Changeset ff381a7 in mainline for uspace/lib/math/generic/trunc.c

Timestamp:

2015-11-02T20:54:19Z (8 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

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

Children:

d8513177

Parents:

3feeab2 (diff), 5265eea4 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge mainline changes.

File:

• uspace/lib/math/generic/trunc.c (modified) (4 diffs)

uspace/lib/math/generic/trunc.c

@@ -1 +1 @@
 /*
+ * Copyright (c) 2015 Jiri Svoboda
  * Copyright (c) 2014 Martin Decky
  * All rights reserved.
@@ -38 +39 @@
 /** Truncate fractional part (round towards zero)
  *
+ * Truncate the fractional part of IEEE 754 single
+ * precision floating point number by zeroing fraction
+ * bits, effectively rounding the number towards zero
+ * to the nearest whole number.
+ *
+ * If the argument is infinity or NaN, an exception
+ * should be indicated. This is not implemented yet.
+ *
+ * @param val Floating point number.
+ *
+ * @return Number rounded towards zero.
+ *
+ */
+float32_t float32_trunc(float32_t val)
+{
+        float32_u v;
+        int32_t exp;
+        
+        v.val = val;
+        exp = v.data.parts.exp - FLOAT32_BIAS;
+        
+        if (exp < 0) {
+                /* -1 < val < 1 => result is +0 or -0 */
+                v.data.parts.exp = 0;
+                v.data.parts.fraction = 0;
+        } else if (exp >= FLOAT32_FRACTION_SIZE) {
+                if (exp == 1024) {
+                        /* val is +inf, -inf or NaN => trigger an exception */
+                        // FIXME TODO
+                }
+                
+                /* All bits in val are relevant for the result */
+        } else {
+                /* Truncate irrelevant fraction bits */
+                v.data.parts.fraction &= ~(UINT32_C(0x007fffff) >> exp);
+        }
+        
+        return v.val;
+}
+
+/** Truncate fractional part (round towards zero)
+ *
  * Truncate the fractional part of IEEE 754 double
  * precision floating point number by zeroing fraction
@@ -51 +94 @@
  *
  */
-float64 trunc_float64(float64 val)
+float64_t float64_trunc(float64_t val)
 {
-        int32_t exp = val.parts.exp - FLOAT64_BIAS;
+        float64_u v;
+        int32_t exp;
+        
+        v.val = val;
+        exp = v.data.parts.exp - FLOAT64_BIAS;
         
         if (exp < 0) {
                 /* -1 < val < 1 => result is +0 or -0 */
-                val.parts.exp = 0;
-                val.parts.fraction = 0;
+                v.data.parts.exp = 0;
+                v.data.parts.fraction = 0;
         } else if (exp >= FLOAT64_FRACTION_SIZE) {
                 if (exp == 1024) {
@@ -68 +115 @@
         } else {
                 /* Truncate irrelevant fraction bits */
-                val.parts.fraction &= ~(UINT64_C(0x000fffffffffffff) >> exp);
+                v.data.parts.fraction &= ~(UINT64_C(0x000fffffffffffff) >> exp);
         }
         
-        return val;
+        return v.val;
 }