Commit 158da8a4 authored by Matthias Braun's avatar Matthias Braun
Browse files

make fltcalc.c more portable (and msvc independent)

parent f12db36c
......@@ -36,19 +36,43 @@
#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include <stdbool.h>
#include "xmalloc.h"
#ifdef _MSC_VER
#include <float.h>
#define isnan(x) _isnan(x)
static inline int isinf(double x)
/*
* portability stuff (why do we even care about the msvc people with their C89?)
*/
static long double string_to_long_double(const char *str)
{
return !_finite(x) && !_isnan(x);
#if __STDC_VERSION__ >= 199901L || _POSIX_C_SOURCE >= 200112L
return strtold(str, NULL);
#else
return strtod(str, NULL);
#endif
}
#define strtold(s, e) strtod(s, e)
#define SIZEOF_LONG_DOUBLE_8
static bool my_isnan(long double val)
{
#if __STDC_VERSION__ >= 199901L
return isnan(val);
#else
/* hopefully the compiler does not optimize aggressively (=incorrect) */
return val != val;
#endif
}
static bool my_isinf(long double val)
{
#if __STDC_VERSION__ >= 199901L
return isinf(val);
#else
/* hopefully the compiler does not optimize aggressively (=incorrect) */
return my_isnan(val-val) && !my_isnan(val);
#endif
}
/** The number of extra precision rounding bits */
#define ROUNDING_BITS 2
......@@ -60,15 +84,25 @@ typedef union {
#else
uint32_t low;
#endif
#ifndef SIZEOF_LONG_DOUBLE_8
uint32_t mid;
#ifdef WORDS_BIGENDIAN
uint32_t low;
#else
uint32_t high;
#endif
} val_ld12;
struct {
#ifdef WORDS_BIGENDIAN
uint32_t high;
#else
uint32_t low;
#endif
#ifdef WORDS_BIGENDIAN
uint32_t low;
#else
uint32_t high;
#endif
} val;
} val_ld8;
volatile long double d;
} value_t;
......@@ -817,7 +851,7 @@ void *fc_val_from_str(const char *str, size_t len, const ieee_descriptor_t *desc
buffer = (char*) alloca(len+1);
memcpy(buffer, str, len);
buffer[len] = '\0';
val = strtold(buffer, NULL);
val = string_to_long_double(buffer);
DEBUGPRINTF(("val_from_str(%s)\n", str));
tmp_desc.exponent_size = 15;
......@@ -836,25 +870,28 @@ fp_value *fc_val_from_ieee754(long double l, const ieee_descriptor_t *desc, fp_v
value_t srcval;
char sign;
uint32_t exponent, mantissa0, mantissa1;
size_t long_double_size = sizeof(long double);
srcval.d = l;
bias_res = ((1 << (desc->exponent_size - 1)) - 1);
#ifdef SIZEOF_LONG_DOUBLE_8
mant_val = 52;
bias_val = 0x3ff;
sign = (srcval.val.high & 0x80000000) != 0;
exponent = (srcval.val.high & 0x7FF00000) >> 20;
mantissa0 = srcval.val.high & 0x000FFFFF;
mantissa1 = srcval.val.low;
#else
mant_val = 63;
bias_val = 0x3fff;
sign = (srcval.val.high & 0x00008000) != 0;
exponent = (srcval.val.high & 0x00007FFF) ;
mantissa0 = srcval.val.mid;
mantissa1 = srcval.val.low;
#endif
if (long_double_size == 8) {
mant_val = 52;
bias_val = 0x3ff;
sign = (srcval.val_ld8.high & 0x80000000) != 0;
exponent = (srcval.val_ld8.high & 0x7FF00000) >> 20;
mantissa0 = srcval.val_ld8.high & 0x000FFFFF;
mantissa1 = srcval.val_ld8.low;
} else {
/* we assume an x86-like 80bit representation of the value... */
assert(sizeof(long double)==12 || sizeof(long double)==16);
mant_val = 63;
bias_val = 0x3fff;
sign = (srcval.val_ld12.high & 0x00008000) != 0;
exponent = (srcval.val_ld12.high & 0x00007FFF) ;
mantissa0 = srcval.val_ld12.mid;
mantissa1 = srcval.val_ld12.low;
}
if (result == NULL) result = calc_buffer;
temp = (char*) alloca(value_size);
......@@ -871,11 +908,11 @@ fp_value *fc_val_from_ieee754(long double l, const ieee_descriptor_t *desc, fp_v
/* 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)) {
if (my_isnan(l)) {
result->desc.clss = FC_NAN;
TRACEPRINTF(("val_from_float resulted in NAN\n"));
return result;
} else if (isinf(l)) {
} else if (my_isinf(l)) {
result->desc.clss = FC_INF;
TRACEPRINTF(("val_from_float resulted in %sINF\n", (result->sign == 1) ? "-" : ""));
return result;
......@@ -942,17 +979,19 @@ long double fc_val_to_ieee754(const fp_value *val)
ieee_descriptor_t desc;
unsigned mantissa_size;
#ifdef SIZEOF_LONG_DOUBLE_8
desc.exponent_size = 11;
desc.mantissa_size = 52;
desc.explicit_one = 0;
desc.clss = FC_NORMAL;
#else
desc.exponent_size = 15;
desc.mantissa_size = 63;
desc.explicit_one = 1;
desc.clss = FC_NORMAL;
#endif
size_t long_double_size = sizeof(long double);
if (long_double_size == 8) {
desc.exponent_size = 11;
desc.mantissa_size = 52;
desc.explicit_one = 0;
desc.clss = FC_NORMAL;
} else {
desc.exponent_size = 15;
desc.mantissa_size = 63;
desc.explicit_one = 1;
desc.clss = FC_NORMAL;
}
mantissa_size = desc.mantissa_size + desc.explicit_one;
temp = (fp_value*) alloca(calc_buffer_size);
......@@ -976,18 +1015,18 @@ long double fc_val_to_ieee754(const fp_value *val)
for (; (byte_offset<<3) < desc.mantissa_size; byte_offset++)
mantissa0 |= sc_sub_bits(_mant(value), mantissa_size, byte_offset) << ((byte_offset - 4) << 3);
#ifdef SIZEOF_LONG_DOUBLE_8
mantissa0 &= 0x000FFFFF; /* get rid of garbage */
buildval.val.high = sign << 31;
buildval.val.high |= exponent << 20;
buildval.val.high |= mantissa0;
buildval.val.low = mantissa1;
#else
buildval.val.high = sign << 15;
buildval.val.high |= exponent;
buildval.val.mid = mantissa0;
buildval.val.low = mantissa1;
#endif
if (long_double_size == 8) {
mantissa0 &= 0x000FFFFF; /* get rid of garbage */
buildval.val_ld8.high = sign << 31;
buildval.val_ld8.high |= exponent << 20;
buildval.val_ld8.high |= mantissa0;
buildval.val_ld8.low = mantissa1;
} else {
buildval.val_ld12.high = sign << 15;
buildval.val_ld12.high |= exponent;
buildval.val_ld12.mid = mantissa0;
buildval.val_ld12.low = mantissa1;
}
TRACEPRINTF(("val_to_float: %d-%x-%x%x\n", sign, exponent, mantissa0, mantissa1));
return buildval.d;
......
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