redo and clean up math.

R=r
DELTA=243  (60 added, 72 deleted, 111 changed)
OCL=22909
CL=22912

1 files changed, 20 insertions, 23 deletions

diff --git a/src/lib/math/sin.go b/src/lib/math/sin.go
index 077506b30..6e3fbb28f 100644
--- a/src/lib/math/sin.go
+++ b/src/lib/math/sin.go
@@ -4,37 +4,34 @@
 
 package math
 
-/*
-	Coefficients are #3370 from Hart & Cheney (18.80D).
-*/
-const
-(
-	sp0	=  .1357884097877375669092680e8;
-	sp1	= -.4942908100902844161158627e7;
-	sp2	=  .4401030535375266501944918e6;
-	sp3	= -.1384727249982452873054457e5;
-	sp4	=  .1459688406665768722226959e3;
-	sq0	=  .8644558652922534429915149e7;
-	sq1	=  .4081792252343299749395779e6;
-	sq2	=  .9463096101538208180571257e4;
-	sq3	=  .1326534908786136358911494e3;
-
-	spiu2	=  .6366197723675813430755350e0;	// 2/pi
-)
+import "math"
 
 func sinus(arg float64, quad int) float64 {
+	// Coefficients are #3370 from Hart & Cheney (18.80D).
+	const
+	(
+		P0	=  .1357884097877375669092680e8;
+		P1	= -.4942908100902844161158627e7;
+		P2	=  .4401030535375266501944918e6;
+		P3	= -.1384727249982452873054457e5;
+		P4	=  .1459688406665768722226959e3;
+		Q0	=  .8644558652922534429915149e7;
+		Q1	=  .4081792252343299749395779e6;
+		Q2	=  .9463096101538208180571257e4;
+		Q3	=  .1326534908786136358911494e3;
+	)
 	x := arg;
 	if(x < 0) {
 		x = -x;
 		quad = quad+2;
 	}
-	x = x * spiu2;	/* underflow? */
+	x = x * (2/Pi);	/* underflow? */
 	var y float64;
 	if x > 32764 {
 		var e float64;
 		e, y = sys.modf(x);
 		e = e + float64(quad);
-		temsp1, f := sys.modf(0.25*e);
+		temp1, f := sys.modf(0.25*e);
 		quad = int(e - 4*f);
 	} else {
 		k := int32(x);
@@ -49,10 +46,10 @@ func sinus(arg float64, quad int) float64 {
 		y = -y;
 	}
 
-	ysq := y*y;
-	temsp1 := ((((sp4*ysq+sp3)*ysq+sp2)*ysq+sp1)*ysq+sp0)*y;
-	temsp2 := ((((ysq+sq3)*ysq+sq2)*ysq+sq1)*ysq+sq0);
-	return temsp1/temsp2;
+	yy := y*y;
+	temp1 := ((((P4*yy+P3)*yy+P2)*yy+P1)*yy+P0)*y;
+	temp2 := ((((yy+Q3)*yy+Q2)*yy+Q1)*yy+Q0);
+	return temp1/temp2;
 }
 
 export func Cos(arg float64) float64 {