Exemple #1
0
dcomplex
csqrt(dcomplex z) {
	dcomplex ans;
	double x, y, t, ax, ay;
	int n, ix, iy, hx, hy, lx, ly;

	x = D_RE(z);
	y = D_IM(z);
	hx = HI_WORD(x);
	lx = LO_WORD(x);
	hy = HI_WORD(y);
	ly = LO_WORD(y);
	ix = hx & 0x7fffffff;
	iy = hy & 0x7fffffff;
	ay = fabs(y);
	ax = fabs(x);
	if (ix >= 0x7ff00000 || iy >= 0x7ff00000) {
		/* x or y is Inf or NaN */
		if (ISINF(iy, ly))
			D_IM(ans) = D_RE(ans) = ay;
		else if (ISINF(ix, lx)) {
			if (hx > 0) {
				D_RE(ans) = ax;
				D_IM(ans) = ay * zero;
			} else {
				D_RE(ans) = ay * zero;
				D_IM(ans) = ax;
			}
		} else
			D_IM(ans) = D_RE(ans) = ax + ay;
	} else if ((iy | ly) == 0) {	/* y = 0 */
		if (hx >= 0) {
			D_RE(ans) = sqrt(ax);
			D_IM(ans) = zero;
		} else {
			D_IM(ans) = sqrt(ax);
			D_RE(ans) = zero;
		}
	} else if (ix >= iy) {
		n = (ix - iy) >> 20;
		if (n >= 30) {	/* x >> y or y=0 */
			t = sqrt(ax);
		} else if (ix >= 0x5f300000) {	/* x > 2**500 */
			ax *= twom601;
			y *= twom601;
			t = two300 * sqrt(ax + sqrt(ax * ax + y * y));
		} else if (iy < 0x20b00000) {	/* y < 2**-500 */
			ax *= two599;
			y *= two599;
			t = twom300 * sqrt(ax + sqrt(ax * ax + y * y));
		} else
			t = sqrt(half * (ax + sqrt(ax * ax + ay * ay)));
		if (hx >= 0) {
			D_RE(ans) = t;
			D_IM(ans) = ay / (t + t);
		} else {
			D_IM(ans) = t;
			D_RE(ans) = ay / (t + t);
		}
	} else {
Exemple #2
0
/*
 * arctan(x):
 *
 *	if (x < 0) {
 *		x = abs(x);
 *		sign = 1;
 *	}
 *	y = arctan(x);
 *	if (sign) {
 *		y = -y;
 *	}
 */
struct fpn *
fpu_atan(struct fpemu *fe)
{
    struct fpn a;
    struct fpn x;
    struct fpn v;

    if (ISNAN(&fe->fe_f2))
        return &fe->fe_f2;
    if (ISZERO(&fe->fe_f2))
        return &fe->fe_f2;

    CPYFPN(&a, &fe->fe_f2);

    if (ISINF(&fe->fe_f2)) {
        /* f2 <- pi/2 */
        fpu_const(&fe->fe_f2, FPU_CONST_PI);
        fe->fe_f2.fp_exp--;

        fe->fe_f2.fp_sign = a.fp_sign;
        return &fe->fe_f2;
    }

    fpu_const(&x, FPU_CONST_1);
    fpu_const(&fe->fe_f2, FPU_CONST_0);
    CPYFPN(&v, &fe->fe_f2);
    fpu_cordit1(fe, &x, &a, &fe->fe_f2, &v);

    return &fe->fe_f2;
}
Exemple #3
0
/*
 * tan(x) = sin(x) / cos(x)
 */
struct fpn *
fpu_tan(struct fpemu *fe)
{
    struct fpn x;
    struct fpn s;
    struct fpn *r;

    if (ISNAN(&fe->fe_f2))
        return &fe->fe_f2;
    if (ISINF(&fe->fe_f2))
        return fpu_newnan(fe);

    /* if x is +0/-0, return +0/-0 */
    if (ISZERO(&fe->fe_f2))
        return &fe->fe_f2;

    CPYFPN(&x, &fe->fe_f2);

    /* sin(x) */
    CPYFPN(&fe->fe_f2, &x);
    r = fpu_sin(fe);
    CPYFPN(&s, r);

    /* cos(x) */
    CPYFPN(&fe->fe_f2, &x);
    r = fpu_cos(fe);
    CPYFPN(&fe->fe_f2, r);

    CPYFPN(&fe->fe_f1, &s);
    r = fpu_div(fe);
    return r;
}
Exemple #4
0
/*
 * arccos(x) = pi/2 - arcsin(x)
 */
struct fpn *
fpu_acos(struct fpemu *fe)
{
    struct fpn *r;

    if (ISNAN(&fe->fe_f2))
        return &fe->fe_f2;
    if (ISINF(&fe->fe_f2))
        return fpu_newnan(fe);

    r = fpu_asin(fe);
    CPYFPN(&fe->fe_f2, r);

    /* pi/2 - asin(x) */
    fpu_const(&fe->fe_f1, FPU_CONST_PI);
    fe->fe_f1.fp_exp--;
    fe->fe_f2.fp_sign = !fe->fe_f2.fp_sign;
    r = fpu_add(fe);

    return r;
}
Exemple #5
0
/*
 *                          x
 * arcsin(x) = arctan(---------------)
 *                     sqrt(1 - x^2)
 */
struct fpn *
fpu_asin(struct fpemu *fe)
{
    struct fpn x;
    struct fpn *r;

    if (ISNAN(&fe->fe_f2))
        return &fe->fe_f2;
    if (ISZERO(&fe->fe_f2))
        return &fe->fe_f2;

    if (ISINF(&fe->fe_f2))
        return fpu_newnan(fe);

    CPYFPN(&x, &fe->fe_f2);

    /* x^2 */
    CPYFPN(&fe->fe_f1, &fe->fe_f2);
    r = fpu_mul(fe);

    /* 1 - x^2 */
    CPYFPN(&fe->fe_f2, r);
    fe->fe_f2.fp_sign = 1;
    fpu_const(&fe->fe_f1, FPU_CONST_1);
    r = fpu_add(fe);

    /* sqrt(1-x^2) */
    CPYFPN(&fe->fe_f2, r);
    r = fpu_sqrt(fe);

    /* x/sqrt */
    CPYFPN(&fe->fe_f2, r);
    CPYFPN(&fe->fe_f1, &x);
    r = fpu_div(fe);

    /* arctan */
    CPYFPN(&fe->fe_f2, r);
    return fpu_atan(fe);
}
Exemple #6
0
/*
 * Our task is to calculate the square root of a floating point number x0.
 * This number x normally has the form:
 *
 *		    exp
 *	x = mant * 2		(where 1 <= mant < 2 and exp is an integer)
 *
 * This can be left as it stands, or the mantissa can be doubled and the
 * exponent decremented:
 *
 *			  exp-1
 *	x = (2 * mant) * 2	(where 2 <= 2 * mant < 4)
 *
 * If the exponent `exp' is even, the square root of the number is best
 * handled using the first form, and is by definition equal to:
 *
 *				exp/2
 *	sqrt(x) = sqrt(mant) * 2
 *
 * If exp is odd, on the other hand, it is convenient to use the second
 * form, giving:
 *
 *				    (exp-1)/2
 *	sqrt(x) = sqrt(2 * mant) * 2
 *
 * In the first case, we have
 *
 *	1 <= mant < 2
 *
 * and therefore
 *
 *	sqrt(1) <= sqrt(mant) < sqrt(2)
 *
 * while in the second case we have
 *
 *	2 <= 2*mant < 4
 *
 * and therefore
 *
 *	sqrt(2) <= sqrt(2*mant) < sqrt(4)
 *
 * so that in any case, we are sure that
 *
 *	sqrt(1) <= sqrt(n * mant) < sqrt(4),	n = 1 or 2
 *
 * or
 *
 *	1 <= sqrt(n * mant) < 2,		n = 1 or 2.
 *
 * This root is therefore a properly formed mantissa for a floating
 * point number.  The exponent of sqrt(x) is either exp/2 or (exp-1)/2
 * as above.  This leaves us with the problem of finding the square root
 * of a fixed-point number in the range [1..4).
 *
 * Though it may not be instantly obvious, the following square root
 * algorithm works for any integer x of an even number of bits, provided
 * that no overflows occur:
 *
 *	let q = 0
 *	for k = NBITS-1 to 0 step -1 do -- for each digit in the answer...
 *		x *= 2			-- multiply by radix, for next digit
 *		if x >= 2q + 2^k then	-- if adding 2^k does not
 *			x -= 2q + 2^k	-- exceed the correct root,
 *			q += 2^k	-- add 2^k and adjust x
 *		fi
 *	done
 *	sqrt = q / 2^(NBITS/2)		-- (and any remainder is in x)
 *
 * If NBITS is odd (so that k is initially even), we can just add another
 * zero bit at the top of x.  Doing so means that q is not going to acquire
 * a 1 bit in the first trip around the loop (since x0 < 2^NBITS).  If the
 * final value in x is not needed, or can be off by a factor of 2, this is
 * equivalant to moving the `x *= 2' step to the bottom of the loop:
 *
 *	for k = NBITS-1 to 0 step -1 do if ... fi; x *= 2; done
 *
 * and the result q will then be sqrt(x0) * 2^floor(NBITS / 2).
 * (Since the algorithm is destructive on x, we will call x's initial
 * value, for which q is some power of two times its square root, x0.)
 *
 * If we insert a loop invariant y = 2q, we can then rewrite this using
 * C notation as:
 *
 *	q = y = 0; x = x0;
 *	for (k = NBITS; --k >= 0;) {
 * #if (NBITS is even)
 *		x *= 2;
 * #endif
 *		t = y + (1 << k);
 *		if (x >= t) {
 *			x -= t;
 *			q += 1 << k;
 *			y += 1 << (k + 1);
 *		}
 * #if (NBITS is odd)
 *		x *= 2;
 * #endif
 *	}
 *
 * If x0 is fixed point, rather than an integer, we can simply alter the
 * scale factor between q and sqrt(x0).  As it happens, we can easily arrange
 * for the scale factor to be 2**0 or 1, so that sqrt(x0) == q.
 *
 * In our case, however, x0 (and therefore x, y, q, and t) are multiword
 * integers, which adds some complication.  But note that q is built one
 * bit at a time, from the top down, and is not used itself in the loop
 * (we use 2q as held in y instead).  This means we can build our answer
 * in an integer, one word at a time, which saves a bit of work.  Also,
 * since 1 << k is always a `new' bit in q, 1 << k and 1 << (k+1) are
 * `new' bits in y and we can set them with an `or' operation rather than
 * a full-blown multiword add.
 *
 * We are almost done, except for one snag.  We must prove that none of our
 * intermediate calculations can overflow.  We know that x0 is in [1..4)
 * and therefore the square root in q will be in [1..2), but what about x,
 * y, and t?
 *
 * We know that y = 2q at the beginning of each loop.  (The relation only
 * fails temporarily while y and q are being updated.)  Since q < 2, y < 4.
 * The sum in t can, in our case, be as much as y+(1<<1) = y+2 < 6, and.
 * Furthermore, we can prove with a bit of work that x never exceeds y by
 * more than 2, so that even after doubling, 0 <= x < 8.  (This is left as
 * an exercise to the reader, mostly because I have become tired of working
 * on this comment.)
 *
 * If our floating point mantissas (which are of the form 1.frac) occupy
 * B+1 bits, our largest intermediary needs at most B+3 bits, or two extra.
 * In fact, we want even one more bit (for a carry, to avoid compares), or
 * three extra.  There is a comment in fpu_emu.h reminding maintainers of
 * this, so we have some justification in assuming it.
 */
struct fpn *
fpu_sqrt(struct fpemu *fe)
{
	struct fpn *x = &fe->fe_f1;
	u_int bit, q, tt;
	u_int x0, x1, x2, x3;
	u_int y0, y1, y2, y3;
	u_int d0, d1, d2, d3;
	int e;
	FPU_DECL_CARRY;

	/*
	 * Take care of special cases first.  In order:
	 *
	 *	sqrt(NaN) = NaN
	 *	sqrt(+0) = +0
	 *	sqrt(-0) = -0
	 *	sqrt(x < 0) = NaN	(including sqrt(-Inf))
	 *	sqrt(+Inf) = +Inf
	 *
	 * Then all that remains are numbers with mantissas in [1..2).
	 */
	DPRINTF(FPE_REG, ("fpu_sqer:\n"));
	DUMPFPN(FPE_REG, x);
	DPRINTF(FPE_REG, ("=>\n"));
	if (ISNAN(x)) {
		fe->fe_cx |= FPSCR_VXSNAN;
		DUMPFPN(FPE_REG, x);
		return (x);
	}
	if (ISZERO(x)) {
		fe->fe_cx |= FPSCR_ZX;
		x->fp_class = FPC_INF;
		DUMPFPN(FPE_REG, x);
		return (x);
	}
	if (x->fp_sign) {
		return (fpu_newnan(fe));
	}
	if (ISINF(x)) {
		fe->fe_cx |= FPSCR_VXSQRT;
		DUMPFPN(FPE_REG, 0);
		return (0);
	}

	/*
	 * Calculate result exponent.  As noted above, this may involve
	 * doubling the mantissa.  We will also need to double x each
	 * time around the loop, so we define a macro for this here, and
	 * we break out the multiword mantissa.
	 */
#ifdef FPU_SHL1_BY_ADD
#define	DOUBLE_X { \
	FPU_ADDS(x3, x3, x3); FPU_ADDCS(x2, x2, x2); \
	FPU_ADDCS(x1, x1, x1); FPU_ADDC(x0, x0, x0); \
}
#else
#define	DOUBLE_X { \
	x0 = (x0 << 1) | (x1 >> 31); x1 = (x1 << 1) | (x2 >> 31); \
	x2 = (x2 << 1) | (x3 >> 31); x3 <<= 1; \
}
#endif
#if (FP_NMANT & 1) != 0
# define ODD_DOUBLE	DOUBLE_X
# define EVEN_DOUBLE	/* nothing */
#else
# define ODD_DOUBLE	/* nothing */
# define EVEN_DOUBLE	DOUBLE_X
#endif
	x0 = x->fp_mant[0];
	x1 = x->fp_mant[1];
	x2 = x->fp_mant[2];
	x3 = x->fp_mant[3];
	e = x->fp_exp;
	if (e & 1)		/* exponent is odd; use sqrt(2mant) */
		DOUBLE_X;
	/* THE FOLLOWING ASSUMES THAT RIGHT SHIFT DOES SIGN EXTENSION */
	x->fp_exp = e >> 1;	/* calculates (e&1 ? (e-1)/2 : e/2 */

	/*
	 * Now calculate the mantissa root.  Since x is now in [1..4),
	 * we know that the first trip around the loop will definitely
	 * set the top bit in q, so we can do that manually and start
	 * the loop at the next bit down instead.  We must be sure to
	 * double x correctly while doing the `known q=1.0'.
	 *
	 * We do this one mantissa-word at a time, as noted above, to
	 * save work.  To avoid `(1U << 31) << 1', we also do the top bit
	 * outside of each per-word loop.
	 *
	 * The calculation `t = y + bit' breaks down into `t0 = y0, ...,
	 * t3 = y3, t? |= bit' for the appropriate word.  Since the bit
	 * is always a `new' one, this means that three of the `t?'s are
	 * just the corresponding `y?'; we use `#define's here for this.
	 * The variable `tt' holds the actual `t?' variable.
	 */

	/* calculate q0 */
#define	t0 tt
	bit = FP_1;
	EVEN_DOUBLE;
	/* if (x >= (t0 = y0 | bit)) { */	/* always true */
		q = bit;
		x0 -= bit;
		y0 = bit << 1;
	/* } */
	ODD_DOUBLE;
	while ((bit >>= 1) != 0) {	/* for remaining bits in q0 */
		EVEN_DOUBLE;
		t0 = y0 | bit;		/* t = y + bit */
		if (x0 >= t0) {		/* if x >= t then */
			x0 -= t0;	/*	x -= t */
			q |= bit;	/*	q += bit */
			y0 |= bit << 1;	/*	y += bit << 1 */
		}
		ODD_DOUBLE;
	}
	x->fp_mant[0] = q;
#undef t0

	/* calculate q1.  note (y0&1)==0. */
#define t0 y0
#define t1 tt
	q = 0;
	y1 = 0;
	bit = 1 << 31;
	EVEN_DOUBLE;
	t1 = bit;
	FPU_SUBS(d1, x1, t1);
	FPU_SUBC(d0, x0, t0);		/* d = x - t */
	if ((int)d0 >= 0) {		/* if d >= 0 (i.e., x >= t) then */
		x0 = d0, x1 = d1;	/*	x -= t */
		q = bit;		/*	q += bit */
		y0 |= 1;		/*	y += bit << 1 */
	}
	ODD_DOUBLE;
	while ((bit >>= 1) != 0) {	/* for remaining bits in q1 */
		EVEN_DOUBLE;		/* as before */
		t1 = y1 | bit;
		FPU_SUBS(d1, x1, t1);
		FPU_SUBC(d0, x0, t0);
		if ((int)d0 >= 0) {
			x0 = d0, x1 = d1;
			q |= bit;
			y1 |= bit << 1;
		}
		ODD_DOUBLE;
	}
	x->fp_mant[1] = q;
#undef t1

	/* calculate q2.  note (y1&1)==0; y0 (aka t0) is fixed. */
#define t1 y1
#define t2 tt
	q = 0;
	y2 = 0;
	bit = 1 << 31;
	EVEN_DOUBLE;
	t2 = bit;
	FPU_SUBS(d2, x2, t2);
	FPU_SUBCS(d1, x1, t1);
	FPU_SUBC(d0, x0, t0);
	if ((int)d0 >= 0) {
		x0 = d0, x1 = d1, x2 = d2;
		q |= bit;
		y1 |= 1;		/* now t1, y1 are set in concrete */
	}
	ODD_DOUBLE;
	while ((bit >>= 1) != 0) {
		EVEN_DOUBLE;
		t2 = y2 | bit;
		FPU_SUBS(d2, x2, t2);
		FPU_SUBCS(d1, x1, t1);
		FPU_SUBC(d0, x0, t0);
		if ((int)d0 >= 0) {
			x0 = d0, x1 = d1, x2 = d2;
			q |= bit;
			y2 |= bit << 1;
		}
		ODD_DOUBLE;
	}
	x->fp_mant[2] = q;
#undef t2

	/* calculate q3.  y0, t0, y1, t1 all fixed; y2, t2, almost done. */
#define t2 y2
#define t3 tt
	q = 0;
	y3 = 0;
	bit = 1 << 31;
	EVEN_DOUBLE;
	t3 = bit;
	FPU_SUBS(d3, x3, t3);
	FPU_SUBCS(d2, x2, t2);
	FPU_SUBCS(d1, x1, t1);
	FPU_SUBC(d0, x0, t0);
	ODD_DOUBLE;
	if ((int)d0 >= 0) {
		x0 = d0, x1 = d1, x2 = d2;
		q |= bit;
		y2 |= 1;
	}
	while ((bit >>= 1) != 0) {
		EVEN_DOUBLE;
		t3 = y3 | bit;
		FPU_SUBS(d3, x3, t3);
		FPU_SUBCS(d2, x2, t2);
		FPU_SUBCS(d1, x1, t1);
		FPU_SUBC(d0, x0, t0);
		if ((int)d0 >= 0) {
			x0 = d0, x1 = d1, x2 = d2;
			q |= bit;
			y3 |= bit << 1;
		}
		ODD_DOUBLE;
	}
	x->fp_mant[3] = q;

	/*
	 * The result, which includes guard and round bits, is exact iff
	 * x is now zero; any nonzero bits in x represent sticky bits.
	 */
	x->fp_sticky = x0 | x1 | x2 | x3;
	DUMPFPN(FPE_REG, x);
	return (x);
}
Exemple #7
0
struct fpn *
fpu_div(struct fpemu *fe)
{
	struct fpn *x = &fe->fe_f1, *y = &fe->fe_f2;
	u_int q, bit;
	u_int r0, r1, r2, r3, d0, d1, d2, d3, y0, y1, y2, y3;
	FPU_DECL_CARRY

	/*
	 * Since divide is not commutative, we cannot just use ORDER.
	 * Check either operand for NaN first; if there is at least one,
	 * order the signalling one (if only one) onto the right, then
	 * return it.  Otherwise we have the following cases:
	 *
	 *	Inf / Inf = NaN, plus NV exception
	 *	Inf / num = Inf [i.e., return x]
	 *	Inf / 0   = Inf [i.e., return x]
	 *	0 / Inf = 0 [i.e., return x]
	 *	0 / num = 0 [i.e., return x]
	 *	0 / 0   = NaN, plus NV exception
	 *	num / Inf = 0
	 *	num / num = num (do the divide)
	 *	num / 0   = Inf, plus DZ exception
	 */
	DPRINTF(FPE_REG, ("fpu_div:\n"));
	DUMPFPN(FPE_REG, x);
	DUMPFPN(FPE_REG, y);
	DPRINTF(FPE_REG, ("=>\n"));
	if (ISNAN(x) || ISNAN(y)) {
		ORDER(x, y);
		fe->fe_cx |= FPSCR_VXSNAN;
		DUMPFPN(FPE_REG, y);
		return (y);
	}
	/*
	 * Need to split the following out cause they generate different
	 * exceptions. 
	 */
	if (ISINF(x)) {
		if (x->fp_class == y->fp_class) {
			fe->fe_cx |= FPSCR_VXIDI;
			return (fpu_newnan(fe));
		}
		DUMPFPN(FPE_REG, x);
		return (x);
	}
	if (ISZERO(x)) {
		fe->fe_cx |= FPSCR_ZX;
		if (x->fp_class == y->fp_class) {
			fe->fe_cx |= FPSCR_VXZDZ;
			return (fpu_newnan(fe));
		}
		DUMPFPN(FPE_REG, x);
		return (x);
	}

	/* all results at this point use XOR of operand signs */
	x->fp_sign ^= y->fp_sign;
	if (ISINF(y)) {
		x->fp_class = FPC_ZERO;
		DUMPFPN(FPE_REG, x);
		return (x);
	}
	if (ISZERO(y)) {
		fe->fe_cx = FPSCR_ZX;
		x->fp_class = FPC_INF;
		DUMPFPN(FPE_REG, x);
		return (x);
	}

	/*
	 * Macros for the divide.  See comments at top for algorithm.
	 * Note that we expand R, D, and Y here.
	 */

#define	SUBTRACT		/* D = R - Y */ \
	FPU_SUBS(d3, r3, y3); FPU_SUBCS(d2, r2, y2); \
	FPU_SUBCS(d1, r1, y1); FPU_SUBC(d0, r0, y0)

#define	NONNEGATIVE		/* D >= 0 */ \
	((int)d0 >= 0)

#ifdef FPU_SHL1_BY_ADD
#define	SHL1			/* R <<= 1 */ \
	FPU_ADDS(r3, r3, r3); FPU_ADDCS(r2, r2, r2); \
	FPU_ADDCS(r1, r1, r1); FPU_ADDC(r0, r0, r0)
#else
#define	SHL1 \
	r0 = (r0 << 1) | (r1 >> 31), r1 = (r1 << 1) | (r2 >> 31), \
	r2 = (r2 << 1) | (r3 >> 31), r3 <<= 1
#endif

#define	LOOP			/* do ... while (bit >>= 1) */ \
	do { \
		SHL1; \
		SUBTRACT; \
		if (NONNEGATIVE) { \
			q |= bit; \
			r0 = d0, r1 = d1, r2 = d2, r3 = d3; \
		} \
	} while ((bit >>= 1) != 0)

#define	WORD(r, i)			/* calculate r->fp_mant[i] */ \
	q = 0; \
	bit = 1 << 31; \
	LOOP; \
	(x)->fp_mant[i] = q

	/* Setup.  Note that we put our result in x. */
	r0 = x->fp_mant[0];
	r1 = x->fp_mant[1];
	r2 = x->fp_mant[2];
	r3 = x->fp_mant[3];
	y0 = y->fp_mant[0];
	y1 = y->fp_mant[1];
	y2 = y->fp_mant[2];
	y3 = y->fp_mant[3];

	bit = FP_1;
	SUBTRACT;
	if (NONNEGATIVE) {
		x->fp_exp -= y->fp_exp;
		r0 = d0, r1 = d1, r2 = d2, r3 = d3;
		q = bit;
		bit >>= 1;
	} else {
Exemple #8
0
/*
 * The multiplication algorithm for normal numbers is as follows:
 *
 * The fraction of the product is built in the usual stepwise fashion.
 * Each step consists of shifting the accumulator right one bit
 * (maintaining any guard bits) and, if the next bit in y is set,
 * adding the multiplicand (x) to the accumulator.  Then, in any case,
 * we advance one bit leftward in y.  Algorithmically:
 *
 *	A = 0;
 *	for (bit = 0; bit < FP_NMANT; bit++) {
 *		sticky |= A & 1, A >>= 1;
 *		if (Y & (1 << bit))
 *			A += X;
 *	}
 *
 * (X and Y here represent the mantissas of x and y respectively.)
 * The resultant accumulator (A) is the product's mantissa.  It may
 * be as large as 11.11111... in binary and hence may need to be
 * shifted right, but at most one bit.
 *
 * Since we do not have efficient multiword arithmetic, we code the
 * accumulator as four separate words, just like any other mantissa.
 * We use local variables in the hope that this is faster than memory.
 * We keep x->fp_mant in locals for the same reason.
 *
 * In the algorithm above, the bits in y are inspected one at a time.
 * We will pick them up 32 at a time and then deal with those 32, one
 * at a time.  Note, however, that we know several things about y:
 *
 *    - the guard and round bits at the bottom are sure to be zero;
 *
 *    - often many low bits are zero (y is often from a single or double
 *	precision source);
 *
 *    - bit FP_NMANT-1 is set, and FP_1*2 fits in a word.
 *
 * We can also test for 32-zero-bits swiftly.  In this case, the center
 * part of the loop---setting sticky, shifting A, and not adding---will
 * run 32 times without adding X to A.  We can do a 32-bit shift faster
 * by simply moving words.  Since zeros are common, we optimize this case.
 * Furthermore, since A is initially zero, we can omit the shift as well
 * until we reach a nonzero word.
 */
struct fpn *
fpu_mul(struct fpemu *fe)
{
	struct fpn *x = &fe->fe_f1, *y = &fe->fe_f2;
	u_int a3, a2, a1, a0, x3, x2, x1, x0, bit, m;
	int sticky;
	FPU_DECL_CARRY;

	/*
	 * Put the `heavier' operand on the right (see fpu_emu.h).
	 * Then we will have one of the following cases, taken in the
	 * following order:
	 *
	 *  - y = NaN.  Implied: if only one is a signalling NaN, y is.
	 *	The result is y.
	 *  - y = Inf.  Implied: x != NaN (is 0, number, or Inf: the NaN
	 *    case was taken care of earlier).
	 *	If x = 0, the result is NaN.  Otherwise the result
	 *	is y, with its sign reversed if x is negative.
	 *  - x = 0.  Implied: y is 0 or number.
	 *	The result is 0 (with XORed sign as usual).
	 *  - other.  Implied: both x and y are numbers.
	 *	The result is x * y (XOR sign, multiply bits, add exponents).
	 */
	DPRINTF(FPE_REG, ("fpu_mul:\n"));
	DUMPFPN(FPE_REG, x);
	DUMPFPN(FPE_REG, y);
	DPRINTF(FPE_REG, ("=>\n"));

	ORDER(x, y);
	if (ISNAN(y)) {
		y->fp_sign ^= x->fp_sign;
		fe->fe_cx |= FPSCR_VXSNAN;
		DUMPFPN(FPE_REG, y);
		return (y);
	}
	if (ISINF(y)) {
		if (ISZERO(x)) {
			fe->fe_cx |= FPSCR_VXIMZ;
			return (fpu_newnan(fe));
		}
		y->fp_sign ^= x->fp_sign;
			DUMPFPN(FPE_REG, y);
		return (y);
	}
	if (ISZERO(x)) {
		x->fp_sign ^= y->fp_sign;
		DUMPFPN(FPE_REG, x);
		return (x);
	}

	/*
	 * Setup.  In the code below, the mask `m' will hold the current
	 * mantissa byte from y.  The variable `bit' denotes the bit
	 * within m.  We also define some macros to deal with everything.
	 */
	x3 = x->fp_mant[3];
	x2 = x->fp_mant[2];
	x1 = x->fp_mant[1];
	x0 = x->fp_mant[0];
	sticky = a3 = a2 = a1 = a0 = 0;

#define	ADD	/* A += X */ \
	FPU_ADDS(a3, a3, x3); \
	FPU_ADDCS(a2, a2, x2); \
	FPU_ADDCS(a1, a1, x1); \
	FPU_ADDC(a0, a0, x0)

#define	SHR1	/* A >>= 1, with sticky */ \
	sticky |= a3 & 1, a3 = (a3 >> 1) | (a2 << 31), \
	a2 = (a2 >> 1) | (a1 << 31), a1 = (a1 >> 1) | (a0 << 31), a0 >>= 1

#define	SHR32	/* A >>= 32, with sticky */ \
	sticky |= a3, a3 = a2, a2 = a1, a1 = a0, a0 = 0

#define	STEP	/* each 1-bit step of the multiplication */ \
	SHR1; if (bit & m) { ADD; }; bit <<= 1

	/*
	 * We are ready to begin.  The multiply loop runs once for each
	 * of the four 32-bit words.  Some words, however, are special.
	 * As noted above, the low order bits of Y are often zero.  Even
	 * if not, the first loop can certainly skip the guard bits.
	 * The last word of y has its highest 1-bit in position FP_NMANT-1,
	 * so we stop the loop when we move past that bit.
	 */
	if ((m = y->fp_mant[3]) == 0) {
		/* SHR32; */			/* unneeded since A==0 */
	} else {
		bit = 1 << FP_NG;
		do {
			STEP;
		} while (bit != 0);
	}
	if ((m = y->fp_mant[2]) == 0) {
		SHR32;
	} else {
		bit = 1;
		do {
			STEP;
		} while (bit != 0);
	}
	if ((m = y->fp_mant[1]) == 0) {
		SHR32;
	} else {
		bit = 1;
		do {
			STEP;
		} while (bit != 0);
	}
	m = y->fp_mant[0];		/* definitely != 0 */
	bit = 1;
	do {
		STEP;
	} while (bit <= m);

	/*
	 * Done with mantissa calculation.  Get exponent and handle
	 * 11.111...1 case, then put result in place.  We reuse x since
	 * it already has the right class (FP_NUM).
	 */
	m = x->fp_exp + y->fp_exp;
	if (a0 >= FP_2) {
		SHR1;
		m++;
	}
	x->fp_sign ^= y->fp_sign;
	x->fp_exp = m;
	x->fp_sticky = sticky;
	x->fp_mant[3] = a3;
	x->fp_mant[2] = a2;
	x->fp_mant[1] = a1;
	x->fp_mant[0] = a0;

	DUMPFPN(FPE_REG, x);
	return (x);
}
int GDens2Update(GDens *ptr)
{
    /* 
       update ptr
     */
    double lpmax, lpsum, psum;
    int i, n = ptr->n;
    
    /* 
       compute various constants
     */
    for(i=0;i<n;i++) 
    {
	double s,
	    x0 = ptr->elm[i].xl,  x1 = ptr->elm[i].xm,  x2 = ptr->elm[i].xr,
	    f0 = ptr->elm[i].lfl, f1 = ptr->elm[i].lfm, f2 = ptr->elm[i].lfr;

	ptr->elm[i].lfmax = f0;			  /* scale and shift */
	f1 -= f0; f2 -= f0; f0 = 0.0;
	x1 -= x0; x2 -= x0; x0 = 0.0;
	
	s = 1./((-SQR(x2) + x2*x1)*x1);
	ptr->elm[i].b = -s*(-f2*SQR(x1) +f1*SQR(x2));
	ptr->elm[i].c = s*(-f2*x1 +f1*x2);
    }
    
    /* 
       compute the integral over each cell, unnormalized
     */
    for(i=0;i<n;i++)
    {
	if (ISZERO(ptr->elm[i].c))
	{
	    if (ISZERO(ptr->elm[i].b))
		ptr->elm[i].lnormc = log(ptr->elm[i].xr-ptr->elm[i].xl);
	    else
	    {
		double tmp = (ptr->elm[i].xr-ptr->elm[i].xl)*ptr->elm[i].b;
		if (fabs(tmp) > FLT_EPSILON)
		{
		    /* 
		       all ok
		    */
		    ptr->elm[i].lnormc = log(fabs(exp((ptr->elm[i].xr-ptr->elm[i].xl)*ptr->elm[i].b) -1.0))
			- log(fabs(ptr->elm[i].b));
		}
		else
		{
		    /* 
		       this is the expansion for small 'tmp'
		    */
		    ptr->elm[i].lnormc = log(fabs(tmp)) - log(fabs(ptr->elm[i].b));
		}
	    }
	}
	else
	{
	    /* 
	       this can (and does) go wrong as the 'erf' and 'erfi' function may fail for high
	       values of the arguments. perhaps we need to intergrate directly
	       int(exp(x^2),x=low...high) ?
	     */
	    
	    double aa = 0.5*ptr->elm[i].b/sqrt(fabs(ptr->elm[i].c));
	    
	    if (ptr->elm[i].c <= 0.0)
		ptr->elm[i].lnormc = -0.25*SQR(ptr->elm[i].b)/ptr->elm[i].c +
		    log(1./(TWODIVSQRTPI*sqrt(-ptr->elm[i].c)))
		    + lerf_diff(sqrt(-ptr->elm[i].c)*(ptr->elm[i].xr-ptr->elm[i].xl) -aa, -aa);
	    else
		ptr->elm[i].lnormc = -0.25*SQR(ptr->elm[i].b)/ptr->elm[i].c +
		    log(1./(TWODIVSQRTPI*sqrt(ptr->elm[i].c)))
		    + lerfi_diff(sqrt(ptr->elm[i].c)*(ptr->elm[i].xr-ptr->elm[i].xl) +aa, aa);
	}
	if (ISINF(ptr->elm[i].lnormc))
	{
	    ptr->elm[i].lnormc = ptr->elm[i].b = ptr->elm[i].c = 0;
	    ptr->elm[i].lp     = ptr->elm[i].lfl = ptr->elm[i].lfm = ptr->elm[i].lfr = ptr->elm[i].lfmax = -FLT_MAX;
	}
	else
	{
	    ptr->elm[i].lp = ptr->elm[i].lnormc + ptr->elm[i].lfmax;
	}
    }

    for(lpmax = ptr->elm[0].lp, i=1;i<n;i++) lpmax = MAX(lpmax, ptr->elm[i].lp);
    for(i=0;i<n;i++) ptr->elm[i].lp -= lpmax;
    for(i=0, psum=0.0;i<n;i++) psum += exp(ptr->elm[i].lp);
    for(lpsum = log(psum), i=0;i<n;i++) ptr->elm[i].lp -= lpsum;
    
    /* 
       speedup the search for regions and sampling
     */
    qsort(ptr->elm, (size_t) ptr->n, sizeof(GDensElm), GDensElmCompare);

    if (0)
    {
	for(i=0;i<n;i++)
	{
	    printf("Gdens2 region %d\n", i);
	    printf("\txl %f xr %f\n", ptr->elm[i].xl, ptr->elm[i].xr);
	    printf("\tlnormc %f lp %f\n", ptr->elm[i].lnormc, ptr->elm[i].lp);
	}
    }

    return 0;
}
Exemple #10
0
/*
 * Perform a compare instruction (with or without unordered exception).
 * This updates the fcc field in the fsr.
 *
 * If either operand is NaN, the result is unordered.  For cmpe, this
 * causes an NV exception.  Everything else is ordered:
 *	|Inf| > |numbers| > |0|.
 * We already arranged for fp_class(Inf) > fp_class(numbers) > fp_class(0),
 * so we get this directly.  Note, however, that two zeros compare equal
 * regardless of sign, while everything else depends on sign.
 *
 * Incidentally, two Infs of the same sign compare equal (per the 80387
 * manual---it would be nice if the SPARC documentation were more
 * complete).
 */
void
__fpu_compare(struct fpemu *fe, int cmpe, int fcc)
{
    struct fpn *a, *b;
    int cc;
    FPU_DECL_CARRY

    a = &fe->fe_f1;
    b = &fe->fe_f2;

    if (ISNAN(a) || ISNAN(b)) {
        /*
         * In any case, we already got an exception for signalling
         * NaNs; here we may replace that one with an identical
         * exception, but so what?.
         */
        if (cmpe)
            fe->fe_cx = FSR_NV;
        cc = FSR_CC_UO;
        goto done;
    }

    /*
     * Must handle both-zero early to avoid sign goofs.  Otherwise,
     * at most one is 0, and if the signs differ we are done.
     */
    if (ISZERO(a) && ISZERO(b)) {
        cc = FSR_CC_EQ;
        goto done;
    }
    if (a->fp_sign) {		/* a < 0 (or -0) */
        if (!b->fp_sign) {	/* b >= 0 (or if a = -0, b > 0) */
            cc = FSR_CC_LT;
            goto done;
        }
    } else {			/* a > 0 (or +0) */
        if (b->fp_sign) {	/* b <= -0 (or if a = +0, b < 0) */
            cc = FSR_CC_GT;
            goto done;
        }
    }

    /*
     * Now the signs are the same (but may both be negative).  All
     * we have left are these cases:
     *
     *	|a| < |b|		[classes or values differ]
     *	|a| > |b|		[classes or values differ]
     *	|a| == |b|		[classes and values identical]
     *
     * We define `diff' here to expand these as:
     *
     *	|a| < |b|, a,b >= 0: a < b => FSR_CC_LT
     *	|a| < |b|, a,b < 0:  a > b => FSR_CC_GT
     *	|a| > |b|, a,b >= 0: a > b => FSR_CC_GT
     *	|a| > |b|, a,b < 0:  a < b => FSR_CC_LT
     */
#define opposite_cc(cc) ((cc) == FSR_CC_LT ? FSR_CC_GT : FSR_CC_LT)
#define	diff(magnitude) (a->fp_sign ? opposite_cc(magnitude) :  (magnitude))
    if (a->fp_class < b->fp_class) {	/* |a| < |b| */
        cc = diff(FSR_CC_LT);
        goto done;
    }
    if (a->fp_class > b->fp_class) {	/* |a| > |b| */
        cc = diff(FSR_CC_GT);
        goto done;
    }
    /* now none can be 0: only Inf and numbers remain */
    if (ISINF(a)) {				/* |Inf| = |Inf| */
        cc = FSR_CC_EQ;
        goto done;
    }
    /*
     * Only numbers remain.  To compare two numbers in magnitude, we
     * simply subtract them.
     */
    a = __fpu_sub(fe);
    if (a->fp_class == FPC_ZERO)
        cc = FSR_CC_EQ;
    else
        cc = diff(FSR_CC_GT);

done:
    fe->fe_fsr = (fe->fe_fsr & fcc_nmask[fcc]) |
                 ((u_long)cc << fcc_shift[fcc]);
}
Exemple #11
0
int pvsnfmt_double(pvsnfmt_vars *info, double d) {
    char *digits;
    int sign = 0;
    int dec;
    double value = d;

    int len;
    int pad = 0;
    //int signwidth = 0;
    int totallen;
    char signchar = 0;
    int leadingzeros = 0;

    int printdigits; /* temporary var used in different contexts */

    int flags = info->flags;
    int width = info->width;
    const char fmt = *(info->fmt);
    int precision = info->precision;

    /* Check for special values first */
    char *special = 0;
    if(ISSNAN(value)) {
        special = "NaN";
    }
    else if(ISQNAN(value)) {
        special = "NaN";
    }
    else if(ISINF(value)) {
        if(value < 0) {
            sign = 1;
        }
        special = "Inf";
    }

    if(special) {
        totallen = len = strlen(special);

        /* Sign (this is silly for NaN but conforming to printf */
        if(flags & (FLAG_SIGNED | FLAG_SIGN_PAD) || sign) {
            if(sign) {
                signchar = '-';
            }
            else if(flags & FLAG_SIGN_PAD) {
                signchar = ' ';
            }
            else {
                signchar = '+';
            }
            totallen++;
        }

        /* Padding */
        if(totallen < width) {
            pad = width - totallen;
        }
        else {
            pad = 0;
        }

        totallen += pad ;

        // haleyjd 05/07/08: this was forgotten!
        if(info->nmax <= 1) {
            return totallen;
        }


        /* Sign now if zeropad */
        if(flags & FLAG_ZERO_PAD && signchar) {
            if(info->nmax > 1) {
                *(info->pinsertion) = signchar;
                info->pinsertion += 1;
                info->nmax -= 1;
            }
        }

        /* Right align */
        if(!(flags & FLAG_LEFT_ALIGN)) {
            if(info->nmax <= 1) {
                pad  = 0;
            }
            else if((int) info->nmax - 1 < pad) {
                pad  = info->nmax - 1;
            }

            if(flags & FLAG_ZERO_PAD) {
                memset(info->pinsertion, '0', pad);
            }
            else {
                memset(info->pinsertion, ' ', pad);
            }
            info->pinsertion += pad ;
            info->nmax -= pad ;
        }

        /* Sign now if not zeropad */
        if(!(flags & FLAG_ZERO_PAD) && signchar) {
            if(info->nmax > 1) {
                *(info->pinsertion) = signchar;
                info->pinsertion += 1;
                info->nmax -= 1;
            }
        }

        if(info->nmax <= 0) {
            len = 0;
        }
        else if((int) info->nmax - 1 < len) {
            len = info->nmax - 1;
        }
        memcpy(info->pinsertion, special, len);
        info->pinsertion += len;
        info->nmax -= len;

        /* Left align */
        if(flags & FLAG_LEFT_ALIGN) {
            if(info->nmax <= 1) {
                pad  = 0;
            }
            else if((int) info->nmax - 1 < pad) {
                pad  = info->nmax - 1;
            }

            memset(info->pinsertion, ' ', pad);
            info->pinsertion += pad ;
            info->nmax -= pad ;
        }

        return totallen;
    }

    if(fmt == 'f') {
        if(precision == UNKNOWN_PRECISION) {
            precision = 6;
        }

        digits = FCVT(value, precision, &dec, &sign);
        len = strlen(digits);

        if(dec > 0) {
            totallen = dec;
        }
        else {
            totallen = 0;
        }

        /* plus 1 for decimal place */
        if(dec <= 0) {
            totallen += 2;    /* and trailing ".0" */
        }
        else if(precision > 0 || flags & FLAG_HASH) {
            totallen += 1;
        }


        /* Determine sign width (0 or 1) */
        if(flags & (FLAG_SIGNED | FLAG_SIGN_PAD) || sign) {
            if(sign) {
                signchar = '-';
            }
            else if(flags & FLAG_SIGN_PAD) {
                signchar = ' ';
            }
            else {
                signchar = '+';
            }
            totallen++;
        }

        /* Determine if leading zeros required */
        if(dec <= 0) {
            leadingzeros = 1 - dec; /* add one for zero before decimal point (0.) */
        }

        if(leadingzeros - 1 > precision) {
            totallen += precision;
        }
        else if(len - dec > 0) {
            totallen += precision;
        }
        else {
            totallen += leadingzeros;
        }

        /* Determine padding width */
        if(totallen < width) {
            pad = width - totallen;
        }

        totallen += pad;
        if(info->nmax <= 1) {
            return totallen;
        }

        /* Now that the length has been calculated, print as much of it
         * as possible into the buffer
         */

        /* Print sign now if padding with zeros */
        if(flags & FLAG_ZERO_PAD && signchar != 0) {
            if(info->nmax > 1) {
                *(info->pinsertion) = signchar;
                info->pinsertion += 1;
                info->nmax -= 1;
            }
        }

        /* Print width padding if right-aligned */
        if(!(flags & FLAG_LEFT_ALIGN)) {
            if(info->nmax <= 1) {
                pad = 0;
            }
            else if((int) info->nmax - 1 < pad) {
                pad = info->nmax - 1;
            }

            if(flags & FLAG_ZERO_PAD) {
                memset(info->pinsertion, '0', pad);
            }
            else {
                memset(info->pinsertion, ' ', pad);
            }

            info->pinsertion += pad;
            info->nmax -= pad;
        }

        /* Print sign now if padding was spaces */
        if(!(flags & FLAG_ZERO_PAD) && signchar != 0) {
            *(info->pinsertion) = signchar;
            info->pinsertion += 1;
            info->nmax -= 1;
        }

        /* Print leading zeros */
        if(leadingzeros) {
            /* Print "0.", then leadingzeros - 1 */
            if(info->nmax > 1) {
                *(info->pinsertion) = '0';
                info->pinsertion += 1;
                info->nmax -= 1;
            }

            if(precision > 0 || flags & FLAG_HASH) {
                if(info->nmax > 1) {
                    *(info->pinsertion) = '.';
                    info->pinsertion += 1;
                    info->nmax -= 1;
                }
            }

            /* WARNING not rounding here!
             * i.e. printf(".3f", 0.0007) gives "0.000" not "0.001"
             *
             * This whole function could do with a rewrite...
             */
            if(leadingzeros - 1 > precision) {
                leadingzeros = precision + 1;
                len = 0;
            }
            /* END WARNING */

            precision -= leadingzeros - 1;

            if(info->nmax <= 1) {
                leadingzeros = 0;
            }
            else if((int) info->nmax /* - 1 */ < leadingzeros /* -1 */) {
                leadingzeros = info->nmax;    /* -1 */
            }

            leadingzeros--;
            memset(info->pinsertion, '0', leadingzeros);
            info->pinsertion += leadingzeros;
            info->nmax -= leadingzeros;
        }

        /* Print digits before decimal place */
        if(dec > 0) {
            if(info->nmax <= 1) {
                printdigits = 0;
            }
            else if((int) info->nmax - 1 < dec) {
                printdigits = info->nmax - 1;
            }
            else {
                printdigits = dec;
            }

            memcpy(info->pinsertion, digits, printdigits);
            info->pinsertion += printdigits;
            info->nmax -= printdigits;

            if(precision > 0 || flags & FLAG_HASH) {
                /* Print decimal place */
                if(info->nmax > 1) {
                    *(info->pinsertion) = '.';
                    info->pinsertion += 1;
                    info->nmax -= 1;
                }

                /* Print trailing zero if no precision but hash given */
                if(precision == 0 && info->nmax > 1) {
                    *(info->pinsertion) = '0';
                    info->pinsertion += 1;
                    info->nmax -= 1;
                }
            }

            /* Bypass the digits we've already printed */
            len -= dec;
            digits += dec;
        }

        /* Print digits after decimal place */
        if(len > precision) {
            len = precision;
        }

        if(info->nmax <= 1) {
            printdigits = 0;
        }
        else if((int) info->nmax - 1 < len) {
            printdigits = info->nmax - 1;
        }
        else {
            printdigits = len;
        }

        memcpy(info->pinsertion, digits, printdigits);
        info->pinsertion += printdigits;
        info->nmax -= printdigits;

        /* Print left-aligned pad */
        if(flags & FLAG_LEFT_ALIGN) {
            if(info->nmax <= 1) {
                pad = 0;
            }
            else if((int) info->nmax - 1 < pad) {
                pad = info->nmax - 1;
            }

            memset(info->pinsertion, ' ', pad);
            info->pinsertion += pad;
            info->nmax -= pad;
        }
        return totallen;
    }

    return 0;
}
static struct fpn *
__fpu_modrem(struct fpemu *fe, int is_mod)
{
	static struct fpn X, Y;
	struct fpn *x, *y, *r;
	uint32_t signX, signY, signQ;
	int j, k, l, q;
	int cmp;

	if (ISNAN(&fe->fe_f1) || ISNAN(&fe->fe_f2))
		return fpu_newnan(fe);
	if (ISINF(&fe->fe_f1) || ISZERO(&fe->fe_f2))
		return fpu_newnan(fe);

	CPYFPN(&X, &fe->fe_f1);
	CPYFPN(&Y, &fe->fe_f2);
	x = &X;
	y = &Y;
	q = 0;
	r = &fe->fe_f2;

	/*
	 * Step 1
	 */
	signX = x->fp_sign;
	signY = y->fp_sign;
	signQ = (signX ^ signY);
	x->fp_sign = y->fp_sign = 0;

	/* Special treatment that just return input value but Q is necessary */
	if (ISZERO(x) || ISINF(y)) {
		r = &fe->fe_f1;
		goto Step7;
	}

	/*
	 * Step 2
	 */
	l = x->fp_exp - y->fp_exp;
	k = 0;
	CPYFPN(r, x);
	if (l >= 0) {
		r->fp_exp -= l;
		j = l;

		/*
		 * Step 3
		 */
		for (;;) {
			cmp = abscmp3(r, y);

			/* Step 3.1 */
			if (cmp == 0)
				break;

			/* Step 3.2 */
			if (cmp > 0) {
				CPYFPN(&fe->fe_f1, r);
				CPYFPN(&fe->fe_f2, y);
				fe->fe_f2.fp_sign = 1;
				r = fpu_add(fe);
				q++;
			}

			/* Step 3.3 */
			if (j == 0)
				goto Step4;

			/* Step 3.4 */
			k++;
			j--;
			q += q;
			r->fp_exp++;
		}
		/* R == Y */
		q++;
		r->fp_class = FPC_ZERO;
		goto Step7;
	}
 Step4:
	r->fp_sign = signX;

	/*
	 * Step 5
	 */
	if (is_mod)
		goto Step7;

	/*
	 * Step 6
	 */
	/* y = y / 2 */
	y->fp_exp--;
	/* abscmp3 ignore sign */
	cmp = abscmp3(r, y);
	/* revert y */
	y->fp_exp++;

	if (cmp > 0 || (cmp == 0 && q % 2)) {
		q++;
		CPYFPN(&fe->fe_f1, r);
		CPYFPN(&fe->fe_f2, y);
		fe->fe_f2.fp_sign = !signX;
		r = fpu_add(fe);
	}

	/*
	 * Step 7
	 */
 Step7:
	q &= 0x7f;
	q |= (signQ << 7);
	fe->fe_fpframe->fpf_fpsr =
	fe->fe_fpsr =
	    (fe->fe_fpsr & ~FPSR_QTT) | (q << 16);
	return r;
}
void minimize_dual(DOUBLE *Xopt, DOUBLE *Xorig, INT length, DOUBLE *SSt, DOUBLE *SXt, DOUBLE *SXtXSt, DOUBLE trXXt, \
					DOUBLE c, INT N, INT K) {

	DOUBLE INTERV = 0.1;
	DOUBLE EXT = 3.0;   
	INT MAX = 20;       
	DOUBLE RATIO = (DOUBLE) 10;  
	DOUBLE SIG = 0.1; 
	DOUBLE RHO = SIG / (DOUBLE) 2;
	INT MN = K * 1;
	
	CHAR lamch_opt = 'U';
	DOUBLE realmin = LAMCH(&lamch_opt);

	DOUBLE red = 1;

	INT i = 0;
	INT ls_failed = 0;
	DOUBLE f0;
	DOUBLE *df0 = (DOUBLE *) MALLOC(MN * sizeof(DOUBLE));
	DOUBLE *dftemp = (DOUBLE *) MALLOC(MN * sizeof(DOUBLE));
	DOUBLE *df3 = (DOUBLE *) MALLOC(MN * sizeof(DOUBLE));
	DOUBLE *s = (DOUBLE *) MALLOC(MN * sizeof(DOUBLE));
	DOUBLE d0;
	INT derivFlag = 1;

	DOUBLE *X = (DOUBLE *) MALLOC(MN * sizeof(DOUBLE));
	datacpy(X, Xorig, MN);
	
	INT maxNK = IMAX(N, K);
	DOUBLE *SStLambda = (DOUBLE *) MALLOC(maxNK * K * sizeof(DOUBLE));
	DOUBLE *tempMatrix = (DOUBLE *) MALLOC(maxNK * K * sizeof(DOUBLE));
	
	dual_obj_grad(&f0, df0, X, SSt, SXt, SXtXSt, trXXt, c, N, K, derivFlag, SStLambda, tempMatrix);
	
	INT incx = 1;
	INT incy = 1;
		
	datacpy(s, df0, MN);
	DOUBLE alpha = -1;
	SCAL(&MN, &alpha, s, &incx);
	
	d0 = - DOT(&MN, s, &incx, s, &incy);
	
	DOUBLE x1;
	DOUBLE x2;
	DOUBLE x3;
	DOUBLE x4;
	DOUBLE *X0 = (DOUBLE *) MALLOC(MN * sizeof(DOUBLE));
	DOUBLE *X3 = (DOUBLE *) MALLOC(MN * sizeof(DOUBLE));
	DOUBLE F0;
	DOUBLE *dF0 = (DOUBLE *) MALLOC(MN * sizeof(DOUBLE));
	INT Mmin;
	DOUBLE f1;
	DOUBLE f2;
	DOUBLE f3;
	DOUBLE f4;
	DOUBLE d1;
	DOUBLE d2;
	DOUBLE d3;
	DOUBLE d4;
	INT success;
	DOUBLE A;
	DOUBLE B;
	DOUBLE sqrtquantity;
	DOUBLE tempnorm;
	DOUBLE tempinprod1;
	DOUBLE tempinprod2;
	DOUBLE tempscalefactor;
	
	x3 = red / (1 - d0);            

	while (i++ < length) {
		datacpy(X0, X, MN);
		datacpy(dF0, df0, MN);
		F0 = f0;
		Mmin = MAX;
		
		while (1) {
			x2 = 0;
			f2 = f0;
			d2 = d0;
			f3 = f0;
			
			datacpy(df3, df0, MN);
			
			success = 0;
			while ((!success) && (Mmin > 0)) {
				Mmin = Mmin - 1;
				
				datacpy(X3, X, MN);
				alpha = x3;
				AXPY(&MN, &alpha, s, &incx, X3, &incy);
				
				dual_obj_grad(&f3, df3, X3, SSt, SXt, SXtXSt, trXXt, c, N, K, derivFlag, SStLambda, tempMatrix);	

				if (ISNAN(f3) || ISINF(f3)) {  /* any(isnan(df3)+isinf(df3)) */
					x3 = (x2 + x3) * 0.5;
				} else {
					success = 1;
				}
			}
			
			if (f3 < F0) {
				datacpy(X0, X, MN);
				alpha = x3;
				AXPY(&MN, &alpha, s, &incx, X0, &incy);
				datacpy(dF0, df3, MN);
				F0 = f3;
			}	
			
			d3 = DOT(&MN, df3, &incx, s, &incy);

			if ((d3 > SIG * d0) || (f3 > f0 + x3 * RHO * d0) || (Mmin == 0)) {
				break;
			}
			
			x1 = x2; 
			f1 = f2; 
			d1 = d2;
			x2 = x3; 
			f2 = f3; 
			d2 = d3;
			A = 6 * (f1 - f2) + 3 * (d2 + d1) * (x2 - x1);
			B = 3 * (f2 - f1) - (2 * d1 + d2) * (x2 - x1);
			sqrtquantity = B * B - A * d1 * (x2 - x1);

			if (sqrtquantity < 0) {
				x3 = x2 * EXT;
			} else {
				x3 = x1 - d1 * SQR(x2 - x1) / (B + SQRT(sqrtquantity));
				if (ISNAN(x3) || ISINF(x3) || (x3 < 0)) {
					x3 = x2 * EXT;
				} else if (x3 > x2 * EXT) {
					x3 = x2 * EXT;
				} else if (x3 < x2 + INTERV * (x2 - x1)) {
					x3 = x2 + INTERV * (x2 - x1);
				}
			}		
		}                
	
		while (((ABS(d3) > - SIG * d0) || (f3 > f0 + x3 * RHO * d0)) && (Mmin > 0)) {
			if ((d3 > 0) || (f3 > f0 + x3 * RHO * d0)) {
				x4 = x3;
				f4 = f3;
				d4 = d3;
			} else {
				x2 = x3;
				f2 = f3;
				d2 = d3;
			}

			if (f4 > f0) {
				x3 = x2 - (0.5 * d2 * SQR(x4 - x2)) / (f4 - f2 - d2 * (x4 - x2));
			} else {
				A = 6 * (f2 - f4) / (x4 - x2) + 3 * (d4 + d2);
				B = 3 * (f4 - f2) - (2 * d2 + d4) * (x4 - x2);
				x3 = x2 + (SQRT(B * B - A * d2 * SQR(x4 - x2)) - B) / A;
			}

			if (ISNAN(x3) || ISINF(x3)) {
				x3 = (x2 + x4) * 0.5;
			}
			x3 = IMAX(IMIN(x3, x4 - INTERV * (x4 - x2)), x2 + INTERV * (x4 - x2));

			datacpy(X3, X, MN);
			alpha = x3;
			AXPY(&MN, &alpha, s, &incx, X3, &incy);			

			dual_obj_grad(&f3, df3, X3, SSt, SXt, SXtXSt, trXXt, c, N, K, derivFlag, SStLambda, tempMatrix);

			if (f3 < F0) {
				datacpy(X0, X, MN);
				alpha = x3;
				AXPY(&MN, &alpha, s, &incx, X0, &incy);
				datacpy(dF0, df3, MN);
				F0 = f3;
			}

			Mmin = Mmin - 1;
			d3 = DOT(&MN, df3, &incx, s, &incy);
			
		}
		
		if ((ABS(d3) < - SIG * d0) && (f3 < f0 + x3 * RHO * d0)) {
			alpha = x3;
			AXPY(&MN, &alpha, s, &incx, X, &incy);
			f0 = f3;
			datacpy(dftemp, df3, MN);
			alpha = -1;
			AXPY(&MN, &alpha, df0, &incx, dftemp, &incy);
			tempinprod1 = DOT(&MN, dftemp, &incx, df3, &incy);
			tempnorm = NRM2(&MN, df0, &incx);
			tempinprod2 = SQR(tempnorm);
			tempscalefactor = tempinprod1 / tempinprod2;

			alpha = tempscalefactor;
			SCAL(&MN, &alpha, s, &incx);
			alpha = -1;
			AXPY(&MN, &alpha, df3, &incx, s, &incy);
			datacpy(df0, df3, MN);
			d3 = d0;
			d0 = DOT(&MN, df0, &incx, s, &incy);

			if (d0 > 0) {
				datacpy(s, df0, MN);
				alpha = -1;
				SCAL(&MN, &alpha, s, &incx);
				tempnorm = NRM2(&MN, s, &incx);
				d0 = - SQR(tempnorm);
			}
			x3 = x3 * IMIN(RATIO, d3 / (d0 - realmin));
			ls_failed = 0;
		} else {
			datacpy(X, X0, MN);
			datacpy(df0, dF0, MN);
			f0 = F0;
			
			if ((ls_failed == 1) || (i > length)) {
				break;
			}
			
			datacpy(s, df0, MN);
			alpha = -1;
			SCAL(&MN, &alpha, s, &incx);
			tempnorm = NRM2(&MN, s, &incx);
			d0 = - SQR(tempnorm);
			x3 = 1 / (1 - d0);
			
			ls_failed = 1;
		}
	}

	datacpy(Xopt, X, MN);
	
	FREE(SStLambda);
	FREE(tempMatrix);
	FREE(df0);
	FREE(dftemp);
	FREE(df3);
	FREE(s);
	FREE(X);
	FREE(X0);
	FREE(X3);
	FREE(dF0);
}
Exemple #14
0
/*
 * sin(x):
 *
 *	if (x < 0) {
 *		x = abs(x);
 *		sign = 1;
 *	}
 *	if (x > 2*pi) {
 *		x %= 2*pi;
 *	}
 *	if (x > pi) {
 *		x -= pi;
 *		sign inverse;
 *	}
 *	if (x > pi/2) {
 *		y = cos(x - pi/2);
 *	} else {
 *		y = sin(x);
 *	}
 *	if (sign) {
 *		y = -y;
 *	}
 */
struct fpn *
fpu_sin(struct fpemu *fe)
{
    struct fpn x;
    struct fpn p;
    struct fpn *r;
    int sign;

    if (ISNAN(&fe->fe_f2))
        return &fe->fe_f2;
    if (ISINF(&fe->fe_f2))
        return fpu_newnan(fe);

    /* if x is +0/-0, return +0/-0 */
    if (ISZERO(&fe->fe_f2))
        return &fe->fe_f2;

    CPYFPN(&x, &fe->fe_f2);

    /* x = abs(input) */
    sign = x.fp_sign;
    x.fp_sign = 0;

    /* p <- 2*pi */
    fpu_const(&p, FPU_CONST_PI);
    p.fp_exp++;

    /*
     * if (x > 2*pi*N)
     *  sin(x) is sin(x - 2*pi*N)
     */
    CPYFPN(&fe->fe_f1, &x);
    CPYFPN(&fe->fe_f2, &p);
    r = fpu_cmp(fe);
    if (r->fp_sign == 0) {
        CPYFPN(&fe->fe_f1, &x);
        CPYFPN(&fe->fe_f2, &p);
        r = fpu_mod(fe);
        CPYFPN(&x, r);
    }

    /* p <- pi */
    p.fp_exp--;

    /*
     * if (x > pi)
     *  sin(x) is -sin(x - pi)
     */
    CPYFPN(&fe->fe_f1, &x);
    CPYFPN(&fe->fe_f2, &p);
    fe->fe_f2.fp_sign = 1;
    r = fpu_add(fe);
    if (r->fp_sign == 0) {
        CPYFPN(&x, r);
        sign ^= 1;
    }

    /* p <- pi/2 */
    p.fp_exp--;

    /*
     * if (x > pi/2)
     *  sin(x) is cos(x - pi/2)
     * else
     *  sin(x)
     */
    CPYFPN(&fe->fe_f1, &x);
    CPYFPN(&fe->fe_f2, &p);
    fe->fe_f2.fp_sign = 1;
    r = fpu_add(fe);
    if (r->fp_sign == 0) {
        __fpu_sincos_cordic(fe, r);
        r = &fe->fe_f2;
    } else {
        __fpu_sincos_cordic(fe, &x);
        r = &fe->fe_f1;
    }
    r->fp_sign = sign;
    return r;
}
Exemple #15
0
int
APPEND (FUNC_PREFIX, ecvt_r) (FLOAT_TYPE value, 
                              int ndigit, 
                              int *decpt, 
                              int *sign, 
                              char *buf, 
                              size_t len)
{
  int exponent = 0;

  if (!ISNAN (value) && !ISINF (value) && value != 0.0) {
      FLOAT_TYPE (*log10_function) (FLOAT_TYPE) = &LOG10;

      if (log10_function) {
         /* Use the reasonable code if -lm is included.  */
         FLOAT_TYPE dexponent;
         dexponent = FLOOR (LOG10 (FABS (value)));
         value *= EXP (dexponent * -M_LN10);
         exponent = (int) dexponent;
      } else {
         /* Slow code that doesn't require -lm functions.  */
         FLOAT_TYPE d;
         if (value < 0.0)
            d = -value;
         else
            d = value;
         if (d < 1.0) {
            do {
               d *= 10.0;
               --exponent;
            } while (d < 1.0);
         } else if (d >= 10.0) {
            do {
               d *= 0.1;
               ++exponent;
            } while (d >= 10.0);
         }
         if (value < 0.0)
            value = -d;
         else
            value = d;
       }
    } else if (value == 0.0)
       /* SUSv2 leaves it unspecified whether *DECPT is 0 or 1 for 0.0.
        * This could be changed to -1 if we want to return 0.  */
        exponent = 0;

    if (ndigit <= 0 && len > 0) {
       buf[0] = '\0';
       *decpt = 1;
       if (!ISINF (value) && !ISNAN (value))
          *sign = value < 0.0;
       else
          *sign = 0;
    } else
       if (APPEND (FUNC_PREFIX, fcvt_r) (value, ndigit - 1, decpt, sign,
                      buf, len))
          return -1;

    *decpt += exponent;
    return 0;
}
Exemple #16
0
struct fpn *
fpu_add(struct fpemu *fe)
{
	struct fpn *x = &fe->fe_f1, *y = &fe->fe_f2, *r;
	u_int r0, r1, r2, r3;
	int rd;

	/*
	 * Put the `heavier' operand on the right (see fpu_emu.h).
	 * Then we will have one of the following cases, taken in the
	 * following order:
	 *
	 *  - y = NaN.  Implied: if only one is a signalling NaN, y is.
	 *	The result is y.
	 *  - y = Inf.  Implied: x != NaN (is 0, number, or Inf: the NaN
	 *    case was taken care of earlier).
	 *	If x = -y, the result is NaN.  Otherwise the result
	 *	is y (an Inf of whichever sign).
	 *  - y is 0.  Implied: x = 0.
	 *	If x and y differ in sign (one positive, one negative),
	 *	the result is +0 except when rounding to -Inf.  If same:
	 *	+0 + +0 = +0; -0 + -0 = -0.
	 *  - x is 0.  Implied: y != 0.
	 *	Result is y.
	 *  - other.  Implied: both x and y are numbers.
	 *	Do addition a la Hennessey & Patterson.
	 */
	DPRINTF(FPE_REG, ("fpu_add:\n"));
	DUMPFPN(FPE_REG, x);
	DUMPFPN(FPE_REG, y);
	DPRINTF(FPE_REG, ("=>\n"));
	ORDER(x, y);
	if (ISNAN(y)) {
		fe->fe_cx |= FPSCR_VXSNAN;
		DUMPFPN(FPE_REG, y);
		return (y);
	}
	if (ISINF(y)) {
		if (ISINF(x) && x->fp_sign != y->fp_sign) {
			fe->fe_cx |= FPSCR_VXISI;
			return (fpu_newnan(fe));
		}
		DUMPFPN(FPE_REG, y);
		return (y);
	}
	rd = ((fe->fe_fpscr) & FPSCR_RN);
	if (ISZERO(y)) {
		if (rd != FSR_RD_RM)	/* only -0 + -0 gives -0 */
			y->fp_sign &= x->fp_sign;
		else			/* any -0 operand gives -0 */
			y->fp_sign |= x->fp_sign;
		DUMPFPN(FPE_REG, y);
		return (y);
	}
	if (ISZERO(x)) {
		DUMPFPN(FPE_REG, y);
		return (y);
	}
	/*
	 * We really have two numbers to add, although their signs may
	 * differ.  Make the exponents match, by shifting the smaller
	 * number right (e.g., 1.011 => 0.1011) and increasing its
	 * exponent (2^3 => 2^4).  Note that we do not alter the exponents
	 * of x and y here.
	 */
	r = &fe->fe_f3;
	r->fp_class = FPC_NUM;
	if (x->fp_exp == y->fp_exp) {
		r->fp_exp = x->fp_exp;
		r->fp_sticky = 0;
	} else {
		if (x->fp_exp < y->fp_exp) {
			/*
			 * Try to avoid subtract case iii (see below).
			 * This also guarantees that x->fp_sticky = 0.
			 */
			SWAP(x, y);
		}
		/* now x->fp_exp > y->fp_exp */
		r->fp_exp = x->fp_exp;
		r->fp_sticky = fpu_shr(y, x->fp_exp - y->fp_exp);
	}
	r->fp_sign = x->fp_sign;
	if (x->fp_sign == y->fp_sign) {
		FPU_DECL_CARRY

		/*
		 * The signs match, so we simply add the numbers.  The result
		 * may be `supernormal' (as big as 1.111...1 + 1.111...1, or
		 * 11.111...0).  If so, a single bit shift-right will fix it
		 * (but remember to adjust the exponent).
		 */
		/* r->fp_mant = x->fp_mant + y->fp_mant */
		FPU_ADDS(r->fp_mant[3], x->fp_mant[3], y->fp_mant[3]);
		FPU_ADDCS(r->fp_mant[2], x->fp_mant[2], y->fp_mant[2]);
		FPU_ADDCS(r->fp_mant[1], x->fp_mant[1], y->fp_mant[1]);
		FPU_ADDC(r0, x->fp_mant[0], y->fp_mant[0]);
		if ((r->fp_mant[0] = r0) >= FP_2) {
			(void) fpu_shr(r, 1);
			r->fp_exp++;
		}
	} else {
		FPU_DECL_CARRY

		/*
		 * The signs differ, so things are rather more difficult.
		 * H&P would have us negate the negative operand and add;
		 * this is the same as subtracting the negative operand.
		 * This is quite a headache.  Instead, we will subtract
		 * y from x, regardless of whether y itself is the negative
		 * operand.  When this is done one of three conditions will
		 * hold, depending on the magnitudes of x and y:
		 *   case i)   |x| > |y|.  The result is just x - y,
		 *	with x's sign, but it may need to be normalized.
		 *   case ii)  |x| = |y|.  The result is 0 (maybe -0)
		 *	so must be fixed up.
		 *   case iii) |x| < |y|.  We goofed; the result should
		 *	be (y - x), with the same sign as y.
		 * We could compare |x| and |y| here and avoid case iii,
		 * but that would take just as much work as the subtract.
		 * We can tell case iii has occurred by an overflow.
		 *
		 * N.B.: since x->fp_exp >= y->fp_exp, x->fp_sticky = 0.
		 */
		/* r->fp_mant = x->fp_mant - y->fp_mant */
		FPU_SET_CARRY(y->fp_sticky);
		FPU_SUBCS(r3, x->fp_mant[3], y->fp_mant[3]);
		FPU_SUBCS(r2, x->fp_mant[2], y->fp_mant[2]);
		FPU_SUBCS(r1, x->fp_mant[1], y->fp_mant[1]);
		FPU_SUBC(r0, x->fp_mant[0], y->fp_mant[0]);
		if (r0 < FP_2) {
			/* cases i and ii */
			if ((r0 | r1 | r2 | r3) == 0) {
				/* case ii */
				r->fp_class = FPC_ZERO;
				r->fp_sign = rd == FSR_RD_RM;
				return (r);
			}
		} else {
			/*
			 * Oops, case iii.  This can only occur when the
			 * exponents were equal, in which case neither
			 * x nor y have sticky bits set.  Flip the sign
			 * (to y's sign) and negate the result to get y - x.
			 */
#ifdef DIAGNOSTIC
			if (x->fp_exp != y->fp_exp || r->fp_sticky)
				panic("fpu_add");
#endif
			r->fp_sign = y->fp_sign;
			FPU_SUBS(r3, 0, r3);
			FPU_SUBCS(r2, 0, r2);
			FPU_SUBCS(r1, 0, r1);
			FPU_SUBC(r0, 0, r0);
		}
		r->fp_mant[3] = r3;
		r->fp_mant[2] = r2;
		r->fp_mant[1] = r1;
		r->fp_mant[0] = r0;
		if (r0 < FP_1)
			fpu_norm(r);
	}
	DUMPFPN(FPE_REG, r);
	return (r);
}
Exemple #17
0
int
APPEND (FUNC_PREFIX, fcvt_r) (FLOAT_TYPE value, 
                              int ndigit, 
                              int *decpt, 
                              int *sign, 
                              char *buf, 
                              size_t len)
{
   int n, i;
   int left;

   if (buf == NULL) {
      __set_errno (EINVAL);
      return -1;
   }

   left = 0;
   if (!ISINF (value) && !ISNAN (value)) {
      /* OK, the following is not entirely correct.  -0.0 is not handled
       * correctly but glibc 2.0 does not have a portable function to
       * implement this test.  
       */
       *sign = value < 0.0;
       if (*sign)
          value = -value;

       if (ndigit < 0) {
          /* Rounding to the left of the decimal point.  */
          while (ndigit < 0) {
             FLOAT_TYPE new_value = value * 0.1;

             if (new_value < 1.0) {
                ndigit = 0;
                break;
             }

             value = new_value;
             ++left;
             ++ndigit;
          }
       }
    } else {
       /* Value is Inf or NaN.  */
       *sign = 0;
    }

    n = strx_nprint (buf, len, "%.*" FLOAT_FMT_FLAG "f", ndigit, value);
    if (n < 0)
       return -1;

    i = 0;
    while (i < n && isdigit (buf[i]))
       ++i;
    *decpt = i;

    if (i == 0)
       /* Value is Inf or NaN.  */
       return 0;

    if (i < n) {
       do
       ++i;
       while (i < n && !isdigit (buf[i]));

       if (*decpt == 1 && buf[0] == '0' && value != 0.0) {
          /* We must not have leading zeroes.  Strip them all out and
           * adjust *DECPT if necessary.  */
          --*decpt;
          while (i < n && buf[i] == '0')
          {
             --*decpt;
             ++i;
          }
       }

       memmove (&buf[MAX (*decpt, 0)], &buf[i], n - i);
       buf[n - (i - MAX (*decpt, 0))] = '\0';
    }

    if (left) {
       *decpt += left;
       if (--len > n) {
          while (left-- > 0 && n < len)
             buf[n++] = '0';
          buf[n] = '\0';
       }
    }

    return 0;
}
Exemple #18
0
/*
 * Perform a compare instruction (with or without unordered exception).
 * This updates the fcc field in the fsr.
 *
 * If either operand is NaN, the result is unordered.  For ordered, this
 * causes an NV exception.  Everything else is ordered:
 *	|Inf| > |numbers| > |0|.
 * We already arranged for fp_class(Inf) > fp_class(numbers) > fp_class(0),
 * so we get this directly.  Note, however, that two zeros compare equal
 * regardless of sign, while everything else depends on sign.
 *
 * Incidentally, two Infs of the same sign compare equal (per the 80387
 * manual---it would be nice if the SPARC documentation were more
 * complete).
 */
void
fpu_compare(struct fpemu *fe, int ordered)
{
	struct fpn *a, *b, *r;
	int cc;

	a = &fe->fe_f1;
	b = &fe->fe_f2;
	r = &fe->fe_f3;

	if (ISNAN(a) || ISNAN(b)) {
		/*
		 * In any case, we already got an exception for signalling
		 * NaNs; here we may replace that one with an identical
		 * exception, but so what?.
		 */
		cc = FPSCR_FU;
		if (ISSNAN(a) || ISSNAN(b))
			cc |= FPSCR_VXSNAN;
		if (ordered) {
			if (fe->fe_fpscr & FPSCR_VE || ISQNAN(a) || ISQNAN(b))
				cc |= FPSCR_VXVC;
		}
		goto done;
	}

	/*
	 * Must handle both-zero early to avoid sign goofs.  Otherwise,
	 * at most one is 0, and if the signs differ we are done.
	 */
	if (ISZERO(a) && ISZERO(b)) {
		cc = FPSCR_FE;
		goto done;
	}
	if (a->fp_sign) {		/* a < 0 (or -0) */
		if (!b->fp_sign) {	/* b >= 0 (or if a = -0, b > 0) */
			cc = FPSCR_FL;
			goto done;
		}
	} else {			/* a > 0 (or +0) */
		if (b->fp_sign) {	/* b <= -0 (or if a = +0, b < 0) */
			cc = FPSCR_FG;
			goto done;
		}
	}

	/*
	 * Now the signs are the same (but may both be negative).  All
	 * we have left are these cases:
	 *
	 *	|a| < |b|		[classes or values differ]
	 *	|a| > |b|		[classes or values differ]
	 *	|a| == |b|		[classes and values identical]
	 *
	 * We define `diff' here to expand these as:
	 *
	 *	|a| < |b|, a,b >= 0: a < b => FSR_CC_LT
	 *	|a| < |b|, a,b < 0:  a > b => FSR_CC_GT
	 *	|a| > |b|, a,b >= 0: a > b => FSR_CC_GT
	 *	|a| > |b|, a,b < 0:  a < b => FSR_CC_LT
	 */
#define opposite_cc(cc) ((cc) == FPSCR_FL ? FPSCR_FG : FPSCR_FL)
#define	diff(magnitude) (a->fp_sign ? opposite_cc(magnitude) :  (magnitude))
	if (a->fp_class < b->fp_class) {	/* |a| < |b| */
		cc = diff(FPSCR_FL);
		goto done;
	}
	if (a->fp_class > b->fp_class) {	/* |a| > |b| */
		cc = diff(FPSCR_FG);
		goto done;
	}
	/* now none can be 0: only Inf and numbers remain */
	if (ISINF(a)) {				/* |Inf| = |Inf| */
		cc = FPSCR_FE;
		goto done;
	}
	fpu_sub(fe);
	if (ISZERO(r))
		cc = FPSCR_FE;
	else if (r->fp_sign)
		cc = FPSCR_FL;
	else
		cc = FPSCR_FG;
done:
	fe->fe_cx = cc;
}
/*
 * Perform a compare instruction (with or without unordered exception).
 * This updates the fcc field in the fsr.
 *
 * If either operand is NaN, the result is unordered.  For cmpe, this
 * causes an NV exception.  Everything else is ordered:
 *	|Inf| > |numbers| > |0|.
 * We already arranged for fp_class(Inf) > fp_class(numbers) > fp_class(0),
 * so we get this directly.  Note, however, that two zeros compare equal
 * regardless of sign, while everything else depends on sign.
 *
 * Incidentally, two Infs of the same sign compare equal (per the 80387
 * manual---it would be nice if the SPARC documentation were more
 * complete).
 */
void
fpu_compare(struct fpemu *fe, int cmpe)
{
	register struct fpn *a, *b;
	register int cc, r3, r2, r1, r0;
	FPU_DECL_CARRY

	a = &fe->fe_f1;
	b = &fe->fe_f2;

	if (ISNAN(a) || ISNAN(b)) {
		/*
		 * In any case, we already got an exception for signalling
		 * NaNs; here we may replace that one with an identical
		 * exception, but so what?.
		 */
		if (cmpe)
			fe->fe_cx = FSR_NV;
		cc = FSR_CC_UO;
		goto done;
	}

	/*
	 * Must handle both-zero early to avoid sign goofs.  Otherwise,
	 * at most one is 0, and if the signs differ we are done.
	 */
	if (ISZERO(a) && ISZERO(b)) {
		cc = FSR_CC_EQ;
		goto done;
	}
	if (a->fp_sign) {		/* a < 0 (or -0) */
		if (!b->fp_sign) {	/* b >= 0 (or if a = -0, b > 0) */
			cc = FSR_CC_LT;
			goto done;
		}
	} else {			/* a > 0 (or +0) */
		if (b->fp_sign) {	/* b <= -0 (or if a = +0, b < 0) */
			cc = FSR_CC_GT;
			goto done;
		}
	}

	/*
	 * Now the signs are the same (but may both be negative).  All
	 * we have left are these cases:
	 *
	 *	|a| < |b|		[classes or values differ]
	 *	|a| > |b|		[classes or values differ]
	 *	|a| == |b|		[classes and values identical]
	 *
	 * We define `diff' here to expand these as:
	 *
	 *	|a| < |b|, a,b >= 0: a < b => FSR_CC_LT
	 *	|a| < |b|, a,b < 0:  a > b => FSR_CC_GT
	 *	|a| > |b|, a,b >= 0: a > b => FSR_CC_GT
	 *	|a| > |b|, a,b < 0:  a < b => FSR_CC_LT
	 */
#define opposite_cc(cc) ((cc) == FSR_CC_LT ? FSR_CC_GT : FSR_CC_LT)
#define	diff(magnitude) (a->fp_sign ? opposite_cc(magnitude) :  (magnitude))
	if (a->fp_class < b->fp_class) {	/* |a| < |b| */
		cc = diff(FSR_CC_LT);
		goto done;
	}
	if (a->fp_class > b->fp_class) {	/* |a| > |b| */
		cc = diff(FSR_CC_GT);
		goto done;
	}
	/* now none can be 0: only Inf and numbers remain */
	if (ISINF(a)) {				/* |Inf| = |Inf| */
		cc = FSR_CC_EQ;
		goto done;
	}
	/*
	 * Only numbers remain.  To compare two numbers in magnitude, we
	 * simply subtract their mantissas.
	 */
	FPU_SUBS(r3, a->fp_mant[0], b->fp_mant[0]);
	FPU_SUBCS(r2, a->fp_mant[1], b->fp_mant[1]);
	FPU_SUBCS(r1, a->fp_mant[2], b->fp_mant[2]);
	FPU_SUBC(r0, a->fp_mant[3], b->fp_mant[3]);
	if (r0 < 0)				/* underflow: |a| < |b| */
		cc = diff(FSR_CC_LT);
	else if ((r0 | r1 | r2 | r3) != 0)	/* |a| > |b| */
		cc = diff(FSR_CC_GT);
	else
		cc = FSR_CC_EQ;		/* |a| == |b| */
done:
	fe->fe_fsr = (fe->fe_fsr & ~FSR_FCC) | (cc << FSR_FCC_SHIFT);
}
Exemple #20
0
void
EditableDenseThreeDimensionalModel::setColumn(size_t index,
                                              const Column &values)
{
    QWriteLocker locker(&m_lock);

    while (index >= m_data.size()) {
	m_data.push_back(Column());
        m_trunc.push_back(0);
    }

    bool allChange = false;

//    if (values.size() > m_yBinCount) m_yBinCount = values.size();

    for (size_t i = 0; i < values.size(); ++i) {
        float value = values[i];
        if (ISNAN(value) || ISINF(value)) {
            continue;
        }
	if (!m_haveExtents || value < m_minimum) {
	    m_minimum = value;
	    allChange = true;
	}
	if (!m_haveExtents || value > m_maximum) {
	    m_maximum = value;
	    allChange = true;
	}
        m_haveExtents = true;
    }

    truncateAndStore(index, values);

//    assert(values == expandAndRetrieve(index));

    long windowStart = index;
    windowStart *= m_resolution;

    if (m_notifyOnAdd) {
	if (allChange) {
	    emit modelChanged();
	} else {
	    emit modelChanged(windowStart, windowStart + m_resolution);
	}
    } else {
	if (allChange) {
	    m_sinceLastNotifyMin = -1;
	    m_sinceLastNotifyMax = -1;
	    emit modelChanged();
	} else {
	    if (m_sinceLastNotifyMin == -1 ||
		windowStart < m_sinceLastNotifyMin) {
		m_sinceLastNotifyMin = windowStart;
	    }
	    if (m_sinceLastNotifyMax == -1 ||
		windowStart > m_sinceLastNotifyMax) {
		m_sinceLastNotifyMax = windowStart;
	    }
	}
    }
}