Reformulate the strcmp-armv7.S selection logic around the architecture
features required by the implementation code rather (some) version of
the architecture that expose those features.
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
Hi!
I've got the situation, that the function strlen() occurs twice in libc.a
(building newlib for ARM-V7a and Size-Optimized).
In newlib/libc/machine/arm/strlen.c there are the pre-processor stetements ...
#if defined (__OPTIMIZE_SIZE__) || defined (PREFER_SIZE_OVER_SPEED) || \
(defined (__thumb__) && !defined (__thumb2__))
/*...*/
#else
#if !(defined(_ISA_ARM_7) || defined(__ARM_ARCH_6T2__))
/*...*/
#endif
and in newlib/libc/machine/arm/strlen-armv7.S the "exclude" begins with
/* 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__)))
But this is not completely contrary to arm/strlen.c (see above)!
To fix the logical statement in arm/strlen-armv7.S there are parentheses needed
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Import the latest version of strlen from the Linaro cortex-strings
package. This version is faster across a variety of block size and
alignments on ARMv7.
newlib/ChangeLog:
2013-06-21 Will Newton <will.newton@linaro.org>
* libc/machine/arm/strlen-armv7.S: Import latest strlen
code from Linaro cortex-strings.
memchr.S.
* libc/machine/arm/arm_asm.h: Add ifdef to allow it to be included
in .S files.
* libc/machine/arm/memchr-stub.c: New file - just selects what to
compile.
* libc/machine/arm/memchr.S: New file - ARMv6t2/v7 version.
* libc/machine/arm/Makefile.am (lib_a_SOURCES): Add strlen-armv7.S.
* libc/machine/arm/strlen-armv7.S: New file.
* libc/machine/arm/strlen.c: Add ifdef optimised code so it isn't
for v7 or 6t2.
* libc/machine/arm/Makefile.in: Regenerate.
Marcus Shawcroft
Corinna Vinschen
Will Newton
Nick Clifton