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| author | Jussi Kivilinna <jussi.kivilinna@iki.fi> | 2023-04-02 20:20:50 +0300 |
|---|---|---|
| committer | Jussi Kivilinna <jussi.kivilinna@iki.fi> | 2023-04-03 21:36:50 +0300 |
| commit | 278ba98497e126358a6b0ee8b566cc62ebb96ab9 (patch) | |
| tree | f1df9262ee5a2f033ef52e4663d06b8834d0b927 | |
| parent | 3660935d2d5053584f2c9349c6ff454c51c8bbfc (diff) | |
| download | libgcrypt-278ba98497e126358a6b0ee8b566cc62ebb96ab9.tar.gz | |
cipher-gcm-ppc: tweak loop structure a bit
* cipher/cipher-gcm-ppc.c (_gcry_ghash_ppc_vpmsum): Increament
'buf' pointer right after use; Use 'for' loop for inner 4-blocks
loop to allow compiler to better optimize loop.
--
Benchmark on POWER9:
Before:
| nanosecs/byte mebibytes/sec cycles/byte
GMAC_AES | 0.226 ns/B 4211 MiB/s 0.521 c/B
After:
| nanosecs/byte mebibytes/sec cycles/byte
GMAC_AES | 0.224 ns/B 4251 MiB/s 0.516 c/B
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>
| -rw-r--r-- | cipher/cipher-gcm-ppc.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/cipher/cipher-gcm-ppc.c b/cipher/cipher-gcm-ppc.c index 4f75e95c..550864c1 100644 --- a/cipher/cipher-gcm-ppc.c +++ b/cipher/cipher-gcm-ppc.c @@ -437,6 +437,7 @@ _gcry_ghash_ppc_vpmsum (byte *result, void *gcm_table, in1 = vec_load_he (16, buf); in2 = vec_load_he (32, buf); in3 = vec_load_he (48, buf); + buf += 64; in0 = vec_be_swap(in0, bswap_const); in1 = vec_be_swap(in1, bswap_const); in2 = vec_be_swap(in2, bswap_const); @@ -464,17 +465,13 @@ _gcry_ghash_ppc_vpmsum (byte *result, void *gcm_table, Xh3 = asm_xor (Xh3, Xh1); /* Gerald Estrin's scheme for parallel multiplication of polynomials */ - while (1) + for (; blocks_remaining > 4; blocks_remaining -= 4) { - buf += 64; - blocks_remaining -= 4; - if (!blocks_remaining) - break; - in0 = vec_load_he (0, buf); in1 = vec_load_he (16, buf); in2 = vec_load_he (32, buf); in3 = vec_load_he (48, buf); + buf += 64; in1 = vec_be_swap(in1, bswap_const); in2 = vec_be_swap(in2, bswap_const); in3 = vec_be_swap(in3, bswap_const); |