qbit/go
1
0
Fork 0
mirror of https://github.com/golang/go synced 2024-11-25 08:47:56 -07:00
Code Releases Activity

move math out of runtime.

Browse Source 
a step toward enforcing package boundaries,
necessary to eliminate global package name space.

R=r
DELTA=581  (310 added, 271 deleted, 0 changed)
OCL=35805
CL=35823
This commit is contained in:
Russ Cox 2009-10-15 23:09:22 -07:00
parent 3c5a570ab4
commit 488ca3c7a6
5 changed files with 137 additions and 98 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
src/pkg/math/Makefile
View File

@ -16,6 +16,7 @@ ALLGOFILES=\
asin.go\
atan.go\
atan2.go\
bits.go\
const.go\
exp.go\
fabs.go\
@ -25,12 +26,12 @@ ALLGOFILES=\
log.go\
pow.go\
pow10.go\
runtime.go\
sin.go\
sinh.go\
sqrt.go\
tan.go\
tanh.go\
unsafe.go\
NOGOFILES=\
$(subst _$(GOARCH).$O,.go,$(OFILES_$(GOARCH)))

105
src/pkg/math/bits.go Normal file
View File

@ -0,0 +1,105 @@
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package math
const (
uvnan = 0x7FF0000000000001;
uvinf = 0x7FF0000000000000;
uvneginf = 0xFFF0000000000000;
mask = 0x7FF;
shift = 64 - 11 - 1;
bias = 1022;
)
// Inf returns positive infinity if sign >= 0, negative infinity if sign < 0.
func Inf(sign int) float64 {
var v uint64;
if sign >= 0 {
v = uvinf;
} else {
v = uvneginf;
}
return Float64frombits(v);
}
// NaN returns an IEEE 754 ``not-a-number'' value.
func NaN() float64 {
return Float64frombits(uvnan);
}
// IsNaN returns whether f is an IEEE 754 ``not-a-number'' value.
func IsNaN(f float64) (is bool) {
x := Float64bits(f);
return uint32(x>>shift) & mask == mask && x != uvinf && x != uvneginf;
}
// IsInf returns whether f is an infinity, according to sign.
// If sign > 0, IsInf returns whether f is positive infinity.
// If sign < 0, IsInf returns whether f is negative infinity.
// If sign == 0, IsInf returns whether f is either infinity.
func IsInf(f float64, sign int) bool {
x := Float64bits(f);
return sign >= 0 && x == uvinf || sign <= 0 && x == uvneginf;
}
// Frexp breaks f into a normalized fraction
// and an integral power of two.
// It returns frac and exp satisfying f == frac × 2<sup>exp</sup>,
// with the absolute value of frac in the interval [½, 1).
func Frexp(f float64) (frac float64, exp int) {
if f == 0 {
return;
}
x := Float64bits(f);
exp = int((x>>shift)&mask) - bias;
x &^= mask<<shift;
x |= bias<<shift;
frac = Float64frombits(x);
return;
}
// Ldexp is the inverse of Frexp.
// It returns frac × 2<sup>exp</sup>.
func Ldexp(frac float64, exp int) float64 {
x := Float64bits(frac);
exp += int(x>>shift) & mask;
if exp <= 0 {
return 0; // underflow
}
if exp >= mask { // overflow
if frac < 0 {
return Inf(-1);
}
return Inf(1);
}
x &^= mask<<shift;
x |= uint64(exp)<<shift;
return Float64frombits(x);
}
// Modf returns integer and fractional floating-point numbers
// that sum to f.
// Integer and frac have the same sign as f.
func Modf(f float64) (int float64, frac float64) {
if f < 1 {
if f < 0 {
int, frac = Modf(-f);
return -int, -frac;
}
return 0, f;
}
x := Float64bits(f);
e := uint(x>>shift)&mask - bias;
// Keep the top 11+e bits, the integer part; clear the rest.
if e < 64-11 {
x &^= 1<<(64-11-e) - 1;
}
int = Float64frombits(x);
frac = f - int;
return;
}

52
src/pkg/math/runtime.go
View File

@ -1,52 +0,0 @@
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package math
// implemented in C, in ../../runtime
// perhaps one day the implementations will move here.
// Float32bits returns the IEEE 754 binary representation of f.
func Float32bits(f float32) (b uint32)
// Float32frombits returns the floating point number corresponding
// to the IEEE 754 binary representation b.
func Float32frombits(b uint32) (f float32)
// Float64bits returns the IEEE 754 binary representation of f.
func Float64bits(f float64) (b uint64)
// Float64frombits returns the floating point number corresponding
// the IEEE 754 binary representation b.
func Float64frombits(b uint64) (f float64)
// Frexp breaks f into a normalized fraction
// and an integral power of two.
// It returns frac and exp satisfying f == frac × 2<sup>exp</sup>,
// with the absolute value of frac in the interval [½, 1).
func Frexp(f float64) (frac float64, exp int)
// Inf returns positive infinity if sign >= 0, negative infinity if sign < 0.
func Inf(sign int32) (f float64)
// IsInf returns whether f is an infinity, according to sign.
// If sign > 0, IsInf returns whether f is positive infinity.
// If sign < 0, IsInf returns whether f is negative infinity.
// If sign == 0, IsInf returns whether f is either infinity.
func IsInf(f float64, sign int) (is bool)
// IsNaN returns whether f is an IEEE 754 ``not-a-number'' value.
func IsNaN(f float64) (is bool)
// Ldexp is the inverse of Frexp.
// It returns frac × 2<sup>exp</sup>.
func Ldexp(frac float64, exp int) (f float64)
// Modf returns integer and fractional floating-point numbers
// that sum to f.
// Integer and frac have the same sign as f.
func Modf(f float64) (integer float64, frac float64)
// NaN returns an IEEE 754 ``not-a-number'' value.
func NaN() (f float64)

30
src/pkg/math/unsafe.go Normal file
View File

@ -0,0 +1,30 @@
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package math
import "unsafe"
// Float32bits returns the IEEE 754 binary representation of f.
func Float32bits(f float32) uint32 {
return *(*uint32)(unsafe.Pointer(&f));
}
// Float32frombits returns the floating point number corresponding
// to the IEEE 754 binary representation b.
func Float32frombits(b uint32) float32 {
return *(*float32)(unsafe.Pointer(&b));
}
// Float64bits returns the IEEE 754 binary representation of f.
func Float64bits(f float64) uint64 {
return *(*uint64)(unsafe.Pointer(&f));
}
// Float64frombits returns the floating point number corresponding
// the IEEE 754 binary representation b.
func Float64frombits(b uint64) float64 {
return *(*float64)(unsafe.Pointer(&b));
}

45
src/pkg/runtime/float.cgo → src/pkg/runtime/float.c
View File

@ -2,7 +2,6 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package math
#include "runtime.h"
static uint64 uvnan = 0x7FF0000000000001ULL;
@ -172,47 +171,3 @@ modf(float64 d, float64 *ip)
return d - dd;
}
func Frexp(f float64) (frac float64, exp int32) {
frac = frexp(f, &exp);
}
func Ldexp(frac float64, exp int32) (f float64) {
f = ldexp(frac, exp);
}
func Modf(f float64) (integer float64, frac float64) {
frac = modf(f, &integer);
}
func IsInf(f float64, sign int32) (is bool) {
is = isInf(f, sign);
}
func IsNaN(f float64) (is bool) {
is = isNaN(f);
}
func Inf(sign int32) (f float64) {
f = Inf(sign);
}
func NaN() (f float64) {
f = NaN();
}
func Float32bits(f float32) (b uint32) {
b = float32tobits(f);
}
func Float64bits(f float64) (b uint64) {
b = float64tobits(f);
}
func Float32frombits(b uint32) (f float32) {
f = float32frombits(b);
}
func Float64frombits(b uint64) (f float64) {
f = float64frombits(b);
}