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- // Copyright 2016 The Go Authors. All rights reserved.
- // Use of this source code is governed by a BSD-style
- // license that can be found in the LICENSE file.
- // +build ignore
- package sha1
- import "internal/cpu"
- //go:noescape
- func blockAVX2(dig *digest, p []byte)
- //go:noescape
- func blockAMD64(dig *digest, p []byte)
- var useAVX2 = cpu.X86.HasAVX2 && cpu.X86.HasBMI1 && cpu.X86.HasBMI2
- func block(dig *digest, p []byte) {
- if useAVX2 && len(p) >= 256 {
- // blockAVX2 calculates sha1 for 2 block per iteration
- // it also interleaves precalculation for next block.
- // So it may read up-to 192 bytes past end of p
- // We may add checks inside blockAVX2, but this will
- // just turn it into a copy of blockAMD64,
- // so call it directly, instead.
- safeLen := len(p) - 128
- if safeLen%128 != 0 {
- safeLen -= 64
- }
- blockAVX2(dig, p[:safeLen])
- blockAMD64(dig, p[safeLen:])
- } else {
- blockAMD64(dig, p)
- }
- }
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