math: add Cbrt and Sincos; x87 versions of Sincos, Frexp, Ldexp

Added special condition and benchmarks for Cbrt, Sincos. Took Frexp and Ldexp out of bits.go.

R=rsc
CC=golang-dev
https://golang.org/cl/206084

1 files changed, 0 insertions, 48 deletions

diff --git a/src/pkg/math/bits.go b/src/pkg/math/bits.go
index ccbcf062f8..d36cd18d76 100644
--- a/src/pkg/math/bits.go
+++ b/src/pkg/math/bits.go
@@ -47,51 +47,3 @@ func IsInf(f float64, sign int) bool {
 	//	return sign >= 0 && x == uvinf || sign <= 0 && x == uvneginf;
 	return sign >= 0 && f > MaxFloat64 || sign <= 0 && f < -MaxFloat64
 }
-
-// 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) {
-	// TODO(rsc): Remove manual inlining of IsNaN, IsInf
-	// when compiler does it for us
-	// special cases
-	switch {
-	case f == 0:
-		return
-	case f < -MaxFloat64 || f > MaxFloat64 || f != f: // IsInf(f, 0) || IsNaN(f):
-		frac = f
-		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 {
-	// TODO(rsc): Remove manual inlining of IsNaN, IsInf
-	// when compiler does it for us
-	// special cases
-	if frac != frac { // IsNaN(frac)
-		return NaN()
-	}
-	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)
-}