Mon, 18 Jun 2012 12:29:21 -0700
7176856: add the JRE name to the error log
Reviewed-by: coleenp, jrose, kvn, twisti
Contributed-by: Krystal Mok <sajia@taobao.com>
1 /*
2 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
25 #include "precompiled.hpp"
26 #include "prims/jni.h"
27 #include "runtime/interfaceSupport.hpp"
28 #include "runtime/sharedRuntime.hpp"
30 // This file contains copies of the fdlibm routines used by
31 // StrictMath. It turns out that it is almost always required to use
32 // these runtime routines; the Intel CPU doesn't meet the Java
33 // specification for sin/cos outside a certain limited argument range,
34 // and the SPARC CPU doesn't appear to have sin/cos instructions. It
35 // also turns out that avoiding the indirect call through function
36 // pointer out to libjava.so in SharedRuntime speeds these routines up
37 // by roughly 15% on both Win32/x86 and Solaris/SPARC.
39 // Enabling optimizations in this file causes incorrect code to be
40 // generated; can not figure out how to turn down optimization for one
41 // file in the IDE on Windows
42 #ifdef WIN32
43 # pragma optimize ( "", off )
44 #endif
46 #include <math.h>
48 // VM_LITTLE_ENDIAN is #defined appropriately in the Makefiles
49 // [jk] this is not 100% correct because the float word order may different
50 // from the byte order (e.g. on ARM)
51 #ifdef VM_LITTLE_ENDIAN
52 # define __HI(x) *(1+(int*)&x)
53 # define __LO(x) *(int*)&x
54 #else
55 # define __HI(x) *(int*)&x
56 # define __LO(x) *(1+(int*)&x)
57 #endif
59 double copysign(double x, double y) {
60 __HI(x) = (__HI(x)&0x7fffffff)|(__HI(y)&0x80000000);
61 return x;
62 }
64 /*
65 * ====================================================
66 * Copyright (c) 1998 Oracle and/or its affiliates. All rights reserved.
67 *
68 * Developed at SunSoft, a Sun Microsystems, Inc. business.
69 * Permission to use, copy, modify, and distribute this
70 * software is freely granted, provided that this notice
71 * is preserved.
72 * ====================================================
73 */
75 /*
76 * scalbn (double x, int n)
77 * scalbn(x,n) returns x* 2**n computed by exponent
78 * manipulation rather than by actually performing an
79 * exponentiation or a multiplication.
80 */
82 static const double
83 two54 = 1.80143985094819840000e+16, /* 0x43500000, 0x00000000 */
84 twom54 = 5.55111512312578270212e-17, /* 0x3C900000, 0x00000000 */
85 hugeX = 1.0e+300,
86 tiny = 1.0e-300;
88 double scalbn (double x, int n) {
89 int k,hx,lx;
90 hx = __HI(x);
91 lx = __LO(x);
92 k = (hx&0x7ff00000)>>20; /* extract exponent */
93 if (k==0) { /* 0 or subnormal x */
94 if ((lx|(hx&0x7fffffff))==0) return x; /* +-0 */
95 x *= two54;
96 hx = __HI(x);
97 k = ((hx&0x7ff00000)>>20) - 54;
98 if (n< -50000) return tiny*x; /*underflow*/
99 }
100 if (k==0x7ff) return x+x; /* NaN or Inf */
101 k = k+n;
102 if (k > 0x7fe) return hugeX*copysign(hugeX,x); /* overflow */
103 if (k > 0) /* normal result */
104 {__HI(x) = (hx&0x800fffff)|(k<<20); return x;}
105 if (k <= -54) {
106 if (n > 50000) /* in case integer overflow in n+k */
107 return hugeX*copysign(hugeX,x); /*overflow*/
108 else return tiny*copysign(tiny,x); /*underflow*/
109 }
110 k += 54; /* subnormal result */
111 __HI(x) = (hx&0x800fffff)|(k<<20);
112 return x*twom54;
113 }
115 /* __ieee754_log(x)
116 * Return the logrithm of x
117 *
118 * Method :
119 * 1. Argument Reduction: find k and f such that
120 * x = 2^k * (1+f),
121 * where sqrt(2)/2 < 1+f < sqrt(2) .
122 *
123 * 2. Approximation of log(1+f).
124 * Let s = f/(2+f) ; based on log(1+f) = log(1+s) - log(1-s)
125 * = 2s + 2/3 s**3 + 2/5 s**5 + .....,
126 * = 2s + s*R
127 * We use a special Reme algorithm on [0,0.1716] to generate
128 * a polynomial of degree 14 to approximate R The maximum error
129 * of this polynomial approximation is bounded by 2**-58.45. In
130 * other words,
131 * 2 4 6 8 10 12 14
132 * R(z) ~ Lg1*s +Lg2*s +Lg3*s +Lg4*s +Lg5*s +Lg6*s +Lg7*s
133 * (the values of Lg1 to Lg7 are listed in the program)
134 * and
135 * | 2 14 | -58.45
136 * | Lg1*s +...+Lg7*s - R(z) | <= 2
137 * | |
138 * Note that 2s = f - s*f = f - hfsq + s*hfsq, where hfsq = f*f/2.
139 * In order to guarantee error in log below 1ulp, we compute log
140 * by
141 * log(1+f) = f - s*(f - R) (if f is not too large)
142 * log(1+f) = f - (hfsq - s*(hfsq+R)). (better accuracy)
143 *
144 * 3. Finally, log(x) = k*ln2 + log(1+f).
145 * = k*ln2_hi+(f-(hfsq-(s*(hfsq+R)+k*ln2_lo)))
146 * Here ln2 is split into two floating point number:
147 * ln2_hi + ln2_lo,
148 * where n*ln2_hi is always exact for |n| < 2000.
149 *
150 * Special cases:
151 * log(x) is NaN with signal if x < 0 (including -INF) ;
152 * log(+INF) is +INF; log(0) is -INF with signal;
153 * log(NaN) is that NaN with no signal.
154 *
155 * Accuracy:
156 * according to an error analysis, the error is always less than
157 * 1 ulp (unit in the last place).
158 *
159 * Constants:
160 * The hexadecimal values are the intended ones for the following
161 * constants. The decimal values may be used, provided that the
162 * compiler will convert from decimal to binary accurately enough
163 * to produce the hexadecimal values shown.
164 */
166 static const double
167 ln2_hi = 6.93147180369123816490e-01, /* 3fe62e42 fee00000 */
168 ln2_lo = 1.90821492927058770002e-10, /* 3dea39ef 35793c76 */
169 Lg1 = 6.666666666666735130e-01, /* 3FE55555 55555593 */
170 Lg2 = 3.999999999940941908e-01, /* 3FD99999 9997FA04 */
171 Lg3 = 2.857142874366239149e-01, /* 3FD24924 94229359 */
172 Lg4 = 2.222219843214978396e-01, /* 3FCC71C5 1D8E78AF */
173 Lg5 = 1.818357216161805012e-01, /* 3FC74664 96CB03DE */
174 Lg6 = 1.531383769920937332e-01, /* 3FC39A09 D078C69F */
175 Lg7 = 1.479819860511658591e-01; /* 3FC2F112 DF3E5244 */
177 static double zero = 0.0;
179 static double __ieee754_log(double x) {
180 double hfsq,f,s,z,R,w,t1,t2,dk;
181 int k,hx,i,j;
182 unsigned lx;
184 hx = __HI(x); /* high word of x */
185 lx = __LO(x); /* low word of x */
187 k=0;
188 if (hx < 0x00100000) { /* x < 2**-1022 */
189 if (((hx&0x7fffffff)|lx)==0)
190 return -two54/zero; /* log(+-0)=-inf */
191 if (hx<0) return (x-x)/zero; /* log(-#) = NaN */
192 k -= 54; x *= two54; /* subnormal number, scale up x */
193 hx = __HI(x); /* high word of x */
194 }
195 if (hx >= 0x7ff00000) return x+x;
196 k += (hx>>20)-1023;
197 hx &= 0x000fffff;
198 i = (hx+0x95f64)&0x100000;
199 __HI(x) = hx|(i^0x3ff00000); /* normalize x or x/2 */
200 k += (i>>20);
201 f = x-1.0;
202 if((0x000fffff&(2+hx))<3) { /* |f| < 2**-20 */
203 if(f==zero) {
204 if (k==0) return zero;
205 else {dk=(double)k; return dk*ln2_hi+dk*ln2_lo;}
206 }
207 R = f*f*(0.5-0.33333333333333333*f);
208 if(k==0) return f-R; else {dk=(double)k;
209 return dk*ln2_hi-((R-dk*ln2_lo)-f);}
210 }
211 s = f/(2.0+f);
212 dk = (double)k;
213 z = s*s;
214 i = hx-0x6147a;
215 w = z*z;
216 j = 0x6b851-hx;
217 t1= w*(Lg2+w*(Lg4+w*Lg6));
218 t2= z*(Lg1+w*(Lg3+w*(Lg5+w*Lg7)));
219 i |= j;
220 R = t2+t1;
221 if(i>0) {
222 hfsq=0.5*f*f;
223 if(k==0) return f-(hfsq-s*(hfsq+R)); else
224 return dk*ln2_hi-((hfsq-(s*(hfsq+R)+dk*ln2_lo))-f);
225 } else {
226 if(k==0) return f-s*(f-R); else
227 return dk*ln2_hi-((s*(f-R)-dk*ln2_lo)-f);
228 }
229 }
231 JRT_LEAF(jdouble, SharedRuntime::dlog(jdouble x))
232 return __ieee754_log(x);
233 JRT_END
235 /* __ieee754_log10(x)
236 * Return the base 10 logarithm of x
237 *
238 * Method :
239 * Let log10_2hi = leading 40 bits of log10(2) and
240 * log10_2lo = log10(2) - log10_2hi,
241 * ivln10 = 1/log(10) rounded.
242 * Then
243 * n = ilogb(x),
244 * if(n<0) n = n+1;
245 * x = scalbn(x,-n);
246 * log10(x) := n*log10_2hi + (n*log10_2lo + ivln10*log(x))
247 *
248 * Note 1:
249 * To guarantee log10(10**n)=n, where 10**n is normal, the rounding
250 * mode must set to Round-to-Nearest.
251 * Note 2:
252 * [1/log(10)] rounded to 53 bits has error .198 ulps;
253 * log10 is monotonic at all binary break points.
254 *
255 * Special cases:
256 * log10(x) is NaN with signal if x < 0;
257 * log10(+INF) is +INF with no signal; log10(0) is -INF with signal;
258 * log10(NaN) is that NaN with no signal;
259 * log10(10**N) = N for N=0,1,...,22.
260 *
261 * Constants:
262 * The hexadecimal values are the intended ones for the following constants.
263 * The decimal values may be used, provided that the compiler will convert
264 * from decimal to binary accurately enough to produce the hexadecimal values
265 * shown.
266 */
268 static const double
269 ivln10 = 4.34294481903251816668e-01, /* 0x3FDBCB7B, 0x1526E50E */
270 log10_2hi = 3.01029995663611771306e-01, /* 0x3FD34413, 0x509F6000 */
271 log10_2lo = 3.69423907715893078616e-13; /* 0x3D59FEF3, 0x11F12B36 */
273 static double __ieee754_log10(double x) {
274 double y,z;
275 int i,k,hx;
276 unsigned lx;
278 hx = __HI(x); /* high word of x */
279 lx = __LO(x); /* low word of x */
281 k=0;
282 if (hx < 0x00100000) { /* x < 2**-1022 */
283 if (((hx&0x7fffffff)|lx)==0)
284 return -two54/zero; /* log(+-0)=-inf */
285 if (hx<0) return (x-x)/zero; /* log(-#) = NaN */
286 k -= 54; x *= two54; /* subnormal number, scale up x */
287 hx = __HI(x); /* high word of x */
288 }
289 if (hx >= 0x7ff00000) return x+x;
290 k += (hx>>20)-1023;
291 i = ((unsigned)k&0x80000000)>>31;
292 hx = (hx&0x000fffff)|((0x3ff-i)<<20);
293 y = (double)(k+i);
294 __HI(x) = hx;
295 z = y*log10_2lo + ivln10*__ieee754_log(x);
296 return z+y*log10_2hi;
297 }
299 JRT_LEAF(jdouble, SharedRuntime::dlog10(jdouble x))
300 return __ieee754_log10(x);
301 JRT_END
304 /* __ieee754_exp(x)
305 * Returns the exponential of x.
306 *
307 * Method
308 * 1. Argument reduction:
309 * Reduce x to an r so that |r| <= 0.5*ln2 ~ 0.34658.
310 * Given x, find r and integer k such that
311 *
312 * x = k*ln2 + r, |r| <= 0.5*ln2.
313 *
314 * Here r will be represented as r = hi-lo for better
315 * accuracy.
316 *
317 * 2. Approximation of exp(r) by a special rational function on
318 * the interval [0,0.34658]:
319 * Write
320 * R(r**2) = r*(exp(r)+1)/(exp(r)-1) = 2 + r*r/6 - r**4/360 + ...
321 * We use a special Reme algorithm on [0,0.34658] to generate
322 * a polynomial of degree 5 to approximate R. The maximum error
323 * of this polynomial approximation is bounded by 2**-59. In
324 * other words,
325 * R(z) ~ 2.0 + P1*z + P2*z**2 + P3*z**3 + P4*z**4 + P5*z**5
326 * (where z=r*r, and the values of P1 to P5 are listed below)
327 * and
328 * | 5 | -59
329 * | 2.0+P1*z+...+P5*z - R(z) | <= 2
330 * | |
331 * The computation of exp(r) thus becomes
332 * 2*r
333 * exp(r) = 1 + -------
334 * R - r
335 * r*R1(r)
336 * = 1 + r + ----------- (for better accuracy)
337 * 2 - R1(r)
338 * where
339 * 2 4 10
340 * R1(r) = r - (P1*r + P2*r + ... + P5*r ).
341 *
342 * 3. Scale back to obtain exp(x):
343 * From step 1, we have
344 * exp(x) = 2^k * exp(r)
345 *
346 * Special cases:
347 * exp(INF) is INF, exp(NaN) is NaN;
348 * exp(-INF) is 0, and
349 * for finite argument, only exp(0)=1 is exact.
350 *
351 * Accuracy:
352 * according to an error analysis, the error is always less than
353 * 1 ulp (unit in the last place).
354 *
355 * Misc. info.
356 * For IEEE double
357 * if x > 7.09782712893383973096e+02 then exp(x) overflow
358 * if x < -7.45133219101941108420e+02 then exp(x) underflow
359 *
360 * Constants:
361 * The hexadecimal values are the intended ones for the following
362 * constants. The decimal values may be used, provided that the
363 * compiler will convert from decimal to binary accurately enough
364 * to produce the hexadecimal values shown.
365 */
367 static const double
368 one = 1.0,
369 halF[2] = {0.5,-0.5,},
370 twom1000= 9.33263618503218878990e-302, /* 2**-1000=0x01700000,0*/
371 o_threshold= 7.09782712893383973096e+02, /* 0x40862E42, 0xFEFA39EF */
372 u_threshold= -7.45133219101941108420e+02, /* 0xc0874910, 0xD52D3051 */
373 ln2HI[2] ={ 6.93147180369123816490e-01, /* 0x3fe62e42, 0xfee00000 */
374 -6.93147180369123816490e-01,},/* 0xbfe62e42, 0xfee00000 */
375 ln2LO[2] ={ 1.90821492927058770002e-10, /* 0x3dea39ef, 0x35793c76 */
376 -1.90821492927058770002e-10,},/* 0xbdea39ef, 0x35793c76 */
377 invln2 = 1.44269504088896338700e+00, /* 0x3ff71547, 0x652b82fe */
378 P1 = 1.66666666666666019037e-01, /* 0x3FC55555, 0x5555553E */
379 P2 = -2.77777777770155933842e-03, /* 0xBF66C16C, 0x16BEBD93 */
380 P3 = 6.61375632143793436117e-05, /* 0x3F11566A, 0xAF25DE2C */
381 P4 = -1.65339022054652515390e-06, /* 0xBEBBBD41, 0xC5D26BF1 */
382 P5 = 4.13813679705723846039e-08; /* 0x3E663769, 0x72BEA4D0 */
384 static double __ieee754_exp(double x) {
385 double y,hi=0,lo=0,c,t;
386 int k=0,xsb;
387 unsigned hx;
389 hx = __HI(x); /* high word of x */
390 xsb = (hx>>31)&1; /* sign bit of x */
391 hx &= 0x7fffffff; /* high word of |x| */
393 /* filter out non-finite argument */
394 if(hx >= 0x40862E42) { /* if |x|>=709.78... */
395 if(hx>=0x7ff00000) {
396 if(((hx&0xfffff)|__LO(x))!=0)
397 return x+x; /* NaN */
398 else return (xsb==0)? x:0.0; /* exp(+-inf)={inf,0} */
399 }
400 if(x > o_threshold) return hugeX*hugeX; /* overflow */
401 if(x < u_threshold) return twom1000*twom1000; /* underflow */
402 }
404 /* argument reduction */
405 if(hx > 0x3fd62e42) { /* if |x| > 0.5 ln2 */
406 if(hx < 0x3FF0A2B2) { /* and |x| < 1.5 ln2 */
407 hi = x-ln2HI[xsb]; lo=ln2LO[xsb]; k = 1-xsb-xsb;
408 } else {
409 k = (int)(invln2*x+halF[xsb]);
410 t = k;
411 hi = x - t*ln2HI[0]; /* t*ln2HI is exact here */
412 lo = t*ln2LO[0];
413 }
414 x = hi - lo;
415 }
416 else if(hx < 0x3e300000) { /* when |x|<2**-28 */
417 if(hugeX+x>one) return one+x;/* trigger inexact */
418 }
419 else k = 0;
421 /* x is now in primary range */
422 t = x*x;
423 c = x - t*(P1+t*(P2+t*(P3+t*(P4+t*P5))));
424 if(k==0) return one-((x*c)/(c-2.0)-x);
425 else y = one-((lo-(x*c)/(2.0-c))-hi);
426 if(k >= -1021) {
427 __HI(y) += (k<<20); /* add k to y's exponent */
428 return y;
429 } else {
430 __HI(y) += ((k+1000)<<20);/* add k to y's exponent */
431 return y*twom1000;
432 }
433 }
435 JRT_LEAF(jdouble, SharedRuntime::dexp(jdouble x))
436 return __ieee754_exp(x);
437 JRT_END
439 /* __ieee754_pow(x,y) return x**y
440 *
441 * n
442 * Method: Let x = 2 * (1+f)
443 * 1. Compute and return log2(x) in two pieces:
444 * log2(x) = w1 + w2,
445 * where w1 has 53-24 = 29 bit trailing zeros.
446 * 2. Perform y*log2(x) = n+y' by simulating muti-precision
447 * arithmetic, where |y'|<=0.5.
448 * 3. Return x**y = 2**n*exp(y'*log2)
449 *
450 * Special cases:
451 * 1. (anything) ** 0 is 1
452 * 2. (anything) ** 1 is itself
453 * 3. (anything) ** NAN is NAN
454 * 4. NAN ** (anything except 0) is NAN
455 * 5. +-(|x| > 1) ** +INF is +INF
456 * 6. +-(|x| > 1) ** -INF is +0
457 * 7. +-(|x| < 1) ** +INF is +0
458 * 8. +-(|x| < 1) ** -INF is +INF
459 * 9. +-1 ** +-INF is NAN
460 * 10. +0 ** (+anything except 0, NAN) is +0
461 * 11. -0 ** (+anything except 0, NAN, odd integer) is +0
462 * 12. +0 ** (-anything except 0, NAN) is +INF
463 * 13. -0 ** (-anything except 0, NAN, odd integer) is +INF
464 * 14. -0 ** (odd integer) = -( +0 ** (odd integer) )
465 * 15. +INF ** (+anything except 0,NAN) is +INF
466 * 16. +INF ** (-anything except 0,NAN) is +0
467 * 17. -INF ** (anything) = -0 ** (-anything)
468 * 18. (-anything) ** (integer) is (-1)**(integer)*(+anything**integer)
469 * 19. (-anything except 0 and inf) ** (non-integer) is NAN
470 *
471 * Accuracy:
472 * pow(x,y) returns x**y nearly rounded. In particular
473 * pow(integer,integer)
474 * always returns the correct integer provided it is
475 * representable.
476 *
477 * Constants :
478 * The hexadecimal values are the intended ones for the following
479 * constants. The decimal values may be used, provided that the
480 * compiler will convert from decimal to binary accurately enough
481 * to produce the hexadecimal values shown.
482 */
484 static const double
485 bp[] = {1.0, 1.5,},
486 dp_h[] = { 0.0, 5.84962487220764160156e-01,}, /* 0x3FE2B803, 0x40000000 */
487 dp_l[] = { 0.0, 1.35003920212974897128e-08,}, /* 0x3E4CFDEB, 0x43CFD006 */
488 zeroX = 0.0,
489 two = 2.0,
490 two53 = 9007199254740992.0, /* 0x43400000, 0x00000000 */
491 /* poly coefs for (3/2)*(log(x)-2s-2/3*s**3 */
492 L1X = 5.99999999999994648725e-01, /* 0x3FE33333, 0x33333303 */
493 L2X = 4.28571428578550184252e-01, /* 0x3FDB6DB6, 0xDB6FABFF */
494 L3X = 3.33333329818377432918e-01, /* 0x3FD55555, 0x518F264D */
495 L4X = 2.72728123808534006489e-01, /* 0x3FD17460, 0xA91D4101 */
496 L5X = 2.30660745775561754067e-01, /* 0x3FCD864A, 0x93C9DB65 */
497 L6X = 2.06975017800338417784e-01, /* 0x3FCA7E28, 0x4A454EEF */
498 lg2 = 6.93147180559945286227e-01, /* 0x3FE62E42, 0xFEFA39EF */
499 lg2_h = 6.93147182464599609375e-01, /* 0x3FE62E43, 0x00000000 */
500 lg2_l = -1.90465429995776804525e-09, /* 0xBE205C61, 0x0CA86C39 */
501 ovt = 8.0085662595372944372e-0017, /* -(1024-log2(ovfl+.5ulp)) */
502 cp = 9.61796693925975554329e-01, /* 0x3FEEC709, 0xDC3A03FD =2/(3ln2) */
503 cp_h = 9.61796700954437255859e-01, /* 0x3FEEC709, 0xE0000000 =(float)cp */
504 cp_l = -7.02846165095275826516e-09, /* 0xBE3E2FE0, 0x145B01F5 =tail of cp_h*/
505 ivln2 = 1.44269504088896338700e+00, /* 0x3FF71547, 0x652B82FE =1/ln2 */
506 ivln2_h = 1.44269502162933349609e+00, /* 0x3FF71547, 0x60000000 =24b 1/ln2*/
507 ivln2_l = 1.92596299112661746887e-08; /* 0x3E54AE0B, 0xF85DDF44 =1/ln2 tail*/
509 double __ieee754_pow(double x, double y) {
510 double z,ax,z_h,z_l,p_h,p_l;
511 double y1,t1,t2,r,s,t,u,v,w;
512 int i0,i1,i,j,k,yisint,n;
513 int hx,hy,ix,iy;
514 unsigned lx,ly;
516 i0 = ((*(int*)&one)>>29)^1; i1=1-i0;
517 hx = __HI(x); lx = __LO(x);
518 hy = __HI(y); ly = __LO(y);
519 ix = hx&0x7fffffff; iy = hy&0x7fffffff;
521 /* y==zero: x**0 = 1 */
522 if((iy|ly)==0) return one;
524 /* +-NaN return x+y */
525 if(ix > 0x7ff00000 || ((ix==0x7ff00000)&&(lx!=0)) ||
526 iy > 0x7ff00000 || ((iy==0x7ff00000)&&(ly!=0)))
527 return x+y;
529 /* determine if y is an odd int when x < 0
530 * yisint = 0 ... y is not an integer
531 * yisint = 1 ... y is an odd int
532 * yisint = 2 ... y is an even int
533 */
534 yisint = 0;
535 if(hx<0) {
536 if(iy>=0x43400000) yisint = 2; /* even integer y */
537 else if(iy>=0x3ff00000) {
538 k = (iy>>20)-0x3ff; /* exponent */
539 if(k>20) {
540 j = ly>>(52-k);
541 if((unsigned)(j<<(52-k))==ly) yisint = 2-(j&1);
542 } else if(ly==0) {
543 j = iy>>(20-k);
544 if((j<<(20-k))==iy) yisint = 2-(j&1);
545 }
546 }
547 }
549 /* special value of y */
550 if(ly==0) {
551 if (iy==0x7ff00000) { /* y is +-inf */
552 if(((ix-0x3ff00000)|lx)==0)
553 return y - y; /* inf**+-1 is NaN */
554 else if (ix >= 0x3ff00000)/* (|x|>1)**+-inf = inf,0 */
555 return (hy>=0)? y: zeroX;
556 else /* (|x|<1)**-,+inf = inf,0 */
557 return (hy<0)?-y: zeroX;
558 }
559 if(iy==0x3ff00000) { /* y is +-1 */
560 if(hy<0) return one/x; else return x;
561 }
562 if(hy==0x40000000) return x*x; /* y is 2 */
563 if(hy==0x3fe00000) { /* y is 0.5 */
564 if(hx>=0) /* x >= +0 */
565 return sqrt(x);
566 }
567 }
569 ax = fabsd(x);
570 /* special value of x */
571 if(lx==0) {
572 if(ix==0x7ff00000||ix==0||ix==0x3ff00000){
573 z = ax; /*x is +-0,+-inf,+-1*/
574 if(hy<0) z = one/z; /* z = (1/|x|) */
575 if(hx<0) {
576 if(((ix-0x3ff00000)|yisint)==0) {
577 #ifdef CAN_USE_NAN_DEFINE
578 z = NAN;
579 #else
580 z = (z-z)/(z-z); /* (-1)**non-int is NaN */
581 #endif
582 } else if(yisint==1)
583 z = -1.0*z; /* (x<0)**odd = -(|x|**odd) */
584 }
585 return z;
586 }
587 }
589 n = (hx>>31)+1;
591 /* (x<0)**(non-int) is NaN */
592 if((n|yisint)==0)
593 #ifdef CAN_USE_NAN_DEFINE
594 return NAN;
595 #else
596 return (x-x)/(x-x);
597 #endif
599 s = one; /* s (sign of result -ve**odd) = -1 else = 1 */
600 if((n|(yisint-1))==0) s = -one;/* (-ve)**(odd int) */
602 /* |y| is huge */
603 if(iy>0x41e00000) { /* if |y| > 2**31 */
604 if(iy>0x43f00000){ /* if |y| > 2**64, must o/uflow */
605 if(ix<=0x3fefffff) return (hy<0)? hugeX*hugeX:tiny*tiny;
606 if(ix>=0x3ff00000) return (hy>0)? hugeX*hugeX:tiny*tiny;
607 }
608 /* over/underflow if x is not close to one */
609 if(ix<0x3fefffff) return (hy<0)? s*hugeX*hugeX:s*tiny*tiny;
610 if(ix>0x3ff00000) return (hy>0)? s*hugeX*hugeX:s*tiny*tiny;
611 /* now |1-x| is tiny <= 2**-20, suffice to compute
612 log(x) by x-x^2/2+x^3/3-x^4/4 */
613 t = ax-one; /* t has 20 trailing zeros */
614 w = (t*t)*(0.5-t*(0.3333333333333333333333-t*0.25));
615 u = ivln2_h*t; /* ivln2_h has 21 sig. bits */
616 v = t*ivln2_l-w*ivln2;
617 t1 = u+v;
618 __LO(t1) = 0;
619 t2 = v-(t1-u);
620 } else {
621 double ss,s2,s_h,s_l,t_h,t_l;
622 n = 0;
623 /* take care subnormal number */
624 if(ix<0x00100000)
625 {ax *= two53; n -= 53; ix = __HI(ax); }
626 n += ((ix)>>20)-0x3ff;
627 j = ix&0x000fffff;
628 /* determine interval */
629 ix = j|0x3ff00000; /* normalize ix */
630 if(j<=0x3988E) k=0; /* |x|<sqrt(3/2) */
631 else if(j<0xBB67A) k=1; /* |x|<sqrt(3) */
632 else {k=0;n+=1;ix -= 0x00100000;}
633 __HI(ax) = ix;
635 /* compute ss = s_h+s_l = (x-1)/(x+1) or (x-1.5)/(x+1.5) */
636 u = ax-bp[k]; /* bp[0]=1.0, bp[1]=1.5 */
637 v = one/(ax+bp[k]);
638 ss = u*v;
639 s_h = ss;
640 __LO(s_h) = 0;
641 /* t_h=ax+bp[k] High */
642 t_h = zeroX;
643 __HI(t_h)=((ix>>1)|0x20000000)+0x00080000+(k<<18);
644 t_l = ax - (t_h-bp[k]);
645 s_l = v*((u-s_h*t_h)-s_h*t_l);
646 /* compute log(ax) */
647 s2 = ss*ss;
648 r = s2*s2*(L1X+s2*(L2X+s2*(L3X+s2*(L4X+s2*(L5X+s2*L6X)))));
649 r += s_l*(s_h+ss);
650 s2 = s_h*s_h;
651 t_h = 3.0+s2+r;
652 __LO(t_h) = 0;
653 t_l = r-((t_h-3.0)-s2);
654 /* u+v = ss*(1+...) */
655 u = s_h*t_h;
656 v = s_l*t_h+t_l*ss;
657 /* 2/(3log2)*(ss+...) */
658 p_h = u+v;
659 __LO(p_h) = 0;
660 p_l = v-(p_h-u);
661 z_h = cp_h*p_h; /* cp_h+cp_l = 2/(3*log2) */
662 z_l = cp_l*p_h+p_l*cp+dp_l[k];
663 /* log2(ax) = (ss+..)*2/(3*log2) = n + dp_h + z_h + z_l */
664 t = (double)n;
665 t1 = (((z_h+z_l)+dp_h[k])+t);
666 __LO(t1) = 0;
667 t2 = z_l-(((t1-t)-dp_h[k])-z_h);
668 }
670 /* split up y into y1+y2 and compute (y1+y2)*(t1+t2) */
671 y1 = y;
672 __LO(y1) = 0;
673 p_l = (y-y1)*t1+y*t2;
674 p_h = y1*t1;
675 z = p_l+p_h;
676 j = __HI(z);
677 i = __LO(z);
678 if (j>=0x40900000) { /* z >= 1024 */
679 if(((j-0x40900000)|i)!=0) /* if z > 1024 */
680 return s*hugeX*hugeX; /* overflow */
681 else {
682 if(p_l+ovt>z-p_h) return s*hugeX*hugeX; /* overflow */
683 }
684 } else if((j&0x7fffffff)>=0x4090cc00 ) { /* z <= -1075 */
685 if(((j-0xc090cc00)|i)!=0) /* z < -1075 */
686 return s*tiny*tiny; /* underflow */
687 else {
688 if(p_l<=z-p_h) return s*tiny*tiny; /* underflow */
689 }
690 }
691 /*
692 * compute 2**(p_h+p_l)
693 */
694 i = j&0x7fffffff;
695 k = (i>>20)-0x3ff;
696 n = 0;
697 if(i>0x3fe00000) { /* if |z| > 0.5, set n = [z+0.5] */
698 n = j+(0x00100000>>(k+1));
699 k = ((n&0x7fffffff)>>20)-0x3ff; /* new k for n */
700 t = zeroX;
701 __HI(t) = (n&~(0x000fffff>>k));
702 n = ((n&0x000fffff)|0x00100000)>>(20-k);
703 if(j<0) n = -n;
704 p_h -= t;
705 }
706 t = p_l+p_h;
707 __LO(t) = 0;
708 u = t*lg2_h;
709 v = (p_l-(t-p_h))*lg2+t*lg2_l;
710 z = u+v;
711 w = v-(z-u);
712 t = z*z;
713 t1 = z - t*(P1+t*(P2+t*(P3+t*(P4+t*P5))));
714 r = (z*t1)/(t1-two)-(w+z*w);
715 z = one-(r-z);
716 j = __HI(z);
717 j += (n<<20);
718 if((j>>20)<=0) z = scalbn(z,n); /* subnormal output */
719 else __HI(z) += (n<<20);
720 return s*z;
721 }
724 JRT_LEAF(jdouble, SharedRuntime::dpow(jdouble x, jdouble y))
725 return __ieee754_pow(x, y);
726 JRT_END
728 #ifdef WIN32
729 # pragma optimize ( "", on )
730 #endif