Index: uspace/lib/softfloat/div.c
===================================================================
--- uspace/lib/softfloat/div.c	(revision 34511297c505e3db8e8d821daa74d5c4cb7abd4c)
+++ uspace/lib/softfloat/div.c	(revision 34511297c505e3db8e8d821daa74d5c4cb7abd4c)
@@ -0,0 +1,542 @@
+/*
+ * Copyright (c) 2005 Josef Cejka
+ * Copyright (c) 2011 Petr Koupy
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup softfloat
+ * @{
+ */
+/** @file Division functions.
+ */
+
+#include "sftypes.h"
+#include "add.h"
+#include "div.h"
+#include "comparison.h"
+#include "mul.h"
+#include "common.h"
+
+/** Divide two single-precision floats.
+ *
+ * @param a Nominator.
+ * @param b Denominator.
+ *
+ * @return Result of division.
+ *
+ */
+float32 div_float32(float32 a, float32 b)
+{
+	float32 result;
+	int32_t aexp, bexp, cexp;
+	uint64_t afrac, bfrac, cfrac;
+	
+	result.parts.sign = a.parts.sign ^ b.parts.sign;
+	
+	if (is_float32_nan(a)) {
+		if (is_float32_signan(a)) {
+			// FIXME: SigNaN
+		}
+		/* NaN */
+		return a;
+	}
+	
+	if (is_float32_nan(b)) {
+		if (is_float32_signan(b)) {
+			// FIXME: SigNaN
+		}
+		/* NaN */
+		return b;
+	}
+	
+	if (is_float32_infinity(a)) {
+		if (is_float32_infinity(b)) {
+			/*FIXME: inf / inf */
+			result.bin = FLOAT32_NAN;
+			return result;
+		}
+		/* inf / num */
+		result.parts.exp = a.parts.exp;
+		result.parts.fraction = a.parts.fraction;
+		return result;
+	}
+	
+	if (is_float32_infinity(b)) {
+		if (is_float32_zero(a)) {
+			/* FIXME 0 / inf */
+			result.parts.exp = 0;
+			result.parts.fraction = 0;
+			return result;
+		}
+		/* FIXME: num / inf*/
+		result.parts.exp = 0;
+		result.parts.fraction = 0;
+		return result;
+	}
+	
+	if (is_float32_zero(b)) {
+		if (is_float32_zero(a)) {
+			/*FIXME: 0 / 0*/
+			result.bin = FLOAT32_NAN;
+			return result;
+		}
+		/* FIXME: division by zero */
+		result.parts.exp = 0;
+		result.parts.fraction = 0;
+		return result;
+	}
+	
+	afrac = a.parts.fraction;
+	aexp = a.parts.exp;
+	bfrac = b.parts.fraction;
+	bexp = b.parts.exp;
+	
+	/* denormalized numbers */
+	if (aexp == 0) {
+		if (afrac == 0) {
+			result.parts.exp = 0;
+			result.parts.fraction = 0;
+			return result;
+		}
+		
+		/* normalize it*/
+		afrac <<= 1;
+		/* afrac is nonzero => it must stop */
+		while (!(afrac & FLOAT32_HIDDEN_BIT_MASK)) {
+			afrac <<= 1;
+			aexp--;
+		}
+	}
+	
+	if (bexp == 0) {
+		bfrac <<= 1;
+		/* bfrac is nonzero => it must stop */
+		while (!(bfrac & FLOAT32_HIDDEN_BIT_MASK)) {
+			bfrac <<= 1;
+			bexp--;
+		}
+	}
+	
+	afrac = (afrac | FLOAT32_HIDDEN_BIT_MASK) << (32 - FLOAT32_FRACTION_SIZE - 1);
+	bfrac = (bfrac | FLOAT32_HIDDEN_BIT_MASK) << (32 - FLOAT32_FRACTION_SIZE);
+	
+	if (bfrac <= (afrac << 1)) {
+		afrac >>= 1;
+		aexp++;
+	}
+	
+	cexp = aexp - bexp + FLOAT32_BIAS - 2;
+	
+	cfrac = (afrac << 32) / bfrac;
+	if ((cfrac & 0x3F) == 0) { 
+		cfrac |= (bfrac * cfrac != afrac << 32);
+	}
+	
+	/* pack and round */
+	
+	/* find first nonzero digit and shift result and detect possibly underflow */
+	while ((cexp > 0) && (cfrac) && (!(cfrac & (FLOAT32_HIDDEN_BIT_MASK << 7)))) {
+		cexp--;
+		cfrac <<= 1;
+		/* TODO: fix underflow */
+	}
+	
+	cfrac += (0x1 << 6); /* FIXME: 7 is not sure*/
+	
+	if (cfrac & (FLOAT32_HIDDEN_BIT_MASK << 7)) {
+		++cexp;
+		cfrac >>= 1;
+	}
+	
+	/* check overflow */
+	if (cexp >= FLOAT32_MAX_EXPONENT) {
+		/* FIXME: overflow, return infinity */
+		result.parts.exp = FLOAT32_MAX_EXPONENT;
+		result.parts.fraction = 0;
+		return result;
+	}
+	
+	if (cexp < 0) {
+		/* FIXME: underflow */
+		result.parts.exp = 0;
+		if ((cexp + FLOAT32_FRACTION_SIZE) < 0) {
+			result.parts.fraction = 0;
+			return result;
+		}
+		cfrac >>= 1;
+		while (cexp < 0) {
+			cexp++;
+			cfrac >>= 1;
+		}
+	} else {
+		result.parts.exp = (uint32_t) cexp;
+	}
+	
+	result.parts.fraction = ((cfrac >> 6) & (~FLOAT32_HIDDEN_BIT_MASK)); 
+	
+	return result;
+}
+
+/** Divide two double-precision floats.
+ *
+ * @param a Nominator.
+ * @param b Denominator.
+ *
+ * @return Result of division.
+ *
+ */
+float64 div_float64(float64 a, float64 b) 
+{
+	float64 result;
+	int64_t aexp, bexp, cexp;
+	uint64_t afrac, bfrac, cfrac; 
+	uint64_t remlo, remhi;
+	uint64_t tmplo, tmphi;
+	
+	result.parts.sign = a.parts.sign ^ b.parts.sign;
+	
+	if (is_float64_nan(a)) {
+		if (is_float64_signan(b)) {
+			// FIXME: SigNaN
+			return b;
+		}
+		
+		if (is_float64_signan(a)) {
+			// FIXME: SigNaN
+		}
+		/* NaN */
+		return a;
+	}
+	
+	if (is_float64_nan(b)) {
+		if (is_float64_signan(b)) {
+			// FIXME: SigNaN
+		}
+		/* NaN */
+		return b;
+	}
+	
+	if (is_float64_infinity(a)) {
+		if (is_float64_infinity(b) || is_float64_zero(b)) {
+			// FIXME: inf / inf
+			result.bin = FLOAT64_NAN;
+			return result;
+		}
+		/* inf / num */
+		result.parts.exp = a.parts.exp;
+		result.parts.fraction = a.parts.fraction;
+		return result;
+	}
+	
+	if (is_float64_infinity(b)) {
+		if (is_float64_zero(a)) {
+			/* FIXME 0 / inf */
+			result.parts.exp = 0;
+			result.parts.fraction = 0;
+			return result;
+		}
+		/* FIXME: num / inf*/
+		result.parts.exp = 0;
+		result.parts.fraction = 0;
+		return result;
+	}
+	
+	if (is_float64_zero(b)) {
+		if (is_float64_zero(a)) {
+			/*FIXME: 0 / 0*/
+			result.bin = FLOAT64_NAN;
+			return result;
+		}
+		/* FIXME: division by zero */
+		result.parts.exp = 0;
+		result.parts.fraction = 0;
+		return result;
+	}
+	
+	afrac = a.parts.fraction;
+	aexp = a.parts.exp;
+	bfrac = b.parts.fraction;
+	bexp = b.parts.exp;
+	
+	/* denormalized numbers */
+	if (aexp == 0) {
+		if (afrac == 0) {
+			result.parts.exp = 0;
+			result.parts.fraction = 0;
+			return result;
+		}
+		
+		/* normalize it*/
+		aexp++;
+		/* afrac is nonzero => it must stop */	
+		while (!(afrac & FLOAT64_HIDDEN_BIT_MASK)) {
+			afrac <<= 1;
+			aexp--;
+		}
+	}
+	
+	if (bexp == 0) {
+		bexp++;
+		/* bfrac is nonzero => it must stop */	
+		while (!(bfrac & FLOAT64_HIDDEN_BIT_MASK)) {
+			bfrac <<= 1;
+			bexp--;
+		}
+	}
+	
+	afrac = (afrac | FLOAT64_HIDDEN_BIT_MASK) << (64 - FLOAT64_FRACTION_SIZE - 2);
+	bfrac = (bfrac | FLOAT64_HIDDEN_BIT_MASK) << (64 - FLOAT64_FRACTION_SIZE - 1);
+	
+	if (bfrac <= (afrac << 1)) {
+		afrac >>= 1;
+		aexp++;
+	}
+	
+	cexp = aexp - bexp + FLOAT64_BIAS - 2; 
+	
+	cfrac = div128est(afrac, 0x0ll, bfrac);
+	
+	if ((cfrac & 0x1FF) <= 2) {
+		mul64(bfrac, cfrac, &tmphi, &tmplo);
+		sub128(afrac, 0x0ll, tmphi, tmplo, &remhi, &remlo);
+		
+		while ((int64_t) remhi < 0) {
+			cfrac--;
+			add128(remhi, remlo, 0x0ll, bfrac, &remhi, &remlo);
+		}
+		cfrac |= (remlo != 0);
+	}
+	
+	/* round and shift */
+	result = finish_float64(cexp, cfrac, result.parts.sign);
+	return result;
+}
+
+/** Divide two quadruple-precision floats.
+ *
+ * @param a Nominator.
+ * @param b Denominator.
+ *
+ * @return Result of division.
+ *
+ */
+float128 div_float128(float128 a, float128 b)
+{
+	float128 result;
+	int64_t aexp, bexp, cexp;
+	uint64_t afrac_hi, afrac_lo, bfrac_hi, bfrac_lo, cfrac_hi, cfrac_lo;
+	uint64_t shift_out;
+	uint64_t rem_hihi, rem_hilo, rem_lohi, rem_lolo;
+	uint64_t tmp_hihi, tmp_hilo, tmp_lohi, tmp_lolo;
+	
+	result.parts.sign = a.parts.sign ^ b.parts.sign;
+	
+	if (is_float128_nan(a)) {
+		if (is_float128_signan(b)) {
+			// FIXME: SigNaN
+			return b;
+		}
+		
+		if (is_float128_signan(a)) {
+			// FIXME: SigNaN
+		}
+		/* NaN */
+		return a;
+	}
+	
+	if (is_float128_nan(b)) {
+		if (is_float128_signan(b)) {
+			// FIXME: SigNaN
+		}
+		/* NaN */
+		return b;
+	}
+	
+	if (is_float128_infinity(a)) {
+		if (is_float128_infinity(b) || is_float128_zero(b)) {
+			// FIXME: inf / inf
+			result.bin.hi = FLOAT128_NAN_HI;
+			result.bin.lo = FLOAT128_NAN_LO;
+			return result;
+		}
+		/* inf / num */
+		result.parts.exp = a.parts.exp;
+		result.parts.frac_hi = a.parts.frac_hi;
+		result.parts.frac_lo = a.parts.frac_lo;
+		return result;
+	}
+	
+	if (is_float128_infinity(b)) {
+		if (is_float128_zero(a)) {
+			// FIXME 0 / inf
+			result.parts.exp = 0;
+			result.parts.frac_hi = 0;
+			result.parts.frac_lo = 0;
+			return result;
+		}
+		// FIXME: num / inf
+		result.parts.exp = 0;
+		result.parts.frac_hi = 0;
+		result.parts.frac_lo = 0;
+		return result;
+	}
+	
+	if (is_float128_zero(b)) {
+		if (is_float128_zero(a)) {
+			// FIXME: 0 / 0
+			result.bin.hi = FLOAT128_NAN_HI;
+			result.bin.lo = FLOAT128_NAN_LO;
+			return result;
+		}
+		// FIXME: division by zero
+		result.parts.exp = 0;
+		result.parts.frac_hi = 0;
+		result.parts.frac_lo = 0;
+		return result;
+	}
+	
+	afrac_hi = a.parts.frac_hi;
+	afrac_lo = a.parts.frac_lo;
+	aexp = a.parts.exp;
+	bfrac_hi = b.parts.frac_hi;
+	bfrac_lo = b.parts.frac_lo;
+	bexp = b.parts.exp;
+	
+	/* denormalized numbers */
+	if (aexp == 0) {
+		if (eq128(afrac_hi, afrac_lo, 0x0ll, 0x0ll)) {
+			result.parts.exp = 0;
+			result.parts.frac_hi = 0;
+			result.parts.frac_lo = 0;
+			return result;
+		}
+		
+		/* normalize it*/
+		aexp++;
+		/* afrac is nonzero => it must stop */
+		and128(afrac_hi, afrac_lo,
+		    FLOAT128_HIDDEN_BIT_MASK_HI, FLOAT128_HIDDEN_BIT_MASK_LO,
+		    &tmp_hihi, &tmp_lolo);
+		while (!lt128(0x0ll, 0x0ll, tmp_hihi, tmp_lolo)) {
+			lshift128(afrac_hi, afrac_lo, 1, &afrac_hi, &afrac_lo);
+			aexp--;
+		}
+	}
+	
+	if (bexp == 0) {
+		bexp++;
+		/* bfrac is nonzero => it must stop */
+		and128(bfrac_hi, bfrac_lo,
+		    FLOAT128_HIDDEN_BIT_MASK_HI, FLOAT128_HIDDEN_BIT_MASK_LO,
+		    &tmp_hihi, &tmp_lolo);
+		while (!lt128(0x0ll, 0x0ll, tmp_hihi, tmp_lolo)) {
+			lshift128(bfrac_hi, bfrac_lo, 1, &bfrac_hi, &bfrac_lo);
+			bexp--;
+		}
+	}
+	
+	or128(afrac_hi, afrac_lo,
+	    FLOAT128_HIDDEN_BIT_MASK_HI, FLOAT128_HIDDEN_BIT_MASK_LO,
+	    &afrac_hi, &afrac_lo);
+	lshift128(afrac_hi, afrac_lo,
+	    (128 - FLOAT128_FRACTION_SIZE - 1), &afrac_hi, &afrac_lo);
+	or128(bfrac_hi, bfrac_lo,
+	    FLOAT128_HIDDEN_BIT_MASK_HI, FLOAT128_HIDDEN_BIT_MASK_LO,
+	    &bfrac_hi, &bfrac_lo);
+	lshift128(bfrac_hi, bfrac_lo,
+	    (128 - FLOAT128_FRACTION_SIZE - 1), &bfrac_hi, &bfrac_lo);
+	
+	if (le128(bfrac_hi, bfrac_lo, afrac_hi, afrac_lo)) {
+		rshift128(afrac_hi, afrac_lo, 1, &afrac_hi, &afrac_lo);
+		aexp++;
+	}
+	
+	cexp = aexp - bexp + FLOAT128_BIAS - 2;
+	
+	cfrac_hi = div128est(afrac_hi, afrac_lo, bfrac_hi);
+	
+	mul128(bfrac_hi, bfrac_lo, 0x0ll, cfrac_hi,
+	    &tmp_lolo /* dummy */, &tmp_hihi, &tmp_hilo, &tmp_lohi);
+	
+	/* sub192(afrac_hi, afrac_lo, 0,
+	 *     tmp_hihi, tmp_hilo, tmp_lohi
+	 *     &rem_hihi, &rem_hilo, &rem_lohi); */
+	sub128(afrac_hi, afrac_lo, tmp_hihi, tmp_hilo, &rem_hihi, &rem_hilo);
+	if (tmp_lohi > 0) {
+		sub128(rem_hihi, rem_hilo, 0x0ll, 0x1ll, &rem_hihi, &rem_hilo);
+	}
+	rem_lohi = -tmp_lohi;
+	
+	while ((int64_t) rem_hihi < 0) {
+		--cfrac_hi;
+		/* add192(rem_hihi, rem_hilo, rem_lohi,
+		 *     0, bfrac_hi, bfrac_lo,
+		 *     &rem_hihi, &rem_hilo, &rem_lohi); */
+		add128(rem_hilo, rem_lohi, bfrac_hi, bfrac_lo, &rem_hilo, &rem_lohi);
+		if (lt128(rem_hilo, rem_lohi, bfrac_hi, bfrac_lo)) {
+			++rem_hihi;
+		}
+	}
+	
+	cfrac_lo = div128est(rem_hilo, rem_lohi, bfrac_lo);
+	
+	if ((cfrac_lo & 0x3FFF) <= 4) {
+		mul128(bfrac_hi, bfrac_lo, 0x0ll, cfrac_lo,
+		    &tmp_hihi /* dummy */, &tmp_hilo, &tmp_lohi, &tmp_lolo);
+		
+		/* sub192(rem_hilo, rem_lohi, 0,
+		 *     tmp_hilo, tmp_lohi, tmp_lolo,
+		 *     &rem_hilo, &rem_lohi, &rem_lolo); */
+		sub128(rem_hilo, rem_lohi, tmp_hilo, tmp_lohi, &rem_hilo, &rem_lohi);
+		if (tmp_lolo > 0) {
+			sub128(rem_hilo, rem_lohi, 0x0ll, 0x1ll, &rem_hilo, &rem_lohi);
+		}
+		rem_lolo = -tmp_lolo;
+		
+		while ((int64_t) rem_hilo < 0) {
+			--cfrac_lo;
+			/* add192(rem_hilo, rem_lohi, rem_lolo,
+			 *     0, bfrac_hi, bfrac_lo,
+			 *     &rem_hilo, &rem_lohi, &rem_lolo); */
+			add128(rem_lohi, rem_lolo, bfrac_hi, bfrac_lo, &rem_lohi, &rem_lolo);
+			if (lt128(rem_lohi, rem_lolo, bfrac_hi, bfrac_lo)) {
+				++rem_hilo;
+			}
+		}
+		
+		cfrac_lo |= ((rem_hilo | rem_lohi | rem_lolo) != 0 );
+	}
+	
+	shift_out = cfrac_lo << (64 - (128 - FLOAT128_FRACTION_SIZE - 1));
+	rshift128(cfrac_hi, cfrac_lo, (128 - FLOAT128_FRACTION_SIZE - 1),
+	    &cfrac_hi, &cfrac_lo);
+	
+	result = finish_float128(cexp, cfrac_hi, cfrac_lo, result.parts.sign, shift_out);
+	return result;
+}
+
+/** @}
+ */
