diff options
Diffstat (limited to 'test/bench/pidigits.go')
| -rw-r--r-- | test/bench/pidigits.go | 50 |
1 files changed, 28 insertions, 22 deletions
diff --git a/test/bench/pidigits.go b/test/bench/pidigits.go index aaa9f53a5..a05515028 100644 --- a/test/bench/pidigits.go +++ b/test/bench/pidigits.go @@ -38,7 +38,7 @@ POSSIBILITY OF SUCH DAMAGE. package main import ( - "bignum" + "big" "flag" "fmt" ) @@ -47,11 +47,14 @@ var n = flag.Int("n", 27, "number of digits") var silent = flag.Bool("s", false, "don't print result") var ( - tmp1 *bignum.Integer - tmp2 *bignum.Integer - numer = bignum.Int(1) - accum = bignum.Int(0) - denom = bignum.Int(1) + tmp1 = big.NewInt(0) + tmp2 = big.NewInt(0) + y2 = big.NewInt(0) + bigk = big.NewInt(0) + numer = big.NewInt(1) + accum = big.NewInt(0) + denom = big.NewInt(1) + ten = big.NewInt(10) ) func extract_digit() int64 { @@ -60,36 +63,39 @@ func extract_digit() int64 { } // Compute (numer * 3 + accum) / denom - tmp1 = numer.Shl(1) - bignum.Iadd(tmp1, tmp1, numer) - bignum.Iadd(tmp1, tmp1, accum) - tmp1, tmp2 := tmp1.QuoRem(denom) + tmp1.Lsh(numer, 1) + tmp1.Add(tmp1, numer) + tmp1.Add(tmp1, accum) + tmp1.DivMod(tmp1, denom, tmp2) // Now, if (numer * 4 + accum) % denom... - bignum.Iadd(tmp2, tmp2, numer) + tmp2.Add(tmp2, numer) // ... is normalized, then the two divisions have the same result. if tmp2.Cmp(denom) >= 0 { return -1 } - return tmp1.Value() + return tmp1.Int64() } func next_term(k int64) { - y2 := k*2 + 1 - - tmp1 = numer.Shl(1) - bignum.Iadd(accum, accum, tmp1) - bignum.Iscale(accum, y2) - bignum.Iscale(numer, k) - bignum.Iscale(denom, y2) + // TODO(eds) If big.Int ever gets a Scale method, y2 and bigk could be int64 + y2.New(k*2 + 1) + bigk.New(k) + + tmp1.Lsh(numer, 1) + accum.Add(accum, tmp1) + accum.Mul(accum, y2) + numer.Mul(numer, bigk) + denom.Mul(denom, y2) } func eliminate_digit(d int64) { - bignum.Isub(accum, accum, denom.Mul1(d)) - bignum.Iscale(accum, 10) - bignum.Iscale(numer, 10) + tmp := big.NewInt(0).Set(denom) + accum.Sub(accum, tmp.Mul(tmp, big.NewInt(d))) + accum.Mul(accum, ten) + numer.Mul(numer, ten) } func printf(s string, arg ...interface{}) { |