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go/test/fixedbugs/issue6866.go
Robert Griesemer 5bb89eb009 cmd/internal/gc: use big.Float to represent Mpflt bits
All multi-precision arithmetic is now based on math/big.

- passes all.bash
- added test cases for fixed bugs

Fixes #7740.
Fixes #6866.

Change-Id: I67268b91766970ced3b928260053ccdce8753d58
Reviewed-on: https://go-review.googlesource.com/7912
Reviewed-by: Russ Cox <rsc@golang.org>
2015-04-02 22:49:47 +00:00

81 lines
1.5 KiB
Go

// run
// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// WARNING: GENERATED FILE - DO NOT MODIFY MANUALLY!
// (To generate, in go/types directory: go test -run=Hilbert -H=2 -out="h2.src")
// This program tests arbitrary precision constant arithmetic
// by generating the constant elements of a Hilbert matrix H,
// its inverse I, and the product P = H*I. The product should
// be the identity matrix.
package main
func main() {
if !ok {
print()
return
}
}
// Hilbert matrix, n = 2
const (
h0_0, h0_1 = 1.0 / (iota + 1), 1.0 / (iota + 2)
h1_0, h1_1
)
// Inverse Hilbert matrix
const (
i0_0 = +1 * b2_1 * b2_1 * b0_0 * b0_0
i0_1 = -2 * b2_0 * b3_1 * b1_0 * b1_0
i1_0 = -2 * b3_1 * b2_0 * b1_1 * b1_1
i1_1 = +3 * b3_0 * b3_0 * b2_1 * b2_1
)
// Product matrix
const (
p0_0 = h0_0*i0_0 + h0_1*i1_0
p0_1 = h0_0*i0_1 + h0_1*i1_1
p1_0 = h1_0*i0_0 + h1_1*i1_0
p1_1 = h1_0*i0_1 + h1_1*i1_1
)
// Verify that product is identity matrix
const ok = p0_0 == 1 && p0_1 == 0 &&
p1_0 == 0 && p1_1 == 1 &&
true
func print() {
println(p0_0, p0_1)
println(p1_0, p1_1)
}
// Binomials
const (
b0_0 = f0 / (f0 * f0)
b1_0 = f1 / (f0 * f1)
b1_1 = f1 / (f1 * f0)
b2_0 = f2 / (f0 * f2)
b2_1 = f2 / (f1 * f1)
b2_2 = f2 / (f2 * f0)
b3_0 = f3 / (f0 * f3)
b3_1 = f3 / (f1 * f2)
b3_2 = f3 / (f2 * f1)
b3_3 = f3 / (f3 * f0)
)
// Factorials
const (
f0 = 1
f1 = 1
f2 = f1 * 2
f3 = f2 * 3
)