gcc/libgo/go/math/dim.go
Ian Lance Taylor 1a2f01efa6 libgo: update to Go1.10beta1
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
2018-01-09 01:23:08 +00:00

86 lines
1.6 KiB
Go

// Copyright 2010 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
// Dim returns the maximum of x-y or 0.
//
// Special cases are:
// Dim(+Inf, +Inf) = NaN
// Dim(-Inf, -Inf) = NaN
// Dim(x, NaN) = Dim(NaN, x) = NaN
func Dim(x, y float64) float64 {
// The special cases result in NaN after the subtraction:
// +Inf - +Inf = NaN
// -Inf - -Inf = NaN
// NaN - y = NaN
// x - NaN = NaN
v := x - y
if v <= 0 {
// v is negative or 0
return 0
}
// v is positive or NaN
return v
}
// Max returns the larger of x or y.
//
// Special cases are:
// Max(x, +Inf) = Max(+Inf, x) = +Inf
// Max(x, NaN) = Max(NaN, x) = NaN
// Max(+0, ±0) = Max(±0, +0) = +0
// Max(-0, -0) = -0
func Max(x, y float64) float64 {
return max(x, y)
}
func max(x, y float64) float64 {
// special cases
switch {
case IsInf(x, 1) || IsInf(y, 1):
return Inf(1)
case IsNaN(x) || IsNaN(y):
return NaN()
case x == 0 && x == y:
if Signbit(x) {
return y
}
return x
}
if x > y {
return x
}
return y
}
// Min returns the smaller of x or y.
//
// Special cases are:
// Min(x, -Inf) = Min(-Inf, x) = -Inf
// Min(x, NaN) = Min(NaN, x) = NaN
// Min(-0, ±0) = Min(±0, -0) = -0
func Min(x, y float64) float64 {
return min(x, y)
}
func min(x, y float64) float64 {
// special cases
switch {
case IsInf(x, -1) || IsInf(y, -1):
return Inf(-1)
case IsNaN(x) || IsNaN(y):
return NaN()
case x == 0 && x == y:
if Signbit(x) {
return x
}
return y
}
if x < y {
return x
}
return y
}