Imported Upstream version 1.4upstream/1.4

1 files changed, 0 insertions, 137 deletions

diff --git a/src/pkg/math/pow.go b/src/pkg/math/pow.go
deleted file mode 100644
index 77af25648..000000000
--- a/src/pkg/math/pow.go
+++ /dev/null
@@ -1,137 +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
-
-func isOddInt(x float64) bool {
-	xi, xf := Modf(x)
-	return xf == 0 && int64(xi)&1 == 1
-}
-
-// Special cases taken from FreeBSD's /usr/src/lib/msun/src/e_pow.c
-// updated by IEEE Std. 754-2008 "Section 9.2.1 Special values".
-
-// Pow returns x**y, the base-x exponential of y.
-//
-// Special cases are (in order):
-//	Pow(x, ±0) = 1 for any x
-//	Pow(1, y) = 1 for any y
-//	Pow(x, 1) = x for any x
-//	Pow(NaN, y) = NaN
-//	Pow(x, NaN) = NaN
-//	Pow(±0, y) = ±Inf for y an odd integer < 0
-//	Pow(±0, -Inf) = +Inf
-//	Pow(±0, +Inf) = +0
-//	Pow(±0, y) = +Inf for finite y < 0 and not an odd integer
-//	Pow(±0, y) = ±0 for y an odd integer > 0
-//	Pow(±0, y) = +0 for finite y > 0 and not an odd integer
-//	Pow(-1, ±Inf) = 1
-//	Pow(x, +Inf) = +Inf for |x| > 1
-//	Pow(x, -Inf) = +0 for |x| > 1
-//	Pow(x, +Inf) = +0 for |x| < 1
-//	Pow(x, -Inf) = +Inf for |x| < 1
-//	Pow(+Inf, y) = +Inf for y > 0
-//	Pow(+Inf, y) = +0 for y < 0
-//	Pow(-Inf, y) = Pow(-0, -y)
-//	Pow(x, y) = NaN for finite x < 0 and finite non-integer y
-func Pow(x, y float64) float64 {
-	switch {
-	case y == 0 || x == 1:
-		return 1
-	case y == 1:
-		return x
-	case y == 0.5:
-		return Sqrt(x)
-	case y == -0.5:
-		return 1 / Sqrt(x)
-	case IsNaN(x) || IsNaN(y):
-		return NaN()
-	case x == 0:
-		switch {
-		case y < 0:
-			if isOddInt(y) {
-				return Copysign(Inf(1), x)
-			}
-			return Inf(1)
-		case y > 0:
-			if isOddInt(y) {
-				return x
-			}
-			return 0
-		}
-	case IsInf(y, 0):
-		switch {
-		case x == -1:
-			return 1
-		case (Abs(x) < 1) == IsInf(y, 1):
-			return 0
-		default:
-			return Inf(1)
-		}
-	case IsInf(x, 0):
-		if IsInf(x, -1) {
-			return Pow(1/x, -y) // Pow(-0, -y)
-		}
-		switch {
-		case y < 0:
-			return 0
-		case y > 0:
-			return Inf(1)
-		}
-	}
-
-	absy := y
-	flip := false
-	if absy < 0 {
-		absy = -absy
-		flip = true
-	}
-	yi, yf := Modf(absy)
-	if yf != 0 && x < 0 {
-		return NaN()
-	}
-	if yi >= 1<<63 {
-		return Exp(y * Log(x))
-	}
-
-	// ans = a1 * 2**ae (= 1 for now).
-	a1 := 1.0
-	ae := 0
-
-	// ans *= x**yf
-	if yf != 0 {
-		if yf > 0.5 {
-			yf--
-			yi++
-		}
-		a1 = Exp(yf * Log(x))
-	}
-
-	// ans *= x**yi
-	// by multiplying in successive squarings
-	// of x according to bits of yi.
-	// accumulate powers of two into exp.
-	x1, xe := Frexp(x)
-	for i := int64(yi); i != 0; i >>= 1 {
-		if i&1 == 1 {
-			a1 *= x1
-			ae += xe
-		}
-		x1 *= x1
-		xe <<= 1
-		if x1 < .5 {
-			x1 += x1
-			xe--
-		}
-	}
-
-	// ans = a1*2**ae
-	// if flip { ans = 1 / ans }
-	// but in the opposite order
-	if flip {
-		a1 = 1 / a1
-		ae = -ae
-	}
-	return Ldexp(a1, ae)
-}