Index: fusl/src/math/__rem_pio2.c |
diff --git a/fusl/src/math/__rem_pio2.c b/fusl/src/math/__rem_pio2.c |
new file mode 100644 |
index 0000000000000000000000000000000000000000..d403f81c792217a195d9680d9356eec17f734f41 |
--- /dev/null |
+++ b/fusl/src/math/__rem_pio2.c |
@@ -0,0 +1,177 @@ |
+/* origin: FreeBSD /usr/src/lib/msun/src/e_rem_pio2.c */ |
+/* |
+ * ==================================================== |
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
+ * |
+ * Developed at SunSoft, a Sun Microsystems, Inc. business. |
+ * Permission to use, copy, modify, and distribute this |
+ * software is freely granted, provided that this notice |
+ * is preserved. |
+ * ==================================================== |
+ * |
+ * Optimized by Bruce D. Evans. |
+ */ |
+/* __rem_pio2(x,y) |
+ * |
+ * return the remainder of x rem pi/2 in y[0]+y[1] |
+ * use __rem_pio2_large() for large x |
+ */ |
+ |
+#include "libm.h" |
+ |
+#if FLT_EVAL_METHOD==0 || FLT_EVAL_METHOD==1 |
+#define EPS DBL_EPSILON |
+#elif FLT_EVAL_METHOD==2 |
+#define EPS LDBL_EPSILON |
+#endif |
+ |
+/* |
+ * invpio2: 53 bits of 2/pi |
+ * pio2_1: first 33 bit of pi/2 |
+ * pio2_1t: pi/2 - pio2_1 |
+ * pio2_2: second 33 bit of pi/2 |
+ * pio2_2t: pi/2 - (pio2_1+pio2_2) |
+ * pio2_3: third 33 bit of pi/2 |
+ * pio2_3t: pi/2 - (pio2_1+pio2_2+pio2_3) |
+ */ |
+static const double |
+toint = 1.5/EPS, |
+invpio2 = 6.36619772367581382433e-01, /* 0x3FE45F30, 0x6DC9C883 */ |
+pio2_1 = 1.57079632673412561417e+00, /* 0x3FF921FB, 0x54400000 */ |
+pio2_1t = 6.07710050650619224932e-11, /* 0x3DD0B461, 0x1A626331 */ |
+pio2_2 = 6.07710050630396597660e-11, /* 0x3DD0B461, 0x1A600000 */ |
+pio2_2t = 2.02226624879595063154e-21, /* 0x3BA3198A, 0x2E037073 */ |
+pio2_3 = 2.02226624871116645580e-21, /* 0x3BA3198A, 0x2E000000 */ |
+pio2_3t = 8.47842766036889956997e-32; /* 0x397B839A, 0x252049C1 */ |
+ |
+/* caller must handle the case when reduction is not needed: |x| ~<= pi/4 */ |
+int __rem_pio2(double x, double *y) |
+{ |
+ union {double f; uint64_t i;} u = {x}; |
+ double_t z,w,t,r,fn; |
+ double tx[3],ty[2]; |
+ uint32_t ix; |
+ int sign, n, ex, ey, i; |
+ |
+ sign = u.i>>63; |
+ ix = u.i>>32 & 0x7fffffff; |
+ if (ix <= 0x400f6a7a) { /* |x| ~<= 5pi/4 */ |
+ if ((ix & 0xfffff) == 0x921fb) /* |x| ~= pi/2 or 2pi/2 */ |
+ goto medium; /* cancellation -- use medium case */ |
+ if (ix <= 0x4002d97c) { /* |x| ~<= 3pi/4 */ |
+ if (!sign) { |
+ z = x - pio2_1; /* one round good to 85 bits */ |
+ y[0] = z - pio2_1t; |
+ y[1] = (z-y[0]) - pio2_1t; |
+ return 1; |
+ } else { |
+ z = x + pio2_1; |
+ y[0] = z + pio2_1t; |
+ y[1] = (z-y[0]) + pio2_1t; |
+ return -1; |
+ } |
+ } else { |
+ if (!sign) { |
+ z = x - 2*pio2_1; |
+ y[0] = z - 2*pio2_1t; |
+ y[1] = (z-y[0]) - 2*pio2_1t; |
+ return 2; |
+ } else { |
+ z = x + 2*pio2_1; |
+ y[0] = z + 2*pio2_1t; |
+ y[1] = (z-y[0]) + 2*pio2_1t; |
+ return -2; |
+ } |
+ } |
+ } |
+ if (ix <= 0x401c463b) { /* |x| ~<= 9pi/4 */ |
+ if (ix <= 0x4015fdbc) { /* |x| ~<= 7pi/4 */ |
+ if (ix == 0x4012d97c) /* |x| ~= 3pi/2 */ |
+ goto medium; |
+ if (!sign) { |
+ z = x - 3*pio2_1; |
+ y[0] = z - 3*pio2_1t; |
+ y[1] = (z-y[0]) - 3*pio2_1t; |
+ return 3; |
+ } else { |
+ z = x + 3*pio2_1; |
+ y[0] = z + 3*pio2_1t; |
+ y[1] = (z-y[0]) + 3*pio2_1t; |
+ return -3; |
+ } |
+ } else { |
+ if (ix == 0x401921fb) /* |x| ~= 4pi/2 */ |
+ goto medium; |
+ if (!sign) { |
+ z = x - 4*pio2_1; |
+ y[0] = z - 4*pio2_1t; |
+ y[1] = (z-y[0]) - 4*pio2_1t; |
+ return 4; |
+ } else { |
+ z = x + 4*pio2_1; |
+ y[0] = z + 4*pio2_1t; |
+ y[1] = (z-y[0]) + 4*pio2_1t; |
+ return -4; |
+ } |
+ } |
+ } |
+ if (ix < 0x413921fb) { /* |x| ~< 2^20*(pi/2), medium size */ |
+medium: |
+ /* rint(x/(pi/2)), Assume round-to-nearest. */ |
+ fn = (double_t)x*invpio2 + toint - toint; |
+ n = (int32_t)fn; |
+ r = x - fn*pio2_1; |
+ w = fn*pio2_1t; /* 1st round, good to 85 bits */ |
+ y[0] = r - w; |
+ u.f = y[0]; |
+ ey = u.i>>52 & 0x7ff; |
+ ex = ix>>20; |
+ if (ex - ey > 16) { /* 2nd round, good to 118 bits */ |
+ t = r; |
+ w = fn*pio2_2; |
+ r = t - w; |
+ w = fn*pio2_2t - ((t-r)-w); |
+ y[0] = r - w; |
+ u.f = y[0]; |
+ ey = u.i>>52 & 0x7ff; |
+ if (ex - ey > 49) { /* 3rd round, good to 151 bits, covers all cases */ |
+ t = r; |
+ w = fn*pio2_3; |
+ r = t - w; |
+ w = fn*pio2_3t - ((t-r)-w); |
+ y[0] = r - w; |
+ } |
+ } |
+ y[1] = (r - y[0]) - w; |
+ return n; |
+ } |
+ /* |
+ * all other (large) arguments |
+ */ |
+ if (ix >= 0x7ff00000) { /* x is inf or NaN */ |
+ y[0] = y[1] = x - x; |
+ return 0; |
+ } |
+ /* set z = scalbn(|x|,-ilogb(x)+23) */ |
+ u.f = x; |
+ u.i &= (uint64_t)-1>>12; |
+ u.i |= (uint64_t)(0x3ff + 23)<<52; |
+ z = u.f; |
+ for (i=0; i < 2; i++) { |
+ tx[i] = (double)(int32_t)z; |
+ z = (z-tx[i])*0x1p24; |
+ } |
+ tx[i] = z; |
+ /* skip zero terms, first term is non-zero */ |
+ while (tx[i] == 0.0) |
+ i--; |
+ n = __rem_pio2_large(tx,ty,(int)(ix>>20)-(0x3ff+23),i+1,1); |
+ if (sign) { |
+ y[0] = -ty[0]; |
+ y[1] = -ty[1]; |
+ return -n; |
+ } |
+ y[0] = ty[0]; |
+ y[1] = ty[1]; |
+ return n; |
+} |