| // 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 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 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 { |
| if clrLen > maxLen { |
| 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[:]) |
| } |
| } |
| }) |
| } |
| } |
