| // 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() { |
| } |