WebSVN – HelenOS-historic – Diff – /uspace/trunk/softfloat/generic/conversion.c

 /*
  * Copyright (C) 2005 Josef Cejka
  * All rights reserved.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
+ *
  * - Redistributions of source code must retain the above copyright
  *   notice, this list of conditions and the following disclaimer.
  * - Redistributions in binary form must reproduce the above copyright
  *   notice, this list of conditions and the following disclaimer in the
  *   documentation and/or other materials provided with the distribution.
  * - The name of the author may not be used to endorse or promote products
  *   derived from this software without specific prior written permission.
+ *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 #include "sftypes.h"
 #include "conversion.h"
+#include "comparison.h"
 float64 convertFloat32ToFloat64(float32 a)
+{
     float64 result;
     __u64 frac;
     result.parts.sign = a.parts.sign;
     result.parts.fraction = a.parts.fraction;
     result.parts.fraction <<= (FLOAT64_FRACTION_SIZE - FLOAT32_FRACTION_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.fraction == 0ll) { /* fix zero */
             result.parts.exp = 0ll;
             return result;
+        }
         frac = result.parts.fraction;
         while (!(frac & (0x10000000000000ll))) {
             frac <<= 1;
             --result.parts.exp;
         };
         ++result.parts.exp;
         result.parts.fraction = frac;
     };
     return result;
-};
+}
 float32 convertFloat64ToFloat32(float64 a)
+{
     float32 result;
     __s32 exp;
     __u64 frac;
     result.parts.sign = a.parts.sign;
     if (isFloat64NaN(a)) {
         result.parts.exp = 0xFF;
         if (isFloat64SigNaN(a)) {
             result.parts.fraction = 0x800000; /* set first bit of fraction nonzero */
             return result;
+        }
         result.parts.fraction = 0x1; /* fraction nonzero but its first bit is zero */
         return result;
     };
     if (isFloat64Infinity(a)) {
         result.parts.fraction = 0;
         result.parts.exp = 0xFF;
         return result;
     };
     exp = (int)a.parts.exp - FLOAT64_BIAS + FLOAT32_BIAS;
     if (exp >= 0xFF) {
         /*FIXME: overflow*/
         result.parts.fraction = 0;
         result.parts.exp = 0xFF;
         return result;
     } else if (exp <= 0 ) {
         /* underflow or denormalized */
         result.parts.exp = 0;
         exp *= -1;
         if (exp > FLOAT32_FRACTION_SIZE ) {
             /* FIXME: underflow */
             result.parts.fraction = 0;
             return result;
         };
         /* denormalized */
         frac = a.parts.fraction;
         frac |= 0x10000000000000ll; /* denormalize and set hidden bit */
         frac >>= (FLOAT64_FRACTION_SIZE - FLOAT32_FRACTION_SIZE + 1);
         while (exp > 0) {
             --exp;
             frac >>= 1;
         };
         result.parts.fraction = frac;
         return result;
     };
     result.parts.exp = exp;
     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);
-};
+}

Subversion Repositories HelenOS-historic

(root)/uspace/trunk/softfloat/generic/conversion.c – Rev 804 → 857