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// Copyright 2023 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 test
import (
"encoding/binary"
"testing"
)
var gv = [16]byte{0, 1, 2, 3, 4, 5, 6, 7, 8}
//go:noinline
func readGlobalUnaligned() uint64 {
return binary.LittleEndian.Uint64(gv[1:])
}
func TestUnalignedGlobal(t *testing.T) {
// Note: this is a test not so much of the result of the read, but of
// the correct compilation of that read. On s390x unaligned global
// accesses fail to compile.
if got, want := readGlobalUnaligned(), uint64(0x0807060504030201); got != want {
t.Errorf("read global %x, want %x", got, want)
}
}
func TestSpillOfExtendedEndianLoads(t *testing.T) {
b := []byte{0xaa, 0xbb, 0xcc, 0xdd}
var testCases = []struct {
fn func([]byte) uint64
want uint64
}{
{readUint16le, 0xbbaa},
{readUint16be, 0xaabb},
{readUint32le, 0xddccbbaa},
{readUint32be, 0xaabbccdd},
}
for _, test := range testCases {
if got := test.fn(b); got != test.want {
t.Errorf("got %x, want %x", got, test.want)
}
}
}
func readUint16le(b []byte) uint64 {
y := uint64(binary.LittleEndian.Uint16(b))
nop() // force spill
return y
}
func readUint16be(b []byte) uint64 {
y := uint64(binary.BigEndian.Uint16(b))
nop() // force spill
return y
}
func readUint32le(b []byte) uint64 {
y := uint64(binary.LittleEndian.Uint32(b))
nop() // force spill
return y
}
func readUint32be(b []byte) uint64 {
y := uint64(binary.BigEndian.Uint32(b))
nop() // force spill
return y
}
//go:noinline
func nop() {
}
type T32 struct {
a, b uint32
}
//go:noinline
func (t *T32) bigEndianLoad() uint64 {
return uint64(t.a)<<32 | uint64(t.b)
}
//go:noinline
func (t *T32) littleEndianLoad() uint64 {
return uint64(t.a) | (uint64(t.b) << 32)
}
//go:noinline
func (t *T32) bigEndianStore(x uint64) {
t.a = uint32(x >> 32)
t.b = uint32(x)
}
//go:noinline
func (t *T32) littleEndianStore(x uint64) {
t.a = uint32(x)
t.b = uint32(x >> 32)
}
type T16 struct {
a, b uint16
}
//go:noinline
func (t *T16) bigEndianLoad() uint32 {
return uint32(t.a)<<16 | uint32(t.b)
}
//go:noinline
func (t *T16) littleEndianLoad() uint32 {
return uint32(t.a) | (uint32(t.b) << 16)
}
//go:noinline
func (t *T16) bigEndianStore(x uint32) {
t.a = uint16(x >> 16)
t.b = uint16(x)
}
//go:noinline
func (t *T16) littleEndianStore(x uint32) {
t.a = uint16(x)
t.b = uint16(x >> 16)
}
type T8 struct {
a, b uint8
}
//go:noinline
func (t *T8) bigEndianLoad() uint16 {
return uint16(t.a)<<8 | uint16(t.b)
}
//go:noinline
func (t *T8) littleEndianLoad() uint16 {
return uint16(t.a) | (uint16(t.b) << 8)
}
//go:noinline
func (t *T8) bigEndianStore(x uint16) {
t.a = uint8(x >> 8)
t.b = uint8(x)
}
//go:noinline
func (t *T8) littleEndianStore(x uint16) {
t.a = uint8(x)
t.b = uint8(x >> 8)
}
func TestIssue64468(t *testing.T) {
t32 := T32{1, 2}
if got, want := t32.bigEndianLoad(), uint64(1<<32+2); got != want {
t.Errorf("T32.bigEndianLoad got %x want %x\n", got, want)
}
if got, want := t32.littleEndianLoad(), uint64(1+2<<32); got != want {
t.Errorf("T32.littleEndianLoad got %x want %x\n", got, want)
}
t16 := T16{1, 2}
if got, want := t16.bigEndianLoad(), uint32(1<<16+2); got != want {
t.Errorf("T16.bigEndianLoad got %x want %x\n", got, want)
}
if got, want := t16.littleEndianLoad(), uint32(1+2<<16); got != want {
t.Errorf("T16.littleEndianLoad got %x want %x\n", got, want)
}
t8 := T8{1, 2}
if got, want := t8.bigEndianLoad(), uint16(1<<8+2); got != want {
t.Errorf("T8.bigEndianLoad got %x want %x\n", got, want)
}
if got, want := t8.littleEndianLoad(), uint16(1+2<<8); got != want {
t.Errorf("T8.littleEndianLoad got %x want %x\n", got, want)
}
t32.bigEndianStore(1<<32 + 2)
if got, want := t32, (T32{1, 2}); got != want {
t.Errorf("T32.bigEndianStore got %x want %x\n", got, want)
}
t32.littleEndianStore(1<<32 + 2)
if got, want := t32, (T32{2, 1}); got != want {
t.Errorf("T32.littleEndianStore got %x want %x\n", got, want)
}
t16.bigEndianStore(1<<16 + 2)
if got, want := t16, (T16{1, 2}); got != want {
t.Errorf("T16.bigEndianStore got %x want %x\n", got, want)
}
t16.littleEndianStore(1<<16 + 2)
if got, want := t16, (T16{2, 1}); got != want {
t.Errorf("T16.littleEndianStore got %x want %x\n", got, want)
}
t8.bigEndianStore(1<<8 + 2)
if got, want := t8, (T8{1, 2}); got != want {
t.Errorf("T8.bigEndianStore got %x want %x\n", got, want)
}
t8.littleEndianStore(1<<8 + 2)
if got, want := t8, (T8{2, 1}); got != want {
t.Errorf("T8.littleEndianStore got %x want %x\n", got, want)
}
}
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