encoders for booleans and numbers.

R=rsc
DELTA=610  (597 added, 5 deleted, 8 changed)
OCL=30934
CL=30939

src/pkg/gob/codec_test.go

@@ -9,6 +9,7 @@ import (
 	"gob";
 	"os";
 	"testing";
+	"unsafe";
 )
 
 // Guarantee encoding format by comparing some encodings to hand-written values
@@ -95,3 +96,354 @@ func TestIntCodec(t *testing.T) {
 	}
 	verifyInt(-1<<63, t);	// a tricky case
 }
+
+
+// The result of encoding three true booleans with field numbers 0, 1, 2
+var boolResult = []byte{0x80, 0x81, 0x81, 0x81, 0x82, 0x81}
+// The result of encoding three numbers = 17 with field numbers 0, 1, 2
+var signedResult = []byte{0x80, 0xa2, 0x81, 0xa2, 0x82, 0xa2}
+var unsignedResult = []byte{0x80, 0x91, 0x81, 0x91, 0x82, 0x91}
+var floatResult = []byte{0x80, 0x40, 0xe2, 0x81, 0x40, 0xe2, 0x82, 0x40, 0xe2}
+
+// Test instruction execution for encoding.
+// Do not run the machine yet; instead do individual instructions crafted by hand.
+func TestScalarEncInstructions(t *testing.T) {
+	var b = new(bytes.Buffer);
+	var state encState;
+
+	// bool
+	{
+		b.Reset();
+		v := true;
+		pv := &v;
+		ppv := &pv;
+		data := (struct { a bool; b *bool; c **bool }){ v, pv, ppv };
+		instr := &encInstr{ encBool, 0, 0, 0 };
+		state.w = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		instr.op(instr, &state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		instr.op(instr, &state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		instr.op(instr, &state);
+		if !bytes.Equal(boolResult, b.Data()) {
+			t.Errorf("bool enc instructions: expected % x got % x", boolResult, b.Data())
+		}
+	}
+
+	// int
+	{
+		b.Reset();
+		v := 17;
+		pv := &v;
+		ppv := &pv;
+		data := (struct { a int; b *int; c **int }){ v, pv, ppv };
+		instr := &encInstr{ encInt, 0, 0, 0 };
+		state.w = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		instr.op(instr, &state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		instr.op(instr, &state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		instr.op(instr, &state);
+		if !bytes.Equal(signedResult, b.Data()) {
+			t.Errorf("int enc instructions: expected % x got % x", signedResult, b.Data())
+		}
+	}
+
+	// uint
+	{
+		b.Reset();
+		v := uint(17);
+		pv := &v;
+		ppv := &pv;
+		data := (struct { a uint; b *uint; c **uint }){ v, pv, ppv };
+		instr := &encInstr{ encUint, 0, 0, 0 };
+		state.w = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		instr.op(instr, &state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		instr.op(instr, &state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		instr.op(instr, &state);
+		if !bytes.Equal(unsignedResult, b.Data()) {
+			t.Errorf("uint enc instructions: expected % x got % x", unsignedResult, b.Data())
+		}
+	}
+
+	// int8
+	{
+		b.Reset();
+		v := int8(17);
+		pv := &v;
+		ppv := &pv;
+		data := (struct { a int8; b *int8; c **int8 }){ v, pv, ppv };
+		instr := &encInstr{ encInt, 0, 0, 0 };
+		state.w = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		instr.op(instr, &state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		instr.op(instr, &state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		instr.op(instr, &state);
+		if !bytes.Equal(signedResult, b.Data()) {
+			t.Errorf("int8 enc instructions: expected % x got % x", signedResult, b.Data())
+		}
+	}
+
+	// uint8
+	{
+		b.Reset();
+		v := uint8(17);
+		pv := &v;
+		ppv := &pv;
+		data := (struct { a uint8; b *uint8; c **uint8 }){ v, pv, ppv };
+		instr := &encInstr{ encUint, 0, 0, 0 };
+		state.w = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		instr.op(instr, &state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		instr.op(instr, &state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		instr.op(instr, &state);
+		if !bytes.Equal(unsignedResult, b.Data()) {
+			t.Errorf("uint8 enc instructions: expected % x got % x", unsignedResult, b.Data())
+		}
+	}
+
+	// int16
+	{
+		b.Reset();
+		v := int16(17);
+		pv := &v;
+		ppv := &pv;
+		data := (struct { a int16; b *int16; c **int16 }){ v, pv, ppv };
+		instr := &encInstr{ encInt16, 0, 0, 0 };
+		state.w = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		instr.op(instr, &state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		instr.op(instr, &state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		instr.op(instr, &state);
+		if !bytes.Equal(signedResult, b.Data()) {
+			t.Errorf("int16 enc instructions: expected % x got % x", signedResult, b.Data())
+		}
+	}
+
+	// uint16
+	{
+		b.Reset();
+		v := uint16(17);
+		pv := &v;
+		ppv := &pv;
+		data := (struct { a uint16; b *uint16; c **uint16 }){ v, pv, ppv };
+		instr := &encInstr{ encUint16, 0, 0, 0 };
+		state.w = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		instr.op(instr, &state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		instr.op(instr, &state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		instr.op(instr, &state);
+		if !bytes.Equal(unsignedResult, b.Data()) {
+			t.Errorf("uint16 enc instructions: expected % x got % x", unsignedResult, b.Data())
+		}
+	}
+
+	// int32
+	{
+		b.Reset();
+		v := int32(17);
+		pv := &v;
+		ppv := &pv;
+		data := (struct { a int32; b *int32; c **int32 }){ v, pv, ppv };
+		instr := &encInstr{ encInt32, 0, 0, 0 };
+		state.w = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		instr.op(instr, &state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		instr.op(instr, &state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		instr.op(instr, &state);
+		if !bytes.Equal(signedResult, b.Data()) {
+			t.Errorf("int32 enc instructions: expected % x got % x", signedResult, b.Data())
+		}
+	}
+
+	// uint32
+	{
+		b.Reset();
+		v := uint32(17);
+		pv := &v;
+		ppv := &pv;
+		data := (struct { a uint32; b *uint32; c **uint32 }){ v, pv, ppv };
+		instr := &encInstr{ encUint32, 0, 0, 0 };
+		state.w = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		instr.op(instr, &state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		instr.op(instr, &state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		instr.op(instr, &state);
+		if !bytes.Equal(unsignedResult, b.Data()) {
+			t.Errorf("uint32 enc instructions: expected % x got % x", unsignedResult, b.Data())
+		}
+	}
+
+	// int64
+	{
+		b.Reset();
+		v := int64(17);
+		pv := &v;
+		ppv := &pv;
+		data := (struct { a int64; b *int64; c **int64 }){ v, pv, ppv };
+		instr := &encInstr{ encInt64, 0, 0, 0 };
+		state.w = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		instr.op(instr, &state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		instr.op(instr, &state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		instr.op(instr, &state);
+		if !bytes.Equal(signedResult, b.Data()) {
+			t.Errorf("int64 enc instructions: expected % x got % x", signedResult, b.Data())
+		}
+	}
+
+	// uint64
+	{
+		b.Reset();
+		v := uint64(17);
+		pv := &v;
+		ppv := &pv;
+		data := (struct { a uint64; b *uint64; c **uint64 }){ v, pv, ppv };
+		instr := &encInstr{ encUint, 0, 0, 0 };
+		state.w = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		instr.op(instr, &state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		instr.op(instr, &state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		instr.op(instr, &state);
+		if !bytes.Equal(unsignedResult, b.Data()) {
+			t.Errorf("uint64 enc instructions: expected % x got % x", unsignedResult, b.Data())
+		}
+	}
+
+	// float
+	{
+		b.Reset();
+		v := float(17);
+		pv := &v;
+		ppv := &pv;
+		data := (struct { a float; b *float; c **float }){ v, pv, ppv };
+		instr := &encInstr{ encFloat, 0, 0, 0 };
+		state.w = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		instr.op(instr, &state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		instr.op(instr, &state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		instr.op(instr, &state);
+		if !bytes.Equal(floatResult, b.Data()) {
+			t.Errorf("float enc instructions: expected % x got % x", floatResult, b.Data())
+		}
+	}
+
+	// float32
+	{
+		b.Reset();
+		v := float32(17);
+		pv := &v;
+		ppv := &pv;
+		data := (struct { a float32; b *float32; c **float32 }){ v, pv, ppv };
+		instr := &encInstr{ encFloat32, 0, 0, 0 };
+		state.w = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		instr.op(instr, &state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		instr.op(instr, &state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		instr.op(instr, &state);
+		if !bytes.Equal(floatResult, b.Data()) {
+			t.Errorf("float32 enc instructions: expected % x got % x", floatResult, b.Data())
+		}
+	}
+
+	// float64
+	{
+		b.Reset();
+		v := float64(17);
+		pv := &v;
+		ppv := &pv;
+		data := (struct { a float64; b *float64; c **float64 }){ v, pv, ppv };
+		instr := &encInstr{ encFloat64, 0, 0, 0 };
+		state.w = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		instr.op(instr, &state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		instr.op(instr, &state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		instr.op(instr, &state);
+		if !bytes.Equal(floatResult, b.Data()) {
+			t.Errorf("float64 enc instructions: expected % x got % x", floatResult, b.Data())
+		}
+	}
+}

src/pkg/gob/encode.go

@@ -6,7 +6,9 @@ package gob
 
 import (
 	"io";
+	"math";
 	"os";
+	"unsafe";
 )
 
 // Integers encode as a variant of Google's protocol buffer varint (varvarint?).
@@ -38,3 +40,246 @@ func EncodeInt(w io.Writer, i int64) os.Error {
 	}
 	return EncodeUint(w, uint64(x))
 }
+
+// The global execution state of an instance of the encoder.
+type encState struct {
+	w	io.Writer;
+	base	uintptr;
+}
+
+// The 'instructions' of the encoding machine
+type encInstr struct {
+	op	func(i *encInstr, state *encState);
+	field		int;	// field number
+	indir	int;	// how many pointer indirections to reach the value in the struct
+	offset	uintptr;	// offset in the structure of the field to encode
+}
+
+func encBool(i *encInstr, state *encState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	for indir := i.indir; indir > 0; indir-- {
+		p = *(*unsafe.Pointer)(p);
+		if p == nil {
+			return
+		}
+	}
+	b := *(*bool)(p);
+	if b {
+		EncodeUint(state.w, uint64(i.field));
+		EncodeUint(state.w, 1);
+	}
+}
+
+func encInt(i *encInstr, state *encState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	for indir := i.indir; indir > 0; indir-- {
+		p = *(*unsafe.Pointer)(p);
+		if p == nil {
+			return
+		}
+	}
+	v := int64(*(*int)(p));
+	if v != 0 {
+		EncodeUint(state.w, uint64(i.field));
+		EncodeInt(state.w, v);
+	}
+}
+
+func encUint(i *encInstr, state *encState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	for indir := i.indir; indir > 0; indir-- {
+		p = *(*unsafe.Pointer)(p);
+		if p == nil {
+			return
+		}
+	}
+	v := uint64(*(*uint)(p));
+	if v != 0 {
+		EncodeUint(state.w, uint64(i.field));
+		EncodeUint(state.w, v);
+	}
+}
+
+func encInt8(i *encInstr, state *encState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	for indir := i.indir; indir > 0; indir-- {
+		p = *(*unsafe.Pointer)(p);
+		if p == nil {
+			return
+		}
+	}
+	v := int64(*(*int8)(p));
+	if v != 0 {
+		EncodeUint(state.w, uint64(i.field));
+		EncodeInt(state.w, v);
+	}
+}
+
+func encUint8(i *encInstr, state *encState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	for indir := i.indir; indir > 0; indir-- {
+		p = *(*unsafe.Pointer)(p);
+		if p == nil {
+			return
+		}
+	}
+	v := uint64(*(*uint8)(p));
+	if v != 0 {
+		EncodeUint(state.w, uint64(i.field));
+		EncodeUint(state.w, v);
+	}
+}
+
+func encInt16(i *encInstr, state *encState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	for indir := i.indir; indir > 0; indir-- {
+		p = *(*unsafe.Pointer)(p);
+		if p == nil {
+			return
+		}
+	}
+	v := int64(*(*int16)(p));
+	if v != 0 {
+		EncodeUint(state.w, uint64(i.field));
+		EncodeInt(state.w, v);
+	}
+}
+
+func encUint16(i *encInstr, state *encState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	for indir := i.indir; indir > 0; indir-- {
+		p = *(*unsafe.Pointer)(p);
+		if p == nil {
+			return
+		}
+	}
+	v := uint64(*(*uint16)(p));
+	if v != 0 {
+		EncodeUint(state.w, uint64(i.field));
+		EncodeUint(state.w, v);
+	}
+}
+
+func encInt32(i *encInstr, state *encState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	for indir := i.indir; indir > 0; indir-- {
+		p = *(*unsafe.Pointer)(p);
+		if p == nil {
+			return
+		}
+	}
+	v := int64(*(*int32)(p));
+	if v != 0 {
+		EncodeUint(state.w, uint64(i.field));
+		EncodeInt(state.w, v);
+	}
+}
+
+func encUint32(i *encInstr, state *encState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	for indir := i.indir; indir > 0; indir-- {
+		p = *(*unsafe.Pointer)(p);
+		if p == nil {
+			return
+		}
+	}
+	v := uint64(*(*uint32)(p));
+	if v != 0 {
+		EncodeUint(state.w, uint64(i.field));
+		EncodeUint(state.w, v);
+	}
+}
+
+func encInt64(i *encInstr, state *encState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	for indir := i.indir; indir > 0; indir-- {
+		p = *(*unsafe.Pointer)(p);
+		if p == nil {
+			return
+		}
+	}
+	v := *(*int64)(p);
+	if v != 0 {
+		EncodeUint(state.w, uint64(i.field));
+		EncodeInt(state.w, v);
+	}
+}
+
+func encUint64(i *encInstr, state *encState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	for indir := i.indir; indir > 0; indir-- {
+		p = *(*unsafe.Pointer)(p);
+		if p == nil {
+			return
+		}
+	}
+	v := *(*uint64)(p);
+	if v != 0 {
+		EncodeUint(state.w, uint64(i.field));
+		EncodeUint(state.w, v);
+	}
+}
+
+// Floating-point numbers are transmitted as uint64s holding the bits
+// of the underlying representation.  They are sent byte-reversed, with
+// the exponent end coming out first, so integer floating point numbers
+// (for example) transmit more compactly.  This routine does the
+// swizzling.
+func floatBits(f float64) uint64 {
+	u := math.Float64bits(f);
+	var v uint64;
+	for i := 0; i < 8; i++ {
+		v <<= 8;
+		v |= u & 0xFF;
+		u >>= 8;
+	}
+	return v;
+}
+
+func encFloat(i *encInstr, state *encState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	for indir := i.indir; indir > 0; indir-- {
+		p = *(*unsafe.Pointer)(p);
+		if p == nil {
+			return
+		}
+	}
+	f := float(*(*float)(p));
+	if f != 0 {
+		v := floatBits(float64(f));
+		EncodeUint(state.w, uint64(i.field));
+		EncodeUint(state.w, v);
+	}
+}
+
+func encFloat32(i *encInstr, state *encState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	for indir := i.indir; indir > 0; indir-- {
+		p = *(*unsafe.Pointer)(p);
+		if p == nil {
+			return
+		}
+	}
+	f := float32(*(*float32)(p));
+	if f != 0 {
+		v := floatBits(float64(f));
+		EncodeUint(state.w, uint64(i.field));
+		EncodeUint(state.w, v);
+	}
+}
+
+func encFloat64(i *encInstr, state *encState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	for indir := i.indir; indir > 0; indir-- {
+		p = *(*unsafe.Pointer)(p);
+		if p == nil {
+			return
+		}
+	}
+	f := *(*float64)(p);
+	if f != 0 {
+		v := floatBits(f);
+		EncodeUint(state.w, uint64(i.field));
+		EncodeUint(state.w, v);
+	}
+}

src/pkg/gob/type.go

@@ -54,8 +54,7 @@ func (t *commonType) Name() string {
 var tBool Type
 var tInt Type
 var tUint Type
-var tFloat32 Type
-var tFloat64 Type
+var tFloat Type
 var tString Type
 var tBytes Type
 
@@ -151,10 +150,8 @@ func newTypeObject(name string, rt reflect.Type) Type {
 		return tInt
 	case reflect.UintKind, reflect.Uint32Kind, reflect.Uint64Kind:
 		return tUint
-	case reflect.FloatKind, reflect.Float32Kind:
-		return tFloat32
-	case reflect.Float64Kind:
-		return tFloat64
+	case reflect.FloatKind, reflect.Float32Kind, reflect.Float64Kind:
+		return tFloat
 	case reflect.StringKind:
 		return tString
 	case reflect.ArrayKind:
@@ -238,8 +235,7 @@ func init() {
 	tBool= bootstrapType("bool", false);
 	tInt = bootstrapType("int", int(0));
 	tUint = bootstrapType("uint", uint(0));
-	tFloat32 = bootstrapType("float32", float32(0));
-	tFloat64 = bootstrapType("float64", float64(0));
+	tFloat = bootstrapType("float", float64(0));
 	// The string for tBytes is "bytes" not "[]byte" to signify its specialness.
 	tBytes = bootstrapType("bytes", make([]byte, 0));
 	tString= bootstrapType("string", "");

src/pkg/gob/type_test.go

@@ -18,8 +18,7 @@ var basicTypes = []typeT {
 	typeT { tBool, "bool" },
 	typeT { tInt, "int" },
 	typeT { tUint, "uint" },
-	typeT { tFloat32, "float32" },
-	typeT { tFloat64, "float64" },
+	typeT { tFloat, "float" },
 	typeT { tBytes, "bytes" },
 	typeT { tString, "string" },
 }
@@ -107,8 +106,8 @@ type Foo struct {
 	b int32;	// will become int
 	c string;
 	d []byte;
-	e *float;	// will become float32
-	f ****float64;	// will become float64
+	e *float;	// will become float
+	f ****float64;	// will become float
 	g *Bar;
 	h *Bar;	// should not interpolate the definition of Bar again
 	i *Foo;	// will not explode
@@ -118,7 +117,7 @@ func TestStructType(t *testing.T) {
 	sstruct := GetType("Foo", Foo{});
 	str := sstruct.String();
 	// If we can print it correctly, we built it correctly.
-	expected := "Foo = struct { a int; b int; c string; d bytes; e float32; f float64; g Bar = struct { x string; }; h Bar; i Foo; }";
+	expected := "Foo = struct { a int; b int; c string; d bytes; e float; f float; g Bar = struct { x string; }; h Bar; i Foo; }";
 	if str != expected {
 		t.Errorf("struct printed as %q; expected %q", str, expected);
 	}