|  | // Copyright 2013 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 runtime_test | 
|  |  | 
|  | import ( | 
|  | "crypto/rand" | 
|  | "encoding/binary" | 
|  | "fmt" | 
|  | "internal/race" | 
|  | "internal/testenv" | 
|  | . "runtime" | 
|  | "sync/atomic" | 
|  | "testing" | 
|  | "unsafe" | 
|  | ) | 
|  |  | 
|  | func TestMemmove(t *testing.T) { | 
|  | if *flagQuick { | 
|  | t.Skip("-quick") | 
|  | } | 
|  | t.Parallel() | 
|  | size := 256 | 
|  | if testing.Short() { | 
|  | size = 128 + 16 | 
|  | } | 
|  | src := make([]byte, size) | 
|  | dst := make([]byte, size) | 
|  | for i := 0; i < size; i++ { | 
|  | src[i] = byte(128 + (i & 127)) | 
|  | } | 
|  | for i := 0; i < size; i++ { | 
|  | dst[i] = byte(i & 127) | 
|  | } | 
|  | for n := 0; n <= size; n++ { | 
|  | for x := 0; x <= size-n; x++ { // offset in src | 
|  | for y := 0; y <= size-n; y++ { // offset in dst | 
|  | copy(dst[y:y+n], src[x:x+n]) | 
|  | for i := 0; i < y; i++ { | 
|  | if dst[i] != byte(i&127) { | 
|  | t.Fatalf("prefix dst[%d] = %d", i, dst[i]) | 
|  | } | 
|  | } | 
|  | for i := y; i < y+n; i++ { | 
|  | if dst[i] != byte(128+((i-y+x)&127)) { | 
|  | t.Fatalf("copied dst[%d] = %d", i, dst[i]) | 
|  | } | 
|  | dst[i] = byte(i & 127) // reset dst | 
|  | } | 
|  | for i := y + n; i < size; i++ { | 
|  | if dst[i] != byte(i&127) { | 
|  | t.Fatalf("suffix dst[%d] = %d", i, dst[i]) | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | func TestMemmoveAlias(t *testing.T) { | 
|  | if *flagQuick { | 
|  | t.Skip("-quick") | 
|  | } | 
|  | t.Parallel() | 
|  | size := 256 | 
|  | if testing.Short() { | 
|  | size = 128 + 16 | 
|  | } | 
|  | buf := make([]byte, size) | 
|  | for i := 0; i < size; i++ { | 
|  | buf[i] = byte(i) | 
|  | } | 
|  | for n := 0; n <= size; n++ { | 
|  | for x := 0; x <= size-n; x++ { // src offset | 
|  | for y := 0; y <= size-n; y++ { // dst offset | 
|  | copy(buf[y:y+n], buf[x:x+n]) | 
|  | for i := 0; i < y; i++ { | 
|  | if buf[i] != byte(i) { | 
|  | t.Fatalf("prefix buf[%d] = %d", i, buf[i]) | 
|  | } | 
|  | } | 
|  | for i := y; i < y+n; i++ { | 
|  | if buf[i] != byte(i-y+x) { | 
|  | t.Fatalf("copied buf[%d] = %d", i, buf[i]) | 
|  | } | 
|  | buf[i] = byte(i) // reset buf | 
|  | } | 
|  | for i := y + n; i < size; i++ { | 
|  | if buf[i] != byte(i) { | 
|  | t.Fatalf("suffix buf[%d] = %d", i, buf[i]) | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | func TestMemmoveLarge0x180000(t *testing.T) { | 
|  | if testing.Short() && testenv.Builder() == "" { | 
|  | t.Skip("-short") | 
|  | } | 
|  |  | 
|  | t.Parallel() | 
|  | if race.Enabled { | 
|  | t.Skip("skipping large memmove test under race detector") | 
|  | } | 
|  | testSize(t, 0x180000) | 
|  | } | 
|  |  | 
|  | func TestMemmoveOverlapLarge0x120000(t *testing.T) { | 
|  | if testing.Short() && testenv.Builder() == "" { | 
|  | t.Skip("-short") | 
|  | } | 
|  |  | 
|  | t.Parallel() | 
|  | if race.Enabled { | 
|  | t.Skip("skipping large memmove test under race detector") | 
|  | } | 
|  | testOverlap(t, 0x120000) | 
|  | } | 
|  |  | 
|  | func testSize(t *testing.T, size int) { | 
|  | src := make([]byte, size) | 
|  | dst := make([]byte, size) | 
|  | _, _ = rand.Read(src) | 
|  | _, _ = rand.Read(dst) | 
|  |  | 
|  | ref := make([]byte, size) | 
|  | copyref(ref, dst) | 
|  |  | 
|  | for n := size - 50; n > 1; n >>= 1 { | 
|  | for x := 0; x <= size-n; x = x*7 + 1 { // offset in src | 
|  | for y := 0; y <= size-n; y = y*9 + 1 { // offset in dst | 
|  | copy(dst[y:y+n], src[x:x+n]) | 
|  | copyref(ref[y:y+n], src[x:x+n]) | 
|  | p := cmpb(dst, ref) | 
|  | if p >= 0 { | 
|  | t.Fatalf("Copy failed, copying from src[%d:%d] to dst[%d:%d].\nOffset %d is different, %v != %v", x, x+n, y, y+n, p, dst[p], ref[p]) | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | func testOverlap(t *testing.T, size int) { | 
|  | src := make([]byte, size) | 
|  | test := make([]byte, size) | 
|  | ref := make([]byte, size) | 
|  | _, _ = rand.Read(src) | 
|  |  | 
|  | for n := size - 50; n > 1; n >>= 1 { | 
|  | for x := 0; x <= size-n; x = x*7 + 1 { // offset in src | 
|  | for y := 0; y <= size-n; y = y*9 + 1 { // offset in dst | 
|  | // Reset input | 
|  | copyref(test, src) | 
|  | copyref(ref, src) | 
|  | copy(test[y:y+n], test[x:x+n]) | 
|  | if y <= x { | 
|  | copyref(ref[y:y+n], ref[x:x+n]) | 
|  | } else { | 
|  | copybw(ref[y:y+n], ref[x:x+n]) | 
|  | } | 
|  | p := cmpb(test, ref) | 
|  | if p >= 0 { | 
|  | t.Fatalf("Copy failed, copying from src[%d:%d] to dst[%d:%d].\nOffset %d is different, %v != %v", x, x+n, y, y+n, p, test[p], ref[p]) | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | } | 
|  |  | 
|  | // Forward copy. | 
|  | func copyref(dst, src []byte) { | 
|  | for i, v := range src { | 
|  | dst[i] = v | 
|  | } | 
|  | } | 
|  |  | 
|  | // Backwards copy | 
|  | func copybw(dst, src []byte) { | 
|  | if len(src) == 0 { | 
|  | return | 
|  | } | 
|  | for i := len(src) - 1; i >= 0; i-- { | 
|  | dst[i] = src[i] | 
|  | } | 
|  | } | 
|  |  | 
|  | // Returns offset of difference | 
|  | func matchLen(a, b []byte, max int) int { | 
|  | a = a[:max] | 
|  | b = b[:max] | 
|  | for i, av := range a { | 
|  | if b[i] != av { | 
|  | return i | 
|  | } | 
|  | } | 
|  | return max | 
|  | } | 
|  |  | 
|  | func cmpb(a, b []byte) int { | 
|  | l := matchLen(a, b, len(a)) | 
|  | if l == len(a) { | 
|  | return -1 | 
|  | } | 
|  | return l | 
|  | } | 
|  |  | 
|  | // Ensure that memmove writes pointers atomically, so the GC won't | 
|  | // observe a partially updated pointer. | 
|  | func TestMemmoveAtomicity(t *testing.T) { | 
|  | if race.Enabled { | 
|  | t.Skip("skip under the race detector -- this test is intentionally racy") | 
|  | } | 
|  |  | 
|  | var x int | 
|  |  | 
|  | for _, backward := range []bool{true, false} { | 
|  | for _, n := range []int{3, 4, 5, 6, 7, 8, 9, 10, 15, 25, 49} { | 
|  | n := n | 
|  |  | 
|  | // test copying [N]*int. | 
|  | sz := uintptr(n * PtrSize) | 
|  | name := fmt.Sprint(sz) | 
|  | if backward { | 
|  | name += "-backward" | 
|  | } else { | 
|  | name += "-forward" | 
|  | } | 
|  | t.Run(name, func(t *testing.T) { | 
|  | // Use overlapping src and dst to force forward/backward copy. | 
|  | var s [100]*int | 
|  | src := s[n-1 : 2*n-1] | 
|  | dst := s[:n] | 
|  | if backward { | 
|  | src, dst = dst, src | 
|  | } | 
|  | for i := range src { | 
|  | src[i] = &x | 
|  | } | 
|  | for i := range dst { | 
|  | dst[i] = nil | 
|  | } | 
|  |  | 
|  | var ready atomic.Uint32 | 
|  | go func() { | 
|  | sp := unsafe.Pointer(&src[0]) | 
|  | dp := unsafe.Pointer(&dst[0]) | 
|  | ready.Store(1) | 
|  | for i := 0; i < 10000; i++ { | 
|  | Memmove(dp, sp, sz) | 
|  | MemclrNoHeapPointers(dp, sz) | 
|  | } | 
|  | ready.Store(2) | 
|  | }() | 
|  |  | 
|  | for ready.Load() == 0 { | 
|  | Gosched() | 
|  | } | 
|  |  | 
|  | for ready.Load() != 2 { | 
|  | for i := range dst { | 
|  | p := dst[i] | 
|  | if p != nil && p != &x { | 
|  | t.Fatalf("got partially updated pointer %p at dst[%d], want either nil or %p", p, i, &x) | 
|  | } | 
|  | } | 
|  | } | 
|  | }) | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | func benchmarkSizes(b *testing.B, sizes []int, fn func(b *testing.B, n int)) { | 
|  | for _, n := range sizes { | 
|  | b.Run(fmt.Sprint(n), func(b *testing.B) { | 
|  | b.SetBytes(int64(n)) | 
|  | fn(b, n) | 
|  | }) | 
|  | } | 
|  | } | 
|  |  | 
|  | var bufSizes = []int{ | 
|  | 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, | 
|  | 32, 64, 128, 256, 512, 1024, 2048, 4096, | 
|  | } | 
|  | var bufSizesOverlap = []int{ | 
|  | 32, 64, 128, 256, 512, 1024, 2048, 4096, | 
|  | } | 
|  |  | 
|  | func BenchmarkMemmove(b *testing.B) { | 
|  | benchmarkSizes(b, bufSizes, func(b *testing.B, n int) { | 
|  | x := make([]byte, n) | 
|  | y := make([]byte, n) | 
|  | for i := 0; i < b.N; i++ { | 
|  | copy(x, y) | 
|  | } | 
|  | }) | 
|  | } | 
|  |  | 
|  | func BenchmarkMemmoveOverlap(b *testing.B) { | 
|  | benchmarkSizes(b, bufSizesOverlap, func(b *testing.B, n int) { | 
|  | x := make([]byte, n+16) | 
|  | for i := 0; i < b.N; i++ { | 
|  | copy(x[16:n+16], x[:n]) | 
|  | } | 
|  | }) | 
|  | } | 
|  |  | 
|  | func BenchmarkMemmoveUnalignedDst(b *testing.B) { | 
|  | benchmarkSizes(b, bufSizes, func(b *testing.B, n int) { | 
|  | x := make([]byte, n+1) | 
|  | y := make([]byte, n) | 
|  | for i := 0; i < b.N; i++ { | 
|  | copy(x[1:], y) | 
|  | } | 
|  | }) | 
|  | } | 
|  |  | 
|  | func BenchmarkMemmoveUnalignedDstOverlap(b *testing.B) { | 
|  | benchmarkSizes(b, bufSizesOverlap, func(b *testing.B, n int) { | 
|  | x := make([]byte, n+16) | 
|  | for i := 0; i < b.N; i++ { | 
|  | copy(x[16:n+16], x[1:n+1]) | 
|  | } | 
|  | }) | 
|  | } | 
|  |  | 
|  | func BenchmarkMemmoveUnalignedSrc(b *testing.B) { | 
|  | benchmarkSizes(b, bufSizes, func(b *testing.B, n int) { | 
|  | x := make([]byte, n) | 
|  | y := make([]byte, n+1) | 
|  | for i := 0; i < b.N; i++ { | 
|  | copy(x, y[1:]) | 
|  | } | 
|  | }) | 
|  | } | 
|  |  | 
|  | func BenchmarkMemmoveUnalignedSrcDst(b *testing.B) { | 
|  | for _, n := range []int{16, 64, 256, 4096, 65536} { | 
|  | buf := make([]byte, (n+8)*2) | 
|  | x := buf[:len(buf)/2] | 
|  | y := buf[len(buf)/2:] | 
|  | for _, off := range []int{0, 1, 4, 7} { | 
|  | b.Run(fmt.Sprint("f_", n, off), func(b *testing.B) { | 
|  | b.SetBytes(int64(n)) | 
|  | for i := 0; i < b.N; i++ { | 
|  | copy(x[off:n+off], y[off:n+off]) | 
|  | } | 
|  | }) | 
|  |  | 
|  | b.Run(fmt.Sprint("b_", n, off), func(b *testing.B) { | 
|  | b.SetBytes(int64(n)) | 
|  | for i := 0; i < b.N; i++ { | 
|  | copy(y[off:n+off], x[off:n+off]) | 
|  | } | 
|  | }) | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkMemmoveUnalignedSrcOverlap(b *testing.B) { | 
|  | benchmarkSizes(b, bufSizesOverlap, func(b *testing.B, n int) { | 
|  | x := make([]byte, n+1) | 
|  | for i := 0; i < b.N; i++ { | 
|  | copy(x[1:n+1], x[:n]) | 
|  | } | 
|  | }) | 
|  | } | 
|  |  | 
|  | func TestMemclr(t *testing.T) { | 
|  | size := 512 | 
|  | if testing.Short() { | 
|  | size = 128 + 16 | 
|  | } | 
|  | mem := make([]byte, size) | 
|  | for i := 0; i < size; i++ { | 
|  | mem[i] = 0xee | 
|  | } | 
|  | for n := 0; n < size; n++ { | 
|  | for x := 0; x <= size-n; x++ { // offset in mem | 
|  | MemclrBytes(mem[x : x+n]) | 
|  | for i := 0; i < x; i++ { | 
|  | if mem[i] != 0xee { | 
|  | t.Fatalf("overwrite prefix mem[%d] = %d", i, mem[i]) | 
|  | } | 
|  | } | 
|  | for i := x; i < x+n; i++ { | 
|  | if mem[i] != 0 { | 
|  | t.Fatalf("failed clear mem[%d] = %d", i, mem[i]) | 
|  | } | 
|  | mem[i] = 0xee | 
|  | } | 
|  | for i := x + n; i < size; i++ { | 
|  | if mem[i] != 0xee { | 
|  | t.Fatalf("overwrite suffix mem[%d] = %d", i, mem[i]) | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkMemclr(b *testing.B) { | 
|  | for _, n := range []int{5, 16, 64, 256, 4096, 65536} { | 
|  | x := make([]byte, n) | 
|  | b.Run(fmt.Sprint(n), func(b *testing.B) { | 
|  | b.SetBytes(int64(n)) | 
|  | for i := 0; i < b.N; i++ { | 
|  | MemclrBytes(x) | 
|  | } | 
|  | }) | 
|  | } | 
|  | for _, m := range []int{1, 4, 8, 16, 64} { | 
|  | x := make([]byte, m<<20) | 
|  | b.Run(fmt.Sprint(m, "M"), func(b *testing.B) { | 
|  | b.SetBytes(int64(m << 20)) | 
|  | for i := 0; i < b.N; i++ { | 
|  | MemclrBytes(x) | 
|  | } | 
|  | }) | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkMemclrUnaligned(b *testing.B) { | 
|  | for _, off := range []int{0, 1, 4, 7} { | 
|  | for _, n := range []int{5, 16, 64, 256, 4096, 65536} { | 
|  | x := make([]byte, n+off) | 
|  | b.Run(fmt.Sprint(off, n), func(b *testing.B) { | 
|  | b.SetBytes(int64(n)) | 
|  | for i := 0; i < b.N; i++ { | 
|  | MemclrBytes(x[off:]) | 
|  | } | 
|  | }) | 
|  | } | 
|  | } | 
|  |  | 
|  | for _, off := range []int{0, 1, 4, 7} { | 
|  | for _, m := range []int{1, 4, 8, 16, 64} { | 
|  | x := make([]byte, (m<<20)+off) | 
|  | b.Run(fmt.Sprint(off, m, "M"), func(b *testing.B) { | 
|  | b.SetBytes(int64(m << 20)) | 
|  | for i := 0; i < b.N; i++ { | 
|  | MemclrBytes(x[off:]) | 
|  | } | 
|  | }) | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkGoMemclr(b *testing.B) { | 
|  | benchmarkSizes(b, []int{5, 16, 64, 256}, func(b *testing.B, n int) { | 
|  | x := make([]byte, n) | 
|  | for i := 0; i < b.N; i++ { | 
|  | for j := range x { | 
|  | x[j] = 0 | 
|  | } | 
|  | } | 
|  | }) | 
|  | } | 
|  |  | 
|  | func BenchmarkMemclrRange(b *testing.B) { | 
|  | type RunData struct { | 
|  | data []int | 
|  | } | 
|  |  | 
|  | benchSizes := []RunData{ | 
|  | {[]int{1043, 1078, 1894, 1582, 1044, 1165, 1467, 1100, 1919, 1562, 1932, 1645, | 
|  | 1412, 1038, 1576, 1200, 1029, 1336, 1095, 1494, 1350, 1025, 1502, 1548, 1316, 1296, | 
|  | 1868, 1639, 1546, 1626, 1642, 1308, 1726, 1665, 1678, 1187, 1515, 1598, 1353, 1237, | 
|  | 1977, 1452, 2012, 1914, 1514, 1136, 1975, 1618, 1536, 1695, 1600, 1733, 1392, 1099, | 
|  | 1358, 1996, 1224, 1783, 1197, 1838, 1460, 1556, 1554, 2020}}, // 1kb-2kb | 
|  | {[]int{3964, 5139, 6573, 7775, 6553, 2413, 3466, 5394, 2469, 7336, 7091, 6745, | 
|  | 4028, 5643, 6164, 3475, 4138, 6908, 7559, 3335, 5660, 4122, 3945, 2082, 7564, 6584, | 
|  | 5111, 2288, 6789, 2797, 4928, 7986, 5163, 5447, 2999, 4968, 3174, 3202, 7908, 8137, | 
|  | 4735, 6161, 4646, 7592, 3083, 5329, 3687, 2754, 3599, 7231, 6455, 2549, 8063, 2189, | 
|  | 7121, 5048, 4277, 6626, 6306, 2815, 7473, 3963, 7549, 7255}}, // 2kb-8kb | 
|  | {[]int{16304, 15936, 15760, 4736, 9136, 11184, 10160, 5952, 14560, 15744, | 
|  | 6624, 5872, 13088, 14656, 14192, 10304, 4112, 10384, 9344, 4496, 11392, 7024, | 
|  | 5200, 10064, 14784, 5808, 13504, 10480, 8512, 4896, 13264, 5600}}, // 4kb-16kb | 
|  | {[]int{164576, 233136, 220224, 183280, 214112, 217248, 228560, 201728}}, // 128kb-256kb | 
|  | } | 
|  |  | 
|  | for _, t := range benchSizes { | 
|  | total := 0 | 
|  | minLen := 0 | 
|  | maxLen := 0 | 
|  |  | 
|  | for _, clrLen := range t.data { | 
|  | maxLen = max(maxLen, clrLen) | 
|  | if clrLen < minLen || minLen == 0 { | 
|  | minLen = clrLen | 
|  | } | 
|  | total += clrLen | 
|  | } | 
|  | buffer := make([]byte, maxLen) | 
|  |  | 
|  | text := "" | 
|  | if minLen >= (1 << 20) { | 
|  | text = fmt.Sprint(minLen>>20, "M ", (maxLen+(1<<20-1))>>20, "M") | 
|  | } else if minLen >= (1 << 10) { | 
|  | text = fmt.Sprint(minLen>>10, "K ", (maxLen+(1<<10-1))>>10, "K") | 
|  | } else { | 
|  | text = fmt.Sprint(minLen, " ", maxLen) | 
|  | } | 
|  | b.Run(text, func(b *testing.B) { | 
|  | b.SetBytes(int64(total)) | 
|  | for i := 0; i < b.N; i++ { | 
|  | for _, clrLen := range t.data { | 
|  | MemclrBytes(buffer[:clrLen]) | 
|  | } | 
|  | } | 
|  | }) | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat7(b *testing.B) { | 
|  | p := new([7]byte) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [7]byte{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat8(b *testing.B) { | 
|  | p := new([8 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [8 / 4]uint32{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat11(b *testing.B) { | 
|  | p := new([11]byte) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [11]byte{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat12(b *testing.B) { | 
|  | p := new([12 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [12 / 4]uint32{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat13(b *testing.B) { | 
|  | p := new([13]byte) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [13]byte{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat14(b *testing.B) { | 
|  | p := new([14]byte) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [14]byte{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat15(b *testing.B) { | 
|  | p := new([15]byte) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [15]byte{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat16(b *testing.B) { | 
|  | p := new([16 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [16 / 4]uint32{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat24(b *testing.B) { | 
|  | p := new([24 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [24 / 4]uint32{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat32(b *testing.B) { | 
|  | p := new([32 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [32 / 4]uint32{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat40(b *testing.B) { | 
|  | p := new([40 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [40 / 4]uint32{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat48(b *testing.B) { | 
|  | p := new([48 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [48 / 4]uint32{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat56(b *testing.B) { | 
|  | p := new([56 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [56 / 4]uint32{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat64(b *testing.B) { | 
|  | p := new([64 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [64 / 4]uint32{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat72(b *testing.B) { | 
|  | p := new([72 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [72 / 4]uint32{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat128(b *testing.B) { | 
|  | p := new([128 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [128 / 4]uint32{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat256(b *testing.B) { | 
|  | p := new([256 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [256 / 4]uint32{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat512(b *testing.B) { | 
|  | p := new([512 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [512 / 4]uint32{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat1024(b *testing.B) { | 
|  | p := new([1024 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [1024 / 4]uint32{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat1032(b *testing.B) { | 
|  | p := new([1032 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [1032 / 4]uint32{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkClearFat1040(b *testing.B) { | 
|  | p := new([1040 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = [1040 / 4]uint32{} | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkCopyFat7(b *testing.B) { | 
|  | var x [7]byte | 
|  | p := new([7]byte) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = x | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkCopyFat8(b *testing.B) { | 
|  | var x [8 / 4]uint32 | 
|  | p := new([8 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = x | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkCopyFat11(b *testing.B) { | 
|  | var x [11]byte | 
|  | p := new([11]byte) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = x | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkCopyFat12(b *testing.B) { | 
|  | var x [12 / 4]uint32 | 
|  | p := new([12 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = x | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkCopyFat13(b *testing.B) { | 
|  | var x [13]byte | 
|  | p := new([13]byte) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = x | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkCopyFat14(b *testing.B) { | 
|  | var x [14]byte | 
|  | p := new([14]byte) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = x | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkCopyFat15(b *testing.B) { | 
|  | var x [15]byte | 
|  | p := new([15]byte) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = x | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkCopyFat16(b *testing.B) { | 
|  | var x [16 / 4]uint32 | 
|  | p := new([16 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = x | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkCopyFat24(b *testing.B) { | 
|  | var x [24 / 4]uint32 | 
|  | p := new([24 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = x | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkCopyFat32(b *testing.B) { | 
|  | var x [32 / 4]uint32 | 
|  | p := new([32 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = x | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkCopyFat64(b *testing.B) { | 
|  | var x [64 / 4]uint32 | 
|  | p := new([64 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = x | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkCopyFat72(b *testing.B) { | 
|  | var x [72 / 4]uint32 | 
|  | p := new([72 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = x | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkCopyFat128(b *testing.B) { | 
|  | var x [128 / 4]uint32 | 
|  | p := new([128 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = x | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkCopyFat256(b *testing.B) { | 
|  | var x [256 / 4]uint32 | 
|  | p := new([256 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = x | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkCopyFat512(b *testing.B) { | 
|  | var x [512 / 4]uint32 | 
|  | p := new([512 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = x | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkCopyFat520(b *testing.B) { | 
|  | var x [520 / 4]uint32 | 
|  | p := new([520 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = x | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkCopyFat1024(b *testing.B) { | 
|  | var x [1024 / 4]uint32 | 
|  | p := new([1024 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = x | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkCopyFat1032(b *testing.B) { | 
|  | var x [1032 / 4]uint32 | 
|  | p := new([1032 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = x | 
|  | } | 
|  | } | 
|  |  | 
|  | func BenchmarkCopyFat1040(b *testing.B) { | 
|  | var x [1040 / 4]uint32 | 
|  | p := new([1040 / 4]uint32) | 
|  | Escape(p) | 
|  | b.ResetTimer() | 
|  | for i := 0; i < b.N; i++ { | 
|  | *p = x | 
|  | } | 
|  | } | 
|  |  | 
|  | // BenchmarkIssue18740 ensures that memmove uses 4 and 8 byte load/store to move 4 and 8 bytes. | 
|  | // It used to do 2 2-byte load/stores, which leads to a pipeline stall | 
|  | // when we try to read the result with one 4-byte load. | 
|  | func BenchmarkIssue18740(b *testing.B) { | 
|  | benchmarks := []struct { | 
|  | name  string | 
|  | nbyte int | 
|  | f     func([]byte) uint64 | 
|  | }{ | 
|  | {"2byte", 2, func(buf []byte) uint64 { return uint64(binary.LittleEndian.Uint16(buf)) }}, | 
|  | {"4byte", 4, func(buf []byte) uint64 { return uint64(binary.LittleEndian.Uint32(buf)) }}, | 
|  | {"8byte", 8, func(buf []byte) uint64 { return binary.LittleEndian.Uint64(buf) }}, | 
|  | } | 
|  |  | 
|  | var g [4096]byte | 
|  | for _, bm := range benchmarks { | 
|  | buf := make([]byte, bm.nbyte) | 
|  | b.Run(bm.name, func(b *testing.B) { | 
|  | for j := 0; j < b.N; j++ { | 
|  | for i := 0; i < 4096; i += bm.nbyte { | 
|  | copy(buf[:], g[i:]) | 
|  | sink += bm.f(buf[:]) | 
|  | } | 
|  | } | 
|  | }) | 
|  | } | 
|  | } | 
|  |  | 
|  | var memclrSink []int8 | 
|  |  | 
|  | func BenchmarkMemclrKnownSize1(b *testing.B) { | 
|  | var x [1]int8 | 
|  |  | 
|  | b.SetBytes(1) | 
|  | for i := 0; i < b.N; i++ { | 
|  | for a := range x { | 
|  | x[a] = 0 | 
|  | } | 
|  | } | 
|  |  | 
|  | memclrSink = x[:] | 
|  | } | 
|  | func BenchmarkMemclrKnownSize2(b *testing.B) { | 
|  | var x [2]int8 | 
|  |  | 
|  | b.SetBytes(2) | 
|  | for i := 0; i < b.N; i++ { | 
|  | for a := range x { | 
|  | x[a] = 0 | 
|  | } | 
|  | } | 
|  |  | 
|  | memclrSink = x[:] | 
|  | } | 
|  | func BenchmarkMemclrKnownSize4(b *testing.B) { | 
|  | var x [4]int8 | 
|  |  | 
|  | b.SetBytes(4) | 
|  | for i := 0; i < b.N; i++ { | 
|  | for a := range x { | 
|  | x[a] = 0 | 
|  | } | 
|  | } | 
|  |  | 
|  | memclrSink = x[:] | 
|  | } | 
|  | func BenchmarkMemclrKnownSize8(b *testing.B) { | 
|  | var x [8]int8 | 
|  |  | 
|  | b.SetBytes(8) | 
|  | for i := 0; i < b.N; i++ { | 
|  | for a := range x { | 
|  | x[a] = 0 | 
|  | } | 
|  | } | 
|  |  | 
|  | memclrSink = x[:] | 
|  | } | 
|  | func BenchmarkMemclrKnownSize16(b *testing.B) { | 
|  | var x [16]int8 | 
|  |  | 
|  | b.SetBytes(16) | 
|  | for i := 0; i < b.N; i++ { | 
|  | for a := range x { | 
|  | x[a] = 0 | 
|  | } | 
|  | } | 
|  |  | 
|  | memclrSink = x[:] | 
|  | } | 
|  | func BenchmarkMemclrKnownSize32(b *testing.B) { | 
|  | var x [32]int8 | 
|  |  | 
|  | b.SetBytes(32) | 
|  | for i := 0; i < b.N; i++ { | 
|  | for a := range x { | 
|  | x[a] = 0 | 
|  | } | 
|  | } | 
|  |  | 
|  | memclrSink = x[:] | 
|  | } | 
|  | func BenchmarkMemclrKnownSize64(b *testing.B) { | 
|  | var x [64]int8 | 
|  |  | 
|  | b.SetBytes(64) | 
|  | for i := 0; i < b.N; i++ { | 
|  | for a := range x { | 
|  | x[a] = 0 | 
|  | } | 
|  | } | 
|  |  | 
|  | memclrSink = x[:] | 
|  | } | 
|  | func BenchmarkMemclrKnownSize112(b *testing.B) { | 
|  | var x [112]int8 | 
|  |  | 
|  | b.SetBytes(112) | 
|  | for i := 0; i < b.N; i++ { | 
|  | for a := range x { | 
|  | x[a] = 0 | 
|  | } | 
|  | } | 
|  |  | 
|  | memclrSink = x[:] | 
|  | } | 
|  |  | 
|  | func BenchmarkMemclrKnownSize128(b *testing.B) { | 
|  | var x [128]int8 | 
|  |  | 
|  | b.SetBytes(128) | 
|  | for i := 0; i < b.N; i++ { | 
|  | for a := range x { | 
|  | x[a] = 0 | 
|  | } | 
|  | } | 
|  |  | 
|  | memclrSink = x[:] | 
|  | } | 
|  |  | 
|  | func BenchmarkMemclrKnownSize192(b *testing.B) { | 
|  | var x [192]int8 | 
|  |  | 
|  | b.SetBytes(192) | 
|  | for i := 0; i < b.N; i++ { | 
|  | for a := range x { | 
|  | x[a] = 0 | 
|  | } | 
|  | } | 
|  |  | 
|  | memclrSink = x[:] | 
|  | } | 
|  |  | 
|  | func BenchmarkMemclrKnownSize248(b *testing.B) { | 
|  | var x [248]int8 | 
|  |  | 
|  | b.SetBytes(248) | 
|  | for i := 0; i < b.N; i++ { | 
|  | for a := range x { | 
|  | x[a] = 0 | 
|  | } | 
|  | } | 
|  |  | 
|  | memclrSink = x[:] | 
|  | } | 
|  |  | 
|  | func BenchmarkMemclrKnownSize256(b *testing.B) { | 
|  | var x [256]int8 | 
|  |  | 
|  | b.SetBytes(256) | 
|  | for i := 0; i < b.N; i++ { | 
|  | for a := range x { | 
|  | x[a] = 0 | 
|  | } | 
|  | } | 
|  |  | 
|  | memclrSink = x[:] | 
|  | } | 
|  | func BenchmarkMemclrKnownSize512(b *testing.B) { | 
|  | var x [512]int8 | 
|  |  | 
|  | b.SetBytes(512) | 
|  | for i := 0; i < b.N; i++ { | 
|  | for a := range x { | 
|  | x[a] = 0 | 
|  | } | 
|  | } | 
|  |  | 
|  | memclrSink = x[:] | 
|  | } | 
|  | func BenchmarkMemclrKnownSize1024(b *testing.B) { | 
|  | var x [1024]int8 | 
|  |  | 
|  | b.SetBytes(1024) | 
|  | for i := 0; i < b.N; i++ { | 
|  | for a := range x { | 
|  | x[a] = 0 | 
|  | } | 
|  | } | 
|  |  | 
|  | memclrSink = x[:] | 
|  | } | 
|  | func BenchmarkMemclrKnownSize4096(b *testing.B) { | 
|  | var x [4096]int8 | 
|  |  | 
|  | b.SetBytes(4096) | 
|  | for i := 0; i < b.N; i++ { | 
|  | for a := range x { | 
|  | x[a] = 0 | 
|  | } | 
|  | } | 
|  |  | 
|  | memclrSink = x[:] | 
|  | } | 
|  | func BenchmarkMemclrKnownSize512KiB(b *testing.B) { | 
|  | var x [524288]int8 | 
|  |  | 
|  | b.SetBytes(524288) | 
|  | for i := 0; i < b.N; i++ { | 
|  | for a := range x { | 
|  | x[a] = 0 | 
|  | } | 
|  | } | 
|  |  | 
|  | memclrSink = x[:] | 
|  | } |