From ae8bce0030810cf999bb2b9868ae5c7c58e6343b Mon Sep 17 00:00:00 2001
From: Andreas Auernhammer <aead@mail.de>
Date: Mon, 30 Apr 2018 19:54:52 +0200
Subject: [PATCH] crypto/{blake2b,blake2s,argon2,chacha20poly1305}: replace CPU
 feature detection

This change removes package specific CPU-feature detection code and
replaces it with x/sys/cpu.

Fixes golang/go#24843

Change-Id: I150dd7b3aeb8eef428c91f9b1df741ceb8a87a24
Reviewed-on: https://go-review.googlesource.com/110355
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
---
 blake2b/blake2bAVX2_amd64.go               | 26 ++++-----
 blake2b/blake2bAVX2_amd64.s                | 12 -----
 blake2b/blake2b_amd64.go                   |  7 ++-
 blake2b/blake2b_amd64.s                    |  9 ----
 11 files changed, 41 insertions(+), 182 deletions(-)

diff --git a/blake2b/blake2bAVX2_amd64.go b/blake2b/blake2bAVX2_amd64.go
index 8c41cf6c7..4d31dd0fd 100644
--- a/blake2b/blake2bAVX2_amd64.go
+++ b/blake2b/blake2bAVX2_amd64.go
@@ -6,21 +6,14 @@

 package blake2b

+import "golang.org/x/sys/cpu"
+
 func init() {
-	useAVX2 = supportsAVX2()
-	useAVX = supportsAVX()
-	useSSE4 = supportsSSE4()
+	useAVX2 = cpu.X86.HasAVX2
+	useAVX = cpu.X86.HasAVX
+	useSSE4 = cpu.X86.HasSSE41
 }

-//go:noescape
-func supportsSSE4() bool
-
-//go:noescape
-func supportsAVX() bool
-
-//go:noescape
-func supportsAVX2() bool
-
 //go:noescape
 func hashBlocksAVX2(h *[8]uint64, c *[2]uint64, flag uint64, blocks []byte)

@@ -31,13 +24,14 @@ func hashBlocksAVX(h *[8]uint64, c *[2]uint64, flag uint64, blocks []byte)
 func hashBlocksSSE4(h *[8]uint64, c *[2]uint64, flag uint64, blocks []byte)

 func hashBlocks(h *[8]uint64, c *[2]uint64, flag uint64, blocks []byte) {
-	if useAVX2 {
+	switch {
+	case useAVX2:
 		hashBlocksAVX2(h, c, flag, blocks)
-	} else if useAVX {
+	case useAVX:
 		hashBlocksAVX(h, c, flag, blocks)
-	} else if useSSE4 {
+	case useSSE4:
 		hashBlocksSSE4(h, c, flag, blocks)
-	} else {
+	default:
 		hashBlocksGeneric(h, c, flag, blocks)
 	}
 }
diff --git a/blake2b/blake2bAVX2_amd64.s b/blake2b/blake2bAVX2_amd64.s
index 784bce6a9..5593b1b3d 100644
--- a/blake2b/blake2bAVX2_amd64.s
+++ b/blake2b/blake2bAVX2_amd64.s
@@ -748,15 +748,3 @@ noinc:

 	MOVQ BP, SP
 	RET
-
-// func supportsAVX2() bool
-TEXT ·supportsAVX2(SB), 4, $0-1
-	MOVQ runtime·support_avx2(SB), AX
-	MOVB AX, ret+0(FP)
-	RET
-
-// func supportsAVX() bool
-TEXT ·supportsAVX(SB), 4, $0-1
-	MOVQ runtime·support_avx(SB), AX
-	MOVB AX, ret+0(FP)
-	RET
diff --git a/blake2b/blake2b_amd64.go b/blake2b/blake2b_amd64.go
index 2ab7c30fc..30e2fcd58 100644
--- a/blake2b/blake2b_amd64.go
+++ b/blake2b/blake2b_amd64.go
@@ -6,13 +6,12 @@

 package blake2b

+import "golang.org/x/sys/cpu"
+
 func init() {
-	useSSE4 = supportsSSE4()
+	useSSE4 = cpu.X86.HasSSE41
 }

-//go:noescape
-func supportsSSE4() bool
-
 //go:noescape
 func hashBlocksSSE4(h *[8]uint64, c *[2]uint64, flag uint64, blocks []byte)

diff --git a/blake2b/blake2b_amd64.s b/blake2b/blake2b_amd64.s
index 64530740b..578e947b3 100644
--- a/blake2b/blake2b_amd64.s
+++ b/blake2b/blake2b_amd64.s
@@ -279,12 +279,3 @@ noinc:

 	MOVQ BP, SP
 	RET
-
-// func supportsSSE4() bool
-TEXT ·supportsSSE4(SB), 4, $0-1
-	MOVL $1, AX
-	CPUID
-	SHRL $19, CX  // Bit 19 indicates SSE4 support
-	ANDL $1, CX  // CX != 0 if support SSE4
-	MOVB CX, ret+0(FP)
-	RET