X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Ftv%2Ffltcalc.c;h=7c5d6fdd15a1eed8f34c49b0d1db5674254e7965;hb=b51296cd3a2238c9e20ded9f914b34c4ac3fe304;hp=3be4cf19c32a8110325a9a0ed751cfdb89af4a68;hpb=ed7dd996981ad697458da401fb1638cc2a1aa977;p=libfirm diff --git a/ir/tv/fltcalc.c b/ir/tv/fltcalc.c index 3be4cf19c..7c5d6fdd1 100644 --- a/ir/tv/fltcalc.c +++ b/ir/tv/fltcalc.c @@ -1,154 +1,1611 @@ -/* fltcalc.c - * Authors: Matthias Heil +/* + * Project: libFIRM + * File name: ir/tv/fltcalc.c + * Purpose: + * Author: + * Modified by: + * Created: 2003 + * CVS-ID: $Id$ + * Copyright: (c) 2003 Universität Karlsruhe + * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE. */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + + #include "fltcalc.h" -#include "ieee754.h" -#include -#include -#include +#include "strcalc.h" + +#include /* need isnan() and isinf() (will be changed)*/ +/* undef some reused constants defined by math.h */ +#ifdef NAN +# undef NAN +#endif + +#ifdef HAVE_INTTYPES_H +# include +#endif +#ifdef HAVE_STRING_H +# include +#endif +#ifdef HAVE_STDLIB_H +# include +#endif +#ifdef HAVE_ALLOCA_H +# include +#endif +#ifdef HAVE_MALLOC_H +# include +#endif #include +#include -/******** - * globals - ********/ -static long double value; +#include "xmalloc.h" + +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 +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 + +/** + * possible float states + */ +typedef enum { + NORMAL, /**< normal representation, implicit 1 */ + ZERO, /**< +/-0 */ + SUBNORMAL, /**< denormals, implicit 0 */ + INF, /**< +/-oo */ + NAN, /**< Not A Number */ +} value_class_t; + +/** A descriptor for an IEEE float value. */ +typedef struct { + unsigned char exponent_size; /**< size of exponent in bits */ + unsigned char mantissa_size; /**< size of mantissa in bits */ + value_class_t clss; /**< state of this float */ +} descriptor_t; + +#define CLEAR_BUFFER(buffer) memset(buffer, 0, calc_buffer_size) -#define CAST_IN(val) (*((long double *)((val)))) -#define CAST_OUT(val) ((void *)&(val)) +/* because variable sized structs are impossible, the internal + * value is represented as a pseudo-struct char array, addressed + * by macros + * struct { + * char sign; // 0 for positive, 1 for negative + * char exp[value_size]; + * char mant[value_size]; + * descriptor_t desc; + * }; + */ +#define _sign(a) (((char*)a)[SIGN_POS]) +#define _exp(a) (&((char*)a)[EXPONENT_POS]) +#define _mant(a) (&((char*)a)[MANTISSA_POS]) +#define _desc(a) (*(descriptor_t *)&((char *)a)[DESCRIPTOR_POS]) + +#define _save_result(x) memcpy((x), sc_get_buffer(), value_size) +#define _shift_right(x, y, b) sc_shr((x), (y), value_size*4, 0, (b)) +#define _shift_left(x, y, b) sc_shl((x), (y), value_size*4, 0, (b)) + +#define FC_DEFINE1(code) \ +char *fc_##code(const void *a, void *result) { \ + return _calc((const char*)a, NULL, FC_##code, (char*)result); \ +} + +#define FC_DEFINE2(code) \ +char *fc_##code(const void *a, const void *b, void *result) { \ + return _calc((const char*)a, (const char*)b, FC_##code, (char*)result); \ +} + +#define FUNC_PTR(code) fc_##code -#define CLEAR_BUFFER() memset((char*)&value, 0, sizeof(long double)) +#if FLTCALC_DEBUG +# define DEBUGPRINTF(x) printf x +#else +# define DEBUGPRINTF(x) ((void)0) +#endif + +#if FLTCALC_TRACE_CALC +# define TRACEPRINTF(x) printf x +#else +# define TRACEPRINTF(x) ((void)0) +#endif + +static char *calc_buffer = NULL; + +static fc_rounding_mode_t rounding_mode; + +static int calc_buffer_size; +static int value_size; +static int SIGN_POS; +static int EXPONENT_POS; +static int MANTISSA_POS; +static int DESCRIPTOR_POS; + +static int max_precision; /******** * private functions ********/ +#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 -/******** - * functions defined in fltcalc.h - ********/ -const void *fc_get_buffer(void) +/** pack machine-like */ +static char* _pack(const char *int_float, char *packed) { - return CAST_OUT(value); + char *shift_val; + char *temp; + char *val_buffer; + + temp = alloca(value_size); + shift_val = alloca(value_size); + + switch (_desc(int_float).clss) { + case NAN: + val_buffer = alloca(calc_buffer_size); + fc_get_qnan(_desc(int_float).exponent_size, _desc(int_float).mantissa_size, val_buffer); + int_float = val_buffer; + break; + + case INF: + val_buffer = alloca(calc_buffer_size); + fc_get_plusinf(_desc(int_float).exponent_size, _desc(int_float).mantissa_size, val_buffer); + _sign(val_buffer) = _sign(int_float); + int_float = val_buffer; + break; + + default: + break; + } + /* pack sign */ + sc_val_from_ulong(_sign(int_float), temp); + + sc_val_from_ulong(_desc(int_float).exponent_size + _desc(int_float).mantissa_size, NULL); + _shift_left(temp, sc_get_buffer(), packed); + + /* extract exponent */ + sc_val_from_ulong(_desc(int_float).mantissa_size, shift_val); + + _shift_left(_exp(int_float), shift_val, temp); + + sc_or(temp, packed, packed); + + /* extract mantissa */ + /* remove 2 rounding bits */ + sc_val_from_ulong(2, shift_val); + _shift_right(_mant(int_float), shift_val, temp); + + /* remove leading 1 (or 0 if denormalized) */ + sc_max_from_bits(_desc(int_float).mantissa_size, 0, shift_val); /* all mantissa bits are 1's */ + sc_and(temp, shift_val, temp); + + /* save result */ + sc_or(temp, packed, packed); + + return packed; } -const int fc_get_buffer_length(void) +char* _normalize(const char *in_val, char *out_val, int sticky) { - return sizeof(long double); + int hsb; + char lsb, guard, round, round_dir = 0; + char *temp; + + temp = alloca(value_size); + + /* +2: save two rounding bits at the end */ + hsb = 2 + _desc(in_val).mantissa_size - sc_get_highest_set_bit(_mant(in_val)) - 1; + + if (in_val != out_val) + { + _sign(out_val) = _sign(in_val); + memcpy(&_desc(out_val), &_desc(in_val), sizeof(descriptor_t)); + } + + _desc(out_val).clss = NORMAL; + + /* mantissa all zeros, so zero exponent (because of explicit one)*/ + if (hsb == 2 + _desc(in_val).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 (!sticky) sticky = sc_had_carry(); + + 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 (!sticky) sticky = sc_had_carry(); + /* denormalized means exponent of zero */ + sc_val_from_ulong(0, _exp(out_val)); + + _desc(out_val).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), _desc(out_val).mantissa_size + 2, 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 = (!_sign(out_val) && (guard || round || sticky)); + break; + case FC_TONEGATIVE: + /* if negative: round to one if the exact value is bigger, else to zero */ + round_dir = (_sign(out_val) && (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", _sign(out_val), 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)); + } + + /* could have rounded down to zero */ + if (sc_is_zero(_mant(out_val)) && (_desc(out_val).clss == SUBNORMAL)) + _desc(out_val).clss = ZERO; + + /* check for rounding overflow */ + hsb = 2 + _desc(out_val).mantissa_size - sc_get_highest_set_bit(_mant(out_val)) - 1; + if ((_desc(out_val).clss != SUBNORMAL) && (hsb < -1)) + { + sc_val_from_ulong(1, temp); + _shift_right(_mant(out_val), temp, _mant(out_val)); + + sc_add(_exp(out_val), temp, _exp(out_val)); + } + else if ((_desc(out_val).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)); + + _desc(out_val).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 << _desc(out_val).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 (_sign(out_val) == 0) + { + /* value is positive */ + switch (rounding_mode) { + case FC_TONEAREST: + case FC_TOPOSITIVE: + _desc(out_val).clss = INF; + break; + + case FC_TONEGATIVE: + case FC_TOZERO: + fc_get_max(_desc(out_val).exponent_size, _desc(out_val).mantissa_size, out_val); + } + } else { + /* value is negative */ + switch (rounding_mode) { + case FC_TONEAREST: + case FC_TONEGATIVE: + _desc(out_val).clss = INF; + break; + + case FC_TOPOSITIVE: + case FC_TOZERO: + fc_get_min(_desc(out_val).exponent_size, _desc(out_val).mantissa_size, out_val); + } + } + } + + return out_val; } -void fc_val_from_str(const char *str, unsigned int len) +/** + * Operations involving NaN's must return NaN + */ +#define handle_NAN(a, b, result) \ +do { \ + if (_desc(a).clss == NAN) { \ + if (a != result) memcpy(result, a, calc_buffer_size); \ + return result; \ + } \ + if (_desc(b).clss == NAN) { \ + if (b != result) memcpy(result, b, calc_buffer_size); \ + return result; \ + } \ +}while (0) + + +/** + * calculate a + b, where a is the value with the bigger exponent + */ +static char* _fadd(const char* a, const char* b, char* result) { - CLEAR_BUFFER(); - value = strtold(str, NULL); + char *temp; + char *exp_diff; + + char sign; + char sticky; + + handle_NAN(a, b, result); + + /* make sure result has a descriptor */ + if (result != a && result != b) + memcpy(&_desc(result), &_desc(a), sizeof(descriptor_t)); + + /* determine if this is an addition or subtraction */ + sign = _sign(a) ^ _sign(b); + + /* produce NaN on inf - inf */ + if (sign && (_desc(a).clss == INF) && (_desc(b).clss == INF)) + return fc_get_qnan(_desc(a).exponent_size, _desc(b).mantissa_size, result); + + 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 */ + _sign(result) = _sign(a); /* abs(a) is bigger and a is negative */ + break; + case 0: /* a == b */ + _sign(result) = (rounding_mode == FC_TONEGATIVE); + break; + case -1: /* a < b */ + _sign(result) = _sign(b); /* abs(b) is bigger and b is negative */ + break; + default: + /* can't be reached */ + break; + } + } + else + _sign(result) = _sign(a); + + /* sign has been taken care of, check for special cases */ + if (_desc(a).clss == ZERO) { + if (b != result) memcpy(result+SIGN_POS+1, b+SIGN_POS+1, calc_buffer_size-SIGN_POS-1); + return result; + } + if (_desc(b).clss == ZERO) { + if (a != result) memcpy(result+SIGN_POS+1, a+SIGN_POS+1, calc_buffer_size-SIGN_POS-1); + return result; + } + + if (_desc(a).clss == INF) { + if (a != result) memcpy(result+SIGN_POS+1, a+SIGN_POS+1, calc_buffer_size-SIGN_POS-1); + return result; + } + if (_desc(b).clss == INF) { + if (b != result) memcpy(result+SIGN_POS+1, b+SIGN_POS+1, calc_buffer_size-SIGN_POS-1); + return result; + } + + /* 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 ((_desc(b).clss == SUBNORMAL) && (_desc(a).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(); + + 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 ((_desc(a).clss == SUBNORMAL) && (_desc(b).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); + + return _normalize(result, result, sticky); } -void fc_val_from_float(long double l) +/** + * calculate a * b + */ +static char* _fmul(const char* a, const char* b, char* result) { - CLEAR_BUFFER(); - value = l; + char *temp; + + handle_NAN(a, b, result); + + temp = alloca(value_size); + + if (result != a && result != b) + memcpy(&_desc(result), &_desc(a), sizeof(descriptor_t)); + + _sign(result) = _sign(a) ^ _sign(b); + + /* produce NaN on 0 * inf */ + if (_desc(a).clss == ZERO) { + if (_desc(b).clss == INF) + fc_get_qnan(_desc(a).exponent_size, _desc(a).mantissa_size, result); + else + if (a != result) memcpy(result+SIGN_POS+1, a+SIGN_POS+1, calc_buffer_size-1); + return result; + } + if (_desc(b).clss == ZERO) { + if (_desc(a).clss == INF) + fc_get_qnan(_desc(a).exponent_size, _desc(a).mantissa_size, result); + else + if (b != result) memcpy(result+SIGN_POS+1, b+SIGN_POS+1, calc_buffer_size-1); + return result; + } + + if (_desc(a).clss == INF) { + if (a != result) memcpy(result+SIGN_POS+1, a+SIGN_POS+1, calc_buffer_size-1); + return result; + } + if (_desc(b).clss == INF) { + if (b != result) memcpy(result+SIGN_POS+1, b+SIGN_POS+1, calc_buffer_size-1); + return result; + } + + /* exp = exp(a) + exp(b) - excess */ + sc_add(_exp(a), _exp(b), _exp(result)); + + sc_val_from_ulong((1<<_desc(a).exponent_size)/2-1, temp); + sc_sub(_exp(result), temp, _exp(result)); + + /* mixed normal, subnormal values introduce an error of 1, correct it */ + if ((_desc(a).clss == SUBNORMAL) ^ (_desc(b).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 + * +2 because of the two rounding bits */ + sc_val_from_ulong(2 + _desc(result).mantissa_size, temp); + + _shift_right(_mant(result), temp, _mant(result)); + + return _normalize(result, result, sc_had_carry()); } -long double fc_val_to_float(const void *val) +/** + * calculate a / b + */ +static char* _fdiv(const char* a, const char* b, char* result) { - return CAST_IN(val); + char *temp, *dividend; + + handle_NAN(a, b, result); + + temp = alloca(value_size); + dividend = alloca(value_size); + + if (result != a && result != b) + memcpy(&_desc(result), &_desc(a), sizeof(descriptor_t)); + + _sign(result) = _sign(a) ^ _sign(b); + + /* produce nan on 0/0 and inf/inf */ + if (_desc(a).clss == ZERO) { + if (_desc(b).clss == ZERO) + /* 0/0 -> nan */ + fc_get_qnan(_desc(a).exponent_size, _desc(a).mantissa_size, result); + else + /* 0/x -> a */ + if (a != result) memcpy(result+SIGN_POS+1, a+SIGN_POS+1, calc_buffer_size-1); + return result; + } + + if (_desc(b).clss == INF) { + if (_desc(a).clss == INF) + /* inf/inf -> nan */ + fc_get_qnan(_desc(a).exponent_size, _desc(a).mantissa_size, result); + else { + /* x/inf -> 0 */ + sc_val_from_ulong(0, NULL); + _save_result(_exp(result)); + _save_result(_mant(result)); + _desc(result).clss = ZERO; + } + return result; + } + + if (_desc(a).clss == INF) { + /* inf/x -> inf */ + if (a != result) memcpy(result+SIGN_POS+1, a+SIGN_POS+1, calc_buffer_size-1); + return result; + } + if (_desc(b).clss == ZERO) { + /* division by zero */ + if (_sign(result)) + fc_get_minusinf(_desc(a).exponent_size, _desc(a).mantissa_size, result); + else + fc_get_plusinf(_desc(a).exponent_size, _desc(a).mantissa_size, result); + return result; + } + + /* exp = exp(a) - exp(b) + excess - 1*/ + sc_sub(_exp(a), _exp(b), _exp(result)); + sc_val_from_ulong((1 << _desc(a).exponent_size)/2-2, temp); + sc_add(_exp(result), temp, _exp(result)); + + /* mixed normal, subnormal values introduce an error of 1, correct it */ + if ((_desc(a).clss == SUBNORMAL) ^ (_desc(b).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(2 + _desc(result).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)); + } + + return _normalize(result, result, sc_had_carry()); } -void fc_get_min(unsigned int num_bits) +static void _power_of_ten(int exp, descriptor_t *desc, char *result) { - CLEAR_BUFFER(); - switch (num_bits) + char *build; + char *temp; + + /* positive sign */ + _sign(result) = 0; + + /* set new descriptor (else result is supposed to already have one) */ + if (desc != NULL) + memcpy(&_desc(result), desc, sizeof(descriptor_t)); + + build = alloca(value_size); + temp = alloca(value_size); + + sc_val_from_ulong((1 << _desc(result).exponent_size)/2-1, _exp(result)); + + if (exp > 0) { - case 32: - value = FLT_MIN; - break; - case 64: - value = DBL_MIN; - break; - case 80: - default: - value = LDBL_MIN; - break; + /* 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(_desc(result).mantissa_size + 2, temp); + + _shift_left(build, temp, _mant(result)); + + _normalize(result, result, 0); + } +} + +/** + * Truncate the fractional part away. + * + * This does not clip to any integer rang. + */ +static char* _trunc(const char *a, char *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; + + temp = alloca(value_size); + + if (a != result) + memcpy(&_desc(result), &_desc(a), sizeof(descriptor_t)); + + exp_bias = (1<<_desc(a).exponent_size)/2-1; + 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)); + _desc(result).clss = ZERO; + + return result; } + + if (exp_val > _desc(a).mantissa_size) { + if (a != result) + memcpy(result, a, calc_buffer_size); + + return result; + } + + /* 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(_desc(a).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); + + return result; } -void fc_get_max(unsigned int num_bits) +/* + * This does value sanity checking(or should do it), sets up any prerequisites, + * calls the proper internal functions, clears up and returns + * the result + */ +char* _calc(const char *a, const char *b, int opcode, char *result) { - CLEAR_BUFFER(); - switch (num_bits) + char *temp; +#ifdef FLTCALC_TRACE_CALC + char *buffer; + + buffer = alloca(100); +#endif + + if (result == NULL) result = calc_buffer; + + TRACEPRINTF(("%s ", fc_print(a, buffer, 100, FC_PACKED))); + switch (opcode) { - case 32: - value = FLT_MAX; + case FC_add: + /* make the value with the bigger exponent the first one */ + TRACEPRINTF(("+ %s ", fc_print(b, buffer, 100, FC_PACKED))); + if (sc_comp(_exp(a), _exp(b)) == -1) + _fadd(b, a, result); + else + _fadd(a, b, result); break; - case 64: - value = DBL_MAX; + case FC_sub: + TRACEPRINTF(("- %s ", fc_print(b, buffer, 100, FC_PACKED))); + temp = alloca(calc_buffer_size); + memcpy(temp, b, calc_buffer_size); + _sign(temp) = !_sign(b); + if (sc_comp(_exp(a), _exp(temp)) == -1) + _fadd(temp, a, result); + else + _fadd(a, temp, result); break; - case 80: - default: - value = LDBL_MAX; + case FC_mul: + TRACEPRINTF(("* %s ", fc_print(b, buffer, 100, FC_PACKED))); + _fmul(a, b, result); + break; + case FC_div: + TRACEPRINTF(("/ %s ", fc_print(b, buffer, 100, FC_PACKED))); + _fdiv(a, b, result); + break; + case FC_neg: + TRACEPRINTF(("negated ")); + if (a != result) memcpy(result, a, calc_buffer_size); + _sign(result) = !_sign(a); + break; + case FC_int: + TRACEPRINTF(("truncated to integer ")); + _trunc(a, result); + break; + case FC_rnd: + TRACEPRINTF(("rounded to integer ")); + assert(0); break; } + + TRACEPRINTF(("= %s\n", fc_print(result, buffer, 100, FC_PACKED))); + return result; +} + +/******** + * functions defined in fltcalc.h + ********/ +const void *fc_get_buffer(void) +{ + return calc_buffer; +} + +int fc_get_buffer_length(void) +{ + return calc_buffer_size; +} + +char* fc_val_from_str(const char *str, unsigned int len, char exp_size, char mant_size, char *result) +{ +#if 0 + enum { + START, + LEFT_OF_DOT, + RIGHT_OF_DOT, + EXP_START, + EXPONENT, + END + }; + + char exp_sign; + int exp_int, hsb, state; + + const char *old_str; + + int pos; + char *mant_str, *exp_val, *power_val; + + if (result == NULL) result = calc_buffer; + + exp_val = alloca(value_size); + power_val = alloca(calc_buffer_size); + mant_str = alloca((len)?(len):(strlen(str))); + + _desc(result).exponent_size = exp_size; + _desc(result).mantissa_size = mant_size; + _desc(result).clss = NORMAL; + + old_str = str; + pos = 0; + exp_int = 0; + state = START; + + while (len == 0 || str-old_str < len) + { + switch (state) { + case START: + switch (*str) { + case '+': + _sign(result) = 0; + state = LEFT_OF_DOT; + str++; + break; + + case '-': + _sign(result) = 1; + state = LEFT_OF_DOT; + str++; + break; + + case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': + _sign(result) = 0; + state = LEFT_OF_DOT; + break; + + case '.': + _sign(result) = 0; + state = RIGHT_OF_DOT; + str++; + break; + + case 'n': + case 'N': + case 'i': + case 'I': + break; + + default: + _fail_char(old_str, len, str - old_str); + } + break; + + case LEFT_OF_DOT: + switch (*str) { + case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': + mant_str[pos++] = *(str++); + break; + + case '.': + state = RIGHT_OF_DOT; + str++; + break; + + case 'e': + case 'E': + state = EXP_START; + str++; + break; + + case '\0': + mant_str[pos] = '\0'; + goto done; + + default: + _fail_char(old_str, len, str - old_str); + } + break; + + case RIGHT_OF_DOT: + switch (*str) { + case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': + mant_str[pos++] = *(str++); + exp_int++; + break; + + case 'e': + case 'E': + state = EXP_START; + str++; + break; + + case '\0': + mant_str[pos] = '\0'; + goto done; + + default: + _fail_char(old_str, len, str - old_str); + } + break; + + case EXP_START: + switch (*str) { + case '-': + exp_sign = 1; + /* fall through */ + case '+': + if (*(str-1) != 'e' && *(str-1) != 'E') _fail_char(old_str, len, str - old_str); + str++; + break; + + case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': + mant_str[pos] = '\0'; + pos = 1; + str++; + state = EXPONENT; + break; + + default: + _fail_char(old_str, len, str - old_str); + } + break; + + case EXPONENT: + switch (*str) { + case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': + pos++; + str++; + break; + + case '\0': goto done; + + default: + _fail_char(old_str, len, str - old_str); + } + } + } /* switch(state) */ + +done: + sc_val_from_str(mant_str, strlen(mant_str), _mant(result)); + + /* shift to put value left of radix point */ + sc_val_from_ulong(mant_size + 2, exp_val); + + _shift_left(_mant(result), exp_val, _mant(result)); + + sc_val_from_ulong((1 << exp_size)/2-1, _exp(result)); + + _normalize(result, result, 0); + + if (state == EXPONENT) { + exp_int -= atoi(str-pos); + } + + _power_of_ten(exp_int, &_desc(result), power_val); + + _fdiv(result, power_val, result); + + return result; +#else + + /* XXX excuse of an implementation to make things work */ + LLDBL val; +#ifdef HAVE_LONG_DOUBLE + val = strtold(str, NULL); +#else + val = strtod(str, NULL); +#endif + + DEBUGPRINTF(("val_from_str(%s)\n", str)); + return fc_val_from_float(val, exp_size, mant_size, result); +#endif } -void fc_get_nan(void) +char* fc_val_from_float(LLDBL l, char exp_size, char mant_size, char* result) { - /* nan: all exponent bit set, non-zero mantissa. not signalling wheni - * msb of mantissa is set (easily found using this struct */ - union ieee854_long_double ld; + char *temp; + int bias_res, bias_val, mant_val; + value_t srcval; + UINT32 sign, exponent, mantissa0, mantissa1; + + srcval.d = l; + bias_res = ((1<> 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); + + _desc(result).exponent_size = exp_size; + _desc(result).mantissa_size = mant_size; + + /* extract sign */ + _sign(result) = 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)) { + _desc(result).clss = NAN; + TRACEPRINTF(("val_from_float resulted in NAN\n")); + return result; + } + else if (isinf(l)) { + _desc(result).clss = INF; + TRACEPRINTF(("val_from_float resulted in %sINF\n", (_sign(result)==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 */ +#ifdef HAVE_EXPLICIT_ONE + sc_val_from_long((exponent-bias_val+bias_res)-(mant_val-mant_size-1), _exp(result)); +#else + sc_val_from_long((exponent-bias_val+bias_res)-(mant_val-mant_size), _exp(result)); +#endif + + /* build mantissa representation */ +#ifndef HAVE_EXPLICIT_ONE + if (exponent != 0) + { + /* insert the hidden bit */ + sc_val_from_ulong(1, temp); + sc_val_from_ulong(mant_val + 2, NULL); + _shift_left(temp, sc_get_buffer(), NULL); + } + else +#endif + { + sc_val_from_ulong(0, NULL); + } + + _save_result(_mant(result)); - CLEAR_BUFFER(); - ld.ieee_nan.negative = 0; - ld.ieee_nan.exponent = 0x7FFF; - ld.ieee_nan.quiet_nan = 1; - ld.ieee_nan.mantissa0 = 42; + /* 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)); - value = ld.d; + /* bits from the lower word */ + sc_val_from_ulong(mantissa1, temp); + sc_val_from_ulong(2, 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; } -void fc_get_inf(void) +LLDBL fc_val_to_float(const void *val) { - /* +-inf: all exponent bit set, sign is easy, one is strange XXX */ - union ieee854_long_double ld; + const char *value; + char *temp = NULL; + + int byte_offset; + + UINT32 sign; + UINT32 exponent; + UINT32 mantissa0; + UINT32 mantissa1; + + value_t buildval; + +#ifdef HAVE_LONG_DOUBLE + char result_exponent = 15; + char result_mantissa = 64; +#else + char result_exponent = 11; + char result_mantissa = 52; +#endif + + temp = alloca(calc_buffer_size); +#ifdef HAVE_EXPLICIT_ONE + value = fc_cast(val, result_exponent, result_mantissa-1, temp); +#else + value = fc_cast(val, result_exponent, result_mantissa, temp); +#endif + + sign = _sign(value); + + /* @@@ 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)) ; - CLEAR_BUFFER(); - ld.ieee_nan.negative = 0; - ld.ieee_nan.exponent = 0x7FFF; - ld.ieee_nan.quiet_nan = 0; - ld.ieee_nan.one = 1; - ld.ieee_nan.mantissa0 = 0; - ld.ieee_nan.mantissa1 = 0; + sc_val_from_ulong(2, NULL); + _shift_right(_mant(value), sc_get_buffer(), _mant(value)); - value = ld.d; + mantissa0 = 0; + mantissa1 = 0; + + for (byte_offset = 0; byte_offset < 4; byte_offset++) + mantissa1 |= sc_sub_bits(_mant(value), result_mantissa, byte_offset) << (byte_offset<<3); + + for (; (byte_offset<<3) < result_mantissa; byte_offset++) + mantissa0 |= sc_sub_bits(_mant(value), result_mantissa, 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; } -void fc_calc(const void *a, const void *b, int opcode) +char* fc_cast(const void *val, char exp_size, char mant_size, char *result) { - CLEAR_BUFFER(); - switch (opcode) + const char *value = (const char*) val; + char *temp; + int exp_offset, val_bias, res_bias; + + if (result == NULL) result = calc_buffer; + temp = alloca(value_size); + + if (_desc(value).exponent_size == exp_size && _desc(value).mantissa_size == mant_size) { - case FC_ADD: - value = CAST_IN(a) + CAST_IN(b); - break; - case FC_SUB: - value = CAST_IN(a) - CAST_IN(b); + if (value != result) memcpy(result, value, calc_buffer_size); + return result; + } + + /* set the descriptor of the new value */ + _desc(result).exponent_size = exp_size; + _desc(result).mantissa_size = mant_size; + _desc(result).clss = _desc(value).clss; + + _sign(result) = _sign(value); + + /* 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<<_desc(value).exponent_size)/2-1; + res_bias = (1<+< 1 because of two extra rounding bits */ + sc_val_from_ulong(mantissa_size + 1, NULL); + _shift_left(_mant(result), sc_get_buffer(), _mant(result)); + + return result; +} + +char* fc_get_plusinf(unsigned int exponent_size, unsigned int mantissa_size, char *result) +{ + if (result == NULL) result = calc_buffer; + + _desc(result).exponent_size = exponent_size; + _desc(result).mantissa_size = mantissa_size; + _desc(result).clss = NORMAL; + + _sign(result) = 0; + + sc_val_from_ulong((1<= 8+_sign(val)) sprintf(buf, "%sINFINITY", _sign(val)?"-":""); + else snprintf(buf, buflen, "%sINF", _sign(val)?"-":NULL); + break; + case NAN: + snprintf(buf, buflen, "NAN"); + break; + case ZERO: + snprintf(buf, buflen, "0.0"); + break; + default: + /* XXX to be implemented */ +#ifdef HAVE_LONG_DOUBLE + /* XXX 30 is arbitrary */ + snprintf(buf, buflen, "%.30LE", fc_val_to_float(val)); +#else + snprintf(buf, buflen, "%.18E", fc_val_to_float(val)); +#endif + } break; - case FC_MUL: - value = CAST_IN(a) * CAST_IN(b); + + case FC_HEX: + switch (_desc(val).clss) { + case INF: + if (buflen >= 8+_sign(val)) sprintf(buf, "%sINFINITY", _sign(val)?"-":""); + else snprintf(buf, buflen, "%sINF", _sign(val)?"-":NULL); + break; + case NAN: + snprintf(buf, buflen, "NAN"); + break; + case ZERO: + snprintf(buf, buflen, "0.0"); + break; + default: +#ifdef HAVE_LONG_DOUBLE + snprintf(buf, buflen, "%LA", fc_val_to_float(val)); +#else + snprintf(buf, buflen, "%A", fc_val_to_float(val)); +#endif + } break; - case FC_DIV: - value = CAST_IN(a) / CAST_IN(b); + + case FC_PACKED: + default: + snprintf(buf, buflen, "%s", sc_print(_pack(val, mul_1), value_size*4, SC_HEX)); break; - case FC_NEG: - value = -CAST_IN(a); } + return buf; } -int fc_comp(const void *a, const void *b) +unsigned char fc_sub_bits(const void *value, unsigned num_bits, unsigned byte_ofs) { - if (CAST_IN(a) == CAST_IN(b)) return 0; - else return (CAST_IN(a) > CAST_IN(b))?(1):(-1); + /* this is used to cache the packed version of the value */ + static char *pack = NULL; + + if (pack == NULL) pack = xmalloc(value_size); + + if (value != NULL) + _pack((const char*)value, pack); + + return sc_sub_bits(pack, num_bits, byte_ofs); } -char *fc_print_dec(const void *a, char *buf, int buflen) +fc_rounding_mode_t fc_set_rounding_mode(fc_rounding_mode_t mode) { - snprintf(buf, buflen, "%1.30Lg", CAST_IN(a)); - return buf; + if (mode == FC_TONEAREST || mode == FC_TOPOSITIVE || mode == FC_TONEGATIVE || mode == FC_TOZERO) + rounding_mode = mode; + + return rounding_mode; +} + +fc_rounding_mode_t fc_get_rounding_mode(void) +{ + return rounding_mode; } + +void init_fltcalc(int precision) +{ + if (calc_buffer == NULL) { + /* does nothing if already init */ + if (precision == 0) precision = FC_DEFAULT_PRECISION; + + init_strcalc(precision + 4); + + /* needs additionally two bits to round, a bit as explicit 1., and one for + * addition overflow */ + max_precision = sc_get_precision() - 4; + if (max_precision < precision) + printf("WARING: not enough precision available, using %d\n", max_precision); + + rounding_mode = FC_TONEAREST; + value_size = sc_get_buffer_length(); + SIGN_POS = 0; + EXPONENT_POS = SIGN_POS + sizeof(char); + MANTISSA_POS = EXPONENT_POS + value_size; + DESCRIPTOR_POS = MANTISSA_POS + value_size; + calc_buffer_size = DESCRIPTOR_POS + sizeof(descriptor_t); + + calc_buffer = xmalloc(calc_buffer_size); + DEBUGPRINTF(("init fltcalc:\n\tVALUE_SIZE = %d\n\tSIGN_POS = %d\n\tEXPONENT_POS = %d\n\tMANTISSA_POS = %d\n\tDESCRIPTOR_POS = %d\n\tCALC_BUFFER_SIZE = %d\n\tcalc_buffer = %p\n\n", value_size, SIGN_POS, EXPONENT_POS, MANTISSA_POS, DESCRIPTOR_POS, 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 + DEBUGPRINTF(("\tWord order is little endian\n\n")); +#endif + } +} + +void finish_fltcalc (void) { + free(calc_buffer); calc_buffer = NULL; +} + +/* definition of interface functions */ +FC_DEFINE2(add) +FC_DEFINE2(sub) +FC_DEFINE2(mul) +FC_DEFINE2(div) +FC_DEFINE1(neg) +FC_DEFINE1(int) +FC_DEFINE1(rnd)