From 626b54c05ab5a1ddee4dff66d4e2dc9a7053af3e Mon Sep 17 00:00:00 2001
From: Kyle Gunger <kgunger12@gmail.com>
Date: Mon, 6 May 2024 02:10:26 -0400
Subject: Some more float conversion
---
src/types.c | 88 +++++++++++++++++++++++++++++++++++++++----------------------
1 file changed, 57 insertions(+), 31 deletions(-)
diff --git a/src/types.c b/src/types.c
index 8fda424..e46a283 100644
--- a/src/types.c
+++ b/src/types.c
@@ -65,7 +65,7 @@ OSMFloatBreakdown _osm_ieee754_enlarge(uint64_t d, uint16_t m_len, uint16_t f_le
// Denormal numbers (TODO)
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
+ 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));
}
@@ -145,13 +145,41 @@ int8_t _osm_is_infinity(const OSMFloatBreakdown b)
/// Handle NaN
double _osm_ieee754_nan(OSMFloatBreakdown b, uint16_t m_len, uint16_t f_len)
{
+ uint64_t out = 0;
+ uint64_t mask = (1 << m_len) - 1;
+
+ // sign
+ out |= b.sign << (m_len + f_len);
+ // mantissa
+ out |= mask << f_len;
+
+ // fraction
+ 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;
+
+#ifdef _OSM_FLOAT_USE_HIGH_BITS
+ out = out << (64 - (m_len + f_len + 1));
+#endif
+ return *(double *)&out;
}
/// Handle subnormal numbers
double _osm_ieee754_subnormal(OSMFloatBreakdown b, uint16_t m_len, uint16_t f_len)
{
// TODO
- return 0;
+ uint64_t out = 0;
+#ifdef _OSM_FLOAT_USE_HIGH_BITS
+ out = out << (64 - (m_len + f_len + 1));
+#endif
+ return *(double *)&out;
}
/**
@@ -160,51 +188,51 @@ double _osm_ieee754_subnormal(OSMFloatBreakdown b, uint16_t m_len, uint16_t f_le
*/
double _osm_ieee754_assemble(OSMFloatBreakdown b, uint16_t m_len, uint16_t f_len)
{
+
+ if (_osm_is_nan(b))
+ return _osm_ieee754_nan(b, m_len, f_len);
+ else if (b.mantissa == 0)
+ return _osm_ieee754_subnormal(b, m_len, f_len);
+
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;
+ if (b.mantissa >= mask)
+ {
+ // Create infinity
+ out |= mask << f_len;
+#ifdef _OSM_FLOAT_USE_HIGH_BITS
+ out = out << (64 - (m_len + f_len + 1));
+#endif
+ return *(double *)&out;
+ }
}
else
{
b.mantissa = OSM_FLOAT_EXPO_BIAS - b.mantissa;
b.mantissa = bias - b.mantissa;
+
+ if (b.mantissa >= mask || b.mantissa == 0)
+ {
+ // wrapped around, should create subnormal
+ return _osm_ieee754_subnormal(b, m_len, f_len);
+ }
}
+ // write mantissa
+ out |= (b.mantissa & mask) << f_len;
+
// Fraction (assumed to be low bits)
mask = (1 << f_len) - 1;
@@ -213,9 +241,6 @@ double _osm_ieee754_assemble(OSMFloatBreakdown b, uint16_t m_len, uint16_t f_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
@@ -231,7 +256,7 @@ 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: The fraction part of NaN values are set to 1
+ * INFO: The fraction part of NaN values are set to 1 in some cases
*
* Should probably be updated with more formats if I was
* feeling frisky.
@@ -317,7 +342,8 @@ OSMColor osm_color_copy(const OSMColor *color)
// char should be just one byte long anyways
size_t len = strlen((char *)color->ex_names[i]) + 1;
uint8_t *buf = malloc(strlen((char *)color->ex_names[i]) + 1);
- memcpy(buf, color->ex_names[i], len);
+ memcpy(buf, color->ex_names[i], len + 1);
+ out.ex_names[i] = buf;
}
return out;
--
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