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| author | Jonathan Swinney <jswinney@amazon.com> | 2024-10-18 18:55:07 +0200 |
|---|---|---|
| committer | Tomas Mraz <tomas@openssl.org> | 2025-01-06 11:43:36 +0100 |
| commit | ebe34f9a62630b45a825bc07a2e9cf52731e836e (patch) | |
| tree | d67734e0db11499a2caba29ed031b2c066b2c59b /crypto/md5/asm/md5-x86_64.pl | |
| parent | openssl-pkeyutl.pod.in: update from SHA-1 to SHA256, fixing default values an... (diff) | |
| download | openssl-ebe34f9a62630b45a825bc07a2e9cf52731e836e.tar.xz openssl-ebe34f9a62630b45a825bc07a2e9cf52731e836e.zip | |
Optimize x86/aarch64 MD5 implementation
As suggested in https://github.com/animetosho/md5-optimisation?tab=readme-ov-file#dependency-shortcut-in-g-function,
we can delay the dependency on 'x' by recognizing that ((x & z) | (y & ~z))
is equivalent to ((x & z) + (y + ~z)) in this scenario, and we can perform
those additions independently, leaving our dependency on x to the final
addition. This speeds it up around 5% on both platforms.
Signed-off-by: Oli Gillespie <ogillesp@amazon.com>
Reviewed-by: Paul Dale <ppzgs1@gmail.com>
Reviewed-by: Hugo Landau <hlandau@devever.net>
(Merged from https://github.com/openssl/openssl/pull/25737)
Diffstat (limited to '')
| -rwxr-xr-x | crypto/md5/asm/md5-x86_64.pl | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/crypto/md5/asm/md5-x86_64.pl b/crypto/md5/asm/md5-x86_64.pl index 6625fb7d08..aa2880a9cd 100755 --- a/crypto/md5/asm/md5-x86_64.pl +++ b/crypto/md5/asm/md5-x86_64.pl @@ -41,7 +41,6 @@ EOF # %r10d = X[k_next] # %r11d = z' (copy of z for the next step) # %r12d = z' (copy of z for the next step) -# Each round2_step() takes about 5.4 clocks (11 instructions, 2.0 IPC) sub round2_step { my ($pos, $dst, $x, $y, $z, $k_next, $T_i, $s) = @_; @@ -53,9 +52,9 @@ sub round2_step lea $T_i($dst,%r10d),$dst /* Const + dst + ... */ and $y, %r11d /* y & (not z) */ mov $k_next*4(%rsi),%r10d /* (NEXT STEP) X[$k_next] */ - or %r11d, %r12d /* (y & (not z)) | (x & z) */ + add %r11d, $dst /* dst += (y & (not z)) */ mov $y, %r11d /* (NEXT STEP) z' = $y */ - add %r12d, $dst /* dst += ... */ + add %r12d, $dst /* dst += (x & z) */ mov $y, %r12d /* (NEXT STEP) z' = $y */ rol \$$s, $dst /* dst <<< s */ add $x, $dst /* dst += x */ |