Make printing faster by avoiding mallocs and some other advances.

Roughly 33% faster for simple cases, probably more for complex ones.

Before:

mallocs per Sprintf(""): 4
mallocs per Sprintf("xxx"): 6
mallocs per Sprintf("%x"): 10
mallocs per Sprintf("%x %x"): 12

Now:

mallocs per Sprintf(""): 2
mallocs per Sprintf("xxx"): 3
mallocs per Sprintf("%x"): 5
mallocs per Sprintf("%x %x"): 7

Speed improves because of avoiding mallocs and also by sharing a bytes.Buffer
between print.go and format.go rather than copying the data back after each
printed item.

Before:

fmt_test.BenchmarkSprintfEmpty	1000000	      1346 ns/op
fmt_test.BenchmarkSprintfString	500000	      3461 ns/op
fmt_test.BenchmarkSprintfInt	500000	      3671 ns/op

Now:

fmt_test.BenchmarkSprintfEmpty	 2000000	       995 ns/op
fmt_test.BenchmarkSprintfString	 1000000	      2745 ns/op
fmt_test.BenchmarkSprintfInt	 1000000	      2391 ns/op
fmt_test.BenchmarkSprintfIntInt	  500000	      3751 ns/op


I believe there is more to get but this is a good milestone.

R=rsc
CC=golang-dev, hong
http://codereview.appspot.com/166076

1 files changed, 184 insertions, 214 deletions

diff --git a/src/pkg/fmt/format.go b/src/pkg/fmt/format.go
index c7b7b9bf3..d09f3522f 100644
--- a/src/pkg/fmt/format.go
+++ b/src/pkg/fmt/format.go
@@ -5,6 +5,7 @@
 package fmt
 
 import (
+	"bytes";
 	"strconv";
 )
 
@@ -16,34 +17,30 @@ const (
 	udigits	= "0123456789ABCDEF";
 )
 
-const padZeros = "0000000000000000000000000000000000000000000000000000000000000000"
-const padSpaces = "                                                                "
+var padZeroBytes = make([]byte, nByte)
+var padSpaceBytes = make([]byte, nByte)
+
+var newline = []byte{'\n'}
 
 func init() {
-	if len(padZeros) != nByte || len(padSpaces) != nByte {
-		panic("fmt padding wrong length")
+	for i := 0; i < nByte; i++ {
+		padZeroBytes[i] = '0';
+		padSpaceBytes[i] = ' ';
 	}
 }
 
 /*
 	Fmt is the raw formatter used by Printf etc.  Not meant for normal use.
+	It prints into a bytes.Buffer that must be set up externally.
 	See print.go for a more palatable interface.
-
-	The model is to accumulate operands into an internal buffer and then
-	retrieve the buffer in one hit using Str(), Putnl(), etc.  The formatting
-	methods return ``self'' so the operations can be chained.
-
-		f := fmt.New();
-		print(f.Fmt_d(1234).Fmt_s("\n").Str());  // create string, print it
-		f.Fmt_d(-1234).Fmt_s("\n").Put();  // print string
-		f.Fmt_ud(1<<63).Putnl();  // print string with automatic newline
 */
 type Fmt struct {
-	buf		string;
+	intbuf		[nByte]byte;
+	buf		*bytes.Buffer;
 	wid		int;
-	wid_present	bool;
+	widPresent	bool;
 	prec		int;
-	prec_present	bool;
+	precPresent	bool;
 	// flags
 	minus	bool;
 	plus	bool;
@@ -52,11 +49,11 @@ type Fmt struct {
 	zero	bool;
 }
 
-func (f *Fmt) clearflags() {
+func (f *Fmt) ClearFlags() {
 	f.wid = 0;
-	f.wid_present = false;
+	f.widPresent = false;
 	f.prec = 0;
-	f.prec_present = false;
+	f.precPresent = false;
 	f.minus = false;
 	f.plus = false;
 	f.sharp = false;
@@ -64,94 +61,98 @@ func (f *Fmt) clearflags() {
 	f.zero = false;
 }
 
-func (f *Fmt) clearbuf()	{ f.buf = "" }
-
-func (f *Fmt) init() {
-	f.clearbuf();
-	f.clearflags();
+func (f *Fmt) Init(buf *bytes.Buffer) {
+	f.buf = buf;
+	f.ClearFlags();
 }
 
-// New returns a new initialized Fmt
-func New() *Fmt {
-	f := new(Fmt);
-	f.init();
-	return f;
-}
-
-// Str returns the buffered contents as a string and resets the Fmt.
-func (f *Fmt) Str() string {
-	s := f.buf;
-	f.clearbuf();
-	f.clearflags();
-	f.buf = "";
-	return s;
-}
-
-// Put writes the buffered contents to stdout and resets the Fmt.
-func (f *Fmt) Put() {
-	print(f.buf);
-	f.clearbuf();
-	f.clearflags();
-}
-
-// Putnl writes the buffered contents to stdout, followed by a newline, and resets the Fmt.
-func (f *Fmt) Putnl() {
-	print(f.buf, "\n");
-	f.clearbuf();
-	f.clearflags();
-}
+func (f *Fmt) Reset()	{ f.ClearFlags() }
 
 // Wp sets the width and precision for formatting the next item.
-func (f *Fmt) Wp(w, p int) *Fmt {
-	f.wid_present = true;
+func (f *Fmt) Wp(w, p int) {
+	f.widPresent = true;
 	f.wid = w;
-	f.prec_present = true;
+	f.precPresent = true;
 	f.prec = p;
-	return f;
 }
 
 // P sets the precision for formatting the next item.
-func (f *Fmt) P(p int) *Fmt {
-	f.prec_present = true;
+func (f *Fmt) P(p int) {
+	f.precPresent = true;
 	f.prec = p;
-	return f;
 }
 
 // W sets the width for formatting the next item.
-func (f *Fmt) W(x int) *Fmt {
-	f.wid_present = true;
+func (f *Fmt) W(x int) {
+	f.widPresent = true;
 	f.wid = x;
-	return f;
 }
 
-// append s to buf, padded on left (w > 0) or right (w < 0 or f.minus)
-// padding is in bytes, not characters (agrees with ANSIC C, not Plan 9 C)
-func (f *Fmt) pad(s string) {
-	if f.wid_present && f.wid != 0 {
-		left := !f.minus;
-		w := f.wid;
-		if w < 0 {
-			left = false;
-			w = -w;
-		}
-		w -= len(s);
-		padding := padSpaces;
+// Compute left and right padding widths (only one will be non-zero).
+func (f *Fmt) computePadding(width int) (padding []byte, leftWidth, rightWidth int) {
+	left := !f.minus;
+	w := f.wid;
+	if w < 0 {
+		left = false;
+		w = -w;
+	}
+	w -= width;
+	if w > 0 {
 		if left && f.zero {
-			padding = padZeros
+			return padZeroBytes, w, 0
 		}
-		if w > 0 {
-			if w > nByte {
-				w = nByte
-			}
-			padding = padding[0:w];
-			if left {
-				s = padding + s
-			} else {
-				s += padding
-			}
+		if left {
+			return padSpaceBytes, w, 0
+		} else {
+			// can't be zero padding on the right
+			return padSpaceBytes, 0, w
+		}
+	}
+	return;
+}
+
+// Generate n bytes of padding.
+func (f *Fmt) writePadding(n int, padding []byte) {
+	for n > 0 {
+		m := n;
+		if m > nByte {
+			m = nByte
 		}
+		f.buf.Write(padding[0:m]);
+		n -= m;
+	}
+}
+
+// Append b to f.buf, padded on left (w > 0) or right (w < 0 or f.minus)
+func (f *Fmt) padBytes(b []byte) {
+	var padding []byte;
+	var left, right int;
+	if f.widPresent && f.wid != 0 {
+		padding, left, right = f.computePadding(len(b))
+	}
+	if left > 0 {
+		f.writePadding(left, padding)
+	}
+	f.buf.Write(b);
+	if right > 0 {
+		f.writePadding(right, padding)
+	}
+}
+
+// append s to buf, padded on left (w > 0) or right (w < 0 or f.minus)
+func (f *Fmt) pad(s string) {
+	var padding []byte;
+	var left, right int;
+	if f.widPresent && f.wid != 0 {
+		padding, left, right = f.computePadding(len(s))
+	}
+	if left > 0 {
+		f.writePadding(left, padding)
+	}
+	f.buf.WriteString(s);
+	if right > 0 {
+		f.writePadding(right, padding)
 	}
-	f.buf += s;
 }
 
 // format val into buf, ending at buf[i].  (printing is easier right-to-left;
@@ -171,19 +172,18 @@ func putint(buf []byte, base, val uint64, digits string) int {
 }
 
 // Fmt_boolean formats a boolean.
-func (f *Fmt) Fmt_boolean(v bool) *Fmt {
+func (f *Fmt) Fmt_boolean(v bool) {
 	if v {
 		f.pad("true")
 	} else {
 		f.pad("false")
 	}
-	f.clearflags();
-	return f;
+	f.ClearFlags();
 }
 
 // integer; interprets prec but not wid.
-func (f *Fmt) integer(a int64, base uint, is_signed bool, digits string) string {
-	var buf [nByte]byte;
+func (f *Fmt) integer(a int64, base uint, is_signed bool, digits string) []byte {
+	var buf []byte = &f.intbuf;
 	negative := is_signed && a < 0;
 	if negative {
 		a = -a
@@ -192,17 +192,17 @@ func (f *Fmt) integer(a int64, base uint, is_signed bool, digits string) string
 	// two ways to ask for extra leading zero digits: %.3d or %03d.
 	// apparently the first cancels the second.
 	prec := 0;
-	if f.prec_present {
+	if f.precPresent {
 		prec = f.prec;
 		f.zero = false;
-	} else if f.zero && f.wid_present && !f.minus && f.wid > 0 {
+	} else if f.zero && f.widPresent && !f.minus && f.wid > 0 {
 		prec = f.wid;
 		if negative || f.plus || f.space {
 			prec--	// leave room for sign
 		}
 	}
 
-	i := putint(&buf, uint64(base), uint64(a), digits);
+	i := putint(buf, uint64(base), uint64(a), digits);
 	for i > 0 && prec > (nByte-1-i) {
 		buf[i] = '0';
 		i--;
@@ -233,147 +233,137 @@ func (f *Fmt) integer(a int64, base uint, is_signed bool, digits string) string
 		buf[i] = ' ';
 		i--;
 	}
-	return string(buf[i+1 : nByte]);
+	return buf[i+1 : nByte];
 }
 
 // Fmt_d64 formats an int64 in decimal.
-func (f *Fmt) Fmt_d64(v int64) *Fmt {
-	f.pad(f.integer(v, 10, true, ldigits));
-	f.clearflags();
-	return f;
+func (f *Fmt) Fmt_d64(v int64) {
+	f.padBytes(f.integer(v, 10, true, ldigits));
+	f.ClearFlags();
 }
 
 // Fmt_d32 formats an int32 in decimal.
-func (f *Fmt) Fmt_d32(v int32) *Fmt	{ return f.Fmt_d64(int64(v)) }
+func (f *Fmt) Fmt_d32(v int32)	{ f.Fmt_d64(int64(v)) }
 
 // Fmt_d formats an int in decimal.
-func (f *Fmt) Fmt_d(v int) *Fmt	{ return f.Fmt_d64(int64(v)) }
+func (f *Fmt) Fmt_d(v int)	{ f.Fmt_d64(int64(v)) }
 
 // Fmt_ud64 formats a uint64 in decimal.
 func (f *Fmt) Fmt_ud64(v uint64) *Fmt {
-	f.pad(f.integer(int64(v), 10, false, ldigits));
-	f.clearflags();
+	f.padBytes(f.integer(int64(v), 10, false, ldigits));
+	f.ClearFlags();
 	return f;
 }
 
 // Fmt_ud32 formats a uint32 in decimal.
-func (f *Fmt) Fmt_ud32(v uint32) *Fmt	{ return f.Fmt_ud64(uint64(v)) }
+func (f *Fmt) Fmt_ud32(v uint32)	{ f.Fmt_ud64(uint64(v)) }
 
 // Fmt_ud formats a uint in decimal.
-func (f *Fmt) Fmt_ud(v uint) *Fmt	{ return f.Fmt_ud64(uint64(v)) }
+func (f *Fmt) Fmt_ud(v uint)	{ f.Fmt_ud64(uint64(v)) }
 
 // Fmt_x64 formats an int64 in hexadecimal.
-func (f *Fmt) Fmt_x64(v int64) *Fmt {
-	f.pad(f.integer(v, 16, true, ldigits));
-	f.clearflags();
-	return f;
+func (f *Fmt) Fmt_x64(v int64) {
+	f.padBytes(f.integer(v, 16, true, ldigits));
+	f.ClearFlags();
 }
 
 // Fmt_x32 formats an int32 in hexadecimal.
-func (f *Fmt) Fmt_x32(v int32) *Fmt	{ return f.Fmt_x64(int64(v)) }
+func (f *Fmt) Fmt_x32(v int32)	{ f.Fmt_x64(int64(v)) }
 
 // Fmt_x formats an int in hexadecimal.
-func (f *Fmt) Fmt_x(v int) *Fmt	{ return f.Fmt_x64(int64(v)) }
+func (f *Fmt) Fmt_x(v int)	{ f.Fmt_x64(int64(v)) }
 
 // Fmt_ux64 formats a uint64 in hexadecimal.
-func (f *Fmt) Fmt_ux64(v uint64) *Fmt {
-	f.pad(f.integer(int64(v), 16, false, ldigits));
-	f.clearflags();
-	return f;
+func (f *Fmt) Fmt_ux64(v uint64) {
+	f.padBytes(f.integer(int64(v), 16, false, ldigits));
+	f.ClearFlags();
 }
 
 // Fmt_ux32 formats a uint32 in hexadecimal.
-func (f *Fmt) Fmt_ux32(v uint32) *Fmt	{ return f.Fmt_ux64(uint64(v)) }
+func (f *Fmt) Fmt_ux32(v uint32)	{ f.Fmt_ux64(uint64(v)) }
 
 // Fmt_ux formats a uint in hexadecimal.
-func (f *Fmt) Fmt_ux(v uint) *Fmt	{ return f.Fmt_ux64(uint64(v)) }
+func (f *Fmt) Fmt_ux(v uint)	{ f.Fmt_ux64(uint64(v)) }
 
 // Fmt_X64 formats an int64 in upper case hexadecimal.
-func (f *Fmt) Fmt_X64(v int64) *Fmt {
-	f.pad(f.integer(v, 16, true, udigits));
-	f.clearflags();
-	return f;
+func (f *Fmt) Fmt_X64(v int64) {
+	f.padBytes(f.integer(v, 16, true, udigits));
+	f.ClearFlags();
 }
 
 // Fmt_X32 formats an int32 in upper case hexadecimal.
-func (f *Fmt) Fmt_X32(v int32) *Fmt	{ return f.Fmt_X64(int64(v)) }
+func (f *Fmt) Fmt_X32(v int32)	{ f.Fmt_X64(int64(v)) }
 
 // Fmt_X formats an int in upper case hexadecimal.
-func (f *Fmt) Fmt_X(v int) *Fmt	{ return f.Fmt_X64(int64(v)) }
+func (f *Fmt) Fmt_X(v int)	{ f.Fmt_X64(int64(v)) }
 
 // Fmt_uX64 formats a uint64 in upper case hexadecimal.
-func (f *Fmt) Fmt_uX64(v uint64) *Fmt {
-	f.pad(f.integer(int64(v), 16, false, udigits));
-	f.clearflags();
-	return f;
+func (f *Fmt) Fmt_uX64(v uint64) {
+	f.padBytes(f.integer(int64(v), 16, false, udigits));
+	f.ClearFlags();
 }
 
 // Fmt_uX32 formats a uint32 in upper case hexadecimal.
-func (f *Fmt) Fmt_uX32(v uint32) *Fmt	{ return f.Fmt_uX64(uint64(v)) }
+func (f *Fmt) Fmt_uX32(v uint32)	{ f.Fmt_uX64(uint64(v)) }
 
 // Fmt_uX formats a uint in upper case hexadecimal.
-func (f *Fmt) Fmt_uX(v uint) *Fmt	{ return f.Fmt_uX64(uint64(v)) }
+func (f *Fmt) Fmt_uX(v uint)	{ f.Fmt_uX64(uint64(v)) }
 
 // Fmt_o64 formats an int64 in octal.
-func (f *Fmt) Fmt_o64(v int64) *Fmt {
-	f.pad(f.integer(v, 8, true, ldigits));
-	f.clearflags();
-	return f;
+func (f *Fmt) Fmt_o64(v int64) {
+	f.padBytes(f.integer(v, 8, true, ldigits));
+	f.ClearFlags();
 }
 
 // Fmt_o32 formats an int32 in octal.
-func (f *Fmt) Fmt_o32(v int32) *Fmt	{ return f.Fmt_o64(int64(v)) }
+func (f *Fmt) Fmt_o32(v int32)	{ f.Fmt_o64(int64(v)) }
 
 // Fmt_o formats an int in octal.
-func (f *Fmt) Fmt_o(v int) *Fmt	{ return f.Fmt_o64(int64(v)) }
+func (f *Fmt) Fmt_o(v int)	{ f.Fmt_o64(int64(v)) }
 
 // Fmt_uo64 formats a uint64 in octal.
-func (f *Fmt) Fmt_uo64(v uint64) *Fmt {
-	f.pad(f.integer(int64(v), 8, false, ldigits));
-	f.clearflags();
-	return f;
+func (f *Fmt) Fmt_uo64(v uint64) {
+	f.padBytes(f.integer(int64(v), 8, false, ldigits));
+	f.ClearFlags();
 }
 
 // Fmt_uo32 formats a uint32 in octal.
-func (f *Fmt) Fmt_uo32(v uint32) *Fmt	{ return f.Fmt_uo64(uint64(v)) }
+func (f *Fmt) Fmt_uo32(v uint32)	{ f.Fmt_uo64(uint64(v)) }
 
 // Fmt_uo formats a uint in octal.
-func (f *Fmt) Fmt_uo(v uint) *Fmt	{ return f.Fmt_uo64(uint64(v)) }
+func (f *Fmt) Fmt_uo(v uint)	{ f.Fmt_uo64(uint64(v)) }
 
 // Fmt_b64 formats a uint64 in binary.
-func (f *Fmt) Fmt_b64(v uint64) *Fmt {
-	f.pad(f.integer(int64(v), 2, false, ldigits));
-	f.clearflags();
-	return f;
+func (f *Fmt) Fmt_b64(v uint64) {
+	f.padBytes(f.integer(int64(v), 2, false, ldigits));
+	f.ClearFlags();
 }
 
 // Fmt_b32 formats a uint32 in binary.
-func (f *Fmt) Fmt_b32(v uint32) *Fmt	{ return f.Fmt_b64(uint64(v)) }
+func (f *Fmt) Fmt_b32(v uint32)	{ f.Fmt_b64(uint64(v)) }
 
 // Fmt_b formats a uint in binary.
-func (f *Fmt) Fmt_b(v uint) *Fmt	{ return f.Fmt_b64(uint64(v)) }
+func (f *Fmt) Fmt_b(v uint)	{ f.Fmt_b64(uint64(v)) }
 
 // Fmt_c formats a Unicode character.
-func (f *Fmt) Fmt_c(v int) *Fmt {
+func (f *Fmt) Fmt_c(v int) {
 	f.pad(string(v));
-	f.clearflags();
-	return f;
+	f.ClearFlags();
 }
 
 // Fmt_s formats a string.
-func (f *Fmt) Fmt_s(s string) *Fmt {
-	if f.prec_present {
+func (f *Fmt) Fmt_s(s string) {
+	if f.precPresent {
 		if f.prec < len(s) {
 			s = s[0:f.prec]
 		}
 	}
 	f.pad(s);
-	f.clearflags();
-	return f;
+	f.ClearFlags();
 }
 
 // Fmt_sx formats a string as a hexadecimal encoding of its bytes.
-func (f *Fmt) Fmt_sx(s string) *Fmt {
+func (f *Fmt) Fmt_sx(s string) {
 	t := "";
 	for i := 0; i < len(s); i++ {
 		if i > 0 && f.space {
@@ -384,12 +374,11 @@ func (f *Fmt) Fmt_sx(s string) *Fmt {
 		t += string(ldigits[v&0xF]);
 	}
 	f.pad(t);
-	f.clearflags();
-	return f;
+	f.ClearFlags();
 }
 
 // Fmt_sX formats a string as an uppercase hexadecimal encoding of its bytes.
-func (f *Fmt) Fmt_sX(s string) *Fmt {
+func (f *Fmt) Fmt_sX(s string) {
 	t := "";
 	for i := 0; i < len(s); i++ {
 		v := s[i];
@@ -397,12 +386,11 @@ func (f *Fmt) Fmt_sX(s string) *Fmt {
 		t += string(udigits[v&0xF]);
 	}
 	f.pad(t);
-	f.clearflags();
-	return f;
+	f.ClearFlags();
 }
 
 // Fmt_q formats a string as a double-quoted, escaped Go string constant.
-func (f *Fmt) Fmt_q(s string) *Fmt {
+func (f *Fmt) Fmt_q(s string) {
 	var quoted string;
 	if f.sharp && strconv.CanBackquote(s) {
 		quoted = "`" + s + "`"
@@ -410,27 +398,25 @@ func (f *Fmt) Fmt_q(s string) *Fmt {
 		quoted = strconv.Quote(s)
 	}
 	f.pad(quoted);
-	f.clearflags();
-	return f;
+	f.ClearFlags();
 }
 
 // floating-point
 
 func doPrec(f *Fmt, def int) int {
-	if f.prec_present {
+	if f.precPresent {
 		return f.prec
 	}
 	return def;
 }
 
-func fmtString(f *Fmt, s string) *Fmt {
+func fmtString(f *Fmt, s string) {
 	f.pad(s);
-	f.clearflags();
-	return f;
+	f.ClearFlags();
 }
 
 // Add a plus sign or space to the string if missing and required.
-func (f *Fmt) plusSpace(s string) *Fmt {
+func (f *Fmt) plusSpace(s string) {
 	if s[0] != '-' {
 		if f.plus {
 			s = "+" + s
@@ -438,94 +424,78 @@ func (f *Fmt) plusSpace(s string) *Fmt {
 			s = " " + s
 		}
 	}
-	return fmtString(f, s);
+	fmtString(f, s);
 }
 
 // Fmt_e64 formats a float64 in the form -1.23e+12.
-func (f *Fmt) Fmt_e64(v float64) *Fmt {
-	return f.plusSpace(strconv.Ftoa64(v, 'e', doPrec(f, 6)))
-}
+func (f *Fmt) Fmt_e64(v float64)	{ f.plusSpace(strconv.Ftoa64(v, 'e', doPrec(f, 6))) }
 
 // Fmt_E64 formats a float64 in the form -1.23E+12.
-func (f *Fmt) Fmt_E64(v float64) *Fmt {
-	return f.plusSpace(strconv.Ftoa64(v, 'E', doPrec(f, 6)))
-}
+func (f *Fmt) Fmt_E64(v float64)	{ f.plusSpace(strconv.Ftoa64(v, 'E', doPrec(f, 6))) }
 
 // Fmt_f64 formats a float64 in the form -1.23.
-func (f *Fmt) Fmt_f64(v float64) *Fmt {
-	return f.plusSpace(strconv.Ftoa64(v, 'f', doPrec(f, 6)))
-}
+func (f *Fmt) Fmt_f64(v float64)	{ f.plusSpace(strconv.Ftoa64(v, 'f', doPrec(f, 6))) }
 
 // Fmt_g64 formats a float64 in the 'f' or 'e' form according to size.
-func (f *Fmt) Fmt_g64(v float64) *Fmt {
-	return f.plusSpace(strconv.Ftoa64(v, 'g', doPrec(f, -1)))
-}
+func (f *Fmt) Fmt_g64(v float64)	{ f.plusSpace(strconv.Ftoa64(v, 'g', doPrec(f, -1))) }
 
 // Fmt_g64 formats a float64 in the 'f' or 'E' form according to size.
-func (f *Fmt) Fmt_G64(v float64) *Fmt {
-	return f.plusSpace(strconv.Ftoa64(v, 'G', doPrec(f, -1)))
-}
+func (f *Fmt) Fmt_G64(v float64)	{ f.plusSpace(strconv.Ftoa64(v, 'G', doPrec(f, -1))) }
 
 // Fmt_fb64 formats a float64 in the form -123p3 (exponent is power of 2).
-func (f *Fmt) Fmt_fb64(v float64) *Fmt	{ return f.plusSpace(strconv.Ftoa64(v, 'b', 0)) }
+func (f *Fmt) Fmt_fb64(v float64)	{ f.plusSpace(strconv.Ftoa64(v, 'b', 0)) }
 
 // float32
 // cannot defer to float64 versions
 // because it will get rounding wrong in corner cases.
 
 // Fmt_e32 formats a float32 in the form -1.23e+12.
-func (f *Fmt) Fmt_e32(v float32) *Fmt {
-	return f.plusSpace(strconv.Ftoa32(v, 'e', doPrec(f, 6)))
-}
+func (f *Fmt) Fmt_e32(v float32)	{ f.plusSpace(strconv.Ftoa32(v, 'e', doPrec(f, 6))) }
 
 // Fmt_E32 formats a float32 in the form -1.23E+12.
-func (f *Fmt) Fmt_E32(v float32) *Fmt {
-	return f.plusSpace(strconv.Ftoa32(v, 'E', doPrec(f, 6)))
-}
+func (f *Fmt) Fmt_E32(v float32)	{ f.plusSpace(strconv.Ftoa32(v, 'E', doPrec(f, 6))) }
 
 // Fmt_f32 formats a float32 in the form -1.23.
-func (f *Fmt) Fmt_f32(v float32) *Fmt {
-	return f.plusSpace(strconv.Ftoa32(v, 'f', doPrec(f, 6)))
-}
+func (f *Fmt) Fmt_f32(v float32)	{ f.plusSpace(strconv.Ftoa32(v, 'f', doPrec(f, 6))) }
 
 // Fmt_g32 formats a float32 in the 'f' or 'e' form according to size.
-func (f *Fmt) Fmt_g32(v float32) *Fmt {
-	return f.plusSpace(strconv.Ftoa32(v, 'g', doPrec(f, -1)))
-}
+func (f *Fmt) Fmt_g32(v float32)	{ f.plusSpace(strconv.Ftoa32(v, 'g', doPrec(f, -1))) }
 
 // Fmt_G32 formats a float32 in the 'f' or 'E' form according to size.
-func (f *Fmt) Fmt_G32(v float32) *Fmt {
-	return f.plusSpace(strconv.Ftoa32(v, 'G', doPrec(f, -1)))
-}
+func (f *Fmt) Fmt_G32(v float32)	{ f.plusSpace(strconv.Ftoa32(v, 'G', doPrec(f, -1))) }
 
 // Fmt_fb32 formats a float32 in the form -123p3 (exponent is power of 2).
-func (f *Fmt) Fmt_fb32(v float32) *Fmt	{ return fmtString(f, strconv.Ftoa32(v, 'b', 0)) }
+func (f *Fmt) Fmt_fb32(v float32)	{ fmtString(f, strconv.Ftoa32(v, 'b', 0)) }
 
 // float
-func (x *Fmt) f(a float) *Fmt {
+func (x *Fmt) f(a float) {
 	if strconv.FloatSize == 32 {
-		return x.Fmt_f32(float32(a))
+		x.Fmt_f32(float32(a))
+	} else {
+		x.Fmt_f64(float64(a))
 	}
-	return x.Fmt_f64(float64(a));
 }
 
-func (x *Fmt) e(a float) *Fmt {
+func (x *Fmt) e(a float) {
 	if strconv.FloatSize == 32 {
-		return x.Fmt_e32(float32(a))
+		x.Fmt_e32(float32(a))
+	} else {
+		x.Fmt_e64(float64(a))
 	}
-	return x.Fmt_e64(float64(a));
 }
 
-func (x *Fmt) g(a float) *Fmt {
+func (x *Fmt) g(a float) {
 	if strconv.FloatSize == 32 {
-		return x.Fmt_g32(float32(a))
+		x.Fmt_g32(float32(a))
+	} else {
+		x.Fmt_g64(float64(a))
 	}
-	return x.Fmt_g64(float64(a));
 }
 
-func (x *Fmt) fb(a float) *Fmt {
+func (x *Fmt) fb(a float) {
 	if strconv.FloatSize == 32 {
-		return x.Fmt_fb32(float32(a))
+		x.Fmt_fb32(float32(a))
+	} else {
+		x.Fmt_fb64(float64(a))
 	}
-	return x.Fmt_fb64(float64(a));
 }