X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fmath%2Fatan2l.c;h=f0937a9794986068b712972342a28fb3500333fa;hb=246f1c811448f37a44b41cd8df8d0ef9736d95f4;hp=48abc05887f80721e850a7309639f90a623f0ab3;hpb=eca1c35e5be967478c8fe9381c6f4652b6645d5e;p=musl

diff --git a/src/math/atan2l.c b/src/math/atan2l.c
index 48abc058..f0937a97 100644
--- a/src/math/atan2l.c
+++ b/src/math/atan2l.c
@@ -24,83 +24,62 @@ long double atan2l(long double y, long double x)
 }
 #elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
 #include "__invtrigl.h"
-static const volatile long double
-tiny = 1.0e-300;
-static const long double
-zero = 0.0,
-pi = 3.14159265358979323846264338327950280e+00L;
 
 long double atan2l(long double y, long double x)
 {
-	union IEEEl2bits ux, uy;
+	union ldshape ux, uy;
 	long double z;
-	int32_t k,m;
-	int16_t exptx, expsignx, expty, expsigny;
+	int m, ex, ey;
 
-	uy.e = y;
-	expsigny = uy.xbits.expsign;
-	expty = expsigny & 0x7fff;
-	ux.e = x;
-	expsignx = ux.xbits.expsign;
-	exptx = expsignx & 0x7fff;
-	if ((exptx==BIAS+LDBL_MAX_EXP &&
-	     ((ux.bits.manh&~LDBL_NBIT)|ux.bits.manl)!=0) || /* x is NaN */
-	    (expty==BIAS+LDBL_MAX_EXP &&
-	     ((uy.bits.manh&~LDBL_NBIT)|uy.bits.manl)!=0))   /* y is NaN */
+	if (isnan(x) || isnan(y))
 		return x+y;
-	if (expsignx==BIAS && ((ux.bits.manh&~LDBL_NBIT)|ux.bits.manl)==0) /* x=1.0 */
+	if (x == 1)
 		return atanl(y);
-	m = ((expsigny>>15)&1) | ((expsignx>>14)&2);  /* 2*sign(x)+sign(y) */
-
-	/* when y = 0 */
-	if (expty==0 && ((uy.bits.manh&~LDBL_NBIT)|uy.bits.manl)==0) {
+	ux.f = x;
+	uy.f = y;
+	ex = ux.i.se & 0x7fff;
+	ey = uy.i.se & 0x7fff;
+	m = 2*(ux.i.se>>15) | uy.i.se>>15;
+	if (y == 0) {
 		switch(m) {
 		case 0:
-		case 1: return y;        /* atan(+-0,+anything)=+-0 */
-		case 2: return  pi+tiny; /* atan(+0,-anything) = pi */
-		case 3: return -pi-tiny; /* atan(-0,-anything) =-pi */
+		case 1: return y;           /* atan(+-0,+anything)=+-0 */
+		case 2: return  2*pio2_hi;  /* atan(+0,-anything) = pi */
+		case 3: return -2*pio2_hi;  /* atan(-0,-anything) =-pi */
 		}
 	}
-	/* when x = 0 */
-	if (exptx==0 && ((ux.bits.manh&~LDBL_NBIT)|ux.bits.manl)==0)
-		return expsigny < 0 ? -pio2_hi-tiny : pio2_hi+tiny;
-	/* when x is INF */
-	if (exptx == BIAS+LDBL_MAX_EXP) {
-		if (expty == BIAS+LDBL_MAX_EXP) {
+	if (x == 0)
+		return m&1 ? -pio2_hi : pio2_hi;
+	if (ex == 0x7fff) {
+		if (ey == 0x7fff) {
 			switch(m) {
-			case 0: return  pio2_hi*0.5+tiny; /* atan(+INF,+INF) */
-			case 1: return -pio2_hi*0.5-tiny; /* atan(-INF,+INF) */
-			case 2: return  1.5*pio2_hi+tiny; /*atan(+INF,-INF)*/
-			case 3: return -1.5*pio2_hi-tiny; /*atan(-INF,-INF)*/
+			case 0: return  pio2_hi/2;   /* atan(+INF,+INF) */
+			case 1: return -pio2_hi/2;   /* atan(-INF,+INF) */
+			case 2: return  1.5*pio2_hi; /* atan(+INF,-INF) */
+			case 3: return -1.5*pio2_hi; /* atan(-INF,-INF) */
 			}
 		} else {
 			switch(m) {
-			case 0: return  zero;    /* atan(+...,+INF) */
-			case 1: return -zero;    /* atan(-...,+INF) */
-			case 2: return  pi+tiny; /* atan(+...,-INF) */
-			case 3: return -pi-tiny; /* atan(-...,-INF) */
+			case 0: return  0.0;        /* atan(+...,+INF) */
+			case 1: return -0.0;        /* atan(-...,+INF) */
+			case 2: return  2*pio2_hi;  /* atan(+...,-INF) */
+			case 3: return -2*pio2_hi;  /* atan(-...,-INF) */
 			}
 		}
 	}
-	/* when y is INF */
-	if (expty == BIAS+LDBL_MAX_EXP)
-		return expsigny < 0 ? -pio2_hi-tiny : pio2_hi+tiny;
-
-	/* compute y/x */
-	k = expty-exptx;
-	if(k > LDBL_MANT_DIG+2) { /* |y/x| huge */
-		z = pio2_hi+pio2_lo;
-		m &= 1;
-	} else if (expsignx < 0 && k < -LDBL_MANT_DIG-2) /* |y/x| tiny, x<0 */
+	if (ex+120 < ey || ey == 0x7fff)
+		return m&1 ? -pio2_hi : pio2_hi;
+	/* z = atan(|y/x|) without spurious underflow */
+	if ((m&2) && ey+120 < ex)  /* |y/x| < 0x1p-120, x<0 */
 		z = 0.0;
-	else                     /* safe to do y/x */
+	else
 		z = atanl(fabsl(y/x));
 	switch (m) {
-	case 0: return z;              /* atan(+,+) */
-	case 1: return -z;             /* atan(-,+) */
-	case 2: return pi - (z-pi_lo); /* atan(+,-) */
+	case 0: return z;               /* atan(+,+) */
+	case 1: return -z;              /* atan(-,+) */
+	case 2: return 2*pio2_hi-(z-2*pio2_lo); /* atan(+,-) */
 	default: /* case 3 */
-		return (z-pi_lo) - pi; /* atan(-,-) */
+		return (z-2*pio2_lo)-2*pio2_hi; /* atan(-,-) */
 	}
 }
 #endif