Changeset feef1cd in mainline for softfloat/generic/conversion.c

Timestamp:

2006-01-08T19:39:07Z (19 years ago)

Author:

Josef Cejka <malyzelenyhnus@…>

Branches:

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

Children:

56a39dde

Parents:

3af72dc

Message:

Added new function for testint 64 bit floats and functions for 32↔64 bit conversion.

File:

• softfloat/generic/conversion.c (modified) (1 diff)

softfloat/generic/conversion.c

@@ -27 +27 @@
  */
 
+#include "sftypes.h"
+#include "conversion.h"
+
+float64 convertFloat32ToFloat64(float32 a) 
+{
+        float64 result;
+        __u64 mant;
+        
+        result.parts.sign = a.parts.sign;
+        result.parts.mantisa = a.parts.mantisa;
+        result.parts.mantisa <<= (FLOAT64_MANTISA_SIZE - FLOAT32_MANTISA_SIZE );
+        
+        if ((isFloat32Infinity(a))||(isFloat32NaN(a))) {
+                result.parts.exp = 0x7FF;
+                /* TODO; check if its correct for SigNaNs*/
+                return result;
+        };
+        
+        result.parts.exp = a.parts.exp + ( (int)FLOAT64_BIAS - FLOAT32_BIAS );
+        if (a.parts.exp == 0) {
+                /* normalize denormalized numbers */
+
+                if (result.parts.mantisa == 0ll) { /* fix zero */
+                        result.parts.exp = 0ll;
+                        return result;
+                }
+                        
+                mant = result.parts.mantisa;
+                
+                while (!(mant & (0x10000000000000ll))) {
+                        mant <<= 1;
+                        --result.parts.exp;
+                };
+                result.parts.mantisa = mant;
+        };
+        
+        return result;
+        
+};
+
+float32 convertFloat64ToFloat32(float64 a) 
+{
+        float32 result;
+        __s32 exp;
+        __u64 mant;
+        
+        result.parts.sign = a.parts.sign;
+        
+        if (isFloat64NaN(a)) {
+                
+                result.parts.exp = 0xFF;
+                
+                if (isFloat64SigNaN(a)) {
+                        result.parts.mantisa = 0x800000; /* set first bit of mantisa nonzero */
+                        return result;
+                }
+        
+                result.parts.mantisa = 0x1; /* mantisa nonzero but its first bit is zero */
+                return result;
+        };
+
+        if (isFloat64Infinity(a)) {
+                result.parts.mantisa = 0;
+                result.parts.exp = 0xFF;
+                return result;
+        };
+
+        exp = (int)a.parts.exp - FLOAT64_BIAS + FLOAT32_BIAS;
+        
+        if (exp >= 0xFF) {
+                /*FIXME: overflow*/
+                result.parts.mantisa = 0;
+                result.parts.exp = 0xFF;
+                return result;
+                
+        } else if (exp <= 0 ) {
+                
+                /* underflow or denormalized */
+                
+                result.parts.exp = 0;
+                
+                exp *= -1;      
+                
+                if (exp > FLOAT32_MANTISA_SIZE ) {
+                        /* FIXME: underflow */
+                        result.parts.mantisa = 0;
+                        return result;
+                };
+                
+                /* denormalized */
+                
+                mant = result.parts.mantisa >> 1; 
+                mant |= 0x10000000000000ll; /* denormalize and set hidden bit */
+                
+                while (exp > 0) {
+                        --exp;
+                        mant >>= 1;
+                };
+                result.parts.mantisa = mant;
+                
+                return result;
+        };
+
+        result.parts.exp = exp;
+        result.parts.mantisa = a.parts.mantisa >> (FLOAT64_MANTISA_SIZE - FLOAT32_MANTISA_SIZE);
+        return result;
+};
+