Changeset afffa1e in mainline for softfloat/generic/conversion.c

Timestamp:

2006-02-20T23:12:05Z (19 years ago)

Author:

Josef Cejka <malyzelenyhnus@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

2cb202e

Parents:

d9f51ccc

Message:

Conversion functions from float to int added.
Files arch.h and types.h from arch subdirectory should be replaced later with equivalent files from libc.

File:

• softfloat/generic/conversion.c (modified) (3 diffs)

softfloat/generic/conversion.c

@@ -29 +29 @@
 #include "sftypes.h"
 #include "conversion.h"
+#include "comparison.h"
 
 float64 convertFloat32ToFloat64(float32 a) 
@@ -67 +68 @@
         return result;
         
-};
+}
 
 float32 convertFloat64ToFloat32(float64 a) 
@@ -136 +137 @@
         result.parts.fraction = a.parts.fraction >> (FLOAT64_FRACTION_SIZE - FLOAT32_FRACTION_SIZE);
         return result;
-};
-
+}
+
+
+/** Helping procedure for converting float32 to uint32
+ * @param a floating point number in normalized form (no NaNs or Inf are checked )
+ * @return unsigned integer
+ */
+static __u32 _float32_to_uint32_helper(float32 a)
+{
+        __u32 frac;
+        
+        if (a.parts.exp < FLOAT32_BIAS) {
+                /*TODO: rounding*/
+                return 0;
+        }
+        
+        frac = a.parts.fraction;
+        
+        frac |= FLOAT32_HIDDEN_BIT_MASK;
+        /* shift fraction to left so hidden bit will be the most significant bit */
+        frac <<= 32 - FLOAT32_FRACTION_SIZE - 1; 
+
+        frac >>= 32 - (a.parts.exp - FLOAT32_BIAS) - 1;
+        if ((a.parts.sign == 1) && (frac != 0)) {
+                frac = ~frac;
+                ++frac;
+        }
+        
+        return frac;
+}
+
+/* Convert float to unsigned int32
+ * FIXME: Im not sure what to return if overflow/underflow happens 
+ *      - now its the biggest or the smallest int
+ */ 
+__u32 float32_to_uint32(float32 a)
+{
+        if (isFloat32NaN(a)) {
+                return MAX_UINT32;
+        }
+        
+        if (isFloat32Infinity(a) || (a.parts.exp >= (32 + FLOAT32_BIAS)))  {
+                if (a.parts.sign) {
+                        return MIN_UINT32;
+                }
+                return MAX_UINT32;
+        }
+        
+        return _float32_to_uint32_helper(a);    
+}
+
+/* Convert float to signed int32
+ * FIXME: Im not sure what to return if overflow/underflow happens 
+ *      - now its the biggest or the smallest int
+ */ 
+__s32 float32_to_int32(float32 a)
+{
+        if (isFloat32NaN(a)) {
+                return MAX_INT32;
+        }
+        
+        if (isFloat32Infinity(a) || (a.parts.exp >= (32 + FLOAT32_BIAS)))  {
+                if (a.parts.sign) {
+                        return MIN_INT32;
+                }
+                return MAX_INT32;
+        }
+        return _float32_to_uint32_helper(a);
+}       
+
+
+