twofish: add ARMv6 assembly implementation
* cipher/Makefile.am: Add 'twofish-armv6.S'. * cipher/twofish-armv6.S: New. * cipher/twofish.c (USE_ARMV6_ASM): New macro. [USE_ARMV6_ASM] (_gcry_twofish_armv6_encrypt_block) (_gcry_twofish_armv6_decrypt_block): New prototypes. [USE_AMDV6_ASM] (twofish_encrypt, twofish_decrypt): Add. [USE_AMD64_ASM] (do_twofish_encrypt, do_twofish_decrypt): Remove. (_gcry_twofish_ctr_enc, _gcry_twofish_cfb_dec): Use 'twofish_encrypt' instead of 'do_twofish_encrypt'. (_gcry_twofish_cbc_dec): Use 'twofish_decrypt' instead of 'do_twofish_decrypt'. * configure.ac [arm]: Add 'twofish-armv6.lo'.
Add optimized ARMv6 assembly implementation for Twofish. Implementation is tuned
for Cortex-A8. Unaligned access handling is done in assembly part.
For now, only enable this on little-endian systems as big-endian correctness
have not been tested yet.
Old (gcc-4.8) vs new (twofish-asm), Cortex-A8 (on armhf):
ECB/Stream CBC CFB OFB CTR CCM --------------- --------------- --------------- --------------- --------------- ---------------
TWOFISH 1.23x 1.25x 1.16x 1.26x 1.16x 1.30x 1.18x 1.17x 1.23x 1.23x 1.22x 1.22x
- Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>