/* * ==================================================== * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. * * Developed at SunPro, a Sun Microsystems, Inc. business. * Permission to use, copy, modify, and distribute this * software is freely granted, provided that this notice * is preserved. * ====================================================
*/
/* * The original fdlibm code used statements like: * n0 = ((*(int*)&one)>>29)^1; * index of high word * * ix0 = *(n0+(int*)&x); * high word of x * * ix1 = *((1-n0)+(int*)&x); * low word of x * * to dig two 32 bit words out of the 64 bit IEEE floating point * value. That is non-ANSI, and, moreover, the gcc instruction * scheduler gets it wrong. We instead use the following macros. * Unlike the original code, we determine the endianness at compile * time, not at run time; I don't see much benefit to selecting * endianness at run time.
*/
/* Get a 64-bit int from a double. */ #define EXTRACT_WORD64(ix,d) \ do { \
ieee_double_shape_type ew_u; \
ew_u.value = (d); \
(ix) = ew_u.xparts.w; \
} while (0)
/* Get the more significant 32 bit int from a double. */
#define GET_HIGH_WORD(i,d) \ do { \
ieee_double_shape_type gh_u; \
gh_u.value = (d); \
(i) = gh_u.parts.msw; \
} while (0)
/* Get the less significant 32 bit int from a double. */
#define GET_LOW_WORD(i,d) \ do { \
ieee_double_shape_type gl_u; \
gl_u.value = (d); \
(i) = gl_u.parts.lsw; \
} while (0)
/* Set a double from a 64-bit int. */ #define INSERT_WORD64(d,ix) \ do { \
ieee_double_shape_type iw_u; \
iw_u.xparts.w = (ix); \
(d) = iw_u.value; \
} while (0)
/* Set the more significant 32 bits of a double from an int. */
#define GET_FLOAT_WORD(i,d) \ do { \
ieee_float_shape_type gf_u; \
gf_u.value = (d); \
(i) = gf_u.word; \
} while (0)
/* Set a float from a 32 bit int. */
#define SET_FLOAT_WORD(d,i) \ do { \
ieee_float_shape_type sf_u; \
sf_u.word = (i); \
(d) = sf_u.value; \
} while (0)
/* * Get expsign and mantissa as 16 bit and 64 bit ints from an 80 bit long * double.
*/
#define EXTRACT_LDBL80_WORDS(ix0,ix1,d) \ do { \ union IEEEl2bits ew_u; \
ew_u.e = (d); \
(ix0) = ew_u.xbits.expsign; \
(ix1) = ew_u.xbits.man; \
} while (0)
/* * Get expsign and mantissa as one 16 bit and two 64 bit ints from a 128 bit * long double.
*/
#define EXTRACT_LDBL128_WORDS(ix0,ix1,ix2,d) \ do { \ union IEEEl2bits ew_u; \
ew_u.e = (d); \
(ix0) = ew_u.xbits.expsign; \
(ix1) = ew_u.xbits.manh; \
(ix2) = ew_u.xbits.manl; \
} while (0)
/* Get expsign as a 16 bit int from a long double. */
#define GET_LDBL_EXPSIGN(i,d) \ do { \ union IEEEl2bits ge_u; \
ge_u.e = (d); \
(i) = ge_u.xbits.expsign; \
} while (0)
/* * Set an 80 bit long double from a 16 bit int expsign and a 64 bit int * mantissa.
*/
#define INSERT_LDBL80_WORDS(d,ix0,ix1) \ do { \ union IEEEl2bits iw_u; \
iw_u.xbits.expsign = (ix0); \
iw_u.xbits.man = (ix1); \
(d) = iw_u.e; \
} while (0)
/* * Set a 128 bit long double from a 16 bit int expsign and two 64 bit ints * comprising the mantissa.
*/
#define INSERT_LDBL128_WORDS(d,ix0,ix1,ix2) \ do { \ union IEEEl2bits iw_u; \
iw_u.xbits.expsign = (ix0); \
iw_u.xbits.manh = (ix1); \
iw_u.xbits.manl = (ix2); \
(d) = iw_u.e; \
} while (0)
/* Set expsign of a long double from a 16 bit int. */
#define SET_LDBL_EXPSIGN(d,v) \ do { \ union IEEEl2bits se_u; \
se_u.e = (d); \
se_u.xbits.expsign = (v); \
(d) = se_u.e; \
} while (0)
#ifdef __i386__ /* Long double constants are broken on i386. */ #define LD80C(m, ex, v) { \
.xbits.man = __CONCAT(m, ULL), \
.xbits.expsign = (0x3fff + (ex)) | ((v) < 0 ? 0x8000 : 0), \
} #else /* The above works on non-i386 too, but we use this to check v. */ #define LD80C(m, ex, v) { .e = (v), } #endif
#ifdef FLT_EVAL_METHOD /* * Attempt to get strict C99 semantics for assignment with non-C99 compilers.
*/ #if !defined(_MSC_VER) && (FLT_EVAL_METHOD == 0 || __GNUC__ == 0) #define STRICT_ASSIGN(type, lval, rval) ((lval) = (rval)) #else #define STRICT_ASSIGN(type, lval, rval) do { \ volatile type __lval; \
\ if (sizeof(type) >= sizeof(longdouble)) \
(lval) = (rval); \ else { \
__lval = (rval); \
(lval) = __lval; \
} \
} while (0) #endif #else #define STRICT_ASSIGN(type, lval, rval) do { \ volatile type __lval; \
\ if (sizeof(type) >= sizeof(longdouble)) \
(lval) = (rval); \ else { \
__lval = (rval); \
(lval) = __lval; \
} \
} while (0) #endif/* FLT_EVAL_METHOD */
/* Support switching the mode to FP_PE if necessary. */ #ifdefined(__i386__) && !defined(NO_FPSETPREC) #define ENTERI() ENTERIT(longdouble) #define ENTERIT(returntype) \
returntype __retval; \
fp_prec_t __oprec; \
\ if ((__oprec = fpgetprec()) != FP_PE) \
fpsetprec(FP_PE) #define RETURNI(x) do { \
__retval = (x); \ if (__oprec != FP_PE) \
fpsetprec(__oprec); \
RETURNF(__retval); \
} while (0) #define ENTERV() \
fp_prec_t __oprec; \
\ if ((__oprec = fpgetprec()) != FP_PE) \
fpsetprec(FP_PE) #define RETURNV() do { \ if (__oprec != FP_PE) \
fpsetprec(__oprec); \ return; \
} while (0) #else #define ENTERI() #define ENTERIT(x) #define RETURNI(x) RETURNF(x) #define ENTERV() #define RETURNV() return #endif
/* Default return statement if hack*_t() is not used. */ #define RETURNF(v) return (v)
/* * 2sum gives the same result as 2sumF without requiring |a| >= |b| or * a == 0, but is slower.
*/ #define _2sum(a, b) do { \
__typeof(a) __s, __w; \
\
__w = (a) + (b); \
__s = __w - (a); \
(b) = ((a) - (__w - __s)) + ((b) - __s); \
(a) = __w; \
} while (0)
/* * 2sumF algorithm. * * "Normalize" the terms in the infinite-precision expression a + b for * the sum of 2 floating point values so that b is as small as possible * relative to 'a'. (The resulting 'a' is the value of the expression in * the same precision as 'a' and the resulting b is the rounding error.) * |a| must be >= |b| or 0, b's type must be no larger than 'a's type, and * exponent overflow or underflow must not occur. This uses a Theorem of * Dekker (1971). See Knuth (1981) 4.2.2 Theorem C. The name "TwoSum" * is apparently due to Skewchuk (1997). * * For this to always work, assignment of a + b to 'a' must not retain any * extra precision in a + b. This is required by C standards but broken * in many compilers. The brokenness cannot be worked around using * STRICT_ASSIGN() like we do elsewhere, since the efficiency of this * algorithm would be destroyed by non-null strict assignments. (The * compilers are correct to be broken -- the efficiency of all floating * point code calculations would be destroyed similarly if they forced the * conversions.) * * Fortunately, a case that works well can usually be arranged by building * any extra precision into the type of 'a' -- 'a' should have type float_t, * double_t or long double. b's type should be no larger than 'a's type. * Callers should use these types with scopes as large as possible, to * reduce their own extra-precision and efficiciency problems. In * particular, they shouldn't convert back and forth just to call here.
*/ #ifdef DEBUG #define _2sumF(a, b) do { \
__typeof(a) __w; \ volatile __typeof(a) __ia, __ib, __r, __vw; \
\
__ia = (a); \
__ib = (b); \
assert(__ia == 0 || fabsl(__ia) >= fabsl(__ib)); \
\
__w = (a) + (b); \
(b) = ((a) - __w) + (b); \
(a) = __w; \
\ /* The next 2 assertions are weak if (a) is already long double. */ \
assert((longdouble)__ia + __ib == (longdouble)(a) + (b)); \
__vw = __ia + __ib; \
__r = __ia - __vw; \
__r += __ib; \
assert(__vw == (a) && __r == (b)); \
} while (0) #else/* !DEBUG */ #define _2sumF(a, b) do { \
__typeof(a) __w; \
\
__w = (a) + (b); \
(b) = ((a) - __w) + (b); \
(a) = __w; \
} while (0) #endif/* DEBUG */
/* * Set x += c, where x is represented in extra precision as a + b. * x must be sufficiently normalized and sufficiently larger than c, * and the result is then sufficiently normalized. * * The details of ordering are that |a| must be >= |c| (so that (a, c) * can be normalized without extra work to swap 'a' with c). The details of * the normalization are that b must be small relative to the normalized 'a'. * Normalization of (a, c) makes the normalized c tiny relative to the * normalized a, so b remains small relative to 'a' in the result. However, * b need not ever be tiny relative to 'a'. For example, b might be about * 2**20 times smaller than 'a' to give about 20 extra bits of precision. * That is usually enough, and adding c (which by normalization is about * 2**53 times smaller than a) cannot change b significantly. However, * cancellation of 'a' with c in normalization of (a, c) may reduce 'a' * significantly relative to b. The caller must ensure that significant * cancellation doesn't occur, either by having c of the same sign as 'a', * or by having |c| a few percent smaller than |a|. Pre-normalization of * (a, b) may help. * * This is a variant of an algorithm of Kahan (see Knuth (1981) 4.2.2 * exercise 19). We gain considerable efficiency by requiring the terms to * be sufficiently normalized and sufficiently increasing.
*/ #define _3sumF(a, b, c) do { \
__typeof(a) __tmp; \
\
__tmp = (c); \
_2sumF(__tmp, (a)); \
(b) += (a); \
(a) = __tmp; \
} while (0)
/* * Common routine to process the arguments to nan(), nanf(), and nanl().
*/ void _scan_nan(uint32_t *__words, int __num_words, constchar *__s);
/* * Mix 0, 1 or 2 NaNs. First add 0 to each arg. This normally just turns * signaling NaNs into quiet NaNs by setting a quiet bit. We do this * because we want to never return a signaling NaN, and also because we * don't want the quiet bit to affect the result. Then mix the converted * args using the specified operation. * * When one arg is NaN, the result is typically that arg quieted. When both * args are NaNs, the result is typically the quietening of the arg whose * mantissa is largest after quietening. When neither arg is NaN, the * result may be NaN because it is indeterminate, or finite for subsequent * construction of a NaN as the indeterminate 0.0L/0.0L. * * Technical complications: the result in bits after rounding to the final * precision might depend on the runtime precision and/or on compiler * optimizations, especially when different register sets are used for * different precisions. Try to make the result not depend on at least the * runtime precision by always doing the main mixing step in long double * precision. Try to reduce dependencies on optimizations by adding the * the 0's in different precisions (unless everything is in long double * precision).
*/ #define nan_mix(x, y) (nan_mix_op((x), (y), +)) #define nan_mix_op(x, y, op) (((x) + 0.0L) op ((y) + 0))
#ifdef _COMPLEX_H
/* * C99 specifies that complex numbers have the same representation as * an array of two elements, where the first element is the real part * and the second element is the imaginary part.
*/ typedefunion { float complex f; float a[2];
} float_complex; typedefunion { double complex f; double a[2];
} double_complex; typedefunion { longdouble complex f; longdouble a[2];
} long_double_complex; #define REALPART(z) ((z).a[0]) #define IMAGPART(z) ((z).a[1])
/* * Inline functions that can be used to construct complex values. * * The C99 standard intends x+I*y to be used for this, but x+I*y is * currently unusable in general since gcc introduces many overflow, * underflow, sign and efficiency bugs by rewriting I*y as * (0.0+I)*(y+0.0*I) and laboriously computing the full complex product. * In particular, I*Inf is corrupted to NaN+I*Inf, and I*-0 is corrupted * to -0.0+I*0.0. * * The C11 standard introduced the macros CMPLX(), CMPLXF() and CMPLXL() * to construct complex values. Compilers that conform to the C99 * standard require the following functions to avoid the above issues.
*/
/* * The rnint() family rounds to the nearest integer for a restricted range * range of args (up to about 2**MANT_DIG). We assume that the current * rounding mode is FE_TONEAREST so that this can be done efficiently. * Extra precision causes more problems in practice, and we only centralize * this here to reduce those problems, and have not solved the efficiency * problems. The exp2() family uses a more delicate version of this that * requires extracting bits from the intermediate value, so it is not * centralized here and should copy any solution of the efficiency problems.
*/
staticinlinedouble
rnint(__double_t x)
{ /* * This casts to double to kill any extra precision. This depends * on the cast being applied to a double_t to avoid compiler bugs * (this is a cleaner version of STRICT_ASSIGN()). This is * inefficient if there actually is extra precision, but is hard * to improve on. We use double_t in the API to minimise conversions * for just calling here. Note that we cannot easily change the * magic number to the one that works directly with double_t, since * the rounding precision is variable at runtime on x86 so the * magic number would need to be variable. Assuming that the * rounding precision is always the default is too fragile. This * and many other complications will move when the default is * changed to FP_PE.
*/ return ((double)(x + 0x1.8p52) - 0x1.8p52);
}
/* * irint() and i64rint() give the same result as casting to their integer * return type provided their arg is a floating point integer. They can * sometimes be more efficient because no rounding is required.
*/ #ifdefined(amd64) || defined(__i386__) #define irint(x) \
(sizeof(x) == sizeof(float) && \ sizeof(__float_t) == sizeof(longdouble) ? irintf(x) : \ sizeof(x) == sizeof(double) && \ sizeof(__double_t) == sizeof(longdouble) ? irintd(x) : \ sizeof(x) == sizeof(longdouble) ? irintl(x) : (int)(x)) #else #define irint(x) ((int)(x)) #endif
#define i64rint(x) ((int64_t)(x)) /* only needed for ld128 so not opt. */
#ifdefined(__i386__) static __inlineint
irintf(float x)
{ int n;
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