Changeset 990 for trunk/src/real.cppTweet

Timestamp:

Sep 28, 2011, 2:59:39 AM (11 years ago)

Author:

sam

Message:

core: implement sin(), cos() and abs() for reals and fix a crash in the
addition and subtraction operators occurring when exponents were too
different.

File:

• trunk/src/real.cpp (modified) (4 diffs)

trunk/src/real.cpp

@@ -130 +130 @@
     int off = e1 - e2 - bigoff * (sizeof(uint16_t) * 8);
 
+    if (bigoff > BIGITS)
+        return *this;
+
     ret.m_signexp = m_signexp;
 
@@ -188 +191 @@
     int bigoff = (e1 - e2) / (sizeof(uint16_t) * 8);
     int off = e1 - e2 - bigoff * (sizeof(uint16_t) * 8);
+
+    if (bigoff > BIGITS)
+        return *this;
 
     ret.m_signexp = m_signexp;
@@ -502 +508 @@
 }
 
+real fabs(real const &x)
+{
+    real ret = x;
+    ret.m_signexp &= 0x7fffffffu;
+    return ret;
+}
+
 real exp(real const &x)
 {
@@ -526 +539 @@
     for (int i = 0; i < square; i++)
         ret = ret * ret;
+
+    return ret;
+}
+
+real sin(real const &x)
+{
+    real ret = 0.0, fact = 1.0, xn = x, x2 = x * x;
+
+    for (int i = 1; ; i += 2)
+    {
+        real newret = ret + xn / fact;
+        if (ret == newret)
+            break;
+        ret = newret;
+        xn *= x2;
+        fact *= (real)(-(i + 1) * (i + 2));
+    }
+
+    return ret;
+}
+
+real cos(real const &x)
+{
+    real ret = 0.0, fact = 1.0, xn = 1.0, x2 = x * x;
+
+    for (int i = 1; ; i += 2)
+    {
+        real newret = ret + xn / fact;
+        if (ret == newret)
+            break;
+        ret = newret;
+        xn *= x2;
+        fact *= (real)(-i * (i + 1));
+    }
 
     return ret;