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[ARM] Factor out the thumb1 -Os implementation. 

The patch moves the inline ASM thumb1 -O2 implementation out into its
own .S file.

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
This commit is contained in:
Marcus Shawcroft 2015-11-10 15:12:30 +00:00
parent bcd5e8e3f9
commit 9959058932
4 changed files with 58 additions and 15 deletions
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6
newlib/ChangeLog
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@ -1,3 +1,9 @@
2015-11-13 Marcus Shawcroft <marcus.shawcroft@arm.com>
* libc/machine/arm/strlen-stub.c: Move T1 -O2 implementation to...
* libc/machine/arm/strlen-thumb1-Os.S: New file.
* libc/machine/arm/strlen.S: Include strlen-thumb1-Os.S.
2015-11-13 Marcus Shawcroft <marcus.shawcroft@arm.com>
* libc/machine/arm/Makefile.am: Adding strlen.S.

15
newlib/libc/machine/arm/strlen-stub.c
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@ -33,20 +33,7 @@
#if defined __OPTIMIZE_SIZE__ || defined PREFER_SIZE_OVER_SPEED
#if defined __thumb__ && !defined __thumb2__
size_t
strlen (const char* str)
{
int scratch;
size_t len;
asm ("mov %0, #0\n"
"1:\n\t"
"ldrb %1, [%2, %0]\n\t"
"add %0, %0, #1\n\t"
"cmp %1, #0\n\t"
"bne 1b"
: "=&r" (len), "=&r" (scratch) : "r" (str) : "memory", "cc");
return len - 1;
}
/* Implemented in strlen.S. */
#else
size_t

50
newlib/libc/machine/arm/strlen-thumb1-Os.S Normal file
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@ -0,0 +1,50 @@
/* 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. */
.macro def_fn f p2align=0
.text
.p2align \p2align
.global \f
.type \f, %function
\f:
.endm
.arch armv4t
.eabi_attribute Tag_also_compatible_with, "\006\013" /* ARMv6-M. */
.eabi_attribute Tag_ARM_ISA_use, 0
.thumb
.syntax unified
def_fn strlen p2align=1
movs r3, #0
1:
ldrb r2, [r0, r3]
adds r3, r3, #1
cmp r2, #0
bne 1b
subs r0, r3, #1
bx lr
.size strlen, . - strlen

2
newlib/libc/machine/arm/strlen.S
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@ -28,7 +28,7 @@
#if defined __OPTIMIZE_SIZE__ || defined PREFER_SIZE_OVER_SPEED
#if defined __thumb__ && !defined __thumb2__
/* Implemented in strlen-stub.c. */
#include "strlen-thumb1-Os.S"
#else
/* Implemented in strlen-stub.c. */