1a2f01efa6
Update the Go library to the 1.10beta1 release.
Requires a few changes to the compiler for modifications to the map
runtime code, and to handle some nowritebarrier cases in the runtime.
Reviewed-on: https://go-review.googlesource.com/86455
gotools/:
* Makefile.am (go_cmd_vet_files): New variable.
(go_cmd_buildid_files, go_cmd_test2json_files): New variables.
(s-zdefaultcc): Change from constants to functions.
(noinst_PROGRAMS): Add vet, buildid, and test2json.
(cgo$(EXEEXT)): Link against $(LIBGOTOOL).
(vet$(EXEEXT)): New target.
(buildid$(EXEEXT)): New target.
(test2json$(EXEEXT)): New target.
(install-exec-local): Install all $(noinst_PROGRAMS).
(uninstall-local): Uninstasll all $(noinst_PROGRAMS).
(check-go-tool): Depend on $(noinst_PROGRAMS). Copy down
objabi.go.
(check-runtime): Depend on $(noinst_PROGRAMS).
(check-cgo-test, check-carchive-test): Likewise.
(check-vet): New target.
(check): Depend on check-vet. Look at cmd_vet-testlog.
(.PHONY): Add check-vet.
* Makefile.in: Rebuild.
From-SVN: r256365
63 lines
1.9 KiB
Go
63 lines
1.9 KiB
Go
// 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 = 0x7FF8000000000001
|
||
uvinf = 0x7FF0000000000000
|
||
uvneginf = 0xFFF0000000000000
|
||
uvone = 0x3FF0000000000000
|
||
mask = 0x7FF
|
||
shift = 64 - 11 - 1
|
||
bias = 1023
|
||
signMask = 1 << 63
|
||
fracMask = 1<<shift - 1
|
||
)
|
||
|
||
// 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 reports whether f is an IEEE 754 ``not-a-number'' value.
|
||
func IsNaN(f float64) (is bool) {
|
||
// IEEE 754 says that only NaNs satisfy f != f.
|
||
// To avoid the floating-point hardware, could use:
|
||
// x := Float64bits(f);
|
||
// return uint32(x>>shift)&mask == mask && x != uvinf && x != uvneginf
|
||
return f != f
|
||
}
|
||
|
||
// IsInf reports whether f is an infinity, according to sign.
|
||
// If sign > 0, IsInf reports whether f is positive infinity.
|
||
// If sign < 0, IsInf reports whether f is negative infinity.
|
||
// If sign == 0, IsInf reports whether f is either infinity.
|
||
func IsInf(f float64, sign int) bool {
|
||
// Test for infinity by comparing against maximum float.
|
||
// To avoid the floating-point hardware, could use:
|
||
// x := Float64bits(f);
|
||
// return sign >= 0 && x == uvinf || sign <= 0 && x == uvneginf;
|
||
return sign >= 0 && f > MaxFloat64 || sign <= 0 && f < -MaxFloat64
|
||
}
|
||
|
||
// normalize returns a normal number y and exponent exp
|
||
// satisfying x == y × 2**exp. It assumes x is finite and non-zero.
|
||
func normalize(x float64) (y float64, exp int) {
|
||
const SmallestNormal = 2.2250738585072014e-308 // 2**-1022
|
||
if Abs(x) < SmallestNormal {
|
||
return x * (1 << 52), -52
|
||
}
|
||
return x, 0
|
||
}
|