Changeset 992ffa6 in mainline for uspace/lib/math/generic

Timestamp:

2015-09-04T06:40:20Z (10 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

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

Children:

01cdd5a

Parents:

bae1e1f

Message:

Add exp(f), log(f), pow(f). Improve precision of sin, cos.

Location:

uspace/lib/math/generic

Files:

• ceil.c (modified) (2 diffs)
• exp.c (added)
• floor.c (modified) (2 diffs)
• log.c (added)
• pow.c (added)
• trig.c (modified) (3 diffs)
• trunc.c (modified) (1 diff)

uspace/lib/math/generic/ceil.c

@@ -48 +48 @@
         float64_u v;
         float64_u r;
-
+        
         v.data = val;
         t.data = trunc_float64(val);
-
+        
         if (val.parts.sign == 1 || v.val == t.val) {
                 r = t;
@@ -57 +57 @@
                 r.val = t.val + 1.0;
         }
-
+        
         return r.data;
 }

uspace/lib/math/generic/floor.c

@@ -49 +49 @@
         float64_u v;
         float64_u r;
-
+        
         v.data = val;
         t.data = trunc_float64(val);
-
+        
         if (val.parts.sign == 0 || v.val == t.val) {
                 r = t;
@@ -58 +58 @@
                 r.val = t.val - 1.0;
         }
-
+        
         return r.data;
 }

uspace/lib/math/generic/trig.c

@@ -36 +36 @@
 #include <trig.h>
 
-#define TAYLOR_DEGREE  13
+#define TAYLOR_DEGREE_32 13
+#define TAYLOR_DEGREE_64 21
 
 /** Precomputed values for factorial (starting from 1!) */
-static float64_t factorials[TAYLOR_DEGREE] = {
+static float64_t factorials[TAYLOR_DEGREE_64] = {
         1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800, 39916800,
-        479001600, 6227020800
+        479001600, 6227020800.0L, 87178291200.0L, 1307674368000.0L,
+        20922789888000.0L, 355687428096000.0L, 6402373705728000.0L,
+        121645100408832000.0L, 2432902008176640000.0L, 51090942171709440000.0L
 };
 
@@ -61 +64 @@
         float64_t nom = 1;
         
-        for (unsigned int i = 0; i < TAYLOR_DEGREE; i++) {
+        for (unsigned int i = 0; i < TAYLOR_DEGREE_64; i++) {
                 nom *= arg;
                 
@@ -90 +93 @@
         float64_t nom = 1;
         
-        for (unsigned int i = 0; i < TAYLOR_DEGREE; i++) {
+        for (unsigned int i = 0; i < TAYLOR_DEGREE_64; i++) {
                 nom *= arg;
                 

uspace/lib/math/generic/trunc.c

@@ -35 +35 @@
 #include <mathtypes.h>
 #include <trunc.h>
+
+/** 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 trunc_float32(float32 val)
+{
+        int32_t exp = val.parts.exp - FLOAT32_BIAS;
+        
+        if (exp < 0) {
+                /* -1 < val < 1 => result is +0 or -0 */
+                val.parts.exp = 0;
+                val.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 */
+                val.parts.fraction &= ~(UINT32_C(0x007fffff) >> exp);
+        }
+        
+        return val;
+}
 
 /** Truncate fractional part (round towards zero)