hilbert now runs.

it's 25% faster and runs with 40% less memory allocation than before

R=rsc
DELTA=20  (15 added, 0 deleted, 5 changed)
OCL=21690
CL=21690

diff --git a/src/lib/bignum.go b/src/lib/bignum.go
index 9da1e7bd241a5646aae2cd701cc5d7b7152dc9e2..a4ea8c97320c74e41d20a5ff972d3a88075b0e0d 100755 (executable)
--- a/src/lib/bignum.go
+++ b/src/lib/bignum.go
@@ -793,7 +793,10 @@ export func Fact(n uint) Natural {
 
 
 export func Binomial(n, k uint) Natural {
-       return MulRange(n-k+1, n).Div(MulRange(1, k));
+       //BUG return MulRange(n-k+1, n).Div(MulRange(1, k));
+       x := MulRange(n-k+1, n);
+       y := MulRange(1, k);
+       return x.Div(y);
 }
 
 

diff --git a/test/hilbert.go b/test/hilbert.go
index 415e957f8416826c6277d0cc053d0bc53462f6b4..15d4ae2972392350e1e398eb5c40d7c99ea2009c 100644 (file)
--- a/test/hilbert.go
+++ b/test/hilbert.go
@@ -82,7 +82,7 @@ func NewHilbert(n int) *Matrix {
 }
 
 
-func MakeRat(x *Big.Natural) *Big.Rational {
+func MakeRat(x Big.Natural) *Big.Rational {
        return Big.MakeRat(Big.MakeInt(false, x), Big.Nat(1));
 }
 
@@ -100,7 +100,12 @@ func NewInverseHilbert(n int) *Matrix {
                        x3 := MakeRat(Big.Binomial(uint(n+j), uint(n-i-1)));
                        x4 := MakeRat(Big.Binomial(uint(i+j), uint(i)));
                        x4 = x4.Mul(x4);
-                       a.set(i, j, x0.Mul(x1).Mul(x2).Mul(x3).Mul(x4));
+                       // BUG a.set(i, j, x0.Mul(x1).Mul(x2).Mul(x3).Mul(x4));
+                       y1 := x0.Mul(x1);
+                       y2 := y1.Mul(x2);
+                       y3 := y2.Mul(x3);
+                       y4 := y3.Mul(x4);
+                       a.set(i, j, y4);
                }
        }
        return a;
@@ -114,7 +119,11 @@ func (a *Matrix) Mul(b *Matrix) *Matrix {
                for j := 0; j < c.m; j++ {
                        x := Zero;
                        for k := 0; k < a.m; k++ {
-                               x = x.Add(a.at(i, k).Mul(b.at(k, j)));
+                               //BUG x = x.Add(a.at(i, k).Mul(b.at(k, j)));
+                               a1 := a.at(i, k);
+                               b1 := b.at(k, j);
+                               a2 := a1.Mul(b1);
+                               x = x.Add(a2);
                        }
                        c.set(i, j, x);
                }
@@ -129,7 +138,10 @@ func (a *Matrix) Eql(b *Matrix) bool {
        }
        for i := 0; i < a.n; i++ {
                for j := 0; j < a.m; j++ {
-                       if a.at(i, j).Cmp(b.at(i,j)) != 0 {
+                       // BUG if a.at(i, j).Cmp(b.at(i,j)) != 0 {
+                       a1 := a.at(i, j);
+                       b1 := b.at(i,j);
+                       if a1.Cmp(b1) != 0 {
                                return false;
                        }
                }