/*
- * Copyright (C) 1995-2007 University of Karlsruhe. All right reserved.
+ * Copyright (C) 1995-2011 University of Karlsruhe. All right reserved.
*
* This file is part of libFirm.
*
#ifndef FIRM_TV_FLTCALC_H
#define FIRM_TV_FLTCALC_H
-#include "firm_config.h"
+#include <stdlib.h>
#include "firm_types.h"
-#ifdef HAVE_LONG_DOUBLE
-/* XXX Set this via autoconf */
-#define HAVE_EXPLICIT_ONE
-typedef long double LLDBL;
-#else
-typedef double LLDBL;
-#endif
-
enum {
FC_DEC,
FC_HEX,
#define FC_DEFAULT_PRECISION 64
-typedef struct _fp_value fp_value;
+/**
+ * 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 ieee_descriptor_t {
+ unsigned char exponent_size; /**< size of exponent in bits */
+ unsigned char mantissa_size; /**< size of mantissa in bits */
+ unsigned char explicit_one; /**< set if the leading one is explicit */
+ unsigned char clss; /**< state of this float */
+} ieee_descriptor_t;
+
+struct fp_value;
+typedef struct fp_value fp_value;
/*@{*/
/** internal buffer access
int fc_get_buffer_length(void);
/*}@*/
-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, size_t len, const ieee_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 LLDBL the value built
- * will be rounded. Therefore only an approximation of the passed float can be
- * expected in this case.
+ * 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
*
- * @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
+ * @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(LLDBL l, char exp_size, char mant_size, fp_value *result);
+fp_value *fc_val_from_ieee754(long double l, const ieee_descriptor_t *desc,
+ fp_value *result);
/** 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
+ * 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
+ * @param val The representation of a float value
+ *
* @return a float value approximating the represented value
*/
-LLDBL fc_val_to_ieee754(const fp_value *val);
+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 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
+ * @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, char exp_size, char mant_size, fp_value *result);
+fp_value *fc_cast(const fp_value *val, const ieee_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 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
+ * @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(unsigned int exponent_size, unsigned int mantissa_size, fp_value *result);
-fp_value *fc_get_max(unsigned int exponent_size, unsigned int mantissa_size, fp_value *result);
-fp_value *fc_get_snan(unsigned int exponent_size, unsigned int mantissa_size, fp_value *result);
-fp_value *fc_get_qnan(unsigned int exponent_size, unsigned int mantissa_size, fp_value *result);
-fp_value *fc_get_plusinf(unsigned int exponent_size, unsigned int mantissa_size, fp_value *result);
-fp_value *fc_get_minusinf(unsigned int exponent_size, unsigned int mantissa_size, fp_value *result);
+fp_value *fc_get_min(const ieee_descriptor_t *desc, fp_value *result);
+fp_value *fc_get_max(const ieee_descriptor_t *desc, fp_value *result);
+fp_value *fc_get_snan(const ieee_descriptor_t *desc, fp_value *result);
+fp_value *fc_get_qnan(const ieee_descriptor_t *desc, fp_value *result);
+fp_value *fc_get_plusinf(const ieee_descriptor_t *desc, fp_value *result);
+fp_value *fc_get_minusinf(const ieee_descriptor_t *desc, fp_value *result);
/*@}*/
int fc_is_zero(const fp_value *a);
*/
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 ieee_descriptor_t *desc);
+
/** Set new rounding mode
* This function sets the rounding mode to one of the following, returning
* the previously set rounding mode.