\t"
|
|
||||||
"eor t1, t1, w1\n\t"
|
|
||||||
"cmp t1, w2, "SHFT2MSB" #24\n\t"
|
|
||||||
"bne 6f\n\t"
|
|
||||||
"ldr w1, [wp1], #4\n\t"
|
|
||||||
"b 1b\n"
|
|
||||||
"4:\n\t"
|
|
||||||
SHFT2LSB" w2, w2, #8\n\t"
|
|
||||||
"b 8f\n"
|
|
||||||
|
|
||||||
"5:\n\t"
|
|
||||||
#ifdef __ARMEB__
|
|
||||||
/* The syndrome value may contain false ones if the string ends
|
|
||||||
with the bytes 0x01 0x00 */
|
|
||||||
"tst w1, #0xff000000\n\t"
|
|
||||||
"itt ne\n\t"
|
|
||||||
"tstne w1, #0x00ff0000\n\t"
|
|
||||||
"tstne w1, #0x0000ff00\n\t"
|
|
||||||
"beq 7f\n\t"
|
|
||||||
#else
|
|
||||||
"bics r3, r3, #0xff000000\n\t"
|
|
||||||
"bne 7f\n\t"
|
|
||||||
#endif
|
|
||||||
"ldrb w2, [wp2]\n\t"
|
|
||||||
SHFT2LSB" t1, w1, #24\n\t"
|
|
||||||
#ifdef __ARMEB__
|
|
||||||
"lsl w2, w2, #24\n\t"
|
|
||||||
#endif
|
|
||||||
"b 8f\n"
|
|
||||||
|
|
||||||
"6:\n\t"
|
|
||||||
SHFT2LSB" t1, w1, #24\n\t"
|
|
||||||
"and w2, w2, #"LSB"\n\t"
|
|
||||||
"b 8f\n"
|
|
||||||
|
|
||||||
/* Critical inner Loop: Block with 2 bytes initial overlap */
|
|
||||||
".p2align 2\n"
|
|
||||||
"2:\n\t"
|
|
||||||
SHFT2MSB" t1, w1, #16\n\t"
|
|
||||||
"sub r3, w1, b1\n\t"
|
|
||||||
SHFT2LSB" t1, t1, #16\n\t"
|
|
||||||
"bic r3, r3, w1\n\t"
|
|
||||||
"cmp t1, w2, "SHFT2LSB" #16\n\t"
|
|
||||||
"bne 4f\n\t"
|
|
||||||
"ands r3, r3, b1, lsl #7\n\t"
|
|
||||||
"it eq\n\t"
|
|
||||||
"ldreq w2, [wp2], #4\n\t"
|
|
||||||
"bne 5f\n\t"
|
|
||||||
"eor t1, t1, w1\n\t"
|
|
||||||
"cmp t1, w2, "SHFT2MSB" #16\n\t"
|
|
||||||
"bne 6f\n\t"
|
|
||||||
"ldr w1, [wp1], #4\n\t"
|
|
||||||
"b 2b\n"
|
|
||||||
|
|
||||||
"5:\n\t"
|
|
||||||
#ifdef __ARMEB__
|
|
||||||
/* The syndrome value may contain false ones if the string ends
|
|
||||||
with the bytes 0x01 0x00 */
|
|
||||||
"tst w1, #0xff000000\n\t"
|
|
||||||
"it ne\n\t"
|
|
||||||
"tstne w1, #0x00ff0000\n\t"
|
|
||||||
"beq 7f\n\t"
|
|
||||||
#else
|
|
||||||
"lsls r3, r3, #16\n\t"
|
|
||||||
"bne 7f\n\t"
|
|
||||||
#endif
|
|
||||||
"ldrh w2, [wp2]\n\t"
|
|
||||||
SHFT2LSB" t1, w1, #16\n\t"
|
|
||||||
#ifdef __ARMEB__
|
|
||||||
"lsl w2, w2, #16\n\t"
|
|
||||||
#endif
|
|
||||||
"b 8f\n"
|
|
||||||
|
|
||||||
"6:\n\t"
|
|
||||||
SHFT2MSB" w2, w2, #16\n\t"
|
|
||||||
SHFT2LSB" t1, w1, #16\n\t"
|
|
||||||
"4:\n\t"
|
|
||||||
SHFT2LSB" w2, w2, #16\n\t"
|
|
||||||
"b 8f\n\t"
|
|
||||||
|
|
||||||
/* Critical inner Loop: Block with 1 byte initial overlap */
|
|
||||||
".p2align 2\n"
|
|
||||||
"3:\n\t"
|
|
||||||
"and t1, w1, #"LSB"\n\t"
|
|
||||||
"cmp t1, w2, "SHFT2LSB" #24\n\t"
|
|
||||||
"sub r3, w1, b1\n\t"
|
|
||||||
"bic r3, r3, w1\n\t"
|
|
||||||
"bne 4f\n\t"
|
|
||||||
"ands r3, r3, b1, lsl #7\n\t"
|
|
||||||
"it eq\n\t"
|
|
||||||
"ldreq w2, [wp2], #4\n\t"
|
|
||||||
"bne 5f\n\t"
|
|
||||||
"eor t1, t1, w1\n\t"
|
|
||||||
"cmp t1, w2, "SHFT2MSB" #8\n\t"
|
|
||||||
"bne 6f\n\t"
|
|
||||||
"ldr w1, [wp1], #4\n\t"
|
|
||||||
"b 3b\n"
|
|
||||||
"4:\n\t"
|
|
||||||
SHFT2LSB" w2, w2, #24\n\t"
|
|
||||||
"b 8f\n"
|
|
||||||
"5:\n\t"
|
|
||||||
/* The syndrome value may contain false ones if the string ends
|
|
||||||
with the bytes 0x01 0x00 */
|
|
||||||
"tst w1, #"LSB"\n\t"
|
|
||||||
"beq 7f\n\t"
|
|
||||||
"ldr w2, [wp2], #4\n"
|
|
||||||
"6:\n\t"
|
|
||||||
SHFT2LSB" t1, w1, #8\n\t"
|
|
||||||
"bic w2, w2, #"MSB"\n\t"
|
|
||||||
"b 8f\n"
|
|
||||||
"7:\n\t"
|
|
||||||
"mov r0, #0\n\t"
|
|
||||||
// "ldmfd sp!, {r4, r5}\n\t"
|
|
||||||
"ldr r4, [sp], #4\n\t"
|
|
||||||
"ldr r5, [sp], #4\n\t"
|
|
||||||
"RETURN\n"
|
|
||||||
"8:\n\t"
|
|
||||||
"and r2, t1, #"LSB"\n\t"
|
|
||||||
"and r0, w2, #"LSB"\n\t"
|
|
||||||
"cmp r0, #1\n\t"
|
|
||||||
"it cs\n\t"
|
|
||||||
"cmpcs r0, r2\n\t"
|
|
||||||
"itt eq\n\t"
|
|
||||||
SHFT2LSB"eq t1, t1, #8\n\t"
|
|
||||||
SHFT2LSB"eq w2, w2, #8\n\t"
|
|
||||||
"beq 8b\n\t"
|
|
||||||
"sub r0, r2, r0\n\t"
|
|
||||||
// "ldmfd sp!, {r4, r5}\n\t"
|
|
||||||
"ldr r4, [sp], #4\n\t"
|
|
||||||
"ldr r5, [sp], #4\n\t"
|
|
||||||
"RETURN");
|
|
||||||
}
|
|
||||||
|
|
||||||
#endif
|
|
||||||
Loading…
Reference in New Issue