Adding upstream version 1.18.10.upstream/1.18.10upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1031 insertions, 0 deletions

diff --git a/src/cmd/compile/internal/test/shift_test.go b/src/cmd/compile/internal/test/shift_test.go
new file mode 100644
index 0000000..ea88f0a
--- /dev/null
+++ b/src/cmd/compile/internal/test/shift_test.go
@@ -0,0 +1,1031 @@
+// Copyright 2016 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 (
+	"reflect"
+	"testing"
+)
+
+// Tests shifts of zero.
+
+//go:noinline
+func ofz64l64(n uint64) int64 {
+	var x int64
+	return x << n
+}
+
+//go:noinline
+func ofz64l32(n uint32) int64 {
+	var x int64
+	return x << n
+}
+
+//go:noinline
+func ofz64l16(n uint16) int64 {
+	var x int64
+	return x << n
+}
+
+//go:noinline
+func ofz64l8(n uint8) int64 {
+	var x int64
+	return x << n
+}
+
+//go:noinline
+func ofz64r64(n uint64) int64 {
+	var x int64
+	return x >> n
+}
+
+//go:noinline
+func ofz64r32(n uint32) int64 {
+	var x int64
+	return x >> n
+}
+
+//go:noinline
+func ofz64r16(n uint16) int64 {
+	var x int64
+	return x >> n
+}
+
+//go:noinline
+func ofz64r8(n uint8) int64 {
+	var x int64
+	return x >> n
+}
+
+//go:noinline
+func ofz64ur64(n uint64) uint64 {
+	var x uint64
+	return x >> n
+}
+
+//go:noinline
+func ofz64ur32(n uint32) uint64 {
+	var x uint64
+	return x >> n
+}
+
+//go:noinline
+func ofz64ur16(n uint16) uint64 {
+	var x uint64
+	return x >> n
+}
+
+//go:noinline
+func ofz64ur8(n uint8) uint64 {
+	var x uint64
+	return x >> n
+}
+
+//go:noinline
+func ofz32l64(n uint64) int32 {
+	var x int32
+	return x << n
+}
+
+//go:noinline
+func ofz32l32(n uint32) int32 {
+	var x int32
+	return x << n
+}
+
+//go:noinline
+func ofz32l16(n uint16) int32 {
+	var x int32
+	return x << n
+}
+
+//go:noinline
+func ofz32l8(n uint8) int32 {
+	var x int32
+	return x << n
+}
+
+//go:noinline
+func ofz32r64(n uint64) int32 {
+	var x int32
+	return x >> n
+}
+
+//go:noinline
+func ofz32r32(n uint32) int32 {
+	var x int32
+	return x >> n
+}
+
+//go:noinline
+func ofz32r16(n uint16) int32 {
+	var x int32
+	return x >> n
+}
+
+//go:noinline
+func ofz32r8(n uint8) int32 {
+	var x int32
+	return x >> n
+}
+
+//go:noinline
+func ofz32ur64(n uint64) uint32 {
+	var x uint32
+	return x >> n
+}
+
+//go:noinline
+func ofz32ur32(n uint32) uint32 {
+	var x uint32
+	return x >> n
+}
+
+//go:noinline
+func ofz32ur16(n uint16) uint32 {
+	var x uint32
+	return x >> n
+}
+
+//go:noinline
+func ofz32ur8(n uint8) uint32 {
+	var x uint32
+	return x >> n
+}
+
+//go:noinline
+func ofz16l64(n uint64) int16 {
+	var x int16
+	return x << n
+}
+
+//go:noinline
+func ofz16l32(n uint32) int16 {
+	var x int16
+	return x << n
+}
+
+//go:noinline
+func ofz16l16(n uint16) int16 {
+	var x int16
+	return x << n
+}
+
+//go:noinline
+func ofz16l8(n uint8) int16 {
+	var x int16
+	return x << n
+}
+
+//go:noinline
+func ofz16r64(n uint64) int16 {
+	var x int16
+	return x >> n
+}
+
+//go:noinline
+func ofz16r32(n uint32) int16 {
+	var x int16
+	return x >> n
+}
+
+//go:noinline
+func ofz16r16(n uint16) int16 {
+	var x int16
+	return x >> n
+}
+
+//go:noinline
+func ofz16r8(n uint8) int16 {
+	var x int16
+	return x >> n
+}
+
+//go:noinline
+func ofz16ur64(n uint64) uint16 {
+	var x uint16
+	return x >> n
+}
+
+//go:noinline
+func ofz16ur32(n uint32) uint16 {
+	var x uint16
+	return x >> n
+}
+
+//go:noinline
+func ofz16ur16(n uint16) uint16 {
+	var x uint16
+	return x >> n
+}
+
+//go:noinline
+func ofz16ur8(n uint8) uint16 {
+	var x uint16
+	return x >> n
+}
+
+//go:noinline
+func ofz8l64(n uint64) int8 {
+	var x int8
+	return x << n
+}
+
+//go:noinline
+func ofz8l32(n uint32) int8 {
+	var x int8
+	return x << n
+}
+
+//go:noinline
+func ofz8l16(n uint16) int8 {
+	var x int8
+	return x << n
+}
+
+//go:noinline
+func ofz8l8(n uint8) int8 {
+	var x int8
+	return x << n
+}
+
+//go:noinline
+func ofz8r64(n uint64) int8 {
+	var x int8
+	return x >> n
+}
+
+//go:noinline
+func ofz8r32(n uint32) int8 {
+	var x int8
+	return x >> n
+}
+
+//go:noinline
+func ofz8r16(n uint16) int8 {
+	var x int8
+	return x >> n
+}
+
+//go:noinline
+func ofz8r8(n uint8) int8 {
+	var x int8
+	return x >> n
+}
+
+//go:noinline
+func ofz8ur64(n uint64) uint8 {
+	var x uint8
+	return x >> n
+}
+
+//go:noinline
+func ofz8ur32(n uint32) uint8 {
+	var x uint8
+	return x >> n
+}
+
+//go:noinline
+func ofz8ur16(n uint16) uint8 {
+	var x uint8
+	return x >> n
+}
+
+//go:noinline
+func ofz8ur8(n uint8) uint8 {
+	var x uint8
+	return x >> n
+}
+
+func TestShiftOfZero(t *testing.T) {
+	if got := ofz64l64(5); got != 0 {
+		t.Errorf("0<<5 == %d, want 0", got)
+	}
+	if got := ofz64l32(5); got != 0 {
+		t.Errorf("0<<5 == %d, want 0", got)
+	}
+	if got := ofz64l16(5); got != 0 {
+		t.Errorf("0<<5 == %d, want 0", got)
+	}
+	if got := ofz64l8(5); got != 0 {
+		t.Errorf("0<<5 == %d, want 0", got)
+	}
+	if got := ofz64r64(5); got != 0 {
+		t.Errorf("0>>5 == %d, want 0", got)
+	}
+	if got := ofz64r32(5); got != 0 {
+		t.Errorf("0>>5 == %d, want 0", got)
+	}
+	if got := ofz64r16(5); got != 0 {
+		t.Errorf("0>>5 == %d, want 0", got)
+	}
+	if got := ofz64r8(5); got != 0 {
+		t.Errorf("0>>5 == %d, want 0", got)
+	}
+	if got := ofz64ur64(5); got != 0 {
+		t.Errorf("0>>>5 == %d, want 0", got)
+	}
+	if got := ofz64ur32(5); got != 0 {
+		t.Errorf("0>>>5 == %d, want 0", got)
+	}
+	if got := ofz64ur16(5); got != 0 {
+		t.Errorf("0>>>5 == %d, want 0", got)
+	}
+	if got := ofz64ur8(5); got != 0 {
+		t.Errorf("0>>>5 == %d, want 0", got)
+	}
+
+	if got := ofz32l64(5); got != 0 {
+		t.Errorf("0<<5 == %d, want 0", got)
+	}
+	if got := ofz32l32(5); got != 0 {
+		t.Errorf("0<<5 == %d, want 0", got)
+	}
+	if got := ofz32l16(5); got != 0 {
+		t.Errorf("0<<5 == %d, want 0", got)
+	}
+	if got := ofz32l8(5); got != 0 {
+		t.Errorf("0<<5 == %d, want 0", got)
+	}
+	if got := ofz32r64(5); got != 0 {
+		t.Errorf("0>>5 == %d, want 0", got)
+	}
+	if got := ofz32r32(5); got != 0 {
+		t.Errorf("0>>5 == %d, want 0", got)
+	}
+	if got := ofz32r16(5); got != 0 {
+		t.Errorf("0>>5 == %d, want 0", got)
+	}
+	if got := ofz32r8(5); got != 0 {
+		t.Errorf("0>>5 == %d, want 0", got)
+	}
+	if got := ofz32ur64(5); got != 0 {
+		t.Errorf("0>>>5 == %d, want 0", got)
+	}
+	if got := ofz32ur32(5); got != 0 {
+		t.Errorf("0>>>5 == %d, want 0", got)
+	}
+	if got := ofz32ur16(5); got != 0 {
+		t.Errorf("0>>>5 == %d, want 0", got)
+	}
+	if got := ofz32ur8(5); got != 0 {
+		t.Errorf("0>>>5 == %d, want 0", got)
+	}
+
+	if got := ofz16l64(5); got != 0 {
+		t.Errorf("0<<5 == %d, want 0", got)
+	}
+	if got := ofz16l32(5); got != 0 {
+		t.Errorf("0<<5 == %d, want 0", got)
+	}
+	if got := ofz16l16(5); got != 0 {
+		t.Errorf("0<<5 == %d, want 0", got)
+	}
+	if got := ofz16l8(5); got != 0 {
+		t.Errorf("0<<5 == %d, want 0", got)
+	}
+	if got := ofz16r64(5); got != 0 {
+		t.Errorf("0>>5 == %d, want 0", got)
+	}
+	if got := ofz16r32(5); got != 0 {
+		t.Errorf("0>>5 == %d, want 0", got)
+	}
+	if got := ofz16r16(5); got != 0 {
+		t.Errorf("0>>5 == %d, want 0", got)
+	}
+	if got := ofz16r8(5); got != 0 {
+		t.Errorf("0>>5 == %d, want 0", got)
+	}
+	if got := ofz16ur64(5); got != 0 {
+		t.Errorf("0>>>5 == %d, want 0", got)
+	}
+	if got := ofz16ur32(5); got != 0 {
+		t.Errorf("0>>>5 == %d, want 0", got)
+	}
+	if got := ofz16ur16(5); got != 0 {
+		t.Errorf("0>>>5 == %d, want 0", got)
+	}
+	if got := ofz16ur8(5); got != 0 {
+		t.Errorf("0>>>5 == %d, want 0", got)
+	}
+
+	if got := ofz8l64(5); got != 0 {
+		t.Errorf("0<<5 == %d, want 0", got)
+	}
+	if got := ofz8l32(5); got != 0 {
+		t.Errorf("0<<5 == %d, want 0", got)
+	}
+	if got := ofz8l16(5); got != 0 {
+		t.Errorf("0<<5 == %d, want 0", got)
+	}
+	if got := ofz8l8(5); got != 0 {
+		t.Errorf("0<<5 == %d, want 0", got)
+	}
+	if got := ofz8r64(5); got != 0 {
+		t.Errorf("0>>5 == %d, want 0", got)
+	}
+	if got := ofz8r32(5); got != 0 {
+		t.Errorf("0>>5 == %d, want 0", got)
+	}
+	if got := ofz8r16(5); got != 0 {
+		t.Errorf("0>>5 == %d, want 0", got)
+	}
+	if got := ofz8r8(5); got != 0 {
+		t.Errorf("0>>5 == %d, want 0", got)
+	}
+	if got := ofz8ur64(5); got != 0 {
+		t.Errorf("0>>>5 == %d, want 0", got)
+	}
+	if got := ofz8ur32(5); got != 0 {
+		t.Errorf("0>>>5 == %d, want 0", got)
+	}
+	if got := ofz8ur16(5); got != 0 {
+		t.Errorf("0>>>5 == %d, want 0", got)
+	}
+	if got := ofz8ur8(5); got != 0 {
+		t.Errorf("0>>>5 == %d, want 0", got)
+	}
+}
+
+//go:noinline
+func byz64l(n int64) int64 {
+	return n << 0
+}
+
+//go:noinline
+func byz64r(n int64) int64 {
+	return n >> 0
+}
+
+//go:noinline
+func byz64ur(n uint64) uint64 {
+	return n >> 0
+}
+
+//go:noinline
+func byz32l(n int32) int32 {
+	return n << 0
+}
+
+//go:noinline
+func byz32r(n int32) int32 {
+	return n >> 0
+}
+
+//go:noinline
+func byz32ur(n uint32) uint32 {
+	return n >> 0
+}
+
+//go:noinline
+func byz16l(n int16) int16 {
+	return n << 0
+}
+
+//go:noinline
+func byz16r(n int16) int16 {
+	return n >> 0
+}
+
+//go:noinline
+func byz16ur(n uint16) uint16 {
+	return n >> 0
+}
+
+//go:noinline
+func byz8l(n int8) int8 {
+	return n << 0
+}
+
+//go:noinline
+func byz8r(n int8) int8 {
+	return n >> 0
+}
+
+//go:noinline
+func byz8ur(n uint8) uint8 {
+	return n >> 0
+}
+
+func TestShiftByZero(t *testing.T) {
+	{
+		var n int64 = 0x5555555555555555
+		if got := byz64l(n); got != n {
+			t.Errorf("%x<<0 == %x, want %x", n, got, n)
+		}
+		if got := byz64r(n); got != n {
+			t.Errorf("%x>>0 == %x, want %x", n, got, n)
+		}
+	}
+	{
+		var n uint64 = 0xaaaaaaaaaaaaaaaa
+		if got := byz64ur(n); got != n {
+			t.Errorf("%x>>>0 == %x, want %x", n, got, n)
+		}
+	}
+
+	{
+		var n int32 = 0x55555555
+		if got := byz32l(n); got != n {
+			t.Errorf("%x<<0 == %x, want %x", n, got, n)
+		}
+		if got := byz32r(n); got != n {
+			t.Errorf("%x>>0 == %x, want %x", n, got, n)
+		}
+	}
+	{
+		var n uint32 = 0xaaaaaaaa
+		if got := byz32ur(n); got != n {
+			t.Errorf("%x>>>0 == %x, want %x", n, got, n)
+		}
+	}
+
+	{
+		var n int16 = 0x5555
+		if got := byz16l(n); got != n {
+			t.Errorf("%x<<0 == %x, want %x", n, got, n)
+		}
+		if got := byz16r(n); got != n {
+			t.Errorf("%x>>0 == %x, want %x", n, got, n)
+		}
+	}
+	{
+		var n uint16 = 0xaaaa
+		if got := byz16ur(n); got != n {
+			t.Errorf("%x>>>0 == %x, want %x", n, got, n)
+		}
+	}
+
+	{
+		var n int8 = 0x55
+		if got := byz8l(n); got != n {
+			t.Errorf("%x<<0 == %x, want %x", n, got, n)
+		}
+		if got := byz8r(n); got != n {
+			t.Errorf("%x>>0 == %x, want %x", n, got, n)
+		}
+	}
+	{
+		var n uint8 = 0x55
+		if got := byz8ur(n); got != n {
+			t.Errorf("%x>>>0 == %x, want %x", n, got, n)
+		}
+	}
+}
+
+//go:noinline
+func two64l(x int64) int64 {
+	return x << 1 << 1
+}
+
+//go:noinline
+func two64r(x int64) int64 {
+	return x >> 1 >> 1
+}
+
+//go:noinline
+func two64ur(x uint64) uint64 {
+	return x >> 1 >> 1
+}
+
+//go:noinline
+func two32l(x int32) int32 {
+	return x << 1 << 1
+}
+
+//go:noinline
+func two32r(x int32) int32 {
+	return x >> 1 >> 1
+}
+
+//go:noinline
+func two32ur(x uint32) uint32 {
+	return x >> 1 >> 1
+}
+
+//go:noinline
+func two16l(x int16) int16 {
+	return x << 1 << 1
+}
+
+//go:noinline
+func two16r(x int16) int16 {
+	return x >> 1 >> 1
+}
+
+//go:noinline
+func two16ur(x uint16) uint16 {
+	return x >> 1 >> 1
+}
+
+//go:noinline
+func two8l(x int8) int8 {
+	return x << 1 << 1
+}
+
+//go:noinline
+func two8r(x int8) int8 {
+	return x >> 1 >> 1
+}
+
+//go:noinline
+func two8ur(x uint8) uint8 {
+	return x >> 1 >> 1
+}
+
+func TestShiftCombine(t *testing.T) {
+	if got, want := two64l(4), int64(16); want != got {
+		t.Errorf("4<<1<<1 == %d, want %d", got, want)
+	}
+	if got, want := two64r(64), int64(16); want != got {
+		t.Errorf("64>>1>>1 == %d, want %d", got, want)
+	}
+	if got, want := two64ur(64), uint64(16); want != got {
+		t.Errorf("64>>1>>1 == %d, want %d", got, want)
+	}
+	if got, want := two32l(4), int32(16); want != got {
+		t.Errorf("4<<1<<1 == %d, want %d", got, want)
+	}
+	if got, want := two32r(64), int32(16); want != got {
+		t.Errorf("64>>1>>1 == %d, want %d", got, want)
+	}
+	if got, want := two32ur(64), uint32(16); want != got {
+		t.Errorf("64>>1>>1 == %d, want %d", got, want)
+	}
+	if got, want := two16l(4), int16(16); want != got {
+		t.Errorf("4<<1<<1 == %d, want %d", got, want)
+	}
+	if got, want := two16r(64), int16(16); want != got {
+		t.Errorf("64>>1>>1 == %d, want %d", got, want)
+	}
+	if got, want := two16ur(64), uint16(16); want != got {
+		t.Errorf("64>>1>>1 == %d, want %d", got, want)
+	}
+	if got, want := two8l(4), int8(16); want != got {
+		t.Errorf("4<<1<<1 == %d, want %d", got, want)
+	}
+	if got, want := two8r(64), int8(16); want != got {
+		t.Errorf("64>>1>>1 == %d, want %d", got, want)
+	}
+	if got, want := two8ur(64), uint8(16); want != got {
+		t.Errorf("64>>1>>1 == %d, want %d", got, want)
+	}
+
+}
+
+//go:noinline
+func three64l(x int64) int64 {
+	return x << 3 >> 1 << 2
+}
+
+//go:noinline
+func three64ul(x uint64) uint64 {
+	return x << 3 >> 1 << 2
+}
+
+//go:noinline
+func three64r(x int64) int64 {
+	return x >> 3 << 1 >> 2
+}
+
+//go:noinline
+func three64ur(x uint64) uint64 {
+	return x >> 3 << 1 >> 2
+}
+
+//go:noinline
+func three32l(x int32) int32 {
+	return x << 3 >> 1 << 2
+}
+
+//go:noinline
+func three32ul(x uint32) uint32 {
+	return x << 3 >> 1 << 2
+}
+
+//go:noinline
+func three32r(x int32) int32 {
+	return x >> 3 << 1 >> 2
+}
+
+//go:noinline
+func three32ur(x uint32) uint32 {
+	return x >> 3 << 1 >> 2
+}
+
+//go:noinline
+func three16l(x int16) int16 {
+	return x << 3 >> 1 << 2
+}
+
+//go:noinline
+func three16ul(x uint16) uint16 {
+	return x << 3 >> 1 << 2
+}
+
+//go:noinline
+func three16r(x int16) int16 {
+	return x >> 3 << 1 >> 2
+}
+
+//go:noinline
+func three16ur(x uint16) uint16 {
+	return x >> 3 << 1 >> 2
+}
+
+//go:noinline
+func three8l(x int8) int8 {
+	return x << 3 >> 1 << 2
+}
+
+//go:noinline
+func three8ul(x uint8) uint8 {
+	return x << 3 >> 1 << 2
+}
+
+//go:noinline
+func three8r(x int8) int8 {
+	return x >> 3 << 1 >> 2
+}
+
+//go:noinline
+func three8ur(x uint8) uint8 {
+	return x >> 3 << 1 >> 2
+}
+
+func TestShiftCombine3(t *testing.T) {
+	if got, want := three64l(4), int64(64); want != got {
+		t.Errorf("4<<1<<1 == %d, want %d", got, want)
+	}
+	if got, want := three64ul(4), uint64(64); want != got {
+		t.Errorf("4<<1<<1 == %d, want %d", got, want)
+	}
+	if got, want := three64r(64), int64(4); want != got {
+		t.Errorf("64>>1>>1 == %d, want %d", got, want)
+	}
+	if got, want := three64ur(64), uint64(4); want != got {
+		t.Errorf("64>>1>>1 == %d, want %d", got, want)
+	}
+	if got, want := three32l(4), int32(64); want != got {
+		t.Errorf("4<<1<<1 == %d, want %d", got, want)
+	}
+	if got, want := three32ul(4), uint32(64); want != got {
+		t.Errorf("4<<1<<1 == %d, want %d", got, want)
+	}
+	if got, want := three32r(64), int32(4); want != got {
+		t.Errorf("64>>1>>1 == %d, want %d", got, want)
+	}
+	if got, want := three32ur(64), uint32(4); want != got {
+		t.Errorf("64>>1>>1 == %d, want %d", got, want)
+	}
+	if got, want := three16l(4), int16(64); want != got {
+		t.Errorf("4<<1<<1 == %d, want %d", got, want)
+	}
+	if got, want := three16ul(4), uint16(64); want != got {
+		t.Errorf("4<<1<<1 == %d, want %d", got, want)
+	}
+	if got, want := three16r(64), int16(4); want != got {
+		t.Errorf("64>>1>>1 == %d, want %d", got, want)
+	}
+	if got, want := three16ur(64), uint16(4); want != got {
+		t.Errorf("64>>1>>1 == %d, want %d", got, want)
+	}
+	if got, want := three8l(4), int8(64); want != got {
+		t.Errorf("4<<1<<1 == %d, want %d", got, want)
+	}
+	if got, want := three8ul(4), uint8(64); want != got {
+		t.Errorf("4<<1<<1 == %d, want %d", got, want)
+	}
+	if got, want := three8r(64), int8(4); want != got {
+		t.Errorf("64>>1>>1 == %d, want %d", got, want)
+	}
+	if got, want := three8ur(64), uint8(4); want != got {
+		t.Errorf("64>>1>>1 == %d, want %d", got, want)
+	}
+}
+
+var (
+	one64  int64  = 1
+	one64u uint64 = 1
+	one32  int32  = 1
+	one32u uint32 = 1
+	one16  int16  = 1
+	one16u uint16 = 1
+	one8   int8   = 1
+	one8u  uint8  = 1
+)
+
+func TestShiftLargeCombine(t *testing.T) {
+	var N uint64 = 0x8000000000000000
+	if one64<<N<<N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one64>>N>>N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one64u>>N>>N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one32<<N<<N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one32>>N>>N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one32u>>N>>N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one16<<N<<N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one16>>N>>N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one16u>>N>>N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one8<<N<<N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one8>>N>>N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one8u>>N>>N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+}
+
+func TestShiftLargeCombine3(t *testing.T) {
+	var N uint64 = 0x8000000000000001
+	if one64<<N>>2<<N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one64u<<N>>2<<N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one64>>N<<2>>N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one64u>>N<<2>>N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one32<<N>>2<<N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one32u<<N>>2<<N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one32>>N<<2>>N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one32u>>N<<2>>N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one16<<N>>2<<N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one16u<<N>>2<<N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one16>>N<<2>>N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one16u>>N<<2>>N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one8<<N>>2<<N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one8u<<N>>2<<N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one8>>N<<2>>N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+	if one8u>>N<<2>>N == 1 {
+		t.Errorf("shift overflow mishandled")
+	}
+}
+
+func TestShiftGeneric(t *testing.T) {
+	for _, test := range [...]struct {
+		valueWidth int
+		signed     bool
+		shiftWidth int
+		left       bool
+		f          interface{}
+	}{
+		{64, true, 64, true, func(n int64, s uint64) int64 { return n << s }},
+		{64, true, 64, false, func(n int64, s uint64) int64 { return n >> s }},
+		{64, false, 64, false, func(n uint64, s uint64) uint64 { return n >> s }},
+		{64, true, 32, true, func(n int64, s uint32) int64 { return n << s }},
+		{64, true, 32, false, func(n int64, s uint32) int64 { return n >> s }},
+		{64, false, 32, false, func(n uint64, s uint32) uint64 { return n >> s }},
+		{64, true, 16, true, func(n int64, s uint16) int64 { return n << s }},
+		{64, true, 16, false, func(n int64, s uint16) int64 { return n >> s }},
+		{64, false, 16, false, func(n uint64, s uint16) uint64 { return n >> s }},
+		{64, true, 8, true, func(n int64, s uint8) int64 { return n << s }},
+		{64, true, 8, false, func(n int64, s uint8) int64 { return n >> s }},
+		{64, false, 8, false, func(n uint64, s uint8) uint64 { return n >> s }},
+
+		{32, true, 64, true, func(n int32, s uint64) int32 { return n << s }},
+		{32, true, 64, false, func(n int32, s uint64) int32 { return n >> s }},
+		{32, false, 64, false, func(n uint32, s uint64) uint32 { return n >> s }},
+		{32, true, 32, true, func(n int32, s uint32) int32 { return n << s }},
+		{32, true, 32, false, func(n int32, s uint32) int32 { return n >> s }},
+		{32, false, 32, false, func(n uint32, s uint32) uint32 { return n >> s }},
+		{32, true, 16, true, func(n int32, s uint16) int32 { return n << s }},
+		{32, true, 16, false, func(n int32, s uint16) int32 { return n >> s }},
+		{32, false, 16, false, func(n uint32, s uint16) uint32 { return n >> s }},
+		{32, true, 8, true, func(n int32, s uint8) int32 { return n << s }},
+		{32, true, 8, false, func(n int32, s uint8) int32 { return n >> s }},
+		{32, false, 8, false, func(n uint32, s uint8) uint32 { return n >> s }},
+
+		{16, true, 64, true, func(n int16, s uint64) int16 { return n << s }},
+		{16, true, 64, false, func(n int16, s uint64) int16 { return n >> s }},
+		{16, false, 64, false, func(n uint16, s uint64) uint16 { return n >> s }},
+		{16, true, 32, true, func(n int16, s uint32) int16 { return n << s }},
+		{16, true, 32, false, func(n int16, s uint32) int16 { return n >> s }},
+		{16, false, 32, false, func(n uint16, s uint32) uint16 { return n >> s }},
+		{16, true, 16, true, func(n int16, s uint16) int16 { return n << s }},
+		{16, true, 16, false, func(n int16, s uint16) int16 { return n >> s }},
+		{16, false, 16, false, func(n uint16, s uint16) uint16 { return n >> s }},
+		{16, true, 8, true, func(n int16, s uint8) int16 { return n << s }},
+		{16, true, 8, false, func(n int16, s uint8) int16 { return n >> s }},
+		{16, false, 8, false, func(n uint16, s uint8) uint16 { return n >> s }},
+
+		{8, true, 64, true, func(n int8, s uint64) int8 { return n << s }},
+		{8, true, 64, false, func(n int8, s uint64) int8 { return n >> s }},
+		{8, false, 64, false, func(n uint8, s uint64) uint8 { return n >> s }},
+		{8, true, 32, true, func(n int8, s uint32) int8 { return n << s }},
+		{8, true, 32, false, func(n int8, s uint32) int8 { return n >> s }},
+		{8, false, 32, false, func(n uint8, s uint32) uint8 { return n >> s }},
+		{8, true, 16, true, func(n int8, s uint16) int8 { return n << s }},
+		{8, true, 16, false, func(n int8, s uint16) int8 { return n >> s }},
+		{8, false, 16, false, func(n uint8, s uint16) uint8 { return n >> s }},
+		{8, true, 8, true, func(n int8, s uint8) int8 { return n << s }},
+		{8, true, 8, false, func(n int8, s uint8) int8 { return n >> s }},
+		{8, false, 8, false, func(n uint8, s uint8) uint8 { return n >> s }},
+	} {
+		fv := reflect.ValueOf(test.f)
+		var args [2]reflect.Value
+		for i := 0; i < test.valueWidth; i++ {
+			// Build value to be shifted.
+			var n int64 = 1
+			for j := 0; j < i; j++ {
+				n <<= 1
+			}
+			args[0] = reflect.ValueOf(n).Convert(fv.Type().In(0))
+			for s := 0; s <= test.shiftWidth; s++ {
+				args[1] = reflect.ValueOf(s).Convert(fv.Type().In(1))
+
+				// Compute desired result. We're testing variable shifts
+				// assuming constant shifts are correct.
+				r := n
+				var op string
+				switch {
+				case test.left:
+					op = "<<"
+					for j := 0; j < s; j++ {
+						r <<= 1
+					}
+					switch test.valueWidth {
+					case 32:
+						r = int64(int32(r))
+					case 16:
+						r = int64(int16(r))
+					case 8:
+						r = int64(int8(r))
+					}
+				case test.signed:
+					op = ">>"
+					switch test.valueWidth {
+					case 32:
+						r = int64(int32(r))
+					case 16:
+						r = int64(int16(r))
+					case 8:
+						r = int64(int8(r))
+					}
+					for j := 0; j < s; j++ {
+						r >>= 1
+					}
+				default:
+					op = ">>>"
+					for j := 0; j < s; j++ {
+						r = int64(uint64(r) >> 1)
+					}
+				}
+
+				// Call function.
+				res := fv.Call(args[:])[0].Convert(reflect.ValueOf(r).Type())
+
+				if res.Int() != r {
+					t.Errorf("%s%dx%d(%x,%x)=%x, want %x", op, test.valueWidth, test.shiftWidth, n, s, res.Int(), r)
+				}
+			}
+		}
+	}
+}