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crypto/sha1: speed up sha1 for very small blocks

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For very small blocks significant time is spent in checkSum function,
adding necessary padding. Instead of writing it byte by byte, copy
encoding/binary PutUint functions, which are compiled into single mov.

name            old time/op    new time/op    delta
Hash8Bytes-6       344ns ± 0%     310ns ± 0%   -9.78%  (p=0.000 n=10+9)
Hash320Bytes-6    1.28µs ± 0%    1.25µs ± 0%   -2.58%  (p=0.000 n=10+10)
Hash1K-6          2.51µs ± 0%    2.47µs ± 0%   -1.67%  (p=0.000 n=10+10)
Hash8K-6          15.8µs ± 0%    15.7µs ± 1%   -0.21%  (p=0.023 n=10+10)

name            old speed      new speed      delta
Hash8Bytes-6    23.2MB/s ± 0%  25.7MB/s ± 0%  +10.77%  (p=0.000 n=10+9)
Hash320Bytes-6   249MB/s ± 0%   256MB/s ± 0%   +2.65%  (p=0.000 n=10+10)
Hash1K-6         408MB/s ± 0%   414MB/s ± 0%   +1.70%  (p=0.000 n=10+10)

Change-Id: I3975ee929465c7dd137d0ca757ad3792a004e1a3
Reviewed-on: https://go-review.googlesource.com/54391
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Giovanni Bajo <rasky@develer.com>
Reviewed-by: Filippo Valsorda <hi@filippo.io>
This commit is contained in:
Ilya Tocar 2017-08-09 13:21:20 -05:00 committed by Filippo Valsorda
parent 27a70ea560
commit dc3b8a193c
1 changed files with 27 additions and 9 deletions
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36
src/crypto/sha1/sha1.go
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@ -104,9 +104,7 @@ func (d *digest) checkSum() [Size]byte {
// Length in bits.
len <<= 3
for i := uint(0); i < 8; i++ {
tmp[i] = byte(len >> (56 - 8*i))
}
putUint64(tmp[:], len)
d.Write(tmp[0:8])
if d.nx != 0 {
@ -114,12 +112,12 @@ func (d *digest) checkSum() [Size]byte {
}
var digest [Size]byte
for i, s := range d.h {
digest[i*4] = byte(s >> 24)
digest[i*4+1] = byte(s >> 16)
digest[i*4+2] = byte(s >> 8)
digest[i*4+3] = byte(s)
}
putUint32(digest[0:], d.h[0])
putUint32(digest[4:], d.h[1])
putUint32(digest[8:], d.h[2])
putUint32(digest[12:], d.h[3])
putUint32(digest[16:], d.h[4])
return digest
}
@ -199,3 +197,23 @@ func Sum(data []byte) [Size]byte {
d.Write(data)
return d.checkSum()
}
func putUint64(x []byte, s uint64) {
_ = x[7]
x[0] = byte(s >> 56)
x[1] = byte(s >> 48)
x[2] = byte(s >> 40)
x[3] = byte(s >> 32)
x[4] = byte(s >> 24)
x[5] = byte(s >> 16)
x[6] = byte(s >> 8)
x[7] = byte(s)
}
func putUint32(x []byte, s uint32) {
_ = x[3]
x[0] = byte(s >> 24)
x[1] = byte(s >> 16)
x[2] = byte(s >> 8)
x[3] = byte(s)
}