+/*
+ * Project: libFIRM
+ * File name: ir/tv/fltcalc.h
+ * Purpose:
+ * Author:
+ * Modified by:
+ * Created: 2003
+ * CVS-ID: $Id$
+ * Copyright: (c) 2003 Universität Karlsruhe
+ * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
+ */
+
#ifndef _FLTCALC_H_
#define _FLTCALC_H_
+#include "firm_config.h"
+
+#ifdef HAVE_LONG_DOUBLE
+/* XXX Set this via autoconf */
+#define HAVE_EXPLICIT_ONE
+typedef long double LLDBL;
+#else
+typedef double LLDBL;
+#endif
+
+typedef enum {
+ FC_add, /**< addition */
+ FC_sub, /**< subtraction */
+ FC_mul, /**< multiplication */
+ FC_div, /**< divide */
+ FC_neg, /**< negate */
+ FC_int, /**< truncate to integer */
+ FC_rnd /**< round to integer */
+} fc_op_t;
+
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)
+/* rounding modes */
+typedef enum {
+ FC_TONEAREST,
+ FC_TOPOSITIVE,
+ FC_TONEGATIVE,
+ FC_TOZERO
+} fc_rounding_mode_t;
+#define FC_DEFAULT_PRECISION 64
+
+#define FC_DECLARE1(code) char* fc_##code(const void *a, void *result)
+#define FC_DECLARE2(code) char* fc_##code(const void *a, const void *b, void *result)
+
+/*@{*/
+/** 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);
+/*}@*/
+
+char* fc_val_from_str(const char *str, unsigned int len, char exp_size, char mant_size, char *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 LLDBL 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 exp_size The number of bits of the new exponent
+ * @param mant_size The number of bits of the new mantissa
+ * @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
+ */
+char* fc_val_from_float(LLDBL l, char exp_size, char mant_size, char *result);
-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);
+/** retrieve the float value of an internal value
+ * This function casts the internal value to LLDBL and returns a LLDBL with
+ * that value.
+ * This implies that values of higher precision than LLDBL 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
+ */
+LLDBL fc_val_to_float(const void *val);
-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);
+/** 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 exp_size The number of bits of the new exponent
+ * @param mant_size The number of bits of the new mantissa
+ * @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
+ */
+char* fc_cast(const void *val, char exp_size, char mant_size, char *result);
-void fc_calc(const void *a, const void *b, int opcode);
-char *fc_print_dec(const void *a);
+/*@{*/
+/** build a special float value
+ * This function builds a representation for a special float value, as indicated by the
+ * function's suffix.
+ *
+ * @param exponent_size The number of bits of exponent of the float type the value
+ * is created for
+ * @param mantissa_size The number of bits of mantissa of the float type the value
+ * is created for
+ * @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
+ */
+char* fc_get_min(unsigned int exponent_size, unsigned int mantissa_size, char* result);
+char* fc_get_max(unsigned int exponent_size, unsigned int mantissa_size, char* result);
+char* fc_get_snan(unsigned int exponent_size, unsigned int mantissa_size, char* result);
+char* fc_get_qnan(unsigned int exponent_size, unsigned int mantissa_size, char* result);
+char* fc_get_plusinf(unsigned int exponent_size, unsigned int mantissa_size, char* result);
+char* fc_get_minusinf(unsigned int exponent_size, unsigned int mantissa_size, char* result);
+/*}@*/
+
+int fc_is_zero(const void *a);
+int fc_is_negative(const void *a);
+int fc_is_inf(const void *a);
+int fc_is_nan(const void *a);
+int fc_is_subnormal(const void *a);
+
+FC_DECLARE2(add);
+FC_DECLARE2(sub);
+FC_DECLARE2(mul);
+FC_DECLARE2(div);
+FC_DECLARE1(neg);
+FC_DECLARE1(int);
+FC_DECLARE1(rnd);
+
+char *fc_print(const void *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 void *a, const void *b);
+/** 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.
+ * 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 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);
+
+/** 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);
+
+/** Get bit representation of a value
+ * This function allows to read a value in encoded form, bytewise.
+ * 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 void *val, unsigned num_bit, unsigned byte_ofs);
+
+void init_fltcalc(int precision);
+void finish_fltcalc (void);
+
#endif /* _FLTCALC_H_ */
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