[armedbear-cvs] r12940 - trunk/abcl/src/org/armedbear/lisp

[Erik Huelsmann]

Author: ehuelsmann
Date: Sat Oct  2 17:39:52 2010
New Revision: 12940

Log:
Fix loss of precision in (expt <non-double> <complex-double>),
fixes last Maxima failure.

Modified:
   trunk/abcl/src/org/armedbear/lisp/Complex.java
   trunk/abcl/src/org/armedbear/lisp/MathFunctions.java

Modified: trunk/abcl/src/org/armedbear/lisp/Complex.java
==============================================================================
--- trunk/abcl/src/org/armedbear/lisp/Complex.java	(original)
+++ trunk/abcl/src/org/armedbear/lisp/Complex.java	Sat Oct  2 17:39:52 2010
@@ -80,6 +80,15 @@
     return imagpart;
   }
 
+  /** Coerces the complex parts into DoubleFloats
+   *
+   * @return a new complex with double-float real and imaginary parts
+   */
+  public LispObject coerceToDoubleFloat() {
+      return getInstance(DoubleFloat.coerceToFloat(realpart),
+                         DoubleFloat.coerceToFloat(imagpart));
+  }
+
   @Override
   public LispObject typeOf()
   {

Modified: trunk/abcl/src/org/armedbear/lisp/MathFunctions.java
==============================================================================
--- trunk/abcl/src/org/armedbear/lisp/MathFunctions.java	(original)
+++ trunk/abcl/src/org/armedbear/lisp/MathFunctions.java	Sat Oct  2 17:39:52 2010
@@ -623,6 +623,34 @@
             }
             // for anything not a rational or complex rational, use
             // float approximation.
+            boolean wantDoubleFloat = false;
+            if (base instanceof DoubleFloat)
+                wantDoubleFloat = true;
+            else if (power instanceof DoubleFloat)
+                wantDoubleFloat = true;
+            else if (base instanceof Complex
+                     && (((Complex)base).getRealPart() instanceof DoubleFloat
+                         || ((Complex)base).getImaginaryPart() instanceof DoubleFloat))
+                wantDoubleFloat = true;
+            else if (power instanceof Complex
+                    && (((Complex)power).getRealPart() instanceof DoubleFloat
+                         || ((Complex)power).getImaginaryPart() instanceof DoubleFloat))
+                wantDoubleFloat = true;
+
+            if (wantDoubleFloat) {
+                if (power instanceof Complex)
+                    power = ((Complex)power).coerceToDoubleFloat();
+                else
+                    power = DoubleFloat.coerceToFloat(power);
+
+                if (base instanceof Complex)
+                    base = ((Complex)base).coerceToDoubleFloat();
+                else
+                    base = DoubleFloat.coerceToFloat(base);
+            }
+
+
+
             if (base instanceof Complex || power instanceof Complex)
                 return exp(power.multiplyBy(log(base)));
             final double x; // base