File size: 4,900 Bytes
e36aeda | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 | // Copyright 2015 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.
// Tests load/store ordering
package main
import "testing"
// testLoadStoreOrder tests for reordering of stores/loads.
func testLoadStoreOrder(t *testing.T) {
z := uint32(1000)
if testLoadStoreOrder_ssa(&z, 100) == 0 {
t.Errorf("testLoadStoreOrder failed")
}
}
//go:noinline
func testLoadStoreOrder_ssa(z *uint32, prec uint) int {
old := *z // load
*z = uint32(prec) // store
if *z < old { // load
return 1
}
return 0
}
func testStoreSize(t *testing.T) {
a := [4]uint16{11, 22, 33, 44}
testStoreSize_ssa(&a[0], &a[2], 77)
want := [4]uint16{77, 22, 33, 44}
if a != want {
t.Errorf("testStoreSize failed. want = %d, got = %d", want, a)
}
}
//go:noinline
func testStoreSize_ssa(p *uint16, q *uint16, v uint32) {
// Test to make sure that (Store ptr (Trunc32to16 val) mem)
// does not end up as a 32-bit store. It must stay a 16 bit store
// even when Trunc32to16 is rewritten to be a nop.
// To ensure that we get rewrite the Trunc32to16 before
// we rewrite the Store, we force the truncate into an
// earlier basic block by using it on both branches.
w := uint16(v)
if p != nil {
*p = w
} else {
*q = w
}
}
//go:noinline
func testExtStore_ssa(p *byte, b bool) int {
x := *p
*p = 7
if b {
return int(x)
}
return 0
}
func testExtStore(t *testing.T) {
const start = 8
var b byte = start
if got := testExtStore_ssa(&b, true); got != start {
t.Errorf("testExtStore failed. want = %d, got = %d", start, got)
}
}
var b int
// testDeadStorePanic_ssa ensures that we don't optimize away stores
// that could be read by after recover(). Modeled after fixedbugs/issue1304.
//
//go:noinline
func testDeadStorePanic_ssa(a int) (r int) {
defer func() {
recover()
r = a
}()
a = 2 // store
b := a - a // optimized to zero
c := 4
a = c / b // store, but panics
a = 3 // store
r = a
return
}
func testDeadStorePanic(t *testing.T) {
if want, got := 2, testDeadStorePanic_ssa(1); want != got {
t.Errorf("testDeadStorePanic failed. want = %d, got = %d", want, got)
}
}
//go:noinline
func loadHitStore8(x int8, p *int8) int32 {
x *= x // try to trash high bits (arch-dependent)
*p = x // store
return int32(*p) // load and cast
}
//go:noinline
func loadHitStoreU8(x uint8, p *uint8) uint32 {
x *= x // try to trash high bits (arch-dependent)
*p = x // store
return uint32(*p) // load and cast
}
//go:noinline
func loadHitStore16(x int16, p *int16) int32 {
x *= x // try to trash high bits (arch-dependent)
*p = x // store
return int32(*p) // load and cast
}
//go:noinline
func loadHitStoreU16(x uint16, p *uint16) uint32 {
x *= x // try to trash high bits (arch-dependent)
*p = x // store
return uint32(*p) // load and cast
}
//go:noinline
func loadHitStore32(x int32, p *int32) int64 {
x *= x // try to trash high bits (arch-dependent)
*p = x // store
return int64(*p) // load and cast
}
//go:noinline
func loadHitStoreU32(x uint32, p *uint32) uint64 {
x *= x // try to trash high bits (arch-dependent)
*p = x // store
return uint64(*p) // load and cast
}
func testLoadHitStore(t *testing.T) {
// Test that sign/zero extensions are kept when a load-hit-store
// is replaced by a register-register move.
{
var in int8 = (1 << 6) + 1
var p int8
got := loadHitStore8(in, &p)
want := int32(in * in)
if got != want {
t.Errorf("testLoadHitStore (int8) failed. want = %d, got = %d", want, got)
}
}
{
var in uint8 = (1 << 6) + 1
var p uint8
got := loadHitStoreU8(in, &p)
want := uint32(in * in)
if got != want {
t.Errorf("testLoadHitStore (uint8) failed. want = %d, got = %d", want, got)
}
}
{
var in int16 = (1 << 10) + 1
var p int16
got := loadHitStore16(in, &p)
want := int32(in * in)
if got != want {
t.Errorf("testLoadHitStore (int16) failed. want = %d, got = %d", want, got)
}
}
{
var in uint16 = (1 << 10) + 1
var p uint16
got := loadHitStoreU16(in, &p)
want := uint32(in * in)
if got != want {
t.Errorf("testLoadHitStore (uint16) failed. want = %d, got = %d", want, got)
}
}
{
var in int32 = (1 << 30) + 1
var p int32
got := loadHitStore32(in, &p)
want := int64(in * in)
if got != want {
t.Errorf("testLoadHitStore (int32) failed. want = %d, got = %d", want, got)
}
}
{
var in uint32 = (1 << 30) + 1
var p uint32
got := loadHitStoreU32(in, &p)
want := uint64(in * in)
if got != want {
t.Errorf("testLoadHitStore (uint32) failed. want = %d, got = %d", want, got)
}
}
}
func TestLoadStore(t *testing.T) {
testLoadStoreOrder(t)
testStoreSize(t)
testExtStore(t)
testDeadStorePanic(t)
testLoadHitStore(t)
}
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