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authorKyle Gunger <kgunger12@gmail.com>2024-05-06 01:03:43 -0400
committerKyle Gunger <kgunger12@gmail.com>2024-05-06 01:03:43 -0400
commite6c126856c7eb9e72a3640d4b3ab5000ac2494ab (patch)
treef7f1d22a9801322bac394dac6341feea6ccf9900 /src/types.c
parenta85727c41263b83f5363b43a15ba02317f3b5081 (diff)
Header structs
Diffstat (limited to 'src/types.c')
-rw-r--r--src/types.c154
1 files changed, 119 insertions, 35 deletions
diff --git a/src/types.c b/src/types.c
index ff0459e..8fda424 100644
--- a/src/types.c
+++ b/src/types.c
@@ -16,9 +16,9 @@ OSMFloatBreakdown osm_float_to_break(OSMFloat f)
{
OSMFloatBreakdown out;
- out.sign = f >> 63;
- out.mantissa = (f >> 52) & 0x7ff;
- out.fraction = f & 0xfffffffffffff;
+ out.sign = f >> (OSM_FLOAT_EXPO_LEN + OSM_FLOAT_FRAC_LEN);
+ out.mantissa = (f >> OSM_FLOAT_FRAC_LEN) & OSM_FLOAT_EXPO_MASK;
+ out.fraction = f & OSM_FLOAT_FRAC_MASK;
return out;
}
@@ -39,32 +39,37 @@ OSMFloatBreakdown _osm_ieee754_enlarge(uint64_t d, uint16_t m_len, uint16_t f_le
mask = (1 << f_len) - 1;
out.fraction = d & mask;
+ // Create corrected mantissa and fraction (if not denormal)
if (out.mantissa >= bias)
{
// non-negative exponent
out.mantissa -= bias;
- out.mantissa += 0x3ff;
+ out.mantissa += OSM_FLOAT_EXPO_BIAS;
}
else if (out.mantissa < bias && out.mantissa > 0)
{
- out.mantissa = bias - out.mantissa; // true exponent (abs value)
- out.mantissa = 0x3ff - out.mantissa; // corrected for double precision numbers (won't overflow since we use this function with smaller mantissa)
- out.fraction = out.fraction << (52 - f_len); // corrected fraction based on difference in bit lengths
+ // true exponent (abs value)
+ out.mantissa = bias - out.mantissa;
+ // corrected for double precision numbers (won't overflow since we use this function with smaller mantissa)
+ out.mantissa = OSM_FLOAT_EXPO_BIAS - out.mantissa;
+ // corrected fraction based on difference in bit lengths
+ out.fraction = out.fraction << (OSM_FLOAT_FRAC_LEN - f_len);
}
-
+
+ // Handle zero and denormal
if (out.mantissa == 0)
{
if (out.fraction == 0)
return out;
// Denormal numbers (TODO)
- out.mantissa = 0x3ff - bias; // corrected mantissa
- out.fraction = out.fraction << (52 - f_len); // corrected fraction based on difference in bit lengths
+ out.mantissa = OSM_FLOAT_EXPO_BIAS - bias;
+ if (OSM_FLOAT_FRAC_LEN)
+ out.fraction = out.fraction << (OSM_FLOAT_FRAC_LEN - f_len); // corrected fraction based on difference in bit lengths
bias = (uint16_t) ceil(log2(out.fraction));
}
-
return out;
}
@@ -112,20 +117,110 @@ OSMFloat osm_break_to_float(OSMFloatBreakdown b)
if (b.sign)
out = 1;
- out = out << 63;
+ out = out << (OSM_FLOAT_FRAC_LEN + OSM_FLOAT_EXPO_LEN);
- out |= (OSMFloat)(b.mantissa & 0x7ff) << 52;
+ out |= (OSMFloat)(b.mantissa & OSM_FLOAT_EXPO_MASK) << OSM_FLOAT_FRAC_LEN;
- out |= b.fraction & 0xfffffffffffff;
+ out |= b.fraction & OSM_FLOAT_FRAC_MASK;
return out;
}
+bool _osm_is_nan(const OSMFloatBreakdown b)
+{
+ return b.mantissa == OSM_FLOAT_EXPO_MASK && b.fraction != 0;
+}
+
+int8_t _osm_is_infinity(const OSMFloatBreakdown b)
+{
+ if (b.mantissa == OSM_FLOAT_EXPO_MASK && b.fraction == 0)
+ {
+ if (b.sign)
+ return -1;
+ return 1;
+ }
+ return 0;
+}
+
+/// Handle NaN
+double _osm_ieee754_nan(OSMFloatBreakdown b, uint16_t m_len, uint16_t f_len)
+{
+}
+
+/// Handle subnormal numbers
+double _osm_ieee754_subnormal(OSMFloatBreakdown b, uint16_t m_len, uint16_t f_len)
+{
+ // TODO
+ return 0;
+}
+
+/**
+ * Converts a breakdown to a floating point number with given mantissa and
+ * fraction length (so long as the format is less than or equal to 64 bits)
+ */
double _osm_ieee754_assemble(OSMFloatBreakdown b, uint16_t m_len, uint16_t f_len)
{
- double out = 0;
- // Check
- return out;
+ uint64_t out = 0;
+
+ // Sign (assumed to be at end)
+ out |= b.sign << (m_len + f_len);
+
+ if (b.mantissa == 0 || )
+ {
+ // denormal numbers (TODO)
+ return *(double *)&out;
+ }
+
+ // Mantissa mask
+ uint64_t mask = (1 << m_len) - 1;
+
+ if (_osm_is_nan(b))
+ {
+ // Handle NaN
+ out |= mask << f_len;
+ if (f_len >= OSM_FLOAT_FRAC_LEN)
+ out |= b.fraction << (f_len - OSM_FLOAT_FRAC_LEN);
+ else
+ out |= b.fraction >> (OSM_FLOAT_FRAC_LEN - f_len);
+
+ // Make sure it's still nan just in case all the
+ // fraction bits got cleared
+ mask = (1 << f_len) - 1;
+ if ((out & mask) == 0)
+ out |= 1;
+
+ return *(double *)&out;
+ }
+
+ // Handle mantissa
+ uint64_t bias = mask >> 1;
+ if (b.mantissa > OSM_FLOAT_EXPO_BIAS)
+ {
+ b.mantissa -= OSM_FLOAT_EXPO_BIAS;
+ b.mantissa += bias;
+ }
+ else
+ {
+ b.mantissa = OSM_FLOAT_EXPO_BIAS - b.mantissa;
+ b.mantissa = bias - b.mantissa;
+ }
+
+ // Fraction (assumed to be low bits)
+ mask = (1 << f_len) - 1;
+
+ if (f_len >= OSM_FLOAT_FRAC_LEN)
+ out |= b.fraction << (f_len - OSM_FLOAT_FRAC_LEN);
+ else
+ out |= b.fraction >> (OSM_FLOAT_FRAC_LEN - f_len);
+
+ if ( && (out & mask) != 0)
+ out &= ~mask;
+
+#ifdef _OSM_FLOAT_USE_HIGH_BITS
+ out = out << (64 - (m_len + f_len + 1));
+#endif
+
+ return *(double *)&out;
}
/*
@@ -136,26 +231,26 @@ double _osm_ieee754_assemble(OSMFloatBreakdown b, uint16_t m_len, uint16_t f_len
*
* WARNING: This code flushes out of bounds values to infinity
*
- * INFO: This code keeps NaN values
+ * INFO: The fraction part of NaN values are set to 1
*
* Should probably be updated with more formats if I was
* feeling frisky.
*/
double osm_break_to_native_float(OSMFloatBreakdown b)
{
- double out = 0;
-
switch(sizeof(double))
{
case 2: {
+ return _osm_ieee754_assemble(b, 5, 10);
} break;
case 4: {
+ return _osm_ieee754_assemble(b, 8, 23);
} break;
case 8: {
OSMFloat f = osm_break_to_float(b);
- out = * (double *) &f;
+ return * (double *) &f;
} break;
default:
@@ -163,10 +258,7 @@ double osm_break_to_native_float(OSMFloatBreakdown b)
break;
}
- if (b.sign)
- out = -out;
-
- return out;
+ return 0;
}
double osm_float_to_native(OSMFloat f)
@@ -187,20 +279,12 @@ OSMFloat osm_native_to_float(double d)
bool osm_is_nan(OSMFloat f)
{
- OSMFloatBreakdown b = osm_float_to_break(f);
- return b.mantissa == 0x3ff && b.fraction != 0;
+ return _osm_is_nan(osm_float_to_break(f));
}
int8_t osm_is_infinity(OSMFloat f)
{
- OSMFloatBreakdown b = osm_float_to_break(f);
- if (b.mantissa == 0x3ff && b.fraction == 0)
- {
- if (b.sign)
- return -1;
- return 1;
- }
- return 0;
+ return _osm_is_infinity(osm_float_to_break(f));
}
OSMColor osm_rgb_to_color(uint8_t r, uint8_t g, uint8_t b)