/*
- * Copyright (C) 1995-2007 University of Karlsruhe. All right reserved.
+ * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
*
* This file is part of libFirm.
*
* @version $Id$
*/
-#ifdef HAVE_CONFIG_H
-# include "config.h"
-#endif
+#include "config.h"
#include "fltcalc.h"
#include "strcalc.h"
#ifdef HAVE_STRING_H
# include <string.h>
#endif
-#ifdef HAVE_STDLIB_H
-# include <stdlib.h>
-#endif
+#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include "xmalloc.h"
+/** The number of extra precision rounding bits */
+#define ROUNDING_BITS 2
+
typedef uint32_t UINT32;
#ifdef HAVE_LONG_DOUBLE
#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)
/* our floating point value */
struct _fp_value {
- descriptor_t desc;
+ ieee_descriptor_t desc;
char sign;
char value[1]; /* exp[value_size] + mant[value_size] */
};
#define _mant(a) &((a)->value[value_size])
#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 _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
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))
/** pack machine-like */
static void *pack(const fp_value *int_float, void *packed) {
- char *shift_val;
- char *temp;
+ char *shift_val;
+ char *temp;
fp_value *val_buffer;
+ int pos;
- temp = alloca(value_size);
+ temp = alloca(value_size);
shift_val = alloca(value_size);
- switch (int_float->desc.clss) {
+ switch ((value_class_t)int_float->desc.clss) {
case NAN:
val_buffer = alloca(calc_buffer_size);
- fc_get_qnan(int_float->desc.exponent_size, int_float->desc.mantissa_size, val_buffer);
+ 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.exponent_size, int_float->desc.mantissa_size, val_buffer);
+ fc_get_plusinf(&int_float->desc, val_buffer);
val_buffer->sign = int_float->sign;
int_float = val_buffer;
break;
default:
break;
}
- /* pack sign */
+ 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);
- sc_val_from_ulong(int_float->desc.exponent_size + int_float->desc.mantissa_size, NULL);
+ 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);
- /* extract exponent */
- sc_val_from_ulong(int_float->desc.mantissa_size, shift_val);
-
+ /* 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 2 rounding bits */
- sc_val_from_ulong(2, shift_val);
+ /* 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(int_float->desc.mantissa_size, 0, shift_val); /* all mantissa bits are 1's */
+ sc_max_from_bits(pos, 0, shift_val); /* all mantissa bits are 1's */
sc_and(temp, shift_val, temp);
- /* save result */
+ /* combine sign|exponent|mantissa */
sc_or(temp, packed, packed);
return packed;
}
-static void normalize(const fp_value *in_val, fp_value *out_val, int sticky) {
+/**
+ * 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);
- /* +2: save two rounding bits at the end */
- hsb = 2 + in_val->desc.mantissa_size - sc_get_highest_set_bit(_mant(in_val)) - 1;
+ /* 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;
out_val->desc.clss = NORMAL;
- /* mantissa all zeros, so zero exponent (because of explicit one)*/
- if (hsb == 2 + in_val->desc.mantissa_size) {
+ /* 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_right(_mant(in_val), temp, _mant(out_val));
/* remember if some bits were shifted away */
- if (!sticky) sticky = sc_had_carry();
-
+ if (sc_had_carry()) {
+ exact = 0;
+ sticky = 1;
+ }
sc_add(_exp(in_val), temp, _exp(out_val));
} else if (hsb > -1) {
/* shift left */
sc_sub(temp, _exp(out_val), NULL);
_shift_right(_mant(out_val), sc_get_buffer(), _mant(out_val));
- if (!sticky) sticky = sc_had_carry();
+ if (sc_had_carry()) {
+ exact = 0;
+ sticky = 1;
+ }
/* denormalized means exponent of zero */
sc_val_from_ulong(0, _exp(out_val));
/* 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 + 2, 0) & 0x7;
+ lsb = sc_sub_bits(_mant(out_val), out_val->desc.mantissa_size + ROUNDING_BITS, 0) & 0x7;
guard = (lsb&0x2)>>1;
round = lsb&0x1;
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 */
out_val->desc.clss = ZERO;
/* check for rounding overflow */
- hsb = 2 + out_val->desc.mantissa_size - sc_get_highest_set_bit(_mant(out_val)) - 1;
+ 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,
case FC_TONEGATIVE:
case FC_TOZERO:
- fc_get_max(out_val->desc.exponent_size, out_val->desc.mantissa_size, out_val);
+ fc_get_max(&out_val->desc, out_val);
}
} else {
/* value is negative */
case FC_TOPOSITIVE:
case FC_TOZERO:
- fc_get_min(out_val->desc.exponent_size, out_val->desc.mantissa_size, out_val);
+ fc_get_min(&out_val->desc, out_val);
}
}
}
+ return exact;
}
/**
- * Operations involving NaN's must return NaN
+ * 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)
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)
- memcpy(&result->desc, &a->desc, sizeof(descriptor_t));
+ 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_get_qnan(a->desc.exponent_size, b->desc.mantissa_size, result);
+ fc_exact = 0;
+ fc_get_qnan(&a->desc, result);
return;
}
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_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
/* resulting exponent is the bigger one */
memmove(_exp(result), _exp(a), value_size);
- normalize(result, result, sticky);
+ 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)
- memcpy(&result->desc, &a->desc, sizeof(descriptor_t));
+ 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.exponent_size, a->desc.mantissa_size, result);
- else {
+ 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.exponent_size, a->desc.mantissa_size, result);
- else {
+ 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;
}
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;
* 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 + result->desc.mantissa_size, temp);
+ * 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;
- normalize(result, result, sc_had_carry());
+ 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)
- memcpy(&result->desc, &a->desc, sizeof(descriptor_t));
+ 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.exponent_size, a->desc.mantissa_size, result);
- else {
+ 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);
}
if (b->desc.clss == INF) {
- if (a->desc.clss == INF)
- /* inf/inf -> nan */
- fc_get_qnan(a->desc.exponent_size, a->desc.mantissa_size, result);
- else {
+ 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));
}
if (a->desc.clss == INF) {
+ fc_exact = 0;
/* inf/x -> inf */
if (a != result)
memcpy(result, a, calc_buffer_size);
return;
}
if (b->desc.clss == ZERO) {
+ fc_exact = 0;
/* division by zero */
if (result->sign)
- fc_get_minusinf(a->desc.exponent_size, a->desc.mantissa_size, result);
+ fc_get_minusinf(&a->desc, result);
else
- fc_get_plusinf(a->desc.exponent_size, a->desc.mantissa_size, result);
+ fc_get_plusinf(&a->desc, result);
return;
}
* 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 + result->desc.mantissa_size, temp);
+ sc_val_from_ulong(ROUNDING_BITS + result->desc.mantissa_size, temp);
_shift_left(_mant(a), temp, dividend);
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;
}
- normalize(result, result, sc_had_carry());
+ fc_exact &= normalize(result, result, sticky);
}
#if 0
-static void _power_of_ten(int exp, descriptor_t *desc, char *result) {
+static void _power_of_ten(int exp, ieee_descriptor_t *desc, char *result) {
char *build;
char *temp;
/* set new descriptor (else result is supposed to already have one) */
if (desc != NULL)
- memcpy(&result->desc, desc, sizeof(descriptor_t));
+ result->desc = *desc;
build = alloca(value_size);
temp = alloca(value_size);
- sc_val_from_ulong((1 << result->desc.exponent_size)/2-1, _exp(result));
+ sc_val_from_ulong((1 << (result->desc.exponent_size - 1)) - 1, _exp(result));
if (exp > 0) {
/* temp is value of ten now */
_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 + 2, temp);
+ sc_val_from_ulong(result->desc.mantissa_size + ROUNDING_BITS, temp);
_shift_left(build, temp, _mant(result));
int exp_bias, exp_val;
char *temp;
+ /* fixme: can be exact */
+ fc_exact = 0;
+
temp = alloca(value_size);
if (a != result)
- memcpy(&result->desc, &a->desc, sizeof(descriptor_t));
+ result->desc = a->desc;
exp_bias = (1 << (a->desc.exponent_size - 1)) - 1;
exp_val = sc_val_to_long(_exp(a)) - exp_bias;
sc_and(_mant(a), temp, _mant(result));
if (a != result) memcpy(_exp(result), _exp(a), value_size);
-
- return;
}
/********
return calc_buffer_size;
}
-void *fc_val_from_str(const char *str, unsigned int len, char exp_size, char mant_size, void *result) {
+void *fc_val_from_str(const char *str, unsigned int len, const ieee_descriptor_t *desc, void *result) {
#if 0
enum {
START,
power_val = alloca(calc_buffer_size);
mant_str = alloca((len)?(len):(strlen(str)));
- result->desc.exponent_size = exp_size;
- result->desc.mantissa_size = mant_size;
- result->desc.clss = NORMAL;
+ 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;
old_str = str;
pos = 0;
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);
+ sc_val_from_ulong(mant_size + ROUNDING_BITS, exp_val);
_shift_left(_mant(result), exp_val, _mant(result));
- sc_val_from_ulong((1 << exp_size)/2-1, _exp(result));
+ sc_val_from_ulong((1 << (exp_size - 1)) - 1, _exp(result));
_normalize(result, result, 0);
return result;
#else
/* XXX excuse of an implementation to make things work */
- LLDBL val;
- fp_value *tmp = alloca(calc_buffer_size);
+ LLDBL val;
+ fp_value *tmp = alloca(calc_buffer_size);
+ ieee_descriptor_t tmp_desc;
(void) len;
#ifdef HAVE_LONG_DOUBLE
val = strtold(str, NULL);
DEBUGPRINTF(("val_from_str(%s)\n", str));
- fc_val_from_ieee754(val, 15, 64, tmp);
+ 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);
#else
val = strtod(str, NULL);
DEBUGPRINTF(("val_from_str(%s)\n", str));
- fc_val_from_ieee754(val, 11, 52, tmp);
+ tmp_desc.exponent_size = 11;
+ tmp_desc.mantissa_size = 52;
+ tmp_desc.explicit_one = 0;
+ tmp_desc.clss = NORMAL;
+ fc_val_from_ieee754(val, &tmp_desc, tmp);
#endif /* HAVE_LONG_DOUBLE */
- return fc_cast(tmp, exp_size, mant_size, result);
+ return fc_cast(tmp, desc, result);
#endif
}
-fp_value *fc_val_from_ieee754(LLDBL l, char exp_size, char mant_size, fp_value *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;
UINT32 sign, exponent, mantissa0, mantissa1;
srcval.d = l;
- bias_res = ((1<<exp_size)/2-1);
+ bias_res = ((1 << (desc->exponent_size - 1)) - 1);
#ifdef HAVE_LONG_DOUBLE
- mant_val = 64;
+ mant_val = 63;
bias_val = 0x3fff;
sign = (srcval.val.high & 0x00008000) != 0;
exponent = (srcval.val.high & 0x00007FFF) ;
if (result == NULL) result = calc_buffer;
temp = alloca(value_size);
- result->desc.exponent_size = exp_size;
- result->desc.mantissa_size = mant_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
+ /* 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;
* 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
+ sc_val_from_long((exponent - bias_val + bias_res) - (mant_val - desc->mantissa_size), _exp(result));
/* 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);
+ sc_val_from_ulong(mant_val + ROUNDING_BITS, NULL);
_shift_left(temp, sc_get_buffer(), NULL);
}
- else
-#endif
- {
+ else {
sc_val_from_ulong(0, NULL);
}
/* bits from the lower word */
sc_val_from_ulong(mantissa1, temp);
- sc_val_from_ulong(2, NULL);
+ sc_val_from_ulong(ROUNDING_BITS, NULL);
_shift_left(temp, sc_get_buffer(), temp);
sc_or(_mant(result), temp, _mant(result));
UINT32 mantissa0;
UINT32 mantissa1;
- value_t buildval;
+ value_t buildval;
+ ieee_descriptor_t desc;
+ unsigned mantissa_size;
#ifdef HAVE_LONG_DOUBLE
- char result_exponent = 15;
- char result_mantissa = 64;
+ desc.exponent_size = 15;
+ desc.mantissa_size = 63;
+ desc.explicit_one = 1;
+ desc.clss = NORMAL;
#else
- char result_exponent = 11;
- char result_mantissa = 52;
+ 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);
-#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
+ value = fc_cast(val, &desc, temp);
sign = value->sign;
* lead to wrong results */
exponent = sc_val_to_long(_exp(value)) ;
- sc_val_from_ulong(2, NULL);
+ 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), result_mantissa, byte_offset) << (byte_offset<<3);
+ mantissa1 |= sc_sub_bits(_mant(value), mantissa_size, 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);
+ 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;
return buildval.d;
}
-fp_value *fc_cast(const fp_value *value, char exp_size, char mant_size, fp_value *result) {
+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 == exp_size && value->desc.mantissa_size == mant_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);
+ }
+
/* set the descriptor of the new value */
- result->desc.exponent_size = exp_size;
- result->desc.mantissa_size = mant_size;
- result->desc.clss = value->desc.clss;
+ 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;
* 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 << (exp_size - 1)) - 1;
+ res_bias = (1 << (desc->exponent_size - 1)) - 1;
- exp_offset = (res_bias - val_bias) - (value->desc.mantissa_size - mant_size);
+ 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));
return result;
}
-fp_value *fc_get_max(unsigned int exponent_size, unsigned int mantissa_size, fp_value *result) {
+fp_value *fc_get_max(const ieee_descriptor_t *desc, fp_value *result) {
if (result == NULL) result = calc_buffer;
- result->desc.exponent_size = exponent_size;
- result->desc.mantissa_size = mantissa_size;
- result->desc.clss = NORMAL;
+ 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<<exponent_size) - 2, _exp(result));
+ sc_val_from_ulong((1 << desc->exponent_size) - 2, _exp(result));
- sc_max_from_bits(mantissa_size + 1, 0, _mant(result));
- sc_val_from_ulong(2, NULL);
+ 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(unsigned int exponent_size, unsigned int mantissa_size, fp_value *result) {
+fp_value *fc_get_min(const ieee_descriptor_t *desc, fp_value *result) {
if (result == NULL) result = calc_buffer;
- fc_get_max(exponent_size, mantissa_size, result);
+ fc_get_max(desc, result);
result->sign = 1;
return result;
}
-fp_value *fc_get_snan(unsigned int exponent_size, unsigned int mantissa_size, fp_value *result) {
+fp_value *fc_get_snan(const ieee_descriptor_t *desc, fp_value *result) {
if (result == NULL) result = calc_buffer;
- result->desc.exponent_size = exponent_size;
- result->desc.mantissa_size = mantissa_size;
- result->desc.clss = NAN;
+ 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<<exponent_size)-1, _exp(result));
+ 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(unsigned int exponent_size, unsigned int mantissa_size, fp_value *result) {
+fp_value *fc_get_qnan(const ieee_descriptor_t *desc, fp_value *result) {
if (result == NULL) result = calc_buffer;
- result->desc.exponent_size = exponent_size;
- result->desc.mantissa_size = mantissa_size;
- result->desc.clss = NAN;
+ 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<<exponent_size)-1, _exp(result));
+ 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(mantissa_size + 1, NULL);
+ 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(unsigned int exponent_size, unsigned int mantissa_size, fp_value *result) {
+fp_value *fc_get_plusinf(const ieee_descriptor_t *desc, fp_value *result) {
if (result == NULL) result = calc_buffer;
- result->desc.exponent_size = exponent_size;
- result->desc.mantissa_size = mantissa_size;
- result->desc.clss = NORMAL;
+ 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<<exponent_size)-1, _exp(result));
+ sc_val_from_ulong((1 << desc->exponent_size) - 1, _exp(result));
sc_val_from_ulong(0, _mant(result));
return result;
}
-fp_value *fc_get_minusinf(unsigned int exponent_size, unsigned int mantissa_size, fp_value *result) {
+fp_value *fc_get_minusinf(const ieee_descriptor_t *desc, fp_value *result) {
if (result == NULL) result = calc_buffer;
- fc_get_plusinf(exponent_size, mantissa_size, result);
+ fc_get_plusinf(desc, result);
result->sign = 1;
return result;
char *fc_print(const fp_value *val, char *buf, int buflen, unsigned base) {
char *mul_1;
+ LLDBL flt_val;
mul_1 = alloca(calc_buffer_size);
switch (base) {
case FC_DEC:
- switch (val->desc.clss) {
+ switch ((value_class_t)val->desc.clss) {
case INF:
- if (buflen >= 8 + val->sign) sprintf(buf, "%sINFINITY", val->sign ? "-":"");
- else snprintf(buf, buflen, "%sINF", val->sign ? "-":NULL);
+ snprintf(buf, buflen, "%cINF", val->sign ? '-' : '+');
break;
case NAN:
- snprintf(buf, buflen, "NAN");
+ snprintf(buf, buflen, "NaN");
break;
case ZERO:
snprintf(buf, buflen, "0.0");
break;
default:
- /* XXX to be implemented */
+ flt_val = fc_val_to_ieee754(val);
#ifdef HAVE_LONG_DOUBLE
/* XXX 30 is arbitrary */
- snprintf(buf, buflen, "%.30LE", fc_val_to_ieee754(val));
+ snprintf(buf, buflen, "%.30LE", flt_val);
#else
- snprintf(buf, buflen, "%.18E", fc_val_to_ieee754(val));
+ snprintf(buf, buflen, "%.18E", flt_val);
#endif
}
break;
case FC_HEX:
- switch (val->desc.clss) {
+ switch ((value_class_t)val->desc.clss) {
case INF:
- if (buflen >= 8+val->sign) sprintf(buf, "%sINFINITY", val->sign?"-":"");
- else snprintf(buf, buflen, "%sINF", val->sign?"-":NULL);
+ snprintf(buf, buflen, "%cINF", val->sign ? '-' : '+');
break;
case NAN:
snprintf(buf, buflen, "NAN");
snprintf(buf, buflen, "0.0");
break;
default:
+ flt_val = fc_val_to_ieee754(val);
#ifdef HAVE_LONG_DOUBLE
- snprintf(buf, buflen, "%LA", fc_val_to_ieee754(val));
+ snprintf(buf, buflen, "%LA", flt_val);
#else
- snprintf(buf, buflen, "%A", fc_val_to_ieee754(val));
+ snprintf(buf, buflen, "%A", flt_val);
#endif
}
break;
/* this is used to cache the packed version of the value */
static char *packed_value = NULL;
- if (packed_value == NULL) packed_value = xmalloc(value_size);
+ 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);
}
+/* Returns non-zero if the mantissa is zero, i.e. 1.0Exxx */
int fc_zero_mantissa(const fp_value *value) {
- return sc_get_lowest_set_bit(_mant(value)) == 2 + value->desc.mantissa_size;
+ 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;
}
+/* 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) {
+ 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;
+}
+
fc_rounding_mode_t fc_set_rounding_mode(fc_rounding_mode_t mode) {
if (mode == FC_TONEAREST || mode == FC_TOPOSITIVE || mode == FC_TONEGATIVE || mode == FC_TOZERO)
/* does nothing if already init */
if (precision == 0) precision = FC_DEFAULT_PRECISION;
- init_strcalc(precision + 4);
+ init_strcalc(precision + 2 + ROUNDING_BITS);
- /* needs additionally two bits to round, a bit as explicit 1., and one for
+ /* needs additionally rounding bits, one bit as explicit 1., and one for
* addition overflow */
- max_precision = sc_get_precision() - 4;
+ max_precision = sc_get_precision() - (2 + ROUNDING_BITS);
if (max_precision < precision)
printf("WARNING: not enough precision available, using %d\n", max_precision);
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) {
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 "));
return result;
}
+/*
+ * 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;
+
+ if (a->sign && !mode_is_signed(dst_mode)) {
+ /* FIXME: for now we cannot convert this */
+ return 0;
+ }
+
+ assert(exp_val >= 0 && "floating point value not integral before fc_flt2int() call");
+ shift = exp_val - (a->desc.mantissa_size + ROUNDING_BITS);
+
+ if (shift > 0) {
+ sc_shlI(_mant(a), shift, 64, 0, result);
+ } else {
+ sc_shrI(_mant(a), -shift, 64, 0, result);
+ }
+
+ /* 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;
+}
projects / libfirm / blobdiff