X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Ftv%2Ffltcalc.c;h=893b93079ff0b38bb0d0c0055aac11bdc579a410;hb=7c36344d22a7c306a4e216f135c974bdb9f6b943;hp=d8d07feb075935f5dc1a98070a4b7ea7db16075d;hpb=d4168aa816241ed8bedac3dba5d62efb8cf8882d;p=libfirm diff --git a/ir/tv/fltcalc.c b/ir/tv/fltcalc.c index d8d07feb0..893b93079 100644 --- a/ir/tv/fltcalc.c +++ b/ir/tv/fltcalc.c @@ -1,203 +1,1634 @@ -/* fltcalc.c - * Authors: Matthias Heil - */ - /* - * TODO: + * Copyright (C) 1995-2010 University of Karlsruhe. All right reserved. + * + * This file is part of libFirm. * - * This code uses the C-type LLDBL to respesent floating - * point values. This is bad because: + * This file may be distributed and/or modified under the terms of the + * GNU General Public License version 2 as published by the Free Software + * Foundation and appearing in the file LICENSE.GPL included in the + * packaging of this file. * - * 1.) It depends on IEEE arithmetic on the compilation engine (hardly a problem) - * 2.) The existance on the type and its bits size (may be identical to double or even float) - * 3.) Arithmetic operations will be done with "higher order" precision, which might be wrong + * Licensees holding valid libFirm Professional Edition licenses may use + * this file in accordance with the libFirm Commercial License. + * Agreement provided with the Software. * - * Replace this code ASAP. + * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE + * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE. */ + +/** + * @file + * @brief tarval floating point calculations + * @date 2003 + * @author Mathias Heil + * @version $Id$ + */ +#include "config.h" + #include "fltcalc.h" +#include "strcalc.h" +#include "error.h" + +#include +/* undef some reused constants defined by math.h */ +#ifdef NAN +# undef NAN +#endif + +#include #include -#include #include #include +#include -#ifdef USE_LONG_DOUBLE -/* have long double type */ +#include "xmalloc.h" -/* only defined in C99 mode */ -extern long double strtold(const char *str, char **end); +#if !defined(HAVE_LONG_DOUBLE) || defined(__CYGWIN__) +/* No strtold on windows and no replacement yet */ +#define strtold(s, e) strtod(s, e) +#endif + +/** The number of extra precision rounding bits */ +#define ROUNDING_BITS 2 -#define strtoLLD strtold +typedef uint32_t UINT32; +#ifdef HAVE_LONG_DOUBLE +#ifdef WORDS_BIGENDIAN +typedef union { + struct { + UINT32 high; + UINT32 mid; + UINT32 low; + } val; + volatile long double d; +} value_t; #else -/* don't have long double type */ +typedef union { + struct { + UINT32 low; + UINT32 mid; + UINT32 high; + } val; + volatile long double d; +} value_t; +#endif +#else +#ifdef WORDS_BIGENDIAN +typedef union { + struct { + UINT32 high; + UINT32 low; + } val; + volatile double d; +} value_t; +#else +typedef union { + struct { + UINT32 low; + UINT32 high; + } val; + volatile double d; +} value_t; +#endif +#endif + +#define CLEAR_BUFFER(buffer) memset(buffer, 0, calc_buffer_size) + +/* our floating point value */ +struct _fp_value { + ieee_descriptor_t desc; + char sign; + char value[1]; /* exp[value_size] + mant[value_size] */ +}; -extern double strtod(const char *str, char **end); +#define _exp(a) &((a)->value[0]) +#define _mant(a) &((a)->value[value_size]) -#define strtoLLD strtod +#define _save_result(x) memcpy((x), sc_get_buffer(), value_size) +#define _shift_right(x, y, res) sc_shr((x), (y), value_size*4, 0, (res)) +#define _shift_left(x, y, res) sc_shl((x), (y), value_size*4, 0, (res)) + +#ifdef FLTCALC_DEBUG +# define DEBUGPRINTF(x) printf x +#else +# define DEBUGPRINTF(x) ((void)0) #endif -/******** - * globals - ********/ -static LLDBL value; +#ifdef FLTCALC_TRACE_CALC +# define TRACEPRINTF(x) printf x +#else +# define TRACEPRINTF(x) ((void)0) +#endif -#define CAST_IN(val) (*((LLDBL *)((val)))) -#define CAST_OUT(val) ((void *)&(val)) +/** The immediate precision. */ +static unsigned immediate_prec = 0; -#define CLEAR_BUFFER() memset((char*)&value, 0, sizeof(LLDBL)) -/******** - * private functions - ********/ +/** A temporal buffer. */ +static fp_value *calc_buffer = NULL; + +/** Current rounding mode.*/ +static fc_rounding_mode_t rounding_mode; + +static int calc_buffer_size; +static int value_size; +static int max_precision; + +/** Exact flag. */ +static int fc_exact = 1; + +#if 0 +static void fail_char(const char *str, unsigned int len, int pos) +{ + if (*(str+pos)) + printf("ERROR: Unexpected character '%c'\n", *(str + pos)); + else + printf("ERROR: Unexpected end of string\n"); + while (len-- && *str) printf("%c", *str++); printf("\n"); + while (pos--) printf(" "); printf("^\n"); + /* the front end has to to check constant strings */ + exit(-1); +} +#endif + +/** pack machine-like */ +static void *pack(const fp_value *int_float, void *packed) +{ + char *shift_val; + char *temp; + fp_value *val_buffer; + int pos; + + temp = alloca(value_size); + shift_val = alloca(value_size); + + switch ((value_class_t)int_float->desc.clss) { + case NAN: + val_buffer = alloca(calc_buffer_size); + fc_get_qnan(&int_float->desc, val_buffer); + int_float = val_buffer; + break; + + case INF: + val_buffer = alloca(calc_buffer_size); + fc_get_plusinf(&int_float->desc, val_buffer); + val_buffer->sign = int_float->sign; + int_float = val_buffer; + break; + + default: + break; + } + assert(int_float->desc.explicit_one <= 1); + + /* pack sign: move it to the left after exponent AND mantissa */ + sc_val_from_ulong(int_float->sign, temp); + + pos = int_float->desc.exponent_size + int_float->desc.mantissa_size + int_float->desc.explicit_one; + sc_val_from_ulong(pos, NULL); + _shift_left(temp, sc_get_buffer(), packed); + + /* pack exponent: move it to the left after mantissa */ + pos = int_float->desc.mantissa_size + int_float->desc.explicit_one; + sc_val_from_ulong(pos, shift_val); + _shift_left(_exp(int_float), shift_val, temp); + + /* combine sign|exponent */ + sc_or(temp, packed, packed); + + /* extract mantissa */ + /* remove rounding bits */ + sc_val_from_ulong(ROUNDING_BITS, shift_val); + _shift_right(_mant(int_float), shift_val, temp); + + /* remove leading 1 (or 0 if denormalized) */ + sc_max_from_bits(pos, 0, shift_val); /* all mantissa bits are 1's */ + sc_and(temp, shift_val, temp); + + /* combine sign|exponent|mantissa */ + sc_or(temp, packed, packed); + + return packed; +} + +/** + * Normalize a fp_value. + * + * @return non-zero if result is exact + */ +static int normalize(const fp_value *in_val, fp_value *out_val, int sticky) +{ + int exact = 1; + int hsb; + char lsb, guard, round, round_dir = 0; + char *temp = alloca(value_size); + + /* save rounding bits at the end */ + hsb = ROUNDING_BITS + in_val->desc.mantissa_size - sc_get_highest_set_bit(_mant(in_val)) - 1; + + if (in_val != out_val) { + out_val->sign = in_val->sign; + memcpy(&out_val->desc, &in_val->desc, sizeof(out_val->desc)); + } + + out_val->desc.clss = NORMAL; + + /* mantissa all zeros, so zero exponent (because of explicit one) */ + if (hsb == ROUNDING_BITS + in_val->desc.mantissa_size) { + sc_val_from_ulong(0, _exp(out_val)); + hsb = -1; + } + + /* shift the first 1 into the left of the radix point (i.e. hsb == -1) */ + if (hsb < -1) { + /* shift right */ + sc_val_from_ulong(-hsb-1, temp); + + _shift_right(_mant(in_val), temp, _mant(out_val)); + + /* remember if some bits were shifted away */ + if (sc_had_carry()) { + exact = 0; + sticky = 1; + } + sc_add(_exp(in_val), temp, _exp(out_val)); + } else if (hsb > -1) { + /* shift left */ + sc_val_from_ulong(hsb+1, temp); + + _shift_left(_mant(in_val), temp, _mant(out_val)); + + sc_sub(_exp(in_val), temp, _exp(out_val)); + } + + /* check for exponent underflow */ + if (sc_is_negative(_exp(out_val)) || sc_is_zero(_exp(out_val))) { + DEBUGPRINTF(("Exponent underflow!\n")); + /* exponent underflow */ + /* shift the mantissa right to have a zero exponent */ + sc_val_from_ulong(1, temp); + sc_sub(temp, _exp(out_val), NULL); + + _shift_right(_mant(out_val), sc_get_buffer(), _mant(out_val)); + if (sc_had_carry()) { + exact = 0; + sticky = 1; + } + /* denormalized means exponent of zero */ + sc_val_from_ulong(0, _exp(out_val)); + + out_val->desc.clss = SUBNORMAL; + } + + /* perform rounding by adding a value that clears the guard bit and the round bit + * and either causes a carry to round up or not */ + /* get the last 3 bits of the value */ + lsb = sc_sub_bits(_mant(out_val), out_val->desc.mantissa_size + ROUNDING_BITS, 0) & 0x7; + guard = (lsb&0x2)>>1; + round = lsb&0x1; + + switch (rounding_mode) { + case FC_TONEAREST: + /* round to nearest representable value, if in doubt choose the version + * with lsb == 0 */ + round_dir = guard && (sticky || round || lsb>>2); + break; + case FC_TOPOSITIVE: + /* if positive: round to one if the exact value is bigger, else to zero */ + round_dir = (!out_val->sign && (guard || round || sticky)); + break; + case FC_TONEGATIVE: + /* if negative: round to one if the exact value is bigger, else to zero */ + round_dir = (out_val->sign && (guard || round || sticky)); + break; + case FC_TOZERO: + /* always round to 0 (chopping mode) */ + round_dir = 0; + break; + } + DEBUGPRINTF(("Rounding (s%d, l%d, g%d, r%d, s%d) %s\n", out_val->sign, lsb>>2, guard, round, sticky, (round_dir)?"up":"down")); + + if (round_dir == 1) { + guard = (round^guard)<<1; + lsb = !(round || guard)<<2 | guard | round; + } else { + lsb = -((guard<<1) | round); + } + + /* add the rounded value */ + if (lsb != 0) { + sc_val_from_long(lsb, temp); + sc_add(_mant(out_val), temp, _mant(out_val)); + exact = 0; + } + + /* could have rounded down to zero */ + if (sc_is_zero(_mant(out_val)) && (out_val->desc.clss == SUBNORMAL)) + out_val->desc.clss = ZERO; + + /* check for rounding overflow */ + hsb = ROUNDING_BITS + out_val->desc.mantissa_size - sc_get_highest_set_bit(_mant(out_val)) - 1; + if ((out_val->desc.clss != SUBNORMAL) && (hsb < -1)) { + sc_val_from_ulong(1, temp); + _shift_right(_mant(out_val), temp, _mant(out_val)); + if (exact && sc_had_carry()) + exact = 0; + sc_add(_exp(out_val), temp, _exp(out_val)); + } else if ((out_val->desc.clss == SUBNORMAL) && (hsb == -1)) { + /* overflow caused the mantissa to be normal again, + * so adapt the exponent accordingly */ + sc_val_from_ulong(1, temp); + sc_add(_exp(out_val), temp, _exp(out_val)); + + out_val->desc.clss = NORMAL; + } + /* no further rounding is needed, because rounding overflow means + * the carry of the original rounding was propagated all the way + * up to the bit left of the radix point. This implies the bits + * to the right are all zeros (rounding is +1) */ + + /* check for exponent overflow */ + sc_val_from_ulong((1 << out_val->desc.exponent_size) - 1, temp); + if (sc_comp(_exp(out_val), temp) != -1) { + DEBUGPRINTF(("Exponent overflow!\n")); + /* exponent overflow, reaction depends on rounding method: + * + * mode | sign of value | result + *-------------------------------------------------------------- + * TO_NEAREST | + | +inf + * | - | -inf + *-------------------------------------------------------------- + * TO_POSITIVE | + | +inf + * | - | smallest representable value + *-------------------------------------------------------------- + * TO_NEAGTIVE | + | largest representable value + * | - | -inf + *-------------------------------------------------------------- + * TO_ZERO | + | largest representable value + * | - | smallest representable value + *--------------------------------------------------------------*/ + if (out_val->sign == 0) { + /* value is positive */ + switch (rounding_mode) { + case FC_TONEAREST: + case FC_TOPOSITIVE: + out_val->desc.clss = INF; + break; + + case FC_TONEGATIVE: + case FC_TOZERO: + fc_get_max(&out_val->desc, out_val); + } + } else { + /* value is negative */ + switch (rounding_mode) { + case FC_TONEAREST: + case FC_TONEGATIVE: + out_val->desc.clss = INF; + break; + + case FC_TOPOSITIVE: + case FC_TOZERO: + fc_get_min(&out_val->desc, out_val); + } + } + } + return exact; +} + +/** + * Operations involving NaN's must return NaN. + * They are NOT exact. + */ +#define handle_NAN(a, b, result) \ +do { \ + if (a->desc.clss == NAN) { \ + if (a != result) memcpy(result, a, calc_buffer_size); \ + fc_exact = 0; \ + return; \ + } \ + if (b->desc.clss == NAN) { \ + if (b != result) memcpy(result, b, calc_buffer_size); \ + fc_exact = 0; \ + return; \ + } \ +}while (0) + + +/** + * calculate a + b, where a is the value with the bigger exponent + */ +static void _fadd(const fp_value *a, const fp_value *b, fp_value *result) +{ + char *temp; + char *exp_diff; + + char sign, res_sign; + char sticky; + + fc_exact = 1; + + handle_NAN(a, b, result); + + /* make sure result has a descriptor */ + if (result != a && result != b) + result->desc = a->desc; + + /* determine if this is an addition or subtraction */ + sign = a->sign ^ b->sign; + + /* produce NaN on inf - inf */ + if (sign && (a->desc.clss == INF) && (b->desc.clss == INF)) { + fc_exact = 0; + fc_get_qnan(&a->desc, result); + return; + } + + temp = alloca(value_size); + exp_diff = alloca(value_size); + + /* get exponent difference */ + sc_sub(_exp(a), _exp(b), exp_diff); + + /* initially set sign to be the sign of a, special treatment of subtraction + * when exponents are equal is required though. + * Also special care about the sign is needed when the mantissas are equal + * (+/- 0 ?) */ + if (sign && sc_val_to_long(exp_diff) == 0) { + switch (sc_comp(_mant(a), _mant(b))) { + case 1: /* a > b */ + res_sign = a->sign; /* abs(a) is bigger and a is negative */ + break; + case 0: /* a == b */ + res_sign = (rounding_mode == FC_TONEGATIVE); + break; + case -1: /* a < b */ + res_sign = b->sign; /* abs(b) is bigger and b is negative */ + break; + default: + /* can't be reached */ + res_sign = 0; + break; + } + } + else + res_sign = a->sign; + result->sign = res_sign; + + /* sign has been taken care of, check for special cases */ + if (a->desc.clss == ZERO || b->desc.clss == INF) { + if (b != result) + memcpy(result, b, calc_buffer_size); + fc_exact = b->desc.clss == NORMAL; + result->sign = res_sign; + return; + } + if (b->desc.clss == ZERO || a->desc.clss == INF) { + if (a != result) + memcpy(result, a, calc_buffer_size); + fc_exact = a->desc.clss == NORMAL; + result->sign = res_sign; + return; + } + + /* shift the smaller value to the right to align the radix point */ + /* subnormals have their radix point shifted to the right, + * take care of this first */ + if ((b->desc.clss == SUBNORMAL) && (a->desc.clss != SUBNORMAL)) { + sc_val_from_ulong(1, temp); + sc_sub(exp_diff, temp, exp_diff); + } + + _shift_right(_mant(b), exp_diff, temp); + sticky = sc_had_carry(); + fc_exact &= !sticky; + + if (sticky && sign) { + /* if subtracting a little more than the represented value or adding a little + * more than the represented value to a negative value this, in addition to the + * still set sticky bit, takes account of the 'little more' */ + char *temp1 = alloca(calc_buffer_size); + sc_val_from_ulong(1, temp1); + sc_add(temp, temp1, temp); + } + + if (sign) { + if (sc_comp(_mant(a), temp) == -1) + sc_sub(temp, _mant(a), _mant(result)); + else + sc_sub(_mant(a), temp, _mant(result)); + } else { + sc_add(_mant(a), temp, _mant(result)); + } + + /* _normalize expects a 'normal' radix point, adding two subnormals + * results in a subnormal radix point -> shifting before normalizing */ + if ((a->desc.clss == SUBNORMAL) && (b->desc.clss == SUBNORMAL)) { + sc_val_from_ulong(1, NULL); + _shift_left(_mant(result), sc_get_buffer(), _mant(result)); + } + + /* resulting exponent is the bigger one */ + memmove(_exp(result), _exp(a), value_size); + + fc_exact &= normalize(result, result, sticky); +} + +/** + * calculate a * b + */ +static void _fmul(const fp_value *a, const fp_value *b, fp_value *result) +{ + int sticky; + char *temp; + char res_sign; + + fc_exact = 1; + + handle_NAN(a, b, result); + + temp = alloca(value_size); + + if (result != a && result != b) + result->desc = a->desc; + + result->sign = res_sign = a->sign ^ b->sign; + + /* produce NaN on 0 * inf */ + if (a->desc.clss == ZERO) { + if (b->desc.clss == INF) { + fc_get_qnan(&a->desc, result); + fc_exact = 0; + } else { + if (a != result) + memcpy(result, a, calc_buffer_size); + result->sign = res_sign; + } + return; + } + if (b->desc.clss == ZERO) { + if (a->desc.clss == INF) { + fc_get_qnan(&a->desc, result); + fc_exact = 0; + } else { + if (b != result) + memcpy(result, b, calc_buffer_size); + result->sign = res_sign; + } + return; + } + + if (a->desc.clss == INF) { + fc_exact = 0; + if (a != result) + memcpy(result, a, calc_buffer_size); + result->sign = res_sign; + return; + } + if (b->desc.clss == INF) { + fc_exact = 0; + if (b != result) + memcpy(result, b, calc_buffer_size); + result->sign = res_sign; + return; + } + + /* exp = exp(a) + exp(b) - excess */ + sc_add(_exp(a), _exp(b), _exp(result)); + + sc_val_from_ulong((1 << (a->desc.exponent_size - 1)) - 1, temp); + sc_sub(_exp(result), temp, _exp(result)); + + /* mixed normal, subnormal values introduce an error of 1, correct it */ + if ((a->desc.clss == SUBNORMAL) ^ (b->desc.clss == SUBNORMAL)) { + sc_val_from_ulong(1, temp); + sc_add(_exp(result), temp, _exp(result)); + } + + sc_mul(_mant(a), _mant(b), _mant(result)); + + /* realign result: after a multiplication the digits right of the radix + * point are the sum of the factors' digits after the radix point. As all + * values are normalized they both have the same amount of these digits, + * which has to be restored by proper shifting + * because of the rounding bits */ + sc_val_from_ulong(ROUNDING_BITS + result->desc.mantissa_size, temp); + + _shift_right(_mant(result), temp, _mant(result)); + sticky = sc_had_carry(); + fc_exact &= !sticky; + + fc_exact &= normalize(result, result, sticky); +} + +/** + * calculate a / b + */ +static void _fdiv(const fp_value *a, const fp_value *b, fp_value *result) +{ + int sticky; + char *temp, *dividend; + char res_sign; + + fc_exact = 1; + + handle_NAN(a, b, result); + + temp = alloca(value_size); + dividend = alloca(value_size); + + if (result != a && result != b) + result->desc = a->desc; + + result->sign = res_sign = a->sign ^ b->sign; + + /* produce NAN on 0/0 and inf/inf */ + if (a->desc.clss == ZERO) { + if (b->desc.clss == ZERO) { + /* 0/0 -> NaN */ + fc_get_qnan(&a->desc, result); + fc_exact = 0; + } else { + /* 0/x -> a */ + if (a != result) + memcpy(result, a, calc_buffer_size); + result->sign = res_sign; + } + return; + } + + if (b->desc.clss == INF) { + fc_exact = 0; + if (a->desc.clss == INF) { + /* inf/inf -> NaN */ + fc_get_qnan(&a->desc, result); + } else { + /* x/inf -> 0 */ + sc_val_from_ulong(0, NULL); + _save_result(_exp(result)); + _save_result(_mant(result)); + result->desc.clss = ZERO; + } + return; + } + + if (a->desc.clss == INF) { + fc_exact = 0; + /* inf/x -> inf */ + if (a != result) + memcpy(result, a, calc_buffer_size); + result->sign = res_sign; + return; + } + if (b->desc.clss == ZERO) { + fc_exact = 0; + /* division by zero */ + if (result->sign) + fc_get_minusinf(&a->desc, result); + else + fc_get_plusinf(&a->desc, result); + return; + } + + /* exp = exp(a) - exp(b) + excess - 1*/ + sc_sub(_exp(a), _exp(b), _exp(result)); + sc_val_from_ulong((1 << (a->desc.exponent_size - 1)) - 2, temp); + sc_add(_exp(result), temp, _exp(result)); + + /* mixed normal, subnormal values introduce an error of 1, correct it */ + if ((a->desc.clss == SUBNORMAL) ^ (b->desc.clss == SUBNORMAL)) { + sc_val_from_ulong(1, temp); + sc_add(_exp(result), temp, _exp(result)); + } + + /* mant(res) = mant(a) / 1/2mant(b) */ + /* to gain more bits of precision in the result the dividend could be + * shifted left, as this operation does not loose bits. This would not + * fit into the integer precision, but due to the rounding bits (which + * are always zero because the values are all normalized) the divisor + * can be shifted right instead to achieve the same result */ + sc_val_from_ulong(ROUNDING_BITS + result->desc.mantissa_size, temp); + + _shift_left(_mant(a), temp, dividend); + + { + char *divisor = alloca(calc_buffer_size); + sc_val_from_ulong(1, divisor); + _shift_right(_mant(b), divisor, divisor); + sc_div(dividend, divisor, _mant(result)); + sticky = sc_had_carry(); + fc_exact &= !sticky; + } + + fc_exact &= normalize(result, result, sticky); +} + +#if 0 +static void _power_of_ten(int exp, ieee_descriptor_t *desc, char *result) +{ + char *build; + char *temp; + + /* positive sign */ + result->sign = 0; + + /* set new descriptor (else result is supposed to already have one) */ + if (desc != NULL) + result->desc = *desc; + + build = alloca(value_size); + temp = alloca(value_size); + + sc_val_from_ulong((1 << (result->desc.exponent_size - 1)) - 1, _exp(result)); + + if (exp > 0) { + /* temp is value of ten now */ + sc_val_from_ulong(10, NULL); + _save_result(temp); + + for (exp--; exp > 0; exp--) { + _save_result(build); + sc_mul(build, temp, NULL); + } + _save_result(build); + + /* temp is amount of left shift needed to put the value left of the radix point */ + sc_val_from_ulong(result->desc.mantissa_size + ROUNDING_BITS, temp); + + _shift_left(build, temp, _mant(result)); + + _normalize(result, result, 0); + } +} +#endif + +/** + * Truncate the fractional part away. + * + * This does not clip to any integer range. + */ +static void _trunc(const fp_value *a, fp_value *result) +{ + /* + * When exponent == 0 all bits left of the radix point + * are the integral part of the value. For 15bit exp_size + * this would require a left shift of max. 16383 bits which + * is too much. + * But it is enough to ensure that no bit right of the radix + * point remains set. This restricts the interesting + * exponents to the interval [0, mant_size-1]. + * Outside this interval the truncated value is either 0 or + * it does not have fractional parts. + */ + + int exp_bias, exp_val; + char *temp; + + /* fixme: can be exact */ + fc_exact = 0; + + temp = alloca(value_size); + + if (a != result) + result->desc = a->desc; + + exp_bias = (1 << (a->desc.exponent_size - 1)) - 1; + exp_val = sc_val_to_long(_exp(a)) - exp_bias; + + if (exp_val < 0) { + sc_val_from_ulong(0, NULL); + _save_result(_exp(result)); + _save_result(_mant(result)); + result->desc.clss = ZERO; + + return; + } + + if (exp_val > a->desc.mantissa_size) { + if (a != result) + memcpy(result, a, calc_buffer_size); + + return; + } + + /* set up a proper mask to delete all bits right of the + * radix point if the mantissa had been shifted until exp == 0 */ + sc_max_from_bits(1 + exp_val, 0, temp); + sc_val_from_long(a->desc.mantissa_size - exp_val + 2, NULL); + _shift_left(temp, sc_get_buffer(), temp); + + /* and the mask and return the result */ + sc_and(_mant(a), temp, _mant(result)); + + if (a != result) { + memcpy(_exp(result), _exp(a), value_size); + result->sign = a->sign; + } +} /******** * functions defined in fltcalc.h ********/ const void *fc_get_buffer(void) { - return CAST_OUT(value); + return calc_buffer; +} + +int fc_get_buffer_length(void) +{ + return calc_buffer_size; +} + +void *fc_val_from_str(const char *str, unsigned int len, const ieee_descriptor_t *desc, void *result) +{ + char *buffer; + + /* XXX excuse of an implementation to make things work */ + LLDBL val; + fp_value *tmp = alloca(calc_buffer_size); + ieee_descriptor_t tmp_desc; + + buffer = alloca(len+1); + memcpy(buffer, str, len); + buffer[len] = '\0'; + val = strtold(buffer, NULL); + + DEBUGPRINTF(("val_from_str(%s)\n", str)); + tmp_desc.exponent_size = 15; + tmp_desc.mantissa_size = 63; + tmp_desc.explicit_one = 1; + tmp_desc.clss = NORMAL; + fc_val_from_ieee754(val, &tmp_desc, tmp); + + return fc_cast(tmp, desc, result); +} + +fp_value *fc_val_from_ieee754(LLDBL l, const ieee_descriptor_t *desc, fp_value *result) +{ + char *temp; + int bias_res, bias_val, mant_val; + value_t srcval; + char sign; + UINT32 exponent, mantissa0, mantissa1; + + srcval.d = l; + bias_res = ((1 << (desc->exponent_size - 1)) - 1); + +#ifdef HAVE_LONG_DOUBLE + mant_val = 63; + bias_val = 0x3fff; + sign = (srcval.val.high & 0x00008000) != 0; + exponent = (srcval.val.high & 0x00007FFF) ; + mantissa0 = srcval.val.mid; + mantissa1 = srcval.val.low; +#else /* no long double */ + mant_val = 52; + bias_val = 0x3ff; + sign = (srcval.val.high & 0x80000000) != 0; + exponent = (srcval.val.high & 0x7FF00000) >> 20; + mantissa0 = srcval.val.high & 0x000FFFFF; + mantissa1 = srcval.val.low; +#endif + +#ifdef HAVE_LONG_DOUBLE + TRACEPRINTF(("val_from_float(%.8X%.8X%.8X)\n", ((int*)&l)[2], ((int*)&l)[1], ((int*)&l)[0]));/* srcval.val.high, srcval.val.mid, srcval.val.low)); */ + DEBUGPRINTF(("(%d-%.4X-%.8X%.8X)\n", sign, exponent, mantissa0, mantissa1)); +#else + TRACEPRINTF(("val_from_float(%.8X%.8X)\n", srcval.val.high, srcval.val.low)); + DEBUGPRINTF(("(%d-%.3X-%.5X%.8X)\n", sign, exponent, mantissa0, mantissa1)); +#endif + + if (result == NULL) result = calc_buffer; + temp = alloca(value_size); + + /* CLEAR the buffer, else some bits might be uninitialized */ + memset(result, 0, fc_get_buffer_length()); + + result->desc.exponent_size = desc->exponent_size; + result->desc.mantissa_size = desc->mantissa_size; + result->desc.explicit_one = desc->explicit_one; + + /* extract sign */ + result->sign = sign; + + /* sign and flag suffice to identify NaN or inf, no exponent/mantissa + * encoding is needed. the function can return immediately in these cases */ + if (isnan(l)) { + result->desc.clss = NAN; + TRACEPRINTF(("val_from_float resulted in NAN\n")); + return result; + } + else if (isinf(l)) { + result->desc.clss = INF; + TRACEPRINTF(("val_from_float resulted in %sINF\n", (result->sign == 1) ? "-" : "")); + return result; + } + + /* build exponent, because input and output exponent and mantissa sizes may differ + * this looks more complicated than it is: unbiased input exponent + output bias, + * minus the mantissa difference which is added again later when the output float + * becomes normalized */ + sc_val_from_long((exponent - bias_val + bias_res) - (mant_val - desc->mantissa_size), _exp(result)); + + /* build mantissa representation */ + if (exponent != 0) { + /* insert the hidden bit */ + sc_val_from_ulong(1, temp); + sc_val_from_ulong(mant_val + ROUNDING_BITS, NULL); + _shift_left(temp, sc_get_buffer(), NULL); + } + else { + sc_val_from_ulong(0, NULL); + } + + _save_result(_mant(result)); + + /* bits from the upper word */ + sc_val_from_ulong(mantissa0, temp); + sc_val_from_ulong(34, NULL); + _shift_left(temp, sc_get_buffer(), temp); + sc_or(_mant(result), temp, _mant(result)); + + /* bits from the lower word */ + sc_val_from_ulong(mantissa1, temp); + sc_val_from_ulong(ROUNDING_BITS, NULL); + _shift_left(temp, sc_get_buffer(), temp); + sc_or(_mant(result), temp, _mant(result)); + + /* _normalize expects the radix point to be normal, so shift mantissa of subnormal + * origin one to the left */ + if (exponent == 0) { + sc_val_from_ulong(1, NULL); + _shift_left(_mant(result), sc_get_buffer(), _mant(result)); + } + + normalize(result, result, 0); + + TRACEPRINTF(("val_from_float results in %s\n", fc_print(result, temp, calc_buffer_size, FC_PACKED))); + + return result; +} + +LLDBL fc_val_to_ieee754(const fp_value *val) +{ + fp_value *value; + fp_value *temp = NULL; + + int byte_offset; + + UINT32 sign; + UINT32 exponent; + UINT32 mantissa0; + UINT32 mantissa1; + + value_t buildval; + ieee_descriptor_t desc; + unsigned mantissa_size; + +#ifdef HAVE_LONG_DOUBLE + desc.exponent_size = 15; + desc.mantissa_size = 63; + desc.explicit_one = 1; + desc.clss = NORMAL; +#else + desc.exponent_size = 11; + desc.mantissa_size = 52; + desc.explicit_one = 0; + desc.clss = NORMAL; +#endif + mantissa_size = desc.mantissa_size + desc.explicit_one; + + temp = alloca(calc_buffer_size); + value = fc_cast(val, &desc, temp); + + sign = value->sign; + + /* @@@ long double exponent is 15bit, so the use of sc_val_to_long should not + * lead to wrong results */ + exponent = sc_val_to_long(_exp(value)) ; + + sc_val_from_ulong(ROUNDING_BITS, NULL); + _shift_right(_mant(value), sc_get_buffer(), _mant(value)); + + mantissa0 = 0; + mantissa1 = 0; + + for (byte_offset = 0; byte_offset < 4; byte_offset++) + mantissa1 |= sc_sub_bits(_mant(value), mantissa_size, byte_offset) << (byte_offset << 3); + + for (; (byte_offset<<3) < desc.mantissa_size; byte_offset++) + mantissa0 |= sc_sub_bits(_mant(value), mantissa_size, byte_offset) << ((byte_offset - 4) << 3); + +#ifdef HAVE_LONG_DOUBLE + buildval.val.high = sign << 15; + buildval.val.high |= exponent; + buildval.val.mid = mantissa0; + buildval.val.low = mantissa1; +#else /* no long double */ + mantissa0 &= 0x000FFFFF; /* get rid of garbage */ + buildval.val.high = sign << 31; + buildval.val.high |= exponent << 20; + buildval.val.high |= mantissa0; + buildval.val.low = mantissa1; +#endif + + TRACEPRINTF(("val_to_float: %d-%x-%x%x\n", sign, exponent, mantissa0, mantissa1)); + return buildval.d; +} + +fp_value *fc_cast(const fp_value *value, const ieee_descriptor_t *desc, fp_value *result) +{ + char *temp; + int exp_offset, val_bias, res_bias; + + if (result == NULL) result = calc_buffer; + temp = alloca(value_size); + + if (value->desc.exponent_size == desc->exponent_size && + value->desc.mantissa_size == desc->mantissa_size && + value->desc.explicit_one == desc->explicit_one) { + if (value != result) + memcpy(result, value, calc_buffer_size); + return result; + } + + if (value->desc.clss == NAN) { + if (sc_get_highest_set_bit(_mant(value)) == value->desc.mantissa_size + 1) + return fc_get_qnan(desc, result); + else + return fc_get_snan(desc, result); + } + else if (value->desc.clss == INF) { + if (value->sign == 0) + return fc_get_plusinf(desc, result); + else + return fc_get_minusinf(desc, result); + } + + /* set the descriptor of the new value */ + result->desc.exponent_size = desc->exponent_size; + result->desc.mantissa_size = desc->mantissa_size; + result->desc.explicit_one = desc->explicit_one; + result->desc.clss = value->desc.clss; + + result->sign = value->sign; + + /* when the mantissa sizes differ normalizing has to shift to align it. + * this would change the exponent, which is unwanted. So calculate this + * offset and add it */ + val_bias = (1 << (value->desc.exponent_size - 1)) - 1; + res_bias = (1 << (desc->exponent_size - 1)) - 1; + + exp_offset = (res_bias - val_bias) - (value->desc.mantissa_size - desc->mantissa_size); + sc_val_from_long(exp_offset, temp); + sc_add(_exp(value), temp, _exp(result)); + + /* _normalize expects normalized radix point */ + if (value->desc.clss == SUBNORMAL) { + sc_val_from_ulong(1, NULL); + _shift_left(_mant(value), sc_get_buffer(), _mant(result)); + } else if (value != result) { + memcpy(_mant(result), _mant(value), value_size); + } else { + memmove(_mant(result), _mant(value), value_size); + } + + normalize(result, result, 0); + TRACEPRINTF(("Cast results in %s\n", fc_print(result, temp, value_size, FC_PACKED))); + return result; +} + +fp_value *fc_get_max(const ieee_descriptor_t *desc, fp_value *result) +{ + if (result == NULL) result = calc_buffer; + + result->desc.exponent_size = desc->exponent_size; + result->desc.mantissa_size = desc->mantissa_size; + result->desc.explicit_one = desc->explicit_one; + result->desc.clss = NORMAL; + + result->sign = 0; + + sc_val_from_ulong((1 << desc->exponent_size) - 2, _exp(result)); + + sc_max_from_bits(desc->mantissa_size + 1, 0, _mant(result)); + sc_val_from_ulong(ROUNDING_BITS, NULL); + _shift_left(_mant(result), sc_get_buffer(), _mant(result)); + + return result; +} + +fp_value *fc_get_min(const ieee_descriptor_t *desc, fp_value *result) +{ + if (result == NULL) result = calc_buffer; + + fc_get_max(desc, result); + result->sign = 1; + + return result; +} + +fp_value *fc_get_snan(const ieee_descriptor_t *desc, fp_value *result) +{ + if (result == NULL) result = calc_buffer; + + result->desc.exponent_size = desc->exponent_size; + result->desc.mantissa_size = desc->mantissa_size; + result->desc.explicit_one = desc->explicit_one; + result->desc.clss = NAN; + + result->sign = 0; + + sc_val_from_ulong((1 << desc->exponent_size) - 1, _exp(result)); + + /* signaling NaN has non-zero mantissa with msb not set */ + sc_val_from_ulong(1, _mant(result)); + + return result; +} + +fp_value *fc_get_qnan(const ieee_descriptor_t *desc, fp_value *result) +{ + if (result == NULL) result = calc_buffer; + + result->desc.exponent_size = desc->exponent_size; + result->desc.mantissa_size = desc->mantissa_size; + result->desc.explicit_one = desc->explicit_one; + result->desc.clss = NAN; + + result->sign = 0; + + sc_val_from_ulong((1 << desc->exponent_size) - 1, _exp(result)); + + /* quiet NaN has the msb of the mantissa set, so shift one there */ + sc_val_from_ulong(1, _mant(result)); + /* mantissa_size >+< 1 because of two extra rounding bits */ + sc_val_from_ulong(desc->mantissa_size + 1, NULL); + _shift_left(_mant(result), sc_get_buffer(), _mant(result)); + + return result; +} + +fp_value *fc_get_plusinf(const ieee_descriptor_t *desc, fp_value *result) +{ + char *mant; + + if (result == NULL) result = calc_buffer; + + result->desc.exponent_size = desc->exponent_size; + result->desc.mantissa_size = desc->mantissa_size; + result->desc.explicit_one = desc->explicit_one; + result->desc.clss = INF; + + result->sign = 0; + + sc_val_from_ulong((1 << desc->exponent_size) - 1, _exp(result)); + + mant = _mant(result); + sc_val_from_ulong(0, mant); + if (desc->explicit_one) { + sc_set_bit_at(mant, result->desc.mantissa_size + ROUNDING_BITS); + } + + return result; +} + +fp_value *fc_get_minusinf(const ieee_descriptor_t *desc, fp_value *result) +{ + if (result == NULL) result = calc_buffer; + + fc_get_plusinf(desc, result); + result->sign = 1; + + return result; +} + +int fc_comp(const fp_value *val_a, const fp_value *val_b) +{ + int mul = 1; + + /* + * shortcut: if both values are identical, they are either + * Unordered if NaN or equal + */ + if (val_a == val_b) + return val_a->desc.clss == NAN ? 2 : 0; + + /* unordered if one is a NaN */ + if (val_a->desc.clss == NAN || val_b->desc.clss == NAN) + return 2; + + /* zero is equal independent of sign */ + if ((val_a->desc.clss == ZERO) && (val_b->desc.clss == ZERO)) + return 0; + + /* different signs make compare easy */ + if (val_a->sign != val_b->sign) + return (val_a->sign == 0) ? (1) : (-1); + + mul = val_a->sign ? -1 : 1; + + /* both infinity means equality */ + if ((val_a->desc.clss == INF) && (val_b->desc.clss == INF)) + return 0; + + /* infinity is bigger than the rest */ + if (val_a->desc.clss == INF) + return 1 * mul; + if (val_b->desc.clss == INF) + return -1 * mul; + + /* check first exponent, that mantissa if equal */ + switch (sc_comp(_exp(val_a), _exp(val_b))) { + case -1: + return -1 * mul; + case 1: + return 1 * mul; + case 0: + return sc_comp(_mant(val_a), _mant(val_b)) * mul; + default: + return 2; + } +} + +int fc_is_zero(const fp_value *a) +{ + return a->desc.clss == ZERO; } -const int fc_get_buffer_length(void) +int fc_is_negative(const fp_value *a) { - return sizeof(LLDBL); + return a->sign; } -void fc_val_from_str(const char *str, unsigned int len) +int fc_is_inf(const fp_value *a) { - CLEAR_BUFFER(); - value = strtoLLD(str, NULL); + return a->desc.clss == INF; } -void fc_val_from_float(LLDBL l) +int fc_is_nan(const fp_value *a) { - CLEAR_BUFFER(); - value = l; + return a->desc.clss == NAN; } -LLDBL fc_val_to_float(const void *val) +int fc_is_subnormal(const fp_value *a) { - return CAST_IN(val); + return a->desc.clss == SUBNORMAL; } -void fc_get_min(unsigned int num_bits) +char *fc_print(const fp_value *val, char *buf, int buflen, unsigned base) { - CLEAR_BUFFER(); - switch (num_bits) - { - case 32: - value = FLT_MIN; - break; - case 64: - value = DBL_MIN; - break; - case 80: - default: - value = LDBL_MIN; - break; - } + char *mul_1; + LLDBL flt_val; + + mul_1 = alloca(calc_buffer_size); + + switch (base) { + case FC_DEC: + switch ((value_class_t)val->desc.clss) { + case INF: + snprintf(buf, buflen, "%cINF", val->sign ? '-' : '+'); + break; + case NAN: + snprintf(buf, buflen, "NaN"); + break; + case ZERO: + snprintf(buf, buflen, "0.0"); + break; + default: + flt_val = fc_val_to_ieee754(val); +#ifdef HAVE_LONG_DOUBLE + /* XXX 30 is arbitrary */ + snprintf(buf, buflen, "%.30LE", flt_val); +#else + snprintf(buf, buflen, "%.18E", flt_val); +#endif + } + break; + + case FC_HEX: + switch ((value_class_t)val->desc.clss) { + case INF: + snprintf(buf, buflen, "%cINF", val->sign ? '-' : '+'); + break; + case NAN: + snprintf(buf, buflen, "NAN"); + break; + case ZERO: + snprintf(buf, buflen, "0.0"); + break; + default: + flt_val = fc_val_to_ieee754(val); +#ifdef HAVE_LONG_DOUBLE + snprintf(buf, buflen, "%LA", flt_val); +#else + snprintf(buf, buflen, "%A", flt_val); +#endif + } + break; + + case FC_PACKED: + default: + snprintf(buf, buflen, "%s", sc_print(pack(val, mul_1), value_size*4, SC_HEX, 0)); + buf[buflen - 1] = '\0'; + break; + } + return buf; } -void fc_get_max(unsigned int num_bits) +unsigned char fc_sub_bits(const fp_value *value, unsigned num_bits, unsigned byte_ofs) { - CLEAR_BUFFER(); - switch (num_bits) - { - case 32: - value = FLT_MAX; - break; - case 64: - value = DBL_MAX; - break; - case 80: - default: - value = LDBL_MAX; - break; - } + /* this is used to cache the packed version of the value */ + static char *packed_value = NULL; + + if (packed_value == NULL) packed_value = XMALLOCN(char, value_size); + + if (value != NULL) + pack(value, packed_value); + + return sc_sub_bits(packed_value, num_bits, byte_ofs); } -void fc_get_nan(void) +/* Returns non-zero if the mantissa is zero, i.e. 1.0Exxx */ +int fc_zero_mantissa(const fp_value *value) { - value = strtoLLD("nan", NULL); + return sc_get_lowest_set_bit(_mant(value)) == ROUNDING_BITS + value->desc.mantissa_size; +} +/* Returns the exponent of a value. */ +int fc_get_exponent(const fp_value *value) +{ + int exp_bias = (1 << (value->desc.exponent_size - 1)) - 1; + return sc_val_to_long(_exp(value)) - exp_bias; } -void fc_get_inf(void) +/* Return non-zero if a given value can be converted lossless into another precision */ +int fc_can_lossless_conv_to(const fp_value *value, const ieee_descriptor_t *desc) { - value = strtoLLD("inf", NULL); + int v; + int exp_bias; + + /* handle some special cases first */ + switch (value->desc.clss) { + case ZERO: + case INF: + case NAN: + return 1; + default: + break; + } + + /* check if the exponent can be encoded: note, 0 and all ones are reserved for the exponent */ + exp_bias = (1 << (desc->exponent_size - 1)) - 1; + v = fc_get_exponent(value) + exp_bias; + if (0 < v && v < (1 << desc->exponent_size) - 1) { + /* exponent can be encoded, now check the mantissa */ + v = value->desc.mantissa_size + ROUNDING_BITS - sc_get_lowest_set_bit(_mant(value)); + return v <= desc->mantissa_size; + } + return 0; } -void fc_calc(const void *a, const void *b, int opcode) + +fc_rounding_mode_t fc_set_rounding_mode(fc_rounding_mode_t mode) { - CLEAR_BUFFER(); - switch (opcode) - { - case FC_ADD: - value = CAST_IN(a) + CAST_IN(b); - break; - case FC_SUB: - value = CAST_IN(a) - CAST_IN(b); - break; - case FC_MUL: - value = CAST_IN(a) * CAST_IN(b); - break; - case FC_DIV: - value = CAST_IN(a) / CAST_IN(b); - break; - case FC_NEG: - value = -CAST_IN(a); - break; - } + if (mode == FC_TONEAREST || mode == FC_TOPOSITIVE || mode == FC_TONEGATIVE || mode == FC_TOZERO) + rounding_mode = mode; + + return rounding_mode; } -int fc_comp(const void *a, const void *b) +fc_rounding_mode_t fc_get_rounding_mode(void) { - if (CAST_IN(a) == CAST_IN(b)) return 0; - else return (CAST_IN(a) > CAST_IN(b))?(1):(-1); + return rounding_mode; } -char *fc_print_dec(const void *a, char *buf, int buflen) +void init_fltcalc(int precision) { -#ifdef USE_LONG_DOUBLE - snprintf(buf, buflen, "%1.30Lg", CAST_IN(a)); + if (calc_buffer == NULL) { + /* does nothing if already init */ + if (precision == 0) precision = FC_DEFAULT_PRECISION; + + init_strcalc(precision + 2 + ROUNDING_BITS); + + /* needs additionally rounding bits, one bit as explicit 1., and one for + * addition overflow */ + max_precision = sc_get_precision() - (2 + ROUNDING_BITS); + if (max_precision < precision) + printf("WARNING: not enough precision available, using %d\n", max_precision); + + rounding_mode = FC_TONEAREST; + value_size = sc_get_buffer_length(); + calc_buffer_size = sizeof(fp_value) + 2*value_size - 1; + + calc_buffer = xmalloc(calc_buffer_size); + memset(calc_buffer, 0, calc_buffer_size); + DEBUGPRINTF(("init fltcalc:\n\tVALUE_SIZE = %d\ntCALC_BUFFER_SIZE = %d\n\tcalc_buffer = %p\n\n", value_size, calc_buffer_size, calc_buffer)); +#ifdef HAVE_LONG_DOUBLE + DEBUGPRINTF(("\tUsing long double (1-15-64) interface\n")); +#else + DEBUGPRINTF(("\tUsing double (1-11-52) interface\n")); +#endif +#ifdef WORDS_BIGENDIAN + DEBUGPRINTF(("\tWord order is big endian\n\n")); #else - snprintf(buf, buflen, "%1.30g", CAST_IN(a)); + DEBUGPRINTF(("\tWord order is little endian\n\n")); #endif - return buf; + } +} + +void finish_fltcalc (void) +{ + free(calc_buffer); calc_buffer = NULL; +} + +#ifdef FLTCALC_TRACE_CALC +static char buffer[100]; +#endif + +/* definition of interface functions */ +fp_value *fc_add(const fp_value *a, const fp_value *b, fp_value *result) +{ + if (result == NULL) result = calc_buffer; + + TRACEPRINTF(("%s ", fc_print(a, buffer, sizeof(buffer), FC_PACKED))); + TRACEPRINTF(("+ %s ", fc_print(b, buffer, sizeof(buffer), FC_PACKED))); + + /* make the value with the bigger exponent the first one */ + if (sc_comp(_exp(a), _exp(b)) == -1) + _fadd(b, a, result); + else + _fadd(a, b, result); + + TRACEPRINTF(("= %s\n", fc_print(result, buffer, sizeof(buffer), FC_PACKED))); + return result; +} + +fp_value *fc_sub(const fp_value *a, const fp_value *b, fp_value *result) +{ + fp_value *temp; + + if (result == NULL) result = calc_buffer; + + TRACEPRINTF(("%s ", fc_print(a, buffer, sizeof(buffer), FC_PACKED))); + TRACEPRINTF(("- %s ", fc_print(b, buffer, sizeof(buffer), FC_PACKED))); + + temp = alloca(calc_buffer_size); + memcpy(temp, b, calc_buffer_size); + temp->sign = !b->sign; + if (sc_comp(_exp(a), _exp(temp)) == -1) + _fadd(temp, a, result); + else + _fadd(a, temp, result); + + TRACEPRINTF(("= %s\n", fc_print(result, buffer, sizeof(buffer), FC_PACKED))); + return result; +} + +fp_value *fc_mul(const fp_value *a, const fp_value *b, fp_value *result) +{ + if (result == NULL) result = calc_buffer; + + TRACEPRINTF(("%s ", fc_print(a, buffer, sizeof(buffer), FC_PACKED))); + TRACEPRINTF(("* %s ", fc_print(b, buffer, sizeof(buffer), FC_PACKED))); + + _fmul(a, b, result); + + TRACEPRINTF(("= %s\n", fc_print(result, buffer, sizeof(buffer), FC_PACKED))); + return result; +} + +fp_value *fc_div(const fp_value *a, const fp_value *b, fp_value *result) +{ + if (result == NULL) result = calc_buffer; + + TRACEPRINTF(("%s ", fc_print(a, buffer, sizeof(buffer), FC_PACKED))); + TRACEPRINTF(("/ %s ", fc_print(b, buffer, sizeof(buffer), FC_PACKED))); + + _fdiv(a, b, result); + + TRACEPRINTF(("= %s\n", fc_print(result, buffer, sizeof(buffer), FC_PACKED))); + return result; +} + +fp_value *fc_neg(const fp_value *a, fp_value *result) +{ + if (result == NULL) result = calc_buffer; + + TRACEPRINTF(("- %s ", fc_print(a, buffer, sizeof(buffer), FC_PACKED))); + + if (a != result) + memcpy(result, a, calc_buffer_size); + result->sign = !a->sign; + + TRACEPRINTF(("= %s\n", fc_print(result, buffer, sizeof(buffer), FC_PACKED))); + return result; } -unsigned char fc_sub_bits(const void *value, unsigned num_bits, unsigned byte_ofs) +fp_value *fc_int(const fp_value *a, fp_value *result) { - LLDBL val = CAST_IN(value); - float f; - double d; + if (result == NULL) result = calc_buffer; - unsigned char *p; - unsigned len; + TRACEPRINTF(("%s ", fc_print(a, buffer, sizeof(buffer), FC_PACKED))); + TRACEPRINTF(("truncated to integer ")); - switch (num_bits) { - case 32: - f = (float)val; - p = (unsigned char *)&f; - len = 4; - break; + _trunc(a, result); - case 64: - d = (double)val; - p = (unsigned char *)&d; - len = 8; - break; + TRACEPRINTF(("= %s\n", fc_print(result, buffer, sizeof(buffer), FC_PACKED))); + return result; +} + +fp_value *fc_rnd(const fp_value *a, fp_value *result) +{ + if (result == NULL) result = calc_buffer; + + (void) a; + TRACEPRINTF(("%s ", fc_print(a, buffer, sizeof(buffer), FC_PACKED))); + TRACEPRINTF(("rounded to integer ")); + + panic("fc_rnd() not yet implemented"); +} + +/* + * convert a floating point value into an sc value ... + */ +int fc_flt2int(const fp_value *a, void *result, ir_mode *dst_mode) +{ + if (a->desc.clss == NORMAL) { + int exp_bias = (1 << (a->desc.exponent_size - 1)) - 1; + int exp_val = sc_val_to_long(_exp(a)) - exp_bias; + int shift, highest; + int mantissa_size; + int tgt_bits; + + if (a->sign && !mode_is_signed(dst_mode)) { + /* FIXME: for now we cannot convert this */ + return 0; + } + + tgt_bits = get_mode_size_bits(dst_mode); + if (mode_is_signed(dst_mode)) + --tgt_bits; - case 80: - p = (unsigned char *)&val; - len = 10; - break; + assert(exp_val >= 0 && "floating point value not integral before fc_flt2int() call"); + mantissa_size = a->desc.mantissa_size + ROUNDING_BITS; + shift = exp_val - mantissa_size; - default: - return 0; - } + if (tgt_bits < mantissa_size + 1) + tgt_bits = mantissa_size + 1; + if (shift > 0) { + sc_shlI(_mant(a), shift, tgt_bits, 0, result); + } else { + sc_shrI(_mant(a), -shift, tgt_bits, 0, result); + } - if (byte_ofs > len) - return 0; - return p[byte_ofs]; + /* check for overflow */ + highest = sc_get_highest_set_bit(result); + + if (mode_is_signed(dst_mode)) { + if (highest == sc_get_lowest_set_bit(result)) { + /* need extra test for MIN_INT */ + if (highest >= (int) get_mode_size_bits(dst_mode)) { + /* FIXME: handle overflow */ + return 0; + } + } else { + if (highest >= (int) get_mode_size_bits(dst_mode) - 1) { + /* FIXME: handle overflow */ + return 0; + } + } + } else { + if (highest >= (int) get_mode_size_bits(dst_mode)) { + /* FIXME: handle overflow */ + return 0; + } + } + + if (a->sign) + sc_neg(result, result); + + return 1; + } + else if (a->desc.clss == ZERO) { + sc_zero(result); + return 1; + } + return 0; +} + + +unsigned fc_set_immediate_precision(unsigned bits) +{ + unsigned old = immediate_prec; + + immediate_prec = bits; + return old; +} + +int fc_is_exact(void) +{ + return fc_exact; }