-#ifndef _FLTCALC_H_
-#define _FLTCALC_H_
+/*
+ * Copyright (C) 1995-2011 University of Karlsruhe. All right reserved.
+ *
+ * This file is part of libFirm.
+ *
+ * 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.
+ *
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
+ *
+ * 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
+ */
+#ifndef FIRM_TV_FLTCALC_H
+#define FIRM_TV_FLTCALC_H
+
+#include <stdlib.h>
+#include "firm_types.h"
+#include "irtypes.h"
enum {
- FC_ADD,
- FC_SUB,
- FC_MUL,
- FC_DIV,
- FC_NEG,
+ FC_DEC,
+ FC_HEX,
+ FC_BIN,
+ FC_PACKED
};
-#define fc_add(a, b) fc_calc((a), (b), FC_ADD)
-#define fc_sub(a, b) fc_calc((a), (b), FC_SUB)
-#define fc_mul(a, b) fc_calc((a), (b), FC_MUL)
-#define fc_div(a, b) fc_calc((a), (b), FC_DIV)
-#define fc_neg(a) fc_calc((a), NULL, FC_NEG)
+/** IEEE-754 Rounding modes. */
+typedef enum {
+ FC_TONEAREST, /**< if unsure, to the nearest even */
+ FC_TOPOSITIVE, /**< to +oo */
+ FC_TONEGATIVE, /**< to -oo */
+ FC_TOZERO /**< to 0 */
+} fc_rounding_mode_t;
+
+#define FC_DEFAULT_PRECISION 64
+
+/**
+ * possible float states
+ */
+typedef enum {
+ FC_NORMAL, /**< normal representation, implicit 1 */
+ FC_ZERO, /**< +/-0 */
+ FC_SUBNORMAL, /**< denormals, implicit 0 */
+ FC_INF, /**< +/-oo */
+ FC_NAN, /**< Not A Number */
+} value_class_t;
+
+struct fp_value;
+typedef struct fp_value fp_value;
+/*@{*/
+/** internal buffer access
+ * All functions that accept NULL as return buffer put their result into an
+ * internal buffer.
+ * @return fc_get_buffer() returns the pointer to the buffer, fc_get_buffer_length()
+ * returns the size of this buffer
+ */
const void *fc_get_buffer(void);
-const int fc_get_buffer_length(void);
+int fc_get_buffer_length(void);
+/*}@*/
+
+void *fc_val_from_str(const char *str, size_t len, const float_descriptor_t *desc, void *result);
+
+/** get the representation of a floating point value
+ * This function tries to builds a representation having the same value as the
+ * float number passed.
+ * If the wished precision is less than the precision of long double the value
+ * built will be rounded. Therefore only an approximation of the passed float
+ * can be expected in this case.
+ *
+ * @param l The floating point number to build a representation for
+ * @param desc The floating point descriptor
+ * @param result A buffer to hold the value built. If this is NULL, the internal
+ * accumulator buffer is used. Note that the buffer must be big
+ * enough to hold the value. Use fc_get_buffer_length() to find out
+ * the size needed
+ *
+ * @return The result pointer passed to the function. If this was NULL this returns
+ * a pointer to the internal accumulator buffer
+ */
+fp_value *fc_val_from_ieee754(long double l, const float_descriptor_t *desc,
+ fp_value *result);
+
+/** retrieve the float value of an internal value
+ * This function casts the internal value to long double and returns a
+ * long double with that value.
+ * This implies that values of higher precision than long double are subject to
+ * rounding, so the returned value might not the same than the actually
+ * represented value.
+ *
+ * @param val The representation of a float value
+ *
+ * @return a float value approximating the represented value
+ */
+long double fc_val_to_ieee754(const fp_value *val);
+
+/** cast a value to another precision
+ * This function changes the precision of a float representation.
+ * If the new precision is less than the original precision the returned
+ * value might not be the same as the original value.
+ *
+ * @param val The value to be casted
+ * @param desc The floating point descriptor
+ * @param result A buffer to hold the value built. If this is NULL, the internal
+ * accumulator buffer is used. Note that the buffer must be big
+ * enough to hold the value. Use fc_get_buffer_length() to find out
+ * the size needed
+ * @return The result pointer passed to the function. If this was NULL this returns
+ * a pointer to the internal accumulator buffer
+ */
+fp_value *fc_cast(const fp_value *val, const float_descriptor_t *desc, fp_value *result);
+
+/*@{*/
+/** build a special float value
+ * This function builds a representation for a special float value, as indicated by the
+ * function's suffix.
+ *
+ * @param desc The floating point descriptor
+ * @param result A buffer to hold the value built. If this is NULL, the internal
+ * accumulator buffer is used. Note that the buffer must be big
+ * enough to hold the value. Use fc_get_buffer_length() to find out
+ * the size needed
+ * @return The result pointer passed to the function. If this was NULL this returns
+ * a pointer to the internal accumulator buffer
+ */
+fp_value *fc_get_min(const float_descriptor_t *desc, fp_value *result);
+fp_value *fc_get_max(const float_descriptor_t *desc, fp_value *result);
+fp_value *fc_get_snan(const float_descriptor_t *desc, fp_value *result);
+fp_value *fc_get_qnan(const float_descriptor_t *desc, fp_value *result);
+fp_value *fc_get_plusinf(const float_descriptor_t *desc, fp_value *result);
+fp_value *fc_get_minusinf(const float_descriptor_t *desc, fp_value *result);
+/*@}*/
+
+int fc_is_zero(const fp_value *a);
+int fc_is_negative(const fp_value *a);
+int fc_is_inf(const fp_value *a);
+int fc_is_nan(const fp_value *a);
+int fc_is_subnormal(const fp_value *a);
+
+fp_value *fc_add(const fp_value *a, const fp_value *b, fp_value *result);
+fp_value *fc_sub(const fp_value *a, const fp_value *b, fp_value *result);
+fp_value *fc_mul(const fp_value *a, const fp_value *b, fp_value *result);
+fp_value *fc_div(const fp_value *a, const fp_value *b, fp_value *result);
+fp_value *fc_neg(const fp_value *a, fp_value *result);
+fp_value *fc_int(const fp_value *a, fp_value *result);
+fp_value *fc_rnd(const fp_value *a, fp_value *result);
+
+char *fc_print(const fp_value *a, char *buf, int buflen, unsigned base);
+
+/** Compare two values
+ * This function compares two values
+ *
+ * @param a Value No. 1
+ * @param b Value No. 2
+ * @result The returned value will be one of
+ * -1 if a < b
+ * 0 if a == b
+ * 1 if a > b
+ * 2 if either value is NaN
+ */
+int fc_comp(const fp_value *a, const fp_value *b);
+
+/**
+ * Converts an floating point value into an integer value.
+ */
+int fc_flt2int(const fp_value *a, void *result, ir_mode *dst_mode);
+
+/**
+ * Returns non-zero if the mantissa is zero, i.e. 1.0Exxx
+ */
+int fc_zero_mantissa(const fp_value *value);
+
+/**
+ * Returns the exponent of a value.
+ */
+int fc_get_exponent(const fp_value *value);
+
+/**
+ * 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 float_descriptor_t *desc);
+
+/** Set new rounding mode
+ * This function sets the rounding mode to one of the following, returning
+ * the previously set rounding mode.
+ * FC_TONEAREST (default):
+ * Any unrepresentable value is rounded to the nearest representable
+ * value. If it lies in the middle the value with the least significant
+ * bit of zero is chosen (the even one).
+ * Values too big to represent will round to +/-infinity.
+ * FC_TONEGATIVE
+ * Any unrepresentable value is rounded towards negative infinity.
+ * Positive values too big to represent will round to the biggest
+ * representable value, negative values too small to represent will
+ * round to -infinity.
+ * FC_TOPOSITIVE
+ * Any unrepresentable value is rounded towards positive infinity
+ * Negative values too small to represent will round to the biggest
+ * representable value, positive values too big to represent will
+ * round to +infinity.
+ * FC_TOZERO
+ * Any unrepresentable value is rounded towards zero, effectively
+ * chopping off any bits beyond the mantissa size.
+ * Values too big to represent will round to the biggest/smallest
+ * representable value.
+ *
+ * These modes correspond to the modes required by the IEEE-754 standard.
+ *
+ * @param mode The new rounding mode. Any value other than the four
+ * defined values will have no effect.
+ * @return The previous rounding mode.
+ *
+ * @see fc_get_rounding_mode()
+ * @see IEEE754, IEEE854 Floating Point Standard
+ */
+fc_rounding_mode_t fc_set_rounding_mode(fc_rounding_mode_t mode);
-void fc_val_from_str(const char *str, unsigned int len);
-void fc_val_from_float(long double l);
-long double fc_val_to_float(const void *val);
+/** Get the rounding mode
+ * This function retrieves the currently used rounding mode
+ *
+ * @return The current rounding mode
+ * @see fc_set_rounding_mode()
+ */
+fc_rounding_mode_t fc_get_rounding_mode(void);
-void fc_get_min(unsigned int num_bits);
-void fc_get_max(unsigned int num_bits);
-void fc_get_nan(void);
-void fc_get_inf(void);
+/** Get bit representation of a value
+ * This function allows to read a value in encoded form, byte wise.
+ * The value will be packed corresponding to the way used by the IEEE
+ * encoding formats, i.e.
+ * One bit sign
+ * exp_size bits exponent + bias
+ * mant_size bits mantissa, without leading 1
+ *
+ * As in IEEE, an exponent of 0 indicates a denormalized number, which
+ * implies a most significant bit of zero instead of one; an exponent
+ * of all ones (2**exp_size - 1) encodes infinity if the mantissa is
+ * all zeros, else Not A Number.
+ *
+ * @param val A pointer to the value. If NULL is passed a copy of the
+ * most recent value passed to this function is used, saving the
+ * packing step. This behavior may be changed in the future.
+ * @param num_bit The maximum number of bits to return. Any bit beyond
+ * num_bit will be returned as zero.
+ * @param byte_ofs The byte index to read, 0 is the least significant
+ * byte.
+ * @return 8 bits of encoded data
+ */
+unsigned char fc_sub_bits(const fp_value *val, unsigned num_bit, unsigned byte_ofs);
-void fc_calc(const void *a, const void *b, int opcode);
-char *fc_print_dec(const void *a, char *buf, int buflen);
-int fc_comp(const void *a, const void *b);
+/**
+ * Returns non-zero if the result of the last operation was exact.
+ */
+int fc_is_exact(void);
-unsigned char fc_sub_bits(const void *val, unsigned num_bit, unsigned byte_ofs);
+void init_fltcalc(int precision);
+void finish_fltcalc(void);
-#endif /* _FLTCALC_H_ */
+#endif /* FIRM_TV_FLTCALC_H */
projects / libfirm / blobdiff