crypto/sha256: add s390x assembly implementation

Renames block to blockGeneric so that it can be called when the
assembly feature check fails. This means making block a var on
platforms without an assembly implementation (similar to the sha1
package).

Also adds a test to check that the fallback path works correctly
when the feature check fails.

name        old speed      new speed       delta
Hash8Bytes  6.42MB/s ± 1%  27.14MB/s ± 0%  +323.01%  (p=0.000 n=10+10)
Hash1K      53.9MB/s ± 0%  511.1MB/s ± 0%  +847.57%   (p=0.000 n=10+9)
Hash8K      57.1MB/s ± 1%  609.7MB/s ± 0%  +967.04%  (p=0.000 n=10+10)

Change-Id: If962b2a5c9160b3a0b76ccee53b2fd809468ed3d
Reviewed-on: https://go-review.googlesource.com/22460
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bill O'Farrell <billotosyr@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/crypto/sha256/fallback_test.go b/src/crypto/sha256/fallback_test.go
new file mode 100644 (file)
index 0000000..5917a48
--- /dev/null
+++ b/src/crypto/sha256/fallback_test.go
@@ -0,0 +1,35 @@
+// 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 s390x
+
+package sha256
+
+import (
+       "fmt"
+       "io"
+       "testing"
+)
+
+// Tests the fallback code path in case the optimized asm
+// implementation cannot be used.
+// See also TestBlockGeneric.
+func TestGenericPath(t *testing.T) {
+       if useAsm == false {
+               t.Skipf("assembly implementation unavailable")
+       }
+       useAsm = false
+       defer func() { useAsm = true }()
+       c := New()
+       in := "ΑΒΓΔΕϜΖΗΘΙΚΛΜΝΞΟΠϺϘΡΣΤΥΦΧΨΩ"
+       gold := "e93d84ec2b22383123be9f713697fb25" +
+               "338c86e2f7d8d1ddc2d89d332dd9d76c"
+       if _, err := io.WriteString(c, in); err != nil {
+               t.Fatalf("could not write to c: %v", err)
+       }
+       out := fmt.Sprintf("%x", c.Sum(nil))
+       if out != gold {
+               t.Fatalf("mismatch: got %s, wanted %s", out, gold)
+       }
+}

diff --git a/src/crypto/sha256/sha256_test.go b/src/crypto/sha256/sha256_test.go
index 9ac8a96dfce168b82d709289217e0900d5e37943..279cf5ad407a065923def977e2df0cf4707abb05 100644 (file)
--- a/src/crypto/sha256/sha256_test.go
+++ b/src/crypto/sha256/sha256_test.go
@@ -7,6 +7,7 @@
 package sha256
 
 import (
+       "crypto/rand"
        "fmt"
        "io"
        "testing"
@@ -150,6 +151,18 @@ func TestBlockSize(t *testing.T) {
        }
 }
 
+// Tests that blockGeneric (pure Go) and block (in assembly for some architectures) match.
+func TestBlockGeneric(t *testing.T) {
+       gen, asm := New().(*digest), New().(*digest)
+       buf := make([]byte, BlockSize*20) // arbitrary factor
+       rand.Read(buf)
+       blockGeneric(gen, buf)
+       block(asm, buf)
+       if *gen != *asm {
+               t.Error("block and blockGeneric resulted in different states")
+       }
+}
+
 var bench = New()
 var buf = make([]byte, 8192)
 

diff --git a/src/crypto/sha256/sha256block.go b/src/crypto/sha256/sha256block.go
index ca5efd156a9d99d2433b77246acf807647666fc2..d43bbf02453a7cd08727e08d9a189daaef945669 100644 (file)
--- a/src/crypto/sha256/sha256block.go
+++ b/src/crypto/sha256/sha256block.go
@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !386,!amd64
-
 // SHA256 block step.
 // In its own file so that a faster assembly or C version
 // can be substituted easily.
@@ -77,7 +75,7 @@ var _K = []uint32{
        0xc67178f2,
 }
 
-func block(dig *digest, p []byte) {
+func blockGeneric(dig *digest, p []byte) {
        var w [64]uint32
        h0, h1, h2, h3, h4, h5, h6, h7 := dig.h[0], dig.h[1], dig.h[2], dig.h[3], dig.h[4], dig.h[5], dig.h[6], dig.h[7]
        for len(p) >= chunk {

diff --git a/src/crypto/sha256/sha256block_decl.go b/src/crypto/sha256/sha256block_decl.go
index 35fe34b98a398cf4e9f92ad9573877b64084c917..e6caff9a74652ee39806644dce7994ad3339ca15 100644 (file)
--- a/src/crypto/sha256/sha256block_decl.go
+++ b/src/crypto/sha256/sha256block_decl.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build 386 amd64
+// +build 386 amd64 s390x
 
 package sha256
 

diff --git a/src/crypto/sha256/sha256block_generic.go b/src/crypto/sha256/sha256block_generic.go
new file mode 100644 (file)
index 0000000..1a01969
--- /dev/null
+++ b/src/crypto/sha256/sha256block_generic.go
@@ -0,0 +1,9 @@
+// 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 !amd64,!386,!s390x
+
+package sha256
+
+var block = blockGeneric

diff --git a/src/crypto/sha256/sha256block_s390x.go b/src/crypto/sha256/sha256block_s390x.go
new file mode 100644 (file)
index 0000000..b7beefe
--- /dev/null
+++ b/src/crypto/sha256/sha256block_s390x.go
@@ -0,0 +1,12 @@
+// 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.
+
+package sha256
+
+// featureCheck reports whether the CPU supports the
+// SHA256 compute intermediate message digest (KIMD)
+// function code.
+func featureCheck() bool
+
+var useAsm = featureCheck()

diff --git a/src/crypto/sha256/sha256block_s390x.s b/src/crypto/sha256/sha256block_s390x.s
new file mode 100644 (file)
index 0000000..ee35991
--- /dev/null
+++ b/src/crypto/sha256/sha256block_s390x.s
@@ -0,0 +1,34 @@
+// 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.
+
+#include "textflag.h"
+
+// func featureCheck() bool
+TEXT ·featureCheck(SB),NOSPLIT,$16-1
+       LA      tmp-16(SP), R1
+       XOR     R0, R0         // query function code is 0
+       WORD    $0xB93E0006    // KIMD (R6 is ignored)
+       MOVBZ   tmp-16(SP), R4 // get the first byte
+       AND     $0x20, R4      // bit 2 (big endian) for SHA256
+       CMPBEQ  R4, $0, nosha256
+       MOVB    $1, ret+0(FP)
+       RET
+nosha256:
+       MOVB    $0, ret+0(FP)
+       RET
+
+// func block(dig *digest, p []byte)
+TEXT ·block(SB),NOSPLIT,$0-32
+       MOVBZ   ·useAsm(SB), R4
+       LMG     dig+0(FP), R1, R3 // R2 = &p[0], R3 = len(p)
+       CMPBNE  R4, $1, generic
+       MOVBZ   $2, R0        // SHA256 function code
+loop:
+       WORD    $0xB93E0002   // KIMD R2
+       BVS     loop          // continue if interrupted
+done:
+       XOR     R0, R0        // restore R0
+       RET
+generic:
+       BR      ·blockGeneric(SB)