runtime: Remove now unnecessary pad field from ParFor.

    
    It is not needed due to the removal of the ctx field.
    
    Reviewed-on: https://go-review.googlesource.com/16525

From-SVN: r229616

5 files changed, 1082 insertions, 246 deletions

diff --git a/libgo/go/reflect/all_test.go b/libgo/go/reflect/all_test.go
index bda87867c74..33ee9ed83cc 100644
--- a/libgo/go/reflect/all_test.go
+++ b/libgo/go/reflect/all_test.go
@@ -15,6 +15,7 @@ import (
 	. "reflect"
 	"runtime"
 	"sort"
+	"strconv"
 	"strings"
 	"sync"
 	"testing"
@@ -1052,6 +1053,11 @@ func TestChan(t *testing.T) {
 		ok = cv.TrySend(ValueOf(6))
 		if !ok {
 			t.Errorf("TrySend on empty chan failed")
+			select {
+			case x := <-c:
+				t.Errorf("TrySend failed but it did send %d", x)
+			default:
+			}
 		} else {
 			if i = <-c; i != 6 {
 				t.Errorf("TrySend 6, recv %d", i)
@@ -1376,7 +1382,7 @@ func selectWatcher() {
 	for {
 		time.Sleep(1 * time.Second)
 		selectWatch.Lock()
-		if selectWatch.info != nil && time.Since(selectWatch.now) > 1*time.Second {
+		if selectWatch.info != nil && time.Since(selectWatch.now) > 10*time.Second {
 			fmt.Fprintf(os.Stderr, "TestSelect:\n%s blocked indefinitely\n", fmtSelect(selectWatch.info))
 			panic("select stuck")
 		}
@@ -1501,6 +1507,17 @@ func TestCallWithStruct(t *testing.T) {
 	}
 }
 
+func BenchmarkCall(b *testing.B) {
+	fv := ValueOf(func(a, b string) {})
+	b.ReportAllocs()
+	b.RunParallel(func(pb *testing.PB) {
+		args := []Value{ValueOf("a"), ValueOf("b")}
+		for pb.Next() {
+			fv.Call(args)
+		}
+	})
+}
+
 func TestMakeFunc(t *testing.T) {
 	f := dummy
 	fv := MakeFunc(TypeOf(f), func(in []Value) []Value { return in })
@@ -2726,6 +2743,8 @@ var tagGetTests = []struct {
 	{`protobuf:"PB(1,2)"`, `rotobuf`, ``},
 	{`protobuf:"PB(1,2)" json:"name"`, `json`, `name`},
 	{`protobuf:"PB(1,2)" json:"name"`, `protobuf`, `PB(1,2)`},
+	{`k0:"values contain spaces" k1:"and\ttabs"`, "k0", "values contain spaces"},
+	{`k0:"values contain spaces" k1:"and\ttabs"`, "k1", "and\ttabs"},
 }
 
 func TestTagGet(t *testing.T) {
@@ -3377,26 +3396,243 @@ func checkSameType(t *testing.T, x, y interface{}) {
 }
 
 func TestArrayOf(t *testing.T) {
-	// TODO(rsc): Finish ArrayOf and enable-test.
-	t.Skip("ArrayOf is not finished (and not exported)")
-
 	// check construction and use of type not in binary
-	type T int
-	at := ArrayOf(10, TypeOf(T(1)))
-	v := New(at).Elem()
-	for i := 0; i < v.Len(); i++ {
-		v.Index(i).Set(ValueOf(T(i)))
-	}
-	s := fmt.Sprint(v.Interface())
-	want := "[0 1 2 3 4 5 6 7 8 9]"
-	if s != want {
-		t.Errorf("constructed array = %s, want %s", s, want)
+	for _, table := range []struct {
+		n          int
+		value      func(i int) interface{}
+		comparable bool
+		want       string
+	}{
+		{
+			n:          0,
+			value:      func(i int) interface{} { type Tint int; return Tint(i) },
+			comparable: true,
+			want:       "[]",
+		},
+		{
+			n:          10,
+			value:      func(i int) interface{} { type Tint int; return Tint(i) },
+			comparable: true,
+			want:       "[0 1 2 3 4 5 6 7 8 9]",
+		},
+		{
+			n:          10,
+			value:      func(i int) interface{} { type Tfloat float64; return Tfloat(i) },
+			comparable: true,
+			want:       "[0 1 2 3 4 5 6 7 8 9]",
+		},
+		{
+			n:          10,
+			value:      func(i int) interface{} { type Tstring string; return Tstring(strconv.Itoa(i)) },
+			comparable: true,
+			want:       "[0 1 2 3 4 5 6 7 8 9]",
+		},
+		{
+			n:          10,
+			value:      func(i int) interface{} { type Tstruct struct{ V int }; return Tstruct{i} },
+			comparable: true,
+			want:       "[{0} {1} {2} {3} {4} {5} {6} {7} {8} {9}]",
+		},
+		{
+			n:          10,
+			value:      func(i int) interface{} { type Tint int; return []Tint{Tint(i)} },
+			comparable: false,
+			want:       "[[0] [1] [2] [3] [4] [5] [6] [7] [8] [9]]",
+		},
+		{
+			n:          10,
+			value:      func(i int) interface{} { type Tint int; return [1]Tint{Tint(i)} },
+			comparable: true,
+			want:       "[[0] [1] [2] [3] [4] [5] [6] [7] [8] [9]]",
+		},
+		{
+			n:          10,
+			value:      func(i int) interface{} { type Tstruct struct{ V [1]int }; return Tstruct{[1]int{i}} },
+			comparable: true,
+			want:       "[{[0]} {[1]} {[2]} {[3]} {[4]} {[5]} {[6]} {[7]} {[8]} {[9]}]",
+		},
+		{
+			n:          10,
+			value:      func(i int) interface{} { type Tstruct struct{ V []int }; return Tstruct{[]int{i}} },
+			comparable: false,
+			want:       "[{[0]} {[1]} {[2]} {[3]} {[4]} {[5]} {[6]} {[7]} {[8]} {[9]}]",
+		},
+		{
+			n:          10,
+			value:      func(i int) interface{} { type TstructUV struct{ U, V int }; return TstructUV{i, i} },
+			comparable: true,
+			want:       "[{0 0} {1 1} {2 2} {3 3} {4 4} {5 5} {6 6} {7 7} {8 8} {9 9}]",
+		},
+		{
+			n: 10,
+			value: func(i int) interface{} {
+				type TstructUV struct {
+					U int
+					V float64
+				}
+				return TstructUV{i, float64(i)}
+			},
+			comparable: true,
+			want:       "[{0 0} {1 1} {2 2} {3 3} {4 4} {5 5} {6 6} {7 7} {8 8} {9 9}]",
+		},
+	} {
+		at := ArrayOf(table.n, TypeOf(table.value(0)))
+		v := New(at).Elem()
+		vok := New(at).Elem()
+		vnot := New(at).Elem()
+		for i := 0; i < v.Len(); i++ {
+			v.Index(i).Set(ValueOf(table.value(i)))
+			vok.Index(i).Set(ValueOf(table.value(i)))
+			j := i
+			if i+1 == v.Len() {
+				j = i + 1
+			}
+			vnot.Index(i).Set(ValueOf(table.value(j))) // make it differ only by last element
+		}
+		s := fmt.Sprint(v.Interface())
+		if s != table.want {
+			t.Errorf("constructed array = %s, want %s", s, table.want)
+		}
+
+		if table.comparable != at.Comparable() {
+			t.Errorf("constructed array (%#v) is comparable=%v, want=%v", v.Interface(), at.Comparable(), table.comparable)
+		}
+		if table.comparable {
+			if table.n > 0 {
+				if DeepEqual(vnot.Interface(), v.Interface()) {
+					t.Errorf(
+						"arrays (%#v) compare ok (but should not)",
+						v.Interface(),
+					)
+				}
+			}
+			if !DeepEqual(vok.Interface(), v.Interface()) {
+				t.Errorf(
+					"arrays (%#v) compare NOT-ok (but should)",
+					v.Interface(),
+				)
+			}
+		}
 	}
 
 	// check that type already in binary is found
+	type T int
 	checkSameType(t, Zero(ArrayOf(5, TypeOf(T(1)))).Interface(), [5]T{})
 }
 
+func TestArrayOfGC(t *testing.T) {
+	type T *uintptr
+	tt := TypeOf(T(nil))
+	const n = 100
+	var x []interface{}
+	for i := 0; i < n; i++ {
+		v := New(ArrayOf(n, tt)).Elem()
+		for j := 0; j < v.Len(); j++ {
+			p := new(uintptr)
+			*p = uintptr(i*n + j)
+			v.Index(j).Set(ValueOf(p).Convert(tt))
+		}
+		x = append(x, v.Interface())
+	}
+	runtime.GC()
+
+	for i, xi := range x {
+		v := ValueOf(xi)
+		for j := 0; j < v.Len(); j++ {
+			k := v.Index(j).Elem().Interface()
+			if k != uintptr(i*n+j) {
+				t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
+			}
+		}
+	}
+}
+
+func TestArrayOfAlg(t *testing.T) {
+	at := ArrayOf(6, TypeOf(byte(0)))
+	v1 := New(at).Elem()
+	v2 := New(at).Elem()
+	if v1.Interface() != v1.Interface() {
+		t.Errorf("constructed array %v not equal to itself", v1.Interface())
+	}
+	v1.Index(5).Set(ValueOf(byte(1)))
+	if i1, i2 := v1.Interface(), v2.Interface(); i1 == i2 {
+		t.Errorf("constructed arrays %v and %v should not be equal", i1, i2)
+	}
+
+	at = ArrayOf(6, TypeOf([]int(nil)))
+	v1 = New(at).Elem()
+	shouldPanic(func() { _ = v1.Interface() == v1.Interface() })
+}
+
+func TestArrayOfGenericAlg(t *testing.T) {
+	at1 := ArrayOf(5, TypeOf(string("")))
+	at := ArrayOf(6, at1)
+	v1 := New(at).Elem()
+	v2 := New(at).Elem()
+	if v1.Interface() != v1.Interface() {
+		t.Errorf("constructed array %v not equal to itself", v1.Interface())
+	}
+
+	v1.Index(0).Index(0).Set(ValueOf("abc"))
+	v2.Index(0).Index(0).Set(ValueOf("efg"))
+	if i1, i2 := v1.Interface(), v2.Interface(); i1 == i2 {
+		t.Errorf("constructed arrays %v and %v should not be equal", i1, i2)
+	}
+
+	v1.Index(0).Index(0).Set(ValueOf("abc"))
+	v2.Index(0).Index(0).Set(ValueOf((v1.Index(0).Index(0).String() + " ")[:3]))
+	if i1, i2 := v1.Interface(), v2.Interface(); i1 != i2 {
+		t.Errorf("constructed arrays %v and %v should be equal", i1, i2)
+	}
+
+	// Test hash
+	m := MakeMap(MapOf(at, TypeOf(int(0))))
+	m.SetMapIndex(v1, ValueOf(1))
+	if i1, i2 := v1.Interface(), v2.Interface(); !m.MapIndex(v2).IsValid() {
+		t.Errorf("constructed arrays %v and %v have different hashes", i1, i2)
+	}
+}
+
+func TestArrayOfDirectIface(t *testing.T) {
+	t.Skip("skipping test because gccgo uses a different directiface value")
+	{
+		type T [1]*byte
+		i1 := Zero(TypeOf(T{})).Interface()
+		v1 := ValueOf(&i1).Elem()
+		p1 := v1.InterfaceData()[1]
+
+		i2 := Zero(ArrayOf(1, PtrTo(TypeOf(int8(0))))).Interface()
+		v2 := ValueOf(&i2).Elem()
+		p2 := v2.InterfaceData()[1]
+
+		if p1 != 0 {
+			t.Errorf("got p1=%v. want=%v", p1, nil)
+		}
+
+		if p2 != 0 {
+			t.Errorf("got p2=%v. want=%v", p2, nil)
+		}
+	}
+	{
+		type T [0]*byte
+		i1 := Zero(TypeOf(T{})).Interface()
+		v1 := ValueOf(&i1).Elem()
+		p1 := v1.InterfaceData()[1]
+
+		i2 := Zero(ArrayOf(0, PtrTo(TypeOf(int8(0))))).Interface()
+		v2 := ValueOf(&i2).Elem()
+		p2 := v2.InterfaceData()[1]
+
+		if p1 == 0 {
+			t.Errorf("got p1=%v. want=not-%v", p1, nil)
+		}
+
+		if p2 == 0 {
+			t.Errorf("got p2=%v. want=not-%v", p2, nil)
+		}
+	}
+}
+
 func TestSliceOf(t *testing.T) {
 	// check construction and use of type not in binary
 	type T int
@@ -3489,6 +3725,26 @@ func TestChanOf(t *testing.T) {
 	checkSameType(t, Zero(ChanOf(BothDir, TypeOf(T1(1)))).Interface(), (chan T1)(nil))
 }
 
+func TestChanOfDir(t *testing.T) {
+	// check construction and use of type not in binary
+	type T string
+	crt := ChanOf(RecvDir, TypeOf(T("")))
+	cst := ChanOf(SendDir, TypeOf(T("")))
+
+	// check that type already in binary is found
+	type T1 int
+	checkSameType(t, Zero(ChanOf(RecvDir, TypeOf(T1(1)))).Interface(), (<-chan T1)(nil))
+	checkSameType(t, Zero(ChanOf(SendDir, TypeOf(T1(1)))).Interface(), (chan<- T1)(nil))
+
+	// check String form of ChanDir
+	if crt.ChanDir().String() != "<-chan" {
+		t.Errorf("chan dir: have %q, want %q", crt.ChanDir().String(), "<-chan")
+	}
+	if cst.ChanDir().String() != "chan<-" {
+		t.Errorf("chan dir: have %q, want %q", cst.ChanDir().String(), "chan<-")
+	}
+}
+
 func TestChanOfGC(t *testing.T) {
 	done := make(chan bool, 1)
 	go func() {
@@ -3632,6 +3888,67 @@ func TestMapOfGCValues(t *testing.T) {
 	}
 }
 
+func TestTypelinksSorted(t *testing.T) {
+	var last string
+	for i, n := range TypeLinks() {
+		if n < last {
+			t.Errorf("typelinks not sorted: %q [%d] > %q [%d]", last, i-1, n, i)
+		}
+		last = n
+	}
+}
+
+func TestFuncOf(t *testing.T) {
+	// check construction and use of type not in binary
+	type K string
+	type V float64
+
+	fn := func(args []Value) []Value {
+		if len(args) != 1 {
+			t.Errorf("args == %v, want exactly one arg", args)
+		} else if args[0].Type() != TypeOf(K("")) {
+			t.Errorf("args[0] is type %v, want %v", args[0].Type, TypeOf(K("")))
+		} else if args[0].String() != "gopher" {
+			t.Errorf("args[0] = %q, want %q", args[0].String(), "gopher")
+		}
+		return []Value{ValueOf(V(3.14))}
+	}
+	v := MakeFunc(FuncOf([]Type{TypeOf(K(""))}, []Type{TypeOf(V(0))}, false), fn)
+
+	outs := v.Call([]Value{ValueOf(K("gopher"))})
+	if len(outs) != 1 {
+		t.Fatalf("v.Call returned %v, want exactly one result", outs)
+	} else if outs[0].Type() != TypeOf(V(0)) {
+		t.Fatalf("c.Call[0] is type %v, want %v", outs[0].Type, TypeOf(V(0)))
+	}
+	f := outs[0].Float()
+	if f != 3.14 {
+		t.Errorf("constructed func returned %f, want %f", f, 3.14)
+	}
+
+	// check that types already in binary are found
+	type T1 int
+	testCases := []struct {
+		in, out  []Type
+		variadic bool
+		want     interface{}
+	}{
+		{in: []Type{TypeOf(T1(0))}, want: (func(T1))(nil)},
+		{in: []Type{TypeOf(int(0))}, want: (func(int))(nil)},
+		{in: []Type{SliceOf(TypeOf(int(0)))}, variadic: true, want: (func(...int))(nil)},
+		{in: []Type{TypeOf(int(0))}, out: []Type{TypeOf(false)}, want: (func(int) bool)(nil)},
+		{in: []Type{TypeOf(int(0))}, out: []Type{TypeOf(false), TypeOf("")}, want: (func(int) (bool, string))(nil)},
+	}
+	for _, tt := range testCases {
+		checkSameType(t, Zero(FuncOf(tt.in, tt.out, tt.variadic)).Interface(), tt.want)
+	}
+
+	// check that variadic requires last element be a slice.
+	FuncOf([]Type{TypeOf(1), TypeOf(""), SliceOf(TypeOf(false))}, nil, true)
+	shouldPanic(func() { FuncOf([]Type{TypeOf(0), TypeOf(""), TypeOf(false)}, nil, true) })
+	shouldPanic(func() { FuncOf(nil, nil, true) })
+}
+
 type B1 struct {
 	X int
 	Y int
@@ -4077,15 +4394,16 @@ func TestCallGC(t *testing.T) {
 }
 
 type funcLayoutTest struct {
-	rcvr, t            Type
-	argsize, retOffset uintptr
-	stack              []byte
+	rcvr, t                  Type
+	size, argsize, retOffset uintptr
+	stack                    []byte // pointer bitmap: 1 is pointer, 0 is scalar (or uninitialized)
+	gc                       []byte
 }
 
 var funcLayoutTests []funcLayoutTest
 
 func init() {
-	var argAlign = PtrSize
+	var argAlign uintptr = PtrSize
 	if runtime.GOARCH == "amd64p32" {
 		argAlign = 2 * PtrSize
 	}
@@ -4097,24 +4415,28 @@ func init() {
 		funcLayoutTest{
 			nil,
 			ValueOf(func(a, b string) string { return "" }).Type(),
+			6 * PtrSize,
 			4 * PtrSize,
 			4 * PtrSize,
-			[]byte{BitsPointer, BitsScalar, BitsPointer},
+			[]byte{1, 0, 1},
+			[]byte{1, 0, 1, 0, 1},
 		})
 
 	var r []byte
 	if PtrSize == 4 {
-		r = []byte{BitsScalar, BitsScalar, BitsScalar, BitsPointer}
+		r = []byte{0, 0, 0, 1}
 	} else {
-		r = []byte{BitsScalar, BitsScalar, BitsPointer}
+		r = []byte{0, 0, 1}
 	}
 	funcLayoutTests = append(funcLayoutTests,
 		funcLayoutTest{
 			nil,
 			ValueOf(func(a, b, c uint32, p *byte, d uint16) {}).Type(),
+			roundup(roundup(3*4, PtrSize)+PtrSize+2, argAlign),
 			roundup(3*4, PtrSize) + PtrSize + 2,
 			roundup(roundup(3*4, PtrSize)+PtrSize+2, argAlign),
 			r,
+			r,
 		})
 
 	funcLayoutTests = append(funcLayoutTests,
@@ -4123,7 +4445,9 @@ func init() {
 			ValueOf(func(a map[int]int, b uintptr, c interface{}) {}).Type(),
 			4 * PtrSize,
 			4 * PtrSize,
-			[]byte{BitsPointer, BitsScalar, BitsPointer, BitsPointer},
+			4 * PtrSize,
+			[]byte{1, 0, 1, 1},
+			[]byte{1, 0, 1, 1},
 		})
 
 	type S struct {
@@ -4136,23 +4460,66 @@ func init() {
 			ValueOf(func(a S) {}).Type(),
 			4 * PtrSize,
 			4 * PtrSize,
-			[]byte{BitsScalar, BitsScalar, BitsPointer, BitsPointer},
+			4 * PtrSize,
+			[]byte{0, 0, 1, 1},
+			[]byte{0, 0, 1, 1},
 		})
 
 	funcLayoutTests = append(funcLayoutTests,
 		funcLayoutTest{
 			ValueOf((*byte)(nil)).Type(),
 			ValueOf(func(a uintptr, b *int) {}).Type(),
+			roundup(3*PtrSize, argAlign),
 			3 * PtrSize,
 			roundup(3*PtrSize, argAlign),
-			[]byte{BitsPointer, BitsScalar, BitsPointer},
+			[]byte{1, 0, 1},
+			[]byte{1, 0, 1},
+		})
+
+	funcLayoutTests = append(funcLayoutTests,
+		funcLayoutTest{
+			nil,
+			ValueOf(func(a uintptr) {}).Type(),
+			roundup(PtrSize, argAlign),
+			PtrSize,
+			roundup(PtrSize, argAlign),
+			[]byte{},
+			[]byte{},
+		})
+
+	funcLayoutTests = append(funcLayoutTests,
+		funcLayoutTest{
+			nil,
+			ValueOf(func() uintptr { return 0 }).Type(),
+			PtrSize,
+			0,
+			0,
+			[]byte{},
+			[]byte{},
+		})
+
+	funcLayoutTests = append(funcLayoutTests,
+		funcLayoutTest{
+			ValueOf(uintptr(0)).Type(),
+			ValueOf(func(a uintptr) {}).Type(),
+			2 * PtrSize,
+			2 * PtrSize,
+			2 * PtrSize,
+			[]byte{1},
+			[]byte{1},
+			// Note: this one is tricky, as the receiver is not a pointer.  But we
+			// pass the receiver by reference to the autogenerated pointer-receiver
+			// version of the function.
 		})
 }
 
 func TestFuncLayout(t *testing.T) {
 	t.Skip("gccgo does not use funcLayout")
 	for _, lt := range funcLayoutTests {
-		_, argsize, retOffset, stack := FuncLayout(lt.t, lt.rcvr)
+		typ, argsize, retOffset, stack, gc, ptrs := FuncLayout(lt.t, lt.rcvr)
+		if typ.Size() != lt.size {
+			t.Errorf("funcLayout(%v, %v).size=%d, want %d", lt.t, lt.rcvr, typ.Size(), lt.size)
+		}
 		if argsize != lt.argsize {
 			t.Errorf("funcLayout(%v, %v).argsize=%d, want %d", lt.t, lt.rcvr, argsize, lt.argsize)
 		}
@@ -4162,5 +4529,260 @@ func TestFuncLayout(t *testing.T) {
 		if !bytes.Equal(stack, lt.stack) {
 			t.Errorf("funcLayout(%v, %v).stack=%v, want %v", lt.t, lt.rcvr, stack, lt.stack)
 		}
+		if !bytes.Equal(gc, lt.gc) {
+			t.Errorf("funcLayout(%v, %v).gc=%v, want %v", lt.t, lt.rcvr, gc, lt.gc)
+		}
+		if ptrs && len(stack) == 0 || !ptrs && len(stack) > 0 {
+			t.Errorf("funcLayout(%v, %v) pointers flag=%v, want %v", lt.t, lt.rcvr, ptrs, !ptrs)
+		}
+	}
+}
+
+func verifyGCBits(t *testing.T, typ Type, bits []byte) {
+	heapBits := GCBits(New(typ).Interface())
+	if !bytes.Equal(heapBits, bits) {
+		t.Errorf("heapBits incorrect for %v\nhave %v\nwant %v", typ, heapBits, bits)
+	}
+}
+
+func verifyGCBitsSlice(t *testing.T, typ Type, cap int, bits []byte) {
+	// Creating a slice causes the runtime to repeat a bitmap,
+	// which exercises a different path from making the compiler
+	// repeat a bitmap for a small array or executing a repeat in
+	// a GC program.
+	val := MakeSlice(typ, 0, cap)
+	data := NewAt(ArrayOf(cap, typ), unsafe.Pointer(val.Pointer()))
+	heapBits := GCBits(data.Interface())
+	// Repeat the bitmap for the slice size, trimming scalars in
+	// the last element.
+	bits = rep(cap, bits)
+	for len(bits) > 2 && bits[len(bits)-1] == 0 {
+		bits = bits[:len(bits)-1]
+	}
+	if !bytes.Equal(heapBits, bits) {
+		t.Errorf("heapBits incorrect for make(%v, 0, %v)\nhave %v\nwant %v", typ, cap, heapBits, bits)
+	}
+}
+
+func TestGCBits(t *testing.T) {
+	t.Skip("gccgo does not use gcbits yet")
+
+	verifyGCBits(t, TypeOf((*byte)(nil)), []byte{1})
+
+	// Building blocks for types seen by the compiler (like [2]Xscalar).
+	// The compiler will create the type structures for the derived types,
+	// including their GC metadata.
+	type Xscalar struct{ x uintptr }
+	type Xptr struct{ x *byte }
+	type Xptrscalar struct {
+		*byte
+		uintptr
+	}
+	type Xscalarptr struct {
+		uintptr
+		*byte
+	}
+	type Xbigptrscalar struct {
+		_ [100]*byte
+		_ [100]uintptr
+	}
+
+	var Tscalar, Tint64, Tptr, Tscalarptr, Tptrscalar, Tbigptrscalar Type
+	{
+		// Building blocks for types constructed by reflect.
+		// This code is in a separate block so that code below
+		// cannot accidentally refer to these.
+		// The compiler must NOT see types derived from these
+		// (for example, [2]Scalar must NOT appear in the program),
+		// or else reflect will use it instead of having to construct one.
+		// The goal is to test the construction.
+		type Scalar struct{ x uintptr }
+		type Ptr struct{ x *byte }
+		type Ptrscalar struct {
+			*byte
+			uintptr
+		}
+		type Scalarptr struct {
+			uintptr
+			*byte
+		}
+		type Bigptrscalar struct {
+			_ [100]*byte
+			_ [100]uintptr
+		}
+		type Int64 int64
+		Tscalar = TypeOf(Scalar{})
+		Tint64 = TypeOf(Int64(0))
+		Tptr = TypeOf(Ptr{})
+		Tscalarptr = TypeOf(Scalarptr{})
+		Tptrscalar = TypeOf(Ptrscalar{})
+		Tbigptrscalar = TypeOf(Bigptrscalar{})
+	}
+
+	empty := []byte{}
+
+	verifyGCBits(t, TypeOf(Xscalar{}), empty)
+	verifyGCBits(t, Tscalar, empty)
+	verifyGCBits(t, TypeOf(Xptr{}), lit(1))
+	verifyGCBits(t, Tptr, lit(1))
+	verifyGCBits(t, TypeOf(Xscalarptr{}), lit(0, 1))
+	verifyGCBits(t, Tscalarptr, lit(0, 1))
+	verifyGCBits(t, TypeOf(Xptrscalar{}), lit(1))
+	verifyGCBits(t, Tptrscalar, lit(1))
+
+	verifyGCBits(t, TypeOf([0]Xptr{}), empty)
+	verifyGCBits(t, ArrayOf(0, Tptr), empty)
+	verifyGCBits(t, TypeOf([1]Xptrscalar{}), lit(1))
+	verifyGCBits(t, ArrayOf(1, Tptrscalar), lit(1))
+	verifyGCBits(t, TypeOf([2]Xscalar{}), empty)
+	verifyGCBits(t, ArrayOf(2, Tscalar), empty)
+	verifyGCBits(t, TypeOf([10000]Xscalar{}), empty)
+	verifyGCBits(t, ArrayOf(10000, Tscalar), empty)
+	verifyGCBits(t, TypeOf([2]Xptr{}), lit(1, 1))
+	verifyGCBits(t, ArrayOf(2, Tptr), lit(1, 1))
+	verifyGCBits(t, TypeOf([10000]Xptr{}), rep(10000, lit(1)))
+	verifyGCBits(t, ArrayOf(10000, Tptr), rep(10000, lit(1)))
+	verifyGCBits(t, TypeOf([2]Xscalarptr{}), lit(0, 1, 0, 1))
+	verifyGCBits(t, ArrayOf(2, Tscalarptr), lit(0, 1, 0, 1))
+	verifyGCBits(t, TypeOf([10000]Xscalarptr{}), rep(10000, lit(0, 1)))
+	verifyGCBits(t, ArrayOf(10000, Tscalarptr), rep(10000, lit(0, 1)))
+	verifyGCBits(t, TypeOf([2]Xptrscalar{}), lit(1, 0, 1))
+	verifyGCBits(t, ArrayOf(2, Tptrscalar), lit(1, 0, 1))
+	verifyGCBits(t, TypeOf([10000]Xptrscalar{}), rep(10000, lit(1, 0)))
+	verifyGCBits(t, ArrayOf(10000, Tptrscalar), rep(10000, lit(1, 0)))
+	verifyGCBits(t, TypeOf([1][10000]Xptrscalar{}), rep(10000, lit(1, 0)))
+	verifyGCBits(t, ArrayOf(1, ArrayOf(10000, Tptrscalar)), rep(10000, lit(1, 0)))
+	verifyGCBits(t, TypeOf([2][10000]Xptrscalar{}), rep(2*10000, lit(1, 0)))
+	verifyGCBits(t, ArrayOf(2, ArrayOf(10000, Tptrscalar)), rep(2*10000, lit(1, 0)))
+	verifyGCBits(t, TypeOf([4]Xbigptrscalar{}), join(rep(3, join(rep(100, lit(1)), rep(100, lit(0)))), rep(100, lit(1))))
+	verifyGCBits(t, ArrayOf(4, Tbigptrscalar), join(rep(3, join(rep(100, lit(1)), rep(100, lit(0)))), rep(100, lit(1))))
+
+	verifyGCBitsSlice(t, TypeOf([]Xptr{}), 0, empty)
+	verifyGCBitsSlice(t, SliceOf(Tptr), 0, empty)
+	verifyGCBitsSlice(t, TypeOf([]Xptrscalar{}), 1, lit(1))
+	verifyGCBitsSlice(t, SliceOf(Tptrscalar), 1, lit(1))
+	verifyGCBitsSlice(t, TypeOf([]Xscalar{}), 2, lit(0))
+	verifyGCBitsSlice(t, SliceOf(Tscalar), 2, lit(0))
+	verifyGCBitsSlice(t, TypeOf([]Xscalar{}), 10000, lit(0))
+	verifyGCBitsSlice(t, SliceOf(Tscalar), 10000, lit(0))
+	verifyGCBitsSlice(t, TypeOf([]Xptr{}), 2, lit(1))
+	verifyGCBitsSlice(t, SliceOf(Tptr), 2, lit(1))
+	verifyGCBitsSlice(t, TypeOf([]Xptr{}), 10000, lit(1))
+	verifyGCBitsSlice(t, SliceOf(Tptr), 10000, lit(1))
+	verifyGCBitsSlice(t, TypeOf([]Xscalarptr{}), 2, lit(0, 1))
+	verifyGCBitsSlice(t, SliceOf(Tscalarptr), 2, lit(0, 1))
+	verifyGCBitsSlice(t, TypeOf([]Xscalarptr{}), 10000, lit(0, 1))
+	verifyGCBitsSlice(t, SliceOf(Tscalarptr), 10000, lit(0, 1))
+	verifyGCBitsSlice(t, TypeOf([]Xptrscalar{}), 2, lit(1, 0))
+	verifyGCBitsSlice(t, SliceOf(Tptrscalar), 2, lit(1, 0))
+	verifyGCBitsSlice(t, TypeOf([]Xptrscalar{}), 10000, lit(1, 0))
+	verifyGCBitsSlice(t, SliceOf(Tptrscalar), 10000, lit(1, 0))
+	verifyGCBitsSlice(t, TypeOf([][10000]Xptrscalar{}), 1, rep(10000, lit(1, 0)))
+	verifyGCBitsSlice(t, SliceOf(ArrayOf(10000, Tptrscalar)), 1, rep(10000, lit(1, 0)))
+	verifyGCBitsSlice(t, TypeOf([][10000]Xptrscalar{}), 2, rep(10000, lit(1, 0)))
+	verifyGCBitsSlice(t, SliceOf(ArrayOf(10000, Tptrscalar)), 2, rep(10000, lit(1, 0)))
+	verifyGCBitsSlice(t, TypeOf([]Xbigptrscalar{}), 4, join(rep(100, lit(1)), rep(100, lit(0))))
+	verifyGCBitsSlice(t, SliceOf(Tbigptrscalar), 4, join(rep(100, lit(1)), rep(100, lit(0))))
+
+	verifyGCBits(t, TypeOf((chan [100]Xscalar)(nil)), lit(1))
+	verifyGCBits(t, ChanOf(BothDir, ArrayOf(100, Tscalar)), lit(1))
+
+	verifyGCBits(t, TypeOf((func([10000]Xscalarptr))(nil)), lit(1))
+	verifyGCBits(t, FuncOf([]Type{ArrayOf(10000, Tscalarptr)}, nil, false), lit(1))
+
+	verifyGCBits(t, TypeOf((map[[10000]Xscalarptr]Xscalar)(nil)), lit(1))
+	verifyGCBits(t, MapOf(ArrayOf(10000, Tscalarptr), Tscalar), lit(1))
+
+	verifyGCBits(t, TypeOf((*[10000]Xscalar)(nil)), lit(1))
+	verifyGCBits(t, PtrTo(ArrayOf(10000, Tscalar)), lit(1))
+
+	verifyGCBits(t, TypeOf(([][10000]Xscalar)(nil)), lit(1))
+	verifyGCBits(t, SliceOf(ArrayOf(10000, Tscalar)), lit(1))
+
+	hdr := make([]byte, 8/PtrSize)
+
+	verifyMapBucket := func(t *testing.T, k, e Type, m interface{}, want []byte) {
+		verifyGCBits(t, MapBucketOf(k, e), want)
+		verifyGCBits(t, CachedBucketOf(TypeOf(m)), want)
+	}
+	verifyMapBucket(t,
+		Tscalar, Tptr,
+		map[Xscalar]Xptr(nil),
+		join(hdr, rep(8, lit(0)), rep(8, lit(1)), lit(1)))
+	verifyMapBucket(t,
+		Tscalarptr, Tptr,
+		map[Xscalarptr]Xptr(nil),
+		join(hdr, rep(8, lit(0, 1)), rep(8, lit(1)), lit(1)))
+	verifyMapBucket(t, Tint64, Tptr,
+		map[int64]Xptr(nil),
+		join(hdr, rep(8, rep(8/PtrSize, lit(0))), rep(8, lit(1)), naclpad(), lit(1)))
+	verifyMapBucket(t,
+		Tscalar, Tscalar,
+		map[Xscalar]Xscalar(nil),
+		empty)
+	verifyMapBucket(t,
+		ArrayOf(2, Tscalarptr), ArrayOf(3, Tptrscalar),
+		map[[2]Xscalarptr][3]Xptrscalar(nil),
+		join(hdr, rep(8*2, lit(0, 1)), rep(8*3, lit(1, 0)), lit(1)))
+	verifyMapBucket(t,
+		ArrayOf(64/PtrSize, Tscalarptr), ArrayOf(64/PtrSize, Tptrscalar),
+		map[[64 / PtrSize]Xscalarptr][64 / PtrSize]Xptrscalar(nil),
+		join(hdr, rep(8*64/PtrSize, lit(0, 1)), rep(8*64/PtrSize, lit(1, 0)), lit(1)))
+	verifyMapBucket(t,
+		ArrayOf(64/PtrSize+1, Tscalarptr), ArrayOf(64/PtrSize, Tptrscalar),
+		map[[64/PtrSize + 1]Xscalarptr][64 / PtrSize]Xptrscalar(nil),
+		join(hdr, rep(8, lit(1)), rep(8*64/PtrSize, lit(1, 0)), lit(1)))
+	verifyMapBucket(t,
+		ArrayOf(64/PtrSize, Tscalarptr), ArrayOf(64/PtrSize+1, Tptrscalar),
+		map[[64 / PtrSize]Xscalarptr][64/PtrSize + 1]Xptrscalar(nil),
+		join(hdr, rep(8*64/PtrSize, lit(0, 1)), rep(8, lit(1)), lit(1)))
+	verifyMapBucket(t,
+		ArrayOf(64/PtrSize+1, Tscalarptr), ArrayOf(64/PtrSize+1, Tptrscalar),
+		map[[64/PtrSize + 1]Xscalarptr][64/PtrSize + 1]Xptrscalar(nil),
+		join(hdr, rep(8, lit(1)), rep(8, lit(1)), lit(1)))
+}
+
+func naclpad() []byte {
+	if runtime.GOARCH == "amd64p32" {
+		return lit(0)
+	}
+	return nil
+}
+
+func rep(n int, b []byte) []byte { return bytes.Repeat(b, n) }
+func join(b ...[]byte) []byte    { return bytes.Join(b, nil) }
+func lit(x ...byte) []byte       { return x }
+
+func TestTypeOfTypeOf(t *testing.T) {
+	// Check that all the type constructors return concrete *rtype implementations.
+	// It's difficult to test directly because the reflect package is only at arm's length.
+	// The easiest thing to do is just call a function that crashes if it doesn't get an *rtype.
+	check := func(name string, typ Type) {
+		if underlying := TypeOf(typ).String(); underlying != "*reflect.rtype" {
+			t.Errorf("%v returned %v, not *reflect.rtype", name, underlying)
+		}
+	}
+
+	type T struct{ int }
+	check("TypeOf", TypeOf(T{}))
+
+	check("ArrayOf", ArrayOf(10, TypeOf(T{})))
+	check("ChanOf", ChanOf(BothDir, TypeOf(T{})))
+	check("FuncOf", FuncOf([]Type{TypeOf(T{})}, nil, false))
+	check("MapOf", MapOf(TypeOf(T{}), TypeOf(T{})))
+	check("PtrTo", PtrTo(TypeOf(T{})))
+	check("SliceOf", SliceOf(TypeOf(T{})))
+}
+
+type XM struct{}
+
+func (*XM) String() string { return "" }
+
+func TestPtrToMethods(t *testing.T) {
+	var y struct{ XM }
+	yp := New(TypeOf(y)).Interface()
+	_, ok := yp.(fmt.Stringer)
+	if !ok {
+		t.Fatal("does not implement Stringer, but should")
 	}
 }
diff --git a/libgo/go/reflect/example_test.go b/libgo/go/reflect/example_test.go
index cca28eeece8..8ebf9765b8d 100644
--- a/libgo/go/reflect/example_test.go
+++ b/libgo/go/reflect/example_test.go
@@ -6,6 +6,8 @@ package reflect_test
 
 import (
 	"fmt"
+	"io"
+	"os"
 	"reflect"
 )
 
@@ -64,3 +66,16 @@ func ExampleStructTag() {
 	// Output:
 	// blue gopher
 }
+
+func ExampleTypeOf() {
+	// As interface types are only used for static typing, a
+	// common idiom to find the reflection Type for an interface
+	// type Foo is to use a *Foo value.
+	writerType := reflect.TypeOf((*io.Writer)(nil)).Elem()
+
+	fileType := reflect.TypeOf((*os.File)(nil))
+	fmt.Println(fileType.Implements(writerType))
+
+	// Output:
+	// true
+}
diff --git a/libgo/go/reflect/export_test.go b/libgo/go/reflect/export_test.go
index 49c45e82b2e..89473d352a7 100644
--- a/libgo/go/reflect/export_test.go
+++ b/libgo/go/reflect/export_test.go
@@ -15,13 +15,29 @@ func IsRO(v Value) bool {
 	return v.flag&flagRO != 0
 }
 
-var ArrayOf = arrayOf
 var CallGC = &callGC
 
 const PtrSize = ptrSize
-const BitsPointer = bitsPointer
-const BitsScalar = bitsScalar
 
-func FuncLayout(t Type, rcvr Type) (frametype Type, argSize, retOffset uintptr, stack []byte) {
+func FuncLayout(t Type, rcvr Type) (frametype Type, argSize, retOffset uintptr, stack []byte, gc []byte, ptrs bool) {
 	return
 }
+
+func TypeLinks() []string {
+	return nil
+}
+
+var GCBits = gcbits
+
+// Will be provided by runtime eventually.
+func gcbits(interface{}) []byte {
+	return nil
+}
+
+func MapBucketOf(x, y Type) Type {
+	return nil
+}
+
+func CachedBucketOf(m Type) Type {
+	return nil
+}
diff --git a/libgo/go/reflect/type.go b/libgo/go/reflect/type.go
index 5cdfba55648..e488938a13f 100644
--- a/libgo/go/reflect/type.go
+++ b/libgo/go/reflect/type.go
@@ -12,7 +12,7 @@
 // for that type.
 //
 // See "The Laws of Reflection" for an introduction to reflection in Go:
-// http://golang.org/doc/articles/laws_of_reflection.html
+// https://golang.org/doc/articles/laws_of_reflection.html
 package reflect
 
 import (
@@ -90,16 +90,16 @@ type Type interface {
 	// Kind returns the specific kind of this type.
 	Kind() Kind
 
-	// Implements returns true if the type implements the interface type u.
+	// Implements reports whether the type implements the interface type u.
 	Implements(u Type) bool
 
-	// AssignableTo returns true if a value of the type is assignable to type u.
+	// AssignableTo reports whether a value of the type is assignable to type u.
 	AssignableTo(u Type) bool
 
-	// ConvertibleTo returns true if a value of the type is convertible to type u.
+	// ConvertibleTo reports whether a value of the type is convertible to type u.
 	ConvertibleTo(u Type) bool
 
-	// Comparable returns true if values of this type are comparable.
+	// Comparable reports whether values of this type are comparable.
 	Comparable() bool
 
 	// Methods applicable only to some types, depending on Kind.
@@ -123,7 +123,7 @@ type Type interface {
 	// It panics if the type's Kind is not Chan.
 	ChanDir() ChanDir
 
-	// IsVariadic returns true if a function type's final input parameter
+	// IsVariadic reports whether a function type's final input parameter
 	// is a "..." parameter.  If so, t.In(t.NumIn() - 1) returns the parameter's
 	// implicit actual type []T.
 	//
@@ -204,9 +204,9 @@ type Type interface {
 // See golang.org/issue/4876 for more details.
 
 /*
- * These data structures are known to the compiler (../../cmd/gc/reflect.c).
+ * These data structures are known to the compiler (../../cmd/internal/gc/reflect.go).
  * A few are known to ../runtime/type.go to convey to debuggers.
- * They are also known to ../runtime/type.h.
+ * They are also known to ../runtime/type.go.
  */
 
 // A Kind represents the specific kind of type that a Type represents.
@@ -255,8 +255,8 @@ type rtype struct {
 	size       uintptr
 	hash       uint32 // hash of type; avoids computation in hash tables
 
-	hashfn  func(unsafe.Pointer, uintptr)                 // hash function
-	equalfn func(unsafe.Pointer, unsafe.Pointer, uintptr) // equality function
+	hashfn  func(unsafe.Pointer, uintptr) uintptr              // hash function
+	equalfn func(unsafe.Pointer, unsafe.Pointer, uintptr) bool // equality function
 
 	gc            unsafe.Pointer // garbage collection data
 	string        *string        // string form; unnecessary  but undeniably useful
@@ -392,7 +392,7 @@ type Method struct {
 	// method name.  It is empty for upper case (exported) method names.
 	// The combination of PkgPath and Name uniquely identifies a method
 	// in a method set.
-	// See http://golang.org/ref/spec#Uniqueness_of_identifiers
+	// See https://golang.org/ref/spec#Uniqueness_of_identifiers
 	Name    string
 	PkgPath string
 
@@ -548,7 +548,7 @@ func (t *uncommonType) MethodByName(name string) (m Method, ok bool) {
 	return
 }
 
-// TODO(rsc): 6g supplies these, but they are not
+// TODO(rsc): gc supplies these, but they are not
 // as efficient as they could be: they have commonType
 // as the receiver instead of *rtype.
 func (t *rtype) NumMethod() int {
@@ -758,7 +758,7 @@ type StructField struct {
 	// Name is the field name.
 	// PkgPath is the package path that qualifies a lower case (unexported)
 	// field name.  It is empty for upper case (exported) field names.
-	// See http://golang.org/ref/spec#Uniqueness_of_identifiers
+	// See https://golang.org/ref/spec#Uniqueness_of_identifiers
 	Name    string
 	PkgPath string
 
@@ -784,8 +784,11 @@ type StructTag string
 // If the tag does not have the conventional format, the value
 // returned by Get is unspecified.
 func (tag StructTag) Get(key string) string {
+	// When modifying this code, also update the validateStructTag code
+	// in golang.org/x/tools/cmd/vet/structtag.go.
+
 	for tag != "" {
-		// skip leading space
+		// Skip leading space.
 		i := 0
 		for i < len(tag) && tag[i] == ' ' {
 			i++
@@ -795,19 +798,21 @@ func (tag StructTag) Get(key string) string {
 			break
 		}
 
-		// scan to colon.
-		// a space or a quote is a syntax error
+		// Scan to colon. A space, a quote or a control character is a syntax error.
+		// Strictly speaking, control chars include the range [0x7f, 0x9f], not just
+		// [0x00, 0x1f], but in practice, we ignore the multi-byte control characters
+		// as it is simpler to inspect the tag's bytes than the tag's runes.
 		i = 0
-		for i < len(tag) && tag[i] != ' ' && tag[i] != ':' && tag[i] != '"' {
+		for i < len(tag) && tag[i] > ' ' && tag[i] != ':' && tag[i] != '"' && tag[i] != 0x7f {
 			i++
 		}
-		if i+1 >= len(tag) || tag[i] != ':' || tag[i+1] != '"' {
+		if i == 0 || i+1 >= len(tag) || tag[i] != ':' || tag[i+1] != '"' {
 			break
 		}
 		name := string(tag[:i])
 		tag = tag[i+1:]
 
-		// scan quoted string to find value
+		// Scan quoted string to find value.
 		i = 1
 		for i < len(tag) && tag[i] != '"' {
 			if tag[i] == '\\' {
@@ -822,7 +827,10 @@ func (tag StructTag) Get(key string) string {
 		tag = tag[i+1:]
 
 		if key == name {
-			value, _ := strconv.Unquote(qvalue)
+			value, err := strconv.Unquote(qvalue)
+			if err != nil {
+				break
+			}
 			return value
 		}
 	}
@@ -1024,8 +1032,8 @@ func (t *structType) FieldByName(name string) (f StructField, present bool) {
 	return t.FieldByNameFunc(func(s string) bool { return s == name })
 }
 
-// TypeOf returns the reflection Type of the value in the interface{}.
-// TypeOf(nil) returns nil.
+// TypeOf returns the reflection Type that represents the dynamic type of i.
+// If i is a nil interface value, TypeOf returns nil.
 func TypeOf(i interface{}) Type {
 	eface := *(*emptyInterface)(unsafe.Pointer(&i))
 	return toType(eface.typ)
@@ -1109,7 +1117,8 @@ func (t *rtype) ptrTo() *rtype {
 		return r.(*rtype)
 	}
 
-	// initialize p using *byte's ptrType as a prototype.
+	// Create a new ptrType starting with the description
+	// of an *unsafe.Pointer.
 	p = new(ptrType)
 	var iptr interface{} = (*unsafe.Pointer)(nil)
 	prototype := *(**ptrType)(unsafe.Pointer(&iptr))
@@ -1145,6 +1154,7 @@ func (t *rtype) ptrTo() *rtype {
 	q := canonicalize(&p.rtype)
 	p = (*ptrType)(unsafe.Pointer(q.(*rtype)))
 
+	ptrMap.m[t] = p
 	ptrMap.Unlock()
 	return &p.rtype
 }
@@ -1211,7 +1221,7 @@ func (t *rtype) Comparable() bool {
 	}
 }
 
-// implements returns true if the type V implements the interface type T.
+// implements reports whether the type V implements the interface type T.
 func implements(T, V *rtype) bool {
 	if T.Kind() != Interface {
 		return false
@@ -1232,7 +1242,7 @@ func implements(T, V *rtype) bool {
 	// methods along the way, or else V does not implement T.
 	// This lets us run the scan in overall linear time instead of
 	// the quadratic time  a naive search would require.
-	// See also ../runtime/iface.c.
+	// See also ../runtime/iface.go.
 	if V.Kind() == Interface {
 		v := (*interfaceType)(unsafe.Pointer(V))
 		i := 0
@@ -1265,9 +1275,9 @@ func implements(T, V *rtype) bool {
 	return false
 }
 
-// directlyAssignable returns true if a value x of type V can be directly
+// directlyAssignable reports whether a value x of type V can be directly
 // assigned (using memmove) to a value of type T.
-// http://golang.org/doc/go_spec.html#Assignability
+// https://golang.org/doc/go_spec.html#Assignability
 // Ignoring the interface rules (implemented elsewhere)
 // and the ideal constant rules (no ideal constants at run time).
 func directlyAssignable(T, V *rtype) bool {
@@ -1445,6 +1455,14 @@ type chanGC struct {
 	end   uintptr // _GC_END
 }
 
+// The funcLookupCache caches FuncOf lookups.
+// FuncOf does not share the common lookupCache since cacheKey is not
+// sufficient to represent functions unambiguously.
+var funcLookupCache struct {
+	sync.RWMutex
+	m map[uint32][]*rtype // keyed by hash calculated in FuncOf
+}
+
 // ChanOf returns the channel type with the given direction and element type.
 // For example, if t represents int, ChanOf(RecvDir, t) represents <-chan int.
 //
@@ -1485,6 +1503,7 @@ func ChanOf(dir ChanDir, t Type) Type {
 	prototype := *(**chanType)(unsafe.Pointer(&ichan))
 	ch := new(chanType)
 	*ch = *prototype
+	ch.dir = uintptr(dir)
 	ch.string = &s
 
 	// gccgo uses a different hash.
@@ -1545,9 +1564,8 @@ func MapOf(key, elem Type) Type {
 
 	// Make a map type.
 	var imap interface{} = (map[unsafe.Pointer]unsafe.Pointer)(nil)
-	prototype := *(**mapType)(unsafe.Pointer(&imap))
 	mt := new(mapType)
-	*mt = *prototype
+	*mt = **(**mapType)(unsafe.Pointer(&imap))
 	mt.string = &s
 
 	// gccgo uses a different hash
@@ -1576,154 +1594,243 @@ func MapOf(key, elem Type) Type {
 	return cachePut(ckey, &mt.rtype)
 }
 
-// gcProg is a helper type for generatation of GC pointer info.
-type gcProg struct {
-	gc     []byte
-	size   uintptr // size of type in bytes
-	hasPtr bool
-}
+// FuncOf returns the function type with the given argument and result types.
+// For example if k represents int and e represents string,
+// FuncOf([]Type{k}, []Type{e}, false) represents func(int) string.
+//
+// The variadic argument controls whether the function is variadic. FuncOf
+// panics if the in[len(in)-1] does not represent a slice and variadic is
+// true.
+func FuncOf(in, out []Type, variadic bool) Type {
+	if variadic && (len(in) == 0 || in[len(in)-1].Kind() != Slice) {
+		panic("reflect.FuncOf: last arg of variadic func must be slice")
+	}
+
+	// Make a func type.
+	var ifunc interface{} = (func())(nil)
+	prototype := *(**funcType)(unsafe.Pointer(&ifunc))
+	ft := new(funcType)
+	*ft = *prototype
+
+	// Build a hash and minimally populate ft.
+	var hash uint32 = 8
+	var fin, fout []*rtype
+	shift := uint(1)
+	for _, in := range in {
+		t := in.(*rtype)
+		fin = append(fin, t)
+		hash += t.hash << shift
+		shift++
+	}
+	shift = 2
+	for _, out := range out {
+		t := out.(*rtype)
+		fout = append(fout, t)
+		hash += t.hash << shift
+		shift++
+	}
+	if variadic {
+		hash++
+	}
+	hash <<= 4
+	ft.hash = hash
+	ft.in = fin
+	ft.out = fout
+	ft.dotdotdot = variadic
 
-func (gc *gcProg) append(v byte) {
-	gc.align(unsafe.Sizeof(uintptr(0)))
-	gc.appendWord(v)
-}
+	// Look in cache.
+	funcLookupCache.RLock()
+	for _, t := range funcLookupCache.m[hash] {
+		if haveIdenticalUnderlyingType(&ft.rtype, t) {
+			funcLookupCache.RUnlock()
+			return t
+		}
+	}
+	funcLookupCache.RUnlock()
 
-// Appends t's type info to the current program.
-func (gc *gcProg) appendProg(t *rtype) {
-	gc.align(uintptr(t.align))
-	if !t.pointers() {
-		gc.size += t.size
-		return
+	// Not in cache, lock and retry.
+	funcLookupCache.Lock()
+	defer funcLookupCache.Unlock()
+	if funcLookupCache.m == nil {
+		funcLookupCache.m = make(map[uint32][]*rtype)
 	}
-	switch t.Kind() {
-	default:
-		panic("reflect: non-pointer type marked as having pointers")
-	case Ptr, UnsafePointer, Chan, Func, Map:
-		gc.appendWord(bitsPointer)
-	case Slice:
-		gc.appendWord(bitsPointer)
-		gc.appendWord(bitsScalar)
-		gc.appendWord(bitsScalar)
-	case String:
-		gc.appendWord(bitsPointer)
-		gc.appendWord(bitsScalar)
-	case Array:
-		c := t.Len()
-		e := t.Elem().common()
-		for i := 0; i < c; i++ {
-			gc.appendProg(e)
+	for _, t := range funcLookupCache.m[hash] {
+		if haveIdenticalUnderlyingType(&ft.rtype, t) {
+			return t
 		}
-	case Interface:
-		gc.appendWord(bitsMultiWord)
-		if t.NumMethod() == 0 {
-			gc.appendWord(bitsEface)
-		} else {
-			gc.appendWord(bitsIface)
-		}
-	case Struct:
-		c := t.NumField()
-		for i := 0; i < c; i++ {
-			gc.appendProg(t.Field(i).Type.common())
-		}
-		gc.align(uintptr(t.align))
 	}
+
+	str := funcStr(ft)
+
+	// Populate the remaining fields of ft and store in cache.
+	ft.string = &str
+	ft.uncommonType = nil
+	ft.ptrToThis = nil
+
+	// TODO(cmang): Generate GC data for funcs.
+	ft.gc = unsafe.Pointer(&ptrDataGCProg)
+
+	funcLookupCache.m[hash] = append(funcLookupCache.m[hash], &ft.rtype)
+
+	return toType(&ft.rtype)
 }
 
-func (gc *gcProg) appendWord(v byte) {
-	ptrsize := unsafe.Sizeof(uintptr(0))
-	if gc.size%ptrsize != 0 {
-		panic("reflect: unaligned GC program")
+// funcStr builds a string representation of a funcType.
+func funcStr(ft *funcType) string {
+	repr := make([]byte, 0, 64)
+	repr = append(repr, "func("...)
+	for i, t := range ft.in {
+		if i > 0 {
+			repr = append(repr, ", "...)
+		}
+		if ft.dotdotdot && i == len(ft.in)-1 {
+			repr = append(repr, "..."...)
+			repr = append(repr, *(*sliceType)(unsafe.Pointer(t)).elem.string...)
+		} else {
+			repr = append(repr, *t.string...)
+		}
 	}
-	nptr := gc.size / ptrsize
-	for uintptr(len(gc.gc)) < nptr/2+1 {
-		gc.gc = append(gc.gc, 0x44) // BitsScalar
+	repr = append(repr, ')')
+	if l := len(ft.out); l == 1 {
+		repr = append(repr, ' ')
+	} else if l > 1 {
+		repr = append(repr, " ("...)
 	}
-	gc.gc[nptr/2] &= ^(3 << ((nptr%2)*4 + 2))
-	gc.gc[nptr/2] |= v << ((nptr%2)*4 + 2)
-	gc.size += ptrsize
-	if v == bitsPointer {
-		gc.hasPtr = true
+	for i, t := range ft.out {
+		if i > 0 {
+			repr = append(repr, ", "...)
+		}
+		repr = append(repr, *t.string...)
 	}
+	if len(ft.out) > 1 {
+		repr = append(repr, ')')
+	}
+	return string(repr)
 }
 
-func (gc *gcProg) finalize() (unsafe.Pointer, bool) {
-	if gc.size == 0 {
-		return nil, false
-	}
-	ptrsize := unsafe.Sizeof(uintptr(0))
-	gc.align(ptrsize)
-	nptr := gc.size / ptrsize
-	for uintptr(len(gc.gc)) < nptr/2+1 {
-		gc.gc = append(gc.gc, 0x44) // BitsScalar
-	}
-	// If number of words is odd, repeat the mask twice.
-	// Compiler does the same.
-	if nptr%2 != 0 {
-		for i := uintptr(0); i < nptr; i++ {
-			gc.appendWord(extractGCWord(gc.gc, i))
+// isReflexive reports whether the == operation on the type is reflexive.
+// That is, x == x for all values x of type t.
+func isReflexive(t *rtype) bool {
+	switch t.Kind() {
+	case Bool, Int, Int8, Int16, Int32, Int64, Uint, Uint8, Uint16, Uint32, Uint64, Uintptr, Chan, Ptr, String, UnsafePointer:
+		return true
+	case Float32, Float64, Complex64, Complex128, Interface:
+		return false
+	case Array:
+		tt := (*arrayType)(unsafe.Pointer(t))
+		return isReflexive(tt.elem)
+	case Struct:
+		tt := (*structType)(unsafe.Pointer(t))
+		for _, f := range tt.fields {
+			if !isReflexive(f.typ) {
+				return false
+			}
 		}
+		return true
+	default:
+		// Func, Map, Slice, Invalid
+		panic("isReflexive called on non-key type " + t.String())
 	}
-	return unsafe.Pointer(&gc.gc[0]), gc.hasPtr
-}
-
-func extractGCWord(gc []byte, i uintptr) byte {
-	return (gc[i/2] >> ((i%2)*4 + 2)) & 3
-}
-
-func (gc *gcProg) align(a uintptr) {
-	gc.size = align(gc.size, a)
 }
 
-// These constants must stay in sync with ../runtime/mgc0.h.
-const (
-	bitsScalar    = 1
-	bitsPointer   = 2
-	bitsMultiWord = 3
-
-	bitsIface = 2
-	bitsEface = 3
-)
-
 // Make sure these routines stay in sync with ../../runtime/hashmap.go!
 // These types exist only for GC, so we only fill out GC relevant info.
 // Currently, that's just size and the GC program.  We also fill in string
 // for possible debugging use.
 const (
-	bucketSize = 8
-	maxKeySize = 128
-	maxValSize = 128
+	bucketSize uintptr = 8
+	maxKeySize uintptr = 128
+	maxValSize uintptr = 128
 )
 
 func bucketOf(ktyp, etyp *rtype) *rtype {
+	// See comment on hmap.overflow in ../runtime/hashmap.go.
+	var kind uint8
+	if ktyp.kind&kindNoPointers != 0 && etyp.kind&kindNoPointers != 0 &&
+		ktyp.size <= maxKeySize && etyp.size <= maxValSize {
+		kind = kindNoPointers
+	}
+
 	if ktyp.size > maxKeySize {
 		ktyp = PtrTo(ktyp).(*rtype)
 	}
 	if etyp.size > maxValSize {
 		etyp = PtrTo(etyp).(*rtype)
 	}
-	ptrsize := unsafe.Sizeof(uintptr(0))
 
-	var gc gcProg
-	// topbits
-	for i := 0; i < int(bucketSize*unsafe.Sizeof(uint8(0))/ptrsize); i++ {
-		gc.append(bitsScalar)
-	}
-	// keys
-	for i := 0; i < bucketSize; i++ {
-		gc.appendProg(ktyp)
-	}
-	// values
-	for i := 0; i < bucketSize; i++ {
-		gc.appendProg(etyp)
-	}
-	// overflow
-	gc.append(bitsPointer)
-	if runtime.GOARCH == "amd64p32" {
-		gc.append(bitsScalar)
+	// Prepare GC data if any.
+	// A bucket is at most bucketSize*(1+maxKeySize+maxValSize)+2*ptrSize bytes,
+	// or 2072 bytes, or 259 pointer-size words, or 33 bytes of pointer bitmap.
+	// Normally the enforced limit on pointer maps is 16 bytes,
+	// but larger ones are acceptable, 33 bytes isn't too too big,
+	// and it's easier to generate a pointer bitmap than a GC program.
+	// Note that since the key and value are known to be <= 128 bytes,
+	// they're guaranteed to have bitmaps instead of GC programs.
+	// var gcdata *byte
+	var ptrdata uintptr
+	var overflowPad uintptr
+
+	// On NaCl, pad if needed to make overflow end at the proper struct alignment.
+	// On other systems, align > ptrSize is not possible.
+	if runtime.GOARCH == "amd64p32" && (ktyp.align > ptrSize || etyp.align > ptrSize) {
+		overflowPad = ptrSize
+	}
+	size := bucketSize*(1+ktyp.size+etyp.size) + overflowPad + ptrSize
+	if size&uintptr(ktyp.align-1) != 0 || size&uintptr(etyp.align-1) != 0 {
+		panic("reflect: bad size computation in MapOf")
+	}
+
+	if kind != kindNoPointers {
+		nptr := (bucketSize*(1+ktyp.size+etyp.size) + ptrSize) / ptrSize
+		mask := make([]byte, (nptr+7)/8)
+		base := bucketSize / ptrSize
+
+		if ktyp.kind&kindNoPointers == 0 {
+			if ktyp.kind&kindGCProg != 0 {
+				panic("reflect: unexpected GC program in MapOf")
+			}
+			kmask := (*[16]byte)(unsafe.Pointer( /*ktyp.gcdata*/ nil))
+			for i := uintptr(0); i < ktyp.size/ptrSize; i++ {
+				if (kmask[i/8]>>(i%8))&1 != 0 {
+					for j := uintptr(0); j < bucketSize; j++ {
+						word := base + j*ktyp.size/ptrSize + i
+						mask[word/8] |= 1 << (word % 8)
+					}
+				}
+			}
+		}
+		base += bucketSize * ktyp.size / ptrSize
+
+		if etyp.kind&kindNoPointers == 0 {
+			if etyp.kind&kindGCProg != 0 {
+				panic("reflect: unexpected GC program in MapOf")
+			}
+			emask := (*[16]byte)(unsafe.Pointer( /*etyp.gcdata*/ nil))
+			for i := uintptr(0); i < etyp.size/ptrSize; i++ {
+				if (emask[i/8]>>(i%8))&1 != 0 {
+					for j := uintptr(0); j < bucketSize; j++ {
+						word := base + j*etyp.size/ptrSize + i
+						mask[word/8] |= 1 << (word % 8)
+					}
+				}
+			}
+		}
+		base += bucketSize * etyp.size / ptrSize
+		base += overflowPad / ptrSize
+
+		word := base
+		mask[word/8] |= 1 << (word % 8)
+		// gcdata = &mask[0]
+		ptrdata = (word + 1) * ptrSize
+
+		// overflow word must be last
+		if ptrdata != size {
+			panic("reflect: bad layout computation in MapOf")
+		}
 	}
 
 	b := new(rtype)
-	b.size = gc.size
+	// b.size = gc.size
 	// b.gc[0], _ = gc.finalize()
 	b.kind |= kindGCProg
 	s := "bucket(" + *ktyp.string + "," + *etyp.string + ")"
@@ -1863,24 +1970,25 @@ func SliceOf(t Type) Type {
 	return cachePut(ckey, &slice.rtype)
 }
 
+// See cmd/compile/internal/gc/reflect.go for derivation of constant.
+const maxPtrmaskBytes = 2048
+
 // ArrayOf returns the array type with the given count and element type.
 // For example, if t represents int, ArrayOf(5, t) represents [5]int.
 //
 // If the resulting type would be larger than the available address space,
 // ArrayOf panics.
-//
-// TODO(rsc): Unexported for now. Export once the alg field is set correctly
-// for the type. This may require significant work.
-//
-// TODO(rsc): TestArrayOf is also disabled. Re-enable.
-func arrayOf(count int, elem Type) Type {
+func ArrayOf(count int, elem Type) Type {
 	typ := elem.(*rtype)
+	// call SliceOf here as it calls cacheGet/cachePut.
+	// ArrayOf also calls cacheGet/cachePut and thus may modify the state of
+	// the lookupCache mutex.
 	slice := SliceOf(elem)
 
 	// Look in cache.
 	ckey := cacheKey{Array, typ, nil, uintptr(count)}
-	if slice := cacheGet(ckey); slice != nil {
-		return slice
+	if array := cacheGet(ckey); array != nil {
+		return array
 	}
 
 	// Look in known types.
@@ -1891,7 +1999,6 @@ func arrayOf(count int, elem Type) Type {
 	prototype := *(**arrayType)(unsafe.Pointer(&iarray))
 	array := new(arrayType)
 	*array = *prototype
-	// TODO: Set extra kind bits correctly.
 	array.string = &s
 
 	// gccgo uses a different hash.
@@ -1908,19 +2015,70 @@ func arrayOf(count int, elem Type) Type {
 		panic("reflect.ArrayOf: array size would exceed virtual address space")
 	}
 	array.size = typ.size * uintptr(count)
+	// if count > 0 && typ.ptrdata != 0 {
+	// 	array.ptrdata = typ.size*uintptr(count-1) + typ.ptrdata
+	// }
 	array.align = typ.align
 	array.fieldAlign = typ.fieldAlign
-	// TODO: array.alg
-	// TODO: array.gc
-	// TODO:
 	array.uncommonType = nil
 	array.ptrToThis = nil
 	array.len = uintptr(count)
 	array.slice = slice.(*rtype)
 
+	array.kind &^= kindNoPointers
+	switch {
+	case typ.kind&kindNoPointers != 0 || array.size == 0:
+		// No pointers.
+		array.kind |= kindNoPointers
+		gc := [...]uintptr{array.size, _GC_END}
+		array.gc = unsafe.Pointer(&gc[0])
+
+	case count == 1:
+		// In memory, 1-element array looks just like the element.
+		array.kind |= typ.kind & kindGCProg
+		array.gc = typ.gc
+
+	default:
+		gc := []uintptr{array.size, _GC_ARRAY_START, 0, uintptr(count), typ.size}
+		gc = appendGCProgram(gc, typ)
+		gc = append(gc, _GC_ARRAY_NEXT, _GC_END)
+		array.gc = unsafe.Pointer(&gc[0])
+	}
+
+	array.kind &^= kindDirectIface
+
+	array.hashfn = func(p unsafe.Pointer, size uintptr) uintptr {
+		ret := uintptr(0)
+		for i := 0; i < count; i++ {
+			ret *= 33
+			ret += typ.hashfn(p, typ.size)
+			p = unsafe.Pointer(uintptr(p) + typ.size)
+		}
+		return ret
+	}
+
+	array.equalfn = func(p1, p2 unsafe.Pointer, size uintptr) bool {
+		for i := 0; i < count; i++ {
+			if !typ.equalfn(p1, p2, typ.size) {
+				return false
+			}
+			p1 = unsafe.Pointer(uintptr(p1) + typ.size)
+			p2 = unsafe.Pointer(uintptr(p2) + typ.size)
+		}
+		return true
+	}
+
 	return cachePut(ckey, &array.rtype)
 }
 
+func appendVarint(x []byte, v uintptr) []byte {
+	for ; v >= 0x80; v >>= 7 {
+		x = append(x, byte(v|0x80))
+	}
+	x = append(x, byte(v))
+	return x
+}
+
 // toType converts from a *rtype to a Type that can be returned
 // to the client of package reflect. In gc, the only concern is that
 // a nil *rtype must be replaced by a nil Type, but in gccgo this
@@ -1969,56 +2127,49 @@ type bitVector struct {
 	data []byte
 }
 
-// append a bit pair to the bitmap.
-func (bv *bitVector) append2(bits uint8) {
-	// assume bv.n is a multiple of 2, since append2 is the only operation.
+// append a bit to the bitmap.
+func (bv *bitVector) append(bit uint8) {
 	if bv.n%8 == 0 {
 		bv.data = append(bv.data, 0)
 	}
-	bv.data[bv.n/8] |= bits << (bv.n % 8)
-	bv.n += 2
+	bv.data[bv.n/8] |= bit << (bv.n % 8)
+	bv.n++
 }
 
-func addTypeBits(bv *bitVector, offset *uintptr, t *rtype) {
-	*offset = align(*offset, uintptr(t.align))
+func addTypeBits(bv *bitVector, offset uintptr, t *rtype) {
 	if t.kind&kindNoPointers != 0 {
-		*offset += t.size
 		return
 	}
 
 	switch Kind(t.kind & kindMask) {
 	case Chan, Func, Map, Ptr, Slice, String, UnsafePointer:
 		// 1 pointer at start of representation
-		for bv.n < 2*uint32(*offset/uintptr(ptrSize)) {
-			bv.append2(bitsScalar)
+		for bv.n < uint32(offset/uintptr(ptrSize)) {
+			bv.append(0)
 		}
-		bv.append2(bitsPointer)
+		bv.append(1)
 
 	case Interface:
 		// 2 pointers
-		for bv.n < 2*uint32(*offset/uintptr(ptrSize)) {
-			bv.append2(bitsScalar)
+		for bv.n < uint32(offset/uintptr(ptrSize)) {
+			bv.append(0)
 		}
-		bv.append2(bitsPointer)
-		bv.append2(bitsPointer)
+		bv.append(1)
+		bv.append(1)
 
 	case Array:
 		// repeat inner type
 		tt := (*arrayType)(unsafe.Pointer(t))
 		for i := 0; i < int(tt.len); i++ {
-			addTypeBits(bv, offset, tt.elem)
+			addTypeBits(bv, offset+uintptr(i)*tt.elem.size, tt.elem)
 		}
 
 	case Struct:
 		// apply fields
 		tt := (*structType)(unsafe.Pointer(t))
-		start := *offset
 		for i := range tt.fields {
 			f := &tt.fields[i]
-			off := start + f.offset
-			addTypeBits(bv, &off, f.typ)
+			addTypeBits(bv, offset+f.offset, f.typ)
 		}
 	}
-
-	*offset += t.size
 }
diff --git a/libgo/go/reflect/value.go b/libgo/go/reflect/value.go
index 7cc4f7f8bfd..a924d8639a2 100644
--- a/libgo/go/reflect/value.go
+++ b/libgo/go/reflect/value.go
@@ -10,7 +10,7 @@ import (
 	"unsafe"
 )
 
-const ptrSize = unsafe.Sizeof((*byte)(nil))
+const ptrSize = 4 << (^uintptr(0) >> 63) // unsafe.Sizeof(uintptr(0)) but an ideal const
 const cannotSet = "cannot set value obtained from unexported struct field"
 
 // Value is the reflection interface to a Go value.
@@ -30,6 +30,10 @@ const cannotSet = "cannot set value obtained from unexported struct field"
 // A Value can be used concurrently by multiple goroutines provided that
 // the underlying Go value can be used concurrently for the equivalent
 // direct operations.
+//
+// Using == on two Values does not compare the underlying values
+// they represent, but rather the contents of the Value structs.
+// To compare two Values, compare the results of the Interface method.
 type Value struct {
 	// typ holds the type of the value represented by a Value.
 	typ *rtype
@@ -104,7 +108,7 @@ func packEface(v Value) interface{} {
 			// TODO: pass safe boolean from valueInterface so
 			// we don't need to copy if safe==true?
 			c := unsafe_New(t)
-			memmove(c, ptr, t.size)
+			typedmemmove(t, c, ptr)
 			ptr = c
 		}
 		e.word = ptr
@@ -173,7 +177,7 @@ type emptyInterface struct {
 
 // nonEmptyInterface is the header for a interface value with methods.
 type nonEmptyInterface struct {
-	// see ../runtime/iface.c:/Itab
+	// see ../runtime/iface.go:/Itab
 	itab *struct {
 		typ *rtype                 // dynamic concrete type
 		fun [100000]unsafe.Pointer // method table
@@ -261,7 +265,7 @@ func (v Value) runes() []rune {
 	return *(*[]rune)(v.ptr)
 }
 
-// CanAddr returns true if the value's address can be obtained with Addr.
+// CanAddr reports whether the value's address can be obtained with Addr.
 // Such values are called addressable.  A value is addressable if it is
 // an element of a slice, an element of an addressable array,
 // a field of an addressable struct, or the result of dereferencing a pointer.
@@ -270,11 +274,11 @@ func (v Value) CanAddr() bool {
 	return v.flag&flagAddr != 0
 }
 
-// CanSet returns true if the value of v can be changed.
+// CanSet reports whether the value of v can be changed.
 // A Value can be changed only if it is addressable and was not
 // obtained by the use of unexported struct fields.
 // If CanSet returns false, calling Set or any type-specific
-// setter (e.g., SetBool, SetInt64) will panic.
+// setter (e.g., SetBool, SetInt) will panic.
 func (v Value) CanSet() bool {
 	return v.flag&(flagAddr|flagRO) == flagAddr
 }
@@ -295,8 +299,8 @@ func (v Value) Call(in []Value) []Value {
 
 // CallSlice calls the variadic function v with the input arguments in,
 // assigning the slice in[len(in)-1] to v's final variadic argument.
-// For example, if len(in) == 3, v.Call(in) represents the Go call v(in[0], in[1], in[2]...).
-// Call panics if v's Kind is not Func or if v is not variadic.
+// For example, if len(in) == 3, v.CallSlice(in) represents the Go call v(in[0], in[1], in[2]...).
+// CallSlice panics if v's Kind is not Func or if v is not variadic.
 // It returns the output results as Values.
 // As in Go, each input argument must be assignable to the
 // type of the function's corresponding input parameter.
@@ -622,7 +626,7 @@ func (v Value) Field(i int) Value {
 	// Either flagIndir is set and v.ptr points at struct,
 	// or flagIndir is not set and v.ptr is the actual struct data.
 	// In the former case, we want v.ptr + offset.
-	// In the latter case, we must be have field.offset = 0,
+	// In the latter case, we must have field.offset = 0,
 	// so v.ptr + field.offset is still okay.
 	ptr := unsafe.Pointer(uintptr(v.ptr) + field.offset)
 	return Value{typ, ptr, fl}
@@ -716,7 +720,7 @@ func (v Value) Index(i int) Value {
 		}
 		tt := (*sliceType)(unsafe.Pointer(v.typ))
 		typ := tt.elem
-		val := unsafe.Pointer(uintptr(s.Data) + uintptr(i)*typ.size)
+		val := arrayAt(s.Data, i, typ.size)
 		fl := flagAddr | flagIndir | v.flag&flagRO | flag(typ.Kind())
 		return Value{typ, val, fl}
 
@@ -725,7 +729,7 @@ func (v Value) Index(i int) Value {
 		if uint(i) >= uint(s.Len) {
 			panic("reflect: string index out of range")
 		}
-		p := unsafe.Pointer(uintptr(s.Data) + uintptr(i))
+		p := arrayAt(s.Data, i, 1)
 		fl := v.flag&flagRO | flag(Uint8) | flagIndir
 		return Value{uint8Type, p, fl}
 	}
@@ -752,7 +756,7 @@ func (v Value) Int() int64 {
 	panic(&ValueError{"reflect.Value.Int", v.kind()})
 }
 
-// CanInterface returns true if Interface can be used without panicking.
+// CanInterface reports whether Interface can be used without panicking.
 func (v Value) CanInterface() bool {
 	if v.flag == 0 {
 		panic(&ValueError{"reflect.Value.CanInterface", Invalid})
@@ -849,7 +853,7 @@ func (v Value) IsNil() bool {
 	panic(&ValueError{"reflect.Value.IsNil", v.kind()})
 }
 
-// IsValid returns true if v represents a value.
+// IsValid reports whether v represents a value.
 // It returns false if v is the zero Value.
 // If IsValid returns false, all other methods except String panic.
 // Most functions and methods never return an invalid value.
@@ -920,7 +924,7 @@ func (v Value) MapIndex(key Value) Value {
 		// Copy result so future changes to the map
 		// won't change the underlying value.
 		c := unsafe_New(typ)
-		memmove(c, e, typ.size)
+		typedmemmove(typ, c, e)
 		return Value{typ, c, fl | flagIndir}
 	} else {
 		return Value{typ, *(*unsafe.Pointer)(e), fl}
@@ -958,7 +962,7 @@ func (v Value) MapKeys() []Value {
 			// Copy result so future changes to the map
 			// won't change the underlying value.
 			c := unsafe_New(keyType)
-			memmove(c, key, keyType.size)
+			typedmemmove(keyType, c, key)
 			a[i] = Value{keyType, c, fl | flagIndir}
 		} else {
 			a[i] = Value{keyType, *(*unsafe.Pointer)(key), fl}
@@ -1026,7 +1030,7 @@ func (v Value) NumField() int {
 	return len(tt.fields)
 }
 
-// OverflowComplex returns true if the complex128 x cannot be represented by v's type.
+// OverflowComplex reports whether the complex128 x cannot be represented by v's type.
 // It panics if v's Kind is not Complex64 or Complex128.
 func (v Value) OverflowComplex(x complex128) bool {
 	k := v.kind()
@@ -1039,7 +1043,7 @@ func (v Value) OverflowComplex(x complex128) bool {
 	panic(&ValueError{"reflect.Value.OverflowComplex", v.kind()})
 }
 
-// OverflowFloat returns true if the float64 x cannot be represented by v's type.
+// OverflowFloat reports whether the float64 x cannot be represented by v's type.
 // It panics if v's Kind is not Float32 or Float64.
 func (v Value) OverflowFloat(x float64) bool {
 	k := v.kind()
@@ -1059,7 +1063,7 @@ func overflowFloat32(x float64) bool {
 	return math.MaxFloat32 < x && x <= math.MaxFloat64
 }
 
-// OverflowInt returns true if the int64 x cannot be represented by v's type.
+// OverflowInt reports whether the int64 x cannot be represented by v's type.
 // It panics if v's Kind is not Int, Int8, int16, Int32, or Int64.
 func (v Value) OverflowInt(x int64) bool {
 	k := v.kind()
@@ -1072,7 +1076,7 @@ func (v Value) OverflowInt(x int64) bool {
 	panic(&ValueError{"reflect.Value.OverflowInt", v.kind()})
 }
 
-// OverflowUint returns true if the uint64 x cannot be represented by v's type.
+// OverflowUint reports whether the uint64 x cannot be represented by v's type.
 // It panics if v's Kind is not Uint, Uintptr, Uint8, Uint16, Uint32, or Uint64.
 func (v Value) OverflowUint(x uint64) bool {
 	k := v.kind()
@@ -1194,7 +1198,7 @@ func (v Value) Set(x Value) {
 	}
 	x = x.assignTo("reflect.Set", v.typ, target)
 	if x.flag&flagIndir != 0 {
-		memmove(v.ptr, x.ptr, v.typ.size)
+		typedmemmove(v.typ, v.ptr, x.ptr)
 	} else {
 		*(*unsafe.Pointer)(v.ptr) = x.ptr
 	}
@@ -1408,7 +1412,7 @@ func (v Value) Slice(i, j int) Value {
 		if i < 0 || j < i || j > s.Len {
 			panic("reflect.Value.Slice: string slice index out of bounds")
 		}
-		t := stringHeader{unsafe.Pointer(uintptr(s.Data) + uintptr(i)), j - i}
+		t := stringHeader{arrayAt(s.Data, i, 1), j - i}
 		return Value{v.typ, unsafe.Pointer(&t), v.flag}
 	}
 
@@ -1424,7 +1428,7 @@ func (v Value) Slice(i, j int) Value {
 	s.Len = j - i
 	s.Cap = cap - i
 	if cap-i > 0 {
-		s.Data = unsafe.Pointer(uintptr(base) + uintptr(i)*typ.elem.Size())
+		s.Data = arrayAt(base, i, typ.elem.Size())
 	} else {
 		// do not advance pointer, to avoid pointing beyond end of slice
 		s.Data = base
@@ -1476,7 +1480,7 @@ func (v Value) Slice3(i, j, k int) Value {
 	s.Len = j - i
 	s.Cap = k - i
 	if k-i > 0 {
-		s.Data = unsafe.Pointer(uintptr(base) + uintptr(i)*typ.elem.Size())
+		s.Data = arrayAt(base, i, typ.elem.Size())
 	} else {
 		// do not advance pointer, to avoid pointing beyond end of slice
 		s.Data = base
@@ -1490,6 +1494,8 @@ func (v Value) Slice3(i, j, k int) Value {
 // String is a special case because of Go's String method convention.
 // Unlike the other getters, it does not panic if v's Kind is not String.
 // Instead, it returns a string of the form "<T value>" where T is v's type.
+// The fmt package treats Values specially. It does not call their String
+// method implicitly but instead prints the concrete values they hold.
 func (v Value) String() string {
 	switch k := v.kind(); k {
 	case Invalid:
@@ -1515,7 +1521,7 @@ func (v Value) TryRecv() (x Value, ok bool) {
 
 // TrySend attempts to send x on the channel v but will not block.
 // It panics if v's Kind is not Chan.
-// It returns true if the value was sent, false otherwise.
+// It reports whether the value was sent.
 // As in Go, x's value must be assignable to the channel's element type.
 func (v Value) TrySend(x Value) bool {
 	v.mustBe(Chan)
@@ -1633,6 +1639,12 @@ func typesMustMatch(what string, t1, t2 Type) {
 	}
 }
 
+// arrayAt returns the i-th element of p, a C-array whose elements are
+// eltSize wide (in bytes).
+func arrayAt(p unsafe.Pointer, i int, eltSize uintptr) unsafe.Pointer {
+	return unsafe.Pointer(uintptr(p) + uintptr(i)*eltSize)
+}
+
 // grow grows the slice s so that it can hold extra more values, allocating
 // more capacity if needed. It also returns the old and new slice lengths.
 func grow(s Value, extra int) (Value, int, int) {
@@ -1708,27 +1720,23 @@ func Copy(dst, src Value) int {
 	se := src.typ.Elem()
 	typesMustMatch("reflect.Copy", de, se)
 
-	n := dst.Len()
-	if sn := src.Len(); n > sn {
-		n = sn
-	}
-
-	// Copy via memmove.
-	var da, sa unsafe.Pointer
+	var ds, ss sliceHeader
 	if dk == Array {
-		da = dst.ptr
+		ds.Data = dst.ptr
+		ds.Len = dst.Len()
+		ds.Cap = ds.Len
 	} else {
-		da = (*sliceHeader)(dst.ptr).Data
+		ds = *(*sliceHeader)(dst.ptr)
 	}
-	if src.flag&flagIndir == 0 {
-		sa = unsafe.Pointer(&src.ptr)
-	} else if sk == Array {
-		sa = src.ptr
+	if sk == Array {
+		ss.Data = src.ptr
+		ss.Len = src.Len()
+		ss.Cap = ss.Len
 	} else {
-		sa = (*sliceHeader)(src.ptr).Data
+		ss = *(*sliceHeader)(src.ptr)
 	}
-	memmove(da, sa, uintptr(n)*de.Size())
-	return n
+
+	return typedslicecopy(de.common(), ds, ss)
 }
 
 // A runtimeSelect is a single case passed to rselect.
@@ -2269,7 +2277,7 @@ func cvtDirect(v Value, typ Type) Value {
 	if f&flagAddr != 0 {
 		// indirect, mutable word - make a copy
 		c := unsafe_New(t)
-		memmove(c, ptr, t.size)
+		typedmemmove(t, c, ptr)
 		ptr = c
 		f &^= flagAddr
 	}
@@ -2311,17 +2319,41 @@ func chansend(t *rtype, ch unsafe.Pointer, val unsafe.Pointer, nb bool) bool
 
 func makechan(typ *rtype, size uint64) (ch unsafe.Pointer)
 func makemap(t *rtype) (m unsafe.Pointer)
+
+//go:noescape
 func mapaccess(t *rtype, m unsafe.Pointer, key unsafe.Pointer) (val unsafe.Pointer)
+
 func mapassign(t *rtype, m unsafe.Pointer, key, val unsafe.Pointer)
+
+//go:noescape
 func mapdelete(t *rtype, m unsafe.Pointer, key unsafe.Pointer)
+
+// m escapes into the return value, but the caller of mapiterinit
+// doesn't let the return value escape.
+//go:noescape
 func mapiterinit(t *rtype, m unsafe.Pointer) unsafe.Pointer
+
+//go:noescape
 func mapiterkey(it unsafe.Pointer) (key unsafe.Pointer)
+
+//go:noescape
 func mapiternext(it unsafe.Pointer)
+
+//go:noescape
 func maplen(m unsafe.Pointer) int
 func call(typ *rtype, fnaddr unsafe.Pointer, isInterface bool, isMethod bool, params *unsafe.Pointer, results *unsafe.Pointer)
 
 func ifaceE2I(t *rtype, src interface{}, dst unsafe.Pointer)
 
+// typedmemmove copies a value of type t to dst from src.
+//go:noescape
+func typedmemmove(t *rtype, dst, src unsafe.Pointer)
+
+// typedslicecopy copies a slice of elemType values from src to dst,
+// returning the number of elements copied.
+//go:noescape
+func typedslicecopy(elemType *rtype, dst, src sliceHeader) int
+
 //go:noescape
 //extern memmove
 func memmove(adst, asrc unsafe.Pointer, n uintptr)