diff options
Diffstat (limited to 'src/cmd/compile/internal/gc/mpfloat.go')
| -rw-r--r-- | src/cmd/compile/internal/gc/mpfloat.go | 357 |
1 files changed, 0 insertions, 357 deletions
diff --git a/src/cmd/compile/internal/gc/mpfloat.go b/src/cmd/compile/internal/gc/mpfloat.go deleted file mode 100644 index 401aef319d..0000000000 --- a/src/cmd/compile/internal/gc/mpfloat.go +++ /dev/null @@ -1,357 +0,0 @@ -// Copyright 2009 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. - -package gc - -import ( - "fmt" - "math" - "math/big" -) - -// implements float arithmetic - -const ( - // Maximum size in bits for Mpints before signalling - // overflow and also mantissa precision for Mpflts. - Mpprec = 512 - // Turn on for constant arithmetic debugging output. - Mpdebug = false -) - -// Mpflt represents a floating-point constant. -type Mpflt struct { - Val big.Float -} - -// Mpcplx represents a complex constant. -type Mpcplx struct { - Real Mpflt - Imag Mpflt -} - -// Use newMpflt (not new(Mpflt)!) to get the correct default precision. -func newMpflt() *Mpflt { - var a Mpflt - a.Val.SetPrec(Mpprec) - return &a -} - -// Use newMpcmplx (not new(Mpcplx)!) to get the correct default precision. -func newMpcmplx() *Mpcplx { - var a Mpcplx - a.Real = *newMpflt() - a.Imag = *newMpflt() - return &a -} - -func (a *Mpflt) SetInt(b *Mpint) { - if b.checkOverflow(0) { - // sign doesn't really matter but copy anyway - a.Val.SetInf(b.Val.Sign() < 0) - return - } - a.Val.SetInt(&b.Val) -} - -func (a *Mpflt) Set(b *Mpflt) { - a.Val.Set(&b.Val) -} - -func (a *Mpflt) Add(b *Mpflt) { - if Mpdebug { - fmt.Printf("\n%v + %v", a, b) - } - - a.Val.Add(&a.Val, &b.Val) - - if Mpdebug { - fmt.Printf(" = %v\n\n", a) - } -} - -func (a *Mpflt) AddFloat64(c float64) { - var b Mpflt - - b.SetFloat64(c) - a.Add(&b) -} - -func (a *Mpflt) Sub(b *Mpflt) { - if Mpdebug { - fmt.Printf("\n%v - %v", a, b) - } - - a.Val.Sub(&a.Val, &b.Val) - - if Mpdebug { - fmt.Printf(" = %v\n\n", a) - } -} - -func (a *Mpflt) Mul(b *Mpflt) { - if Mpdebug { - fmt.Printf("%v\n * %v\n", a, b) - } - - a.Val.Mul(&a.Val, &b.Val) - - if Mpdebug { - fmt.Printf(" = %v\n\n", a) - } -} - -func (a *Mpflt) MulFloat64(c float64) { - var b Mpflt - - b.SetFloat64(c) - a.Mul(&b) -} - -func (a *Mpflt) Quo(b *Mpflt) { - if Mpdebug { - fmt.Printf("%v\n / %v\n", a, b) - } - - a.Val.Quo(&a.Val, &b.Val) - - if Mpdebug { - fmt.Printf(" = %v\n\n", a) - } -} - -func (a *Mpflt) Cmp(b *Mpflt) int { - return a.Val.Cmp(&b.Val) -} - -func (a *Mpflt) CmpFloat64(c float64) int { - if c == 0 { - return a.Val.Sign() // common case shortcut - } - return a.Val.Cmp(big.NewFloat(c)) -} - -func (a *Mpflt) Float64() float64 { - x, _ := a.Val.Float64() - - // check for overflow - if math.IsInf(x, 0) && nsavederrors+nerrors == 0 { - Fatalf("ovf in Mpflt Float64") - } - - return x + 0 // avoid -0 (should not be needed, but be conservative) -} - -func (a *Mpflt) Float32() float64 { - x32, _ := a.Val.Float32() - x := float64(x32) - - // check for overflow - if math.IsInf(x, 0) && nsavederrors+nerrors == 0 { - Fatalf("ovf in Mpflt Float32") - } - - return x + 0 // avoid -0 (should not be needed, but be conservative) -} - -func (a *Mpflt) SetFloat64(c float64) { - if Mpdebug { - fmt.Printf("\nconst %g", c) - } - - // convert -0 to 0 - if c == 0 { - c = 0 - } - a.Val.SetFloat64(c) - - if Mpdebug { - fmt.Printf(" = %v\n", a) - } -} - -func (a *Mpflt) Neg() { - // avoid -0 - if a.Val.Sign() != 0 { - a.Val.Neg(&a.Val) - } -} - -func (a *Mpflt) SetString(as string) { - f, _, err := a.Val.Parse(as, 0) - if err != nil { - yyerror("malformed constant: %s (%v)", as, err) - a.Val.SetFloat64(0) - return - } - - if f.IsInf() { - yyerror("constant too large: %s", as) - a.Val.SetFloat64(0) - return - } - - // -0 becomes 0 - if f.Sign() == 0 && f.Signbit() { - a.Val.SetFloat64(0) - } -} - -func (f *Mpflt) String() string { - return f.Val.Text('b', 0) -} - -func (fvp *Mpflt) GoString() string { - // determine sign - sign := "" - f := &fvp.Val - if f.Sign() < 0 { - sign = "-" - f = new(big.Float).Abs(f) - } - - // Don't try to convert infinities (will not terminate). - if f.IsInf() { - return sign + "Inf" - } - - // Use exact fmt formatting if in float64 range (common case): - // proceed if f doesn't underflow to 0 or overflow to inf. - if x, _ := f.Float64(); f.Sign() == 0 == (x == 0) && !math.IsInf(x, 0) { - return fmt.Sprintf("%s%.6g", sign, x) - } - - // Out of float64 range. Do approximate manual to decimal - // conversion to avoid precise but possibly slow Float - // formatting. - // f = mant * 2**exp - var mant big.Float - exp := f.MantExp(&mant) // 0.5 <= mant < 1.0 - - // approximate float64 mantissa m and decimal exponent d - // f ~ m * 10**d - m, _ := mant.Float64() // 0.5 <= m < 1.0 - d := float64(exp) * (math.Ln2 / math.Ln10) // log_10(2) - - // adjust m for truncated (integer) decimal exponent e - e := int64(d) - m *= math.Pow(10, d-float64(e)) - - // ensure 1 <= m < 10 - switch { - case m < 1-0.5e-6: - // The %.6g format below rounds m to 5 digits after the - // decimal point. Make sure that m*10 < 10 even after - // rounding up: m*10 + 0.5e-5 < 10 => m < 1 - 0.5e6. - m *= 10 - e-- - case m >= 10: - m /= 10 - e++ - } - - return fmt.Sprintf("%s%.6ge%+d", sign, m, e) -} - -// complex multiply v *= rv -// (a, b) * (c, d) = (a*c - b*d, b*c + a*d) -func (v *Mpcplx) Mul(rv *Mpcplx) { - var ac, ad, bc, bd Mpflt - - ac.Set(&v.Real) - ac.Mul(&rv.Real) // ac - - bd.Set(&v.Imag) - bd.Mul(&rv.Imag) // bd - - bc.Set(&v.Imag) - bc.Mul(&rv.Real) // bc - - ad.Set(&v.Real) - ad.Mul(&rv.Imag) // ad - - v.Real.Set(&ac) - v.Real.Sub(&bd) // ac-bd - - v.Imag.Set(&bc) - v.Imag.Add(&ad) // bc+ad -} - -// complex divide v /= rv -// (a, b) / (c, d) = ((a*c + b*d), (b*c - a*d))/(c*c + d*d) -func (v *Mpcplx) Div(rv *Mpcplx) bool { - if rv.Real.CmpFloat64(0) == 0 && rv.Imag.CmpFloat64(0) == 0 { - return false - } - - var ac, ad, bc, bd, cc_plus_dd Mpflt - - cc_plus_dd.Set(&rv.Real) - cc_plus_dd.Mul(&rv.Real) // cc - - ac.Set(&rv.Imag) - ac.Mul(&rv.Imag) // dd - cc_plus_dd.Add(&ac) // cc+dd - - // We already checked that c and d are not both zero, but we can't - // assume that c²+d² != 0 follows, because for tiny values of c - // and/or d c²+d² can underflow to zero. Check that c²+d² is - // nonzero, return if it's not. - if cc_plus_dd.CmpFloat64(0) == 0 { - return false - } - - ac.Set(&v.Real) - ac.Mul(&rv.Real) // ac - - bd.Set(&v.Imag) - bd.Mul(&rv.Imag) // bd - - bc.Set(&v.Imag) - bc.Mul(&rv.Real) // bc - - ad.Set(&v.Real) - ad.Mul(&rv.Imag) // ad - - v.Real.Set(&ac) - v.Real.Add(&bd) // ac+bd - v.Real.Quo(&cc_plus_dd) // (ac+bd)/(cc+dd) - - v.Imag.Set(&bc) - v.Imag.Sub(&ad) // bc-ad - v.Imag.Quo(&cc_plus_dd) // (bc+ad)/(cc+dd) - - return true -} - -func (v *Mpcplx) String() string { - return fmt.Sprintf("(%s+%si)", v.Real.String(), v.Imag.String()) -} - -func (v *Mpcplx) GoString() string { - var re string - sre := v.Real.CmpFloat64(0) - if sre != 0 { - re = v.Real.GoString() - } - - var im string - sim := v.Imag.CmpFloat64(0) - if sim != 0 { - im = v.Imag.GoString() - } - - switch { - case sre == 0 && sim == 0: - return "0" - case sre == 0: - return im + "i" - case sim == 0: - return re - case sim < 0: - return fmt.Sprintf("(%s%si)", re, im) - default: - return fmt.Sprintf("(%s+%si)", re, im) - } -} |
