internal: use arrays instead of make for simple values. (#22)

Fixes #16

benchmarks_test.go

@@ -27,11 +27,11 @@ import (
 
 func benchmarkHash(b *testing.B, hash func() hash.Hash) {
 	b.SetBytes(1024 * 1024)
-	data := make([]byte, 1024)
+	var data [1024]byte
 	for i := 0; i < b.N; i++ {
 		h := hash()
 		for j := 0; j < 1024; j++ {
-			h.Write(data)
+			h.Write(data[:])
 		}
 		h.Sum(nil)
 	}
@@ -59,7 +59,7 @@ func BenchmarkComparisonBlake2B(b *testing.B) {
 
 // Benchmark blake2b implementation.
 var bench = New512()
-var buf = make([]byte, 128*1024)
+var buf [128 * 1024]byte
 
 func benchmarkSize(b *testing.B, size int) {
 	b.SetBytes(int64(size))

compressAvx2_amd64.go

@@ -23,11 +23,12 @@ package blake2b
 func compressAVX2Loop(p []uint8, in, iv, t, f, shffle, out []uint64)
 
 func compressAVX2(d *digest, p []uint8) {
+	var (
+		in     [8]uint64
+		out    [8]uint64
+		shffle [8]uint64
+	)
 
-	in := make([]uint64, 8, 8)
-	out := make([]uint64, 8, 8)
-
-	shffle := make([]uint64, 8, 8)
 	// vector for PSHUFB instruction
 	shffle[0] = 0x0201000706050403
 	shffle[1] = 0x0a09080f0e0d0c0b
@@ -40,7 +41,7 @@ func compressAVX2(d *digest, p []uint8) {
 
 	in[0], in[1], in[2], in[3], in[4], in[5], in[6], in[7] = d.h[0], d.h[1], d.h[2], d.h[3], d.h[4], d.h[5], d.h[6], d.h[7]
 
-	compressAVX2Loop(p, in, iv[:], d.t[:], d.f[:], shffle, out)
+	compressAVX2Loop(p, in[:], iv[:], d.t[:], d.f[:], shffle[:], out[:])
 
 	d.h[0], d.h[1], d.h[2], d.h[3], d.h[4], d.h[5], d.h[6], d.h[7] = out[0], out[1], out[2], out[3], out[4], out[5], out[6], out[7]
 }

compressAvx_amd64.go

@@ -23,18 +23,19 @@ package blake2b
 func blockAVXLoop(p []uint8, in, iv, t, f, shffle, out []uint64)
 
 func compressAVX(d *digest, p []uint8) {
+	var (
+		in     [8]uint64
+		out    [8]uint64
+		shffle [2]uint64
+	)
 
-	in := make([]uint64, 8, 8)
-	out := make([]uint64, 8, 8)
-
-	shffle := make([]uint64, 2, 2)
 	// vector for PSHUFB instruction
 	shffle[0] = 0x0201000706050403
 	shffle[1] = 0x0a09080f0e0d0c0b
 
 	in[0], in[1], in[2], in[3], in[4], in[5], in[6], in[7] = d.h[0], d.h[1], d.h[2], d.h[3], d.h[4], d.h[5], d.h[6], d.h[7]
 
-	blockAVXLoop(p, in, iv[:], d.t[:], d.f[:], shffle, out)
+	blockAVXLoop(p, in[:], iv[:], d.t[:], d.f[:], shffle[:], out[:])
 
 	d.h[0], d.h[1], d.h[2], d.h[3], d.h[4], d.h[5], d.h[6], d.h[7] = out[0], out[1], out[2], out[3], out[4], out[5], out[6], out[7]
 }

compressSse_amd64.go

@@ -23,18 +23,19 @@ package blake2b
 func blockSSELoop(p []uint8, in, iv, t, f, shffle, out []uint64)
 
 func compressSSE(d *digest, p []uint8) {
+	var (
+		in     [8]uint64
+		out    [8]uint64
+		shffle [2]uint64
+	)
 
-	in := make([]uint64, 8, 8)
-	out := make([]uint64, 8, 8)
-
-	shffle := make([]uint64, 2, 2)
 	// vector for PSHUFB instruction
 	shffle[0] = 0x0201000706050403
 	shffle[1] = 0x0a09080f0e0d0c0b
 
 	in[0], in[1], in[2], in[3], in[4], in[5], in[6], in[7] = d.h[0], d.h[1], d.h[2], d.h[3], d.h[4], d.h[5], d.h[6], d.h[7]
 
-	blockSSELoop(p, in, iv[:], d.t[:], d.f[:], shffle, out)
+	blockSSELoop(p, in[:], iv[:], d.t[:], d.f[:], shffle[:], out[:])
 
 	d.h[0], d.h[1], d.h[2], d.h[3], d.h[4], d.h[5], d.h[6], d.h[7] = out[0], out[1], out[2], out[3], out[4], out[5], out[6], out[7]
 }

compress_generic.go

@@ -26,12 +26,13 @@ func compressGeneric(d *digest, p []uint8) {
 		v13 := iv[5] ^ d.t[1]
 		v14 := iv[6] ^ d.f[0]
 		v15 := iv[7] ^ d.f[1]
-		var m [16]uint64
 
 		j := 0
-		for i := 0; i < 16; i++ {
-			m[i] = uint64(p[j]) | uint64(p[j+1])<<8 | uint64(p[j+2])<<16 | uint64(p[j+3])<<24 |
-				uint64(p[j+4])<<32 | uint64(p[j+5])<<40 | uint64(p[j+6])<<48 | uint64(p[j+7])<<56
+		var m [16]uint64
+		for i := range m {
+			m[i] = uint64(p[j]) | uint64(p[j+1])<<8 | uint64(p[j+2])<<16 |
+				uint64(p[j+3])<<24 | uint64(p[j+4])<<32 | uint64(p[j+5])<<40 |
+				uint64(p[j+6])<<48 | uint64(p[j+7])<<56
 			j += 8
 		}