Support source compilation on s390 and ppc64le (#4859)

NOTE: This doesn't validate that minio will work fine
on these platforms and is tested. Since we do not validate
on these architectures this is to be treated as just a build fix.

Fixes #4858

vendor/github.com/minio/sha256-simd/README.md

@@ -8,20 +8,48 @@ This package is designed as a drop-in replacement for `crypto/sha256`. For Intel
 
 This package uses Golang assembly and as such does not depend on cgo. The Intel versions are based on the implementations as described in "Fast SHA-256 Implementations on Intel Architecture Processors" by J. Guilford et al.
 
+## Drop-In Replacement
+
+Following code snippet shows you how you can directly replace wherever `crypto/sha256` is used can be replaced with `github.com/minio/sha256-simd`.
+
+Before:
+```go
+import "crypto/sha256"
+
+func main() {
+        ...
+	shaWriter := sha256.New()
+	io.Copy(shaWriter, file)
+        ...
+}
+```
+
+After:
+```go
+import "github.com/minio/sha256-simd"
+
+func main() {
+        ...
+	shaWriter := sha256.New()
+	io.Copy(shaWriter, file)
+        ...
+}
+```
+
 ## Performance
 
 Below is the speed in MB/s for a single core (ranked fast to slow) as well as the factor of improvement over `crypto/sha256` (when applicable).
 
-| Processor                         | Package                      |       Speed | Improvement |
-| --------------------------------- | ---------------------------- | -----------:| -----------:|
-| 1.2 GHz ARM Cortex-A53            | minio/sha256-simd (ARM64)    |  638.2 MB/s |        105x |
-| 2.4 GHz Intel Xeon CPU E5-2620 v3 | minio/sha256-simd (AVX2) (*) |  355.0 MB/s |       1.88x |
-| 2.4 GHz Intel Xeon CPU E5-2620 v3 | minio/sha256-simd (AVX)      |  306.0 MB/s |       1.62x |
-| 2.4 GHz Intel Xeon CPU E5-2620 v3 | minio/sha256-simd (SSE)      |  298.7 MB/s |       1.58x |
-| 2.4 GHz Intel Xeon CPU E5-2620 v3 | crypto/sha256                |  189.2 MB/s |             |
-| 1.2 GHz ARM Cortex-A53            | crypto/sha256                |    6.1 MB/s |             |
+| Processor                         | Package                   |       Speed | Improvement |
+| --------------------------------- | ------------------------- | -----------:| -----------:|
+| 1.2 GHz ARM Cortex-A53            | minio/sha256-simd (ARM64) |  638.2 MB/s |        105x |
+| 2.4 GHz Intel Xeon CPU E5-2620 v3 | minio/sha256-simd (AVX2)  |  355.0 MB/s |       1.88x |
+| 2.4 GHz Intel Xeon CPU E5-2620 v3 | minio/sha256-simd (AVX)   |  306.0 MB/s |       1.62x |
+| 2.4 GHz Intel Xeon CPU E5-2620 v3 | minio/sha256-simd (SSE)   |  298.7 MB/s |       1.58x |
+| 2.4 GHz Intel Xeon CPU E5-2620 v3 | crypto/sha256             |  189.2 MB/s |             |
+| 1.2 GHz ARM Cortex-A53            | crypto/sha256             |    6.1 MB/s |             |
 
-(*) Measured with the "unrolled"/"demacro-ed" AVX2 version. Due to some Golang assembly restrictions the AVX2 version that uses `defines` loses about 15% performance. The optimized version is contained in the git history so for maximum speed you want to do this after getting: `git cat-file blob 586b6e > sha256blockAvx2_amd64.s` (or vendor it for your project; see [here](https://github.com/minio/sha256-simd/blob/13b11bdf9b0580a756a111492d2ae382bab7ec79/sha256blockAvx2_amd64.s) to view it in its full glory).
+Note that the AVX2 version is measured with the "unrolled"/"demacro-ed" version. Due to some Golang assembly restrictions the AVX2 version that uses `defines` loses about 15% performance (you can see the macrofied version, which is a little bit easier to read, [here](https://github.com/minio/sha256-simd/blob/e1b0a493b71bb31e3f1bf82d3b8cbd0d6960dfa6/sha256blockAvx2_amd64.s)).
  
  See further down for detailed performance.
  

vendor/github.com/minio/sha256-simd/cpuid_other.go

@@ -13,6 +13,8 @@
 // limitations under the License.
 //
 
+// +build ppc64 ppc64le mips mipsle mips64 mips64le s390x
+
 package sha256
 
 func cpuid(op uint32) (eax, ebx, ecx, edx uint32) {

vendor/github.com/minio/sha256-simd/sha256block_arm64.s

@@ -19,7 +19,7 @@
 //
 
 //
-// Based on implementaion as found in  https://github.com/jocover/sha256-armv8
+// Based on implementation as found in https://github.com/jocover/sha256-armv8
 //
 // Use github.com/minio/asm2plan9s on this file to assemble ARM instructions to
 // their Plan9 equivalents

vendor/github.com/minio/sha256-simd/sha256block_other.go

@@ -13,20 +13,11 @@
 // limitations under the License.
 //
 
+// +build ppc64 ppc64le mips mipsle mips64 mips64le s390x
+
 package sha256
 
-func cpuid(op uint32) (eax, ebx, ecx, edx uint32) {
-	return 0, 0, 0, 0
-}
-
-func cpuidex(op, op2 uint32) (eax, ebx, ecx, edx uint32) {
-	return 0, 0, 0, 0
-}
-
-func xgetbv(index uint32) (eax, edx uint32) {
-	return 0, 0
-}
-
-func haveArmSha() bool {
-	return false
-}
+func blockAvx2Go(dig *digest, p []byte) {}
+func blockAvxGo(dig *digest, p []byte)  {}
+func blockSsseGo(dig *digest, p []byte) {}
+func blockArmGo(dig *digest, p []byte)  {}

vendor/github.com/minio/sha256-simd/sha256block_ppc64.go

@@ -1,22 +0,0 @@
-/*
- * Minio Cloud Storage, (C) 2016 Minio, Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package sha256
-
-func blockAvx2Go(dig *digest, p []byte) {}
-func blockAvxGo(dig *digest, p []byte)  {}
-func blockSsseGo(dig *digest, p []byte) {}
-func blockArmGo(dig *digest, p []byte)  {}

vendor/github.com/minio/sha256-simd/sha256block_ppc64le.go

@@ -1,22 +0,0 @@
-/*
- * Minio Cloud Storage, (C) 2016 Minio, Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package sha256
-
-func blockAvx2Go(dig *digest, p []byte) {}
-func blockAvxGo(dig *digest, p []byte)  {}
-func blockSsseGo(dig *digest, p []byte) {}
-func blockArmGo(dig *digest, p []byte)  {}

vendor/vendor.json

@@ -348,10 +348,10 @@
 			"revisionTime": "2017-06-19T22:00:32Z"
 		},
 		{
-			"checksumSHA1": "URVle4qtadmW9w9BulDRHY3kxnA=",
+			"checksumSHA1": "cYuXpiVBMypgkEr0Wqd79jPPyBg=",
 			"path": "github.com/minio/sha256-simd",
-			"revision": "e82e73b775766b9011503e80e6772fc32b9afc5b",
-			"revisionTime": "2016-12-19T23:17:30Z"
+			"revision": "43ed500fe4d485d97534014d9f98521216240002",
+			"revisionTime": "2017-08-28T17:39:33Z"
 		},
 		{
 			"checksumSHA1": "zvQr4zOz1/g/Fui6co0sctxrJ28=",