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-rw-r--r--src/math/hypotl.c148
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+/* origin: FreeBSD /usr/src/lib/msun/src/e_hypotl.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.
+ * ====================================================
+ */
+/* long double version of hypot(). See comments in hypot.c. */
+
+#include "libm.h"
+
+#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
+long double hypotl(long double x, long double y)
+{
+ return hypot(x, y);
+}
+#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
+
+#define GET_LDBL_EXPSIGN(i, v) do { \
+ union IEEEl2bits uv; \
+ \
+ uv.e = v; \
+ i = uv.xbits.expsign; \
+} while (0)
+
+#define GET_LDBL_MAN(h, l, v) do { \
+ union IEEEl2bits uv; \
+ \
+ uv.e = v; \
+ h = uv.bits.manh; \
+ l = uv.bits.manl; \
+} while (0)
+
+#define SET_LDBL_EXPSIGN(v, i) do { \
+ union IEEEl2bits uv; \
+ \
+ uv.e = v; \
+ uv.xbits.expsign = i; \
+ v = uv.e; \
+} while (0)
+
+#undef GET_HIGH_WORD
+#define GET_HIGH_WORD(i, v) GET_LDBL_EXPSIGN(i, v)
+#undef SET_HIGH_WORD
+#define SET_HIGH_WORD(v, i) SET_LDBL_EXPSIGN(v, i)
+
+#define DESW(exp) (exp) /* delta expsign word */
+#define ESW(exp) (MAX_EXP - 1 + (exp)) /* expsign word */
+#define MANT_DIG LDBL_MANT_DIG
+#define MAX_EXP LDBL_MAX_EXP
+
+#if LDBL_MANL_SIZE > 32
+typedef uint64_t man_t;
+#else
+typedef uint32_t man_t;
+#endif
+
+long double hypotl(long double x, long double y)
+{
+ long double a=x,b=y,t1,t2,y1,y2,w;
+ int32_t j,k,ha,hb;
+
+ GET_HIGH_WORD(ha, x);
+ ha &= 0x7fff;
+ GET_HIGH_WORD(hb, y);
+ hb &= 0x7fff;
+ if (hb > ha) {
+ a = y;
+ b = x;
+ j=ha; ha=hb; hb=j;
+ } else {
+ a = x;
+ b = y;
+ }
+ a = fabsl(a);
+ b = fabsl(b);
+ if (ha - hb > DESW(MANT_DIG+7)) /* x/y > 2**(MANT_DIG+7) */
+ return a+b;
+ k = 0;
+ if (ha > ESW(MAX_EXP/2-12)) { /* a>2**(MAX_EXP/2-12) */
+ if (ha >= ESW(MAX_EXP)) { /* Inf or NaN */
+ man_t manh, manl;
+ /* Use original arg order iff result is NaN; quieten sNaNs. */
+ w = fabsl(x+0.0)-fabsl(y+0.0);
+ GET_LDBL_MAN(manh,manl,a);
+ if (manh == LDBL_NBIT && manl == 0) w = a;
+ GET_LDBL_MAN(manh,manl,b);
+ if (hb >= ESW(MAX_EXP) && manh == LDBL_NBIT && manl == 0) w = b;
+ return w;
+ }
+ /* scale a and b by 2**-(MAX_EXP/2+88) */
+ ha -= DESW(MAX_EXP/2+88); hb -= DESW(MAX_EXP/2+88);
+ k += MAX_EXP/2+88;
+ SET_HIGH_WORD(a, ha);
+ SET_HIGH_WORD(b, hb);
+ }
+ if (hb < ESW(-(MAX_EXP/2-12))) { /* b < 2**-(MAX_EXP/2-12) */
+ if (hb <= 0) { /* subnormal b or 0 */
+ man_t manh, manl;
+ GET_LDBL_MAN(manh,manl,b);
+ if ((manh|manl) == 0)
+ return a;
+ t1 = 0;
+ SET_HIGH_WORD(t1, ESW(MAX_EXP-2)); /* t1 = 2^(MAX_EXP-2) */
+ b *= t1;
+ a *= t1;
+ k -= MAX_EXP-2;
+ } else { /* scale a and b by 2^(MAX_EXP/2+88) */
+ ha += DESW(MAX_EXP/2+88);
+ hb += DESW(MAX_EXP/2+88);
+ k -= MAX_EXP/2+88;
+ SET_HIGH_WORD(a, ha);
+ SET_HIGH_WORD(b, hb);
+ }
+ }
+ /* medium size a and b */
+ w = a - b;
+ if (w > b) {
+ t1 = a;
+ union IEEEl2bits uv;
+ uv.e = t1; uv.bits.manl = 0; t1 = uv.e;
+ t2 = a-t1;
+ w = sqrtl(t1*t1-(b*(-b)-t2*(a+t1)));
+ } else {
+ a = a+a;
+ y1 = b;
+ union IEEEl2bits uv;
+ uv.e = y1; uv.bits.manl = 0; y1 = uv.e;
+ y2 = b - y1;
+ t1 = a;
+ uv.e = t1; uv.bits.manl = 0; t1 = uv.e;
+ t2 = a - t1;
+ w = sqrtl(t1*y1-(w*(-w)-(t1*y2+t2*b)));
+ }
+ if(k!=0) {
+ uint32_t high;
+ t1 = 1.0;
+ GET_HIGH_WORD(high, t1);
+ SET_HIGH_WORD(t1, high+DESW(k));
+ return t1*w;
+ }
+ return w;
+}
+#endif