This patch generates LDRD/STRD sequences for movmemqi and movmemdi when source and destination buffers are aligned. It is disabled when optimizing for code size, becasue LDM/STM is preferable in such cases. It is enabled for performance for CPUs that set "prefer_ldrd_strd" tune flag. This flag is currently set only for cortex-a15.
The patch consists of the following changes:
* movmemqi/movemdi call a new function that generates (whenever possible) a
sequence of LDRD/STRD that is expected to achieve the best performance on
Cortex-A15.
* adjusted existing test for gcc's internal memcpy to accept LDRD/STRD as
well as LDM/STM.
gcc/ChangeLog
2011-10-28 Greta Yorsh <greta.yo...@arm.com>
* config/arm/arm.md (movmemdi,movmemqi): Generate LDRD/STRD under
certain conditions.
* config/arm/arm-protos.h (gen_movmem_ldrd_strd): New prototype.
* config/arm/arm.c (gen_movmem_ldrd_strd): New function.
gcc/testsuite/ChangeLog
2011-10-28 Greta Yorsh <greta.yo...@arm.com>
* gcc.target/arm/unaligned-memcpy-4.c: Adjust the test by separating
between configurations that prefer LDRD/STRD from those that prefer
LDM/STM. This file remains for LDM/STM case.
* gcc.target/arm/unaligned-memcpy-5.c: New file.
* gcc.target/arm/unaligned-memcpy.inc: New file.
5-internal-memcpy.patch
Description: Binary data
