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Diffstat (limited to 'src/cmd/compile/internal/gc/mpint.go')
| -rw-r--r-- | src/cmd/compile/internal/gc/mpint.go | 304 |
1 files changed, 0 insertions, 304 deletions
diff --git a/src/cmd/compile/internal/gc/mpint.go b/src/cmd/compile/internal/gc/mpint.go deleted file mode 100644 index 340350bca7..0000000000 --- a/src/cmd/compile/internal/gc/mpint.go +++ /dev/null @@ -1,304 +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/big" -) - -// implements integer arithmetic - -// Mpint represents an integer constant. -type Mpint struct { - Val big.Int - Ovf bool // set if Val overflowed compiler limit (sticky) - Rune bool // set if syntax indicates default type rune -} - -func (a *Mpint) SetOverflow() { - a.Val.SetUint64(1) // avoid spurious div-zero errors - a.Ovf = true -} - -func (a *Mpint) checkOverflow(extra int) bool { - // We don't need to be precise here, any reasonable upper limit would do. - // For now, use existing limit so we pass all the tests unchanged. - if a.Val.BitLen()+extra > Mpprec { - a.SetOverflow() - } - return a.Ovf -} - -func (a *Mpint) Set(b *Mpint) { - a.Val.Set(&b.Val) -} - -func (a *Mpint) SetFloat(b *Mpflt) bool { - // avoid converting huge floating-point numbers to integers - // (2*Mpprec is large enough to permit all tests to pass) - if b.Val.MantExp(nil) > 2*Mpprec { - a.SetOverflow() - return false - } - - if _, acc := b.Val.Int(&a.Val); acc == big.Exact { - return true - } - - const delta = 16 // a reasonably small number of bits > 0 - var t big.Float - t.SetPrec(Mpprec - delta) - - // try rounding down a little - t.SetMode(big.ToZero) - t.Set(&b.Val) - if _, acc := t.Int(&a.Val); acc == big.Exact { - return true - } - - // try rounding up a little - t.SetMode(big.AwayFromZero) - t.Set(&b.Val) - if _, acc := t.Int(&a.Val); acc == big.Exact { - return true - } - - a.Ovf = false - return false -} - -func (a *Mpint) Add(b *Mpint) { - if a.Ovf || b.Ovf { - if nsavederrors+nerrors == 0 { - Fatalf("ovf in Mpint Add") - } - a.SetOverflow() - return - } - - a.Val.Add(&a.Val, &b.Val) - - if a.checkOverflow(0) { - yyerror("constant addition overflow") - } -} - -func (a *Mpint) Sub(b *Mpint) { - if a.Ovf || b.Ovf { - if nsavederrors+nerrors == 0 { - Fatalf("ovf in Mpint Sub") - } - a.SetOverflow() - return - } - - a.Val.Sub(&a.Val, &b.Val) - - if a.checkOverflow(0) { - yyerror("constant subtraction overflow") - } -} - -func (a *Mpint) Mul(b *Mpint) { - if a.Ovf || b.Ovf { - if nsavederrors+nerrors == 0 { - Fatalf("ovf in Mpint Mul") - } - a.SetOverflow() - return - } - - a.Val.Mul(&a.Val, &b.Val) - - if a.checkOverflow(0) { - yyerror("constant multiplication overflow") - } -} - -func (a *Mpint) Quo(b *Mpint) { - if a.Ovf || b.Ovf { - if nsavederrors+nerrors == 0 { - Fatalf("ovf in Mpint Quo") - } - a.SetOverflow() - return - } - - a.Val.Quo(&a.Val, &b.Val) - - if a.checkOverflow(0) { - // can only happen for div-0 which should be checked elsewhere - yyerror("constant division overflow") - } -} - -func (a *Mpint) Rem(b *Mpint) { - if a.Ovf || b.Ovf { - if nsavederrors+nerrors == 0 { - Fatalf("ovf in Mpint Rem") - } - a.SetOverflow() - return - } - - a.Val.Rem(&a.Val, &b.Val) - - if a.checkOverflow(0) { - // should never happen - yyerror("constant modulo overflow") - } -} - -func (a *Mpint) Or(b *Mpint) { - if a.Ovf || b.Ovf { - if nsavederrors+nerrors == 0 { - Fatalf("ovf in Mpint Or") - } - a.SetOverflow() - return - } - - a.Val.Or(&a.Val, &b.Val) -} - -func (a *Mpint) And(b *Mpint) { - if a.Ovf || b.Ovf { - if nsavederrors+nerrors == 0 { - Fatalf("ovf in Mpint And") - } - a.SetOverflow() - return - } - - a.Val.And(&a.Val, &b.Val) -} - -func (a *Mpint) AndNot(b *Mpint) { - if a.Ovf || b.Ovf { - if nsavederrors+nerrors == 0 { - Fatalf("ovf in Mpint AndNot") - } - a.SetOverflow() - return - } - - a.Val.AndNot(&a.Val, &b.Val) -} - -func (a *Mpint) Xor(b *Mpint) { - if a.Ovf || b.Ovf { - if nsavederrors+nerrors == 0 { - Fatalf("ovf in Mpint Xor") - } - a.SetOverflow() - return - } - - a.Val.Xor(&a.Val, &b.Val) -} - -func (a *Mpint) Lsh(b *Mpint) { - if a.Ovf || b.Ovf { - if nsavederrors+nerrors == 0 { - Fatalf("ovf in Mpint Lsh") - } - a.SetOverflow() - return - } - - s := b.Int64() - if s < 0 || s >= Mpprec { - msg := "shift count too large" - if s < 0 { - msg = "invalid negative shift count" - } - yyerror("%s: %d", msg, s) - a.SetInt64(0) - return - } - - if a.checkOverflow(int(s)) { - yyerror("constant shift overflow") - return - } - a.Val.Lsh(&a.Val, uint(s)) -} - -func (a *Mpint) Rsh(b *Mpint) { - if a.Ovf || b.Ovf { - if nsavederrors+nerrors == 0 { - Fatalf("ovf in Mpint Rsh") - } - a.SetOverflow() - return - } - - s := b.Int64() - if s < 0 { - yyerror("invalid negative shift count: %d", s) - if a.Val.Sign() < 0 { - a.SetInt64(-1) - } else { - a.SetInt64(0) - } - return - } - - a.Val.Rsh(&a.Val, uint(s)) -} - -func (a *Mpint) Cmp(b *Mpint) int { - return a.Val.Cmp(&b.Val) -} - -func (a *Mpint) CmpInt64(c int64) int { - if c == 0 { - return a.Val.Sign() // common case shortcut - } - return a.Val.Cmp(big.NewInt(c)) -} - -func (a *Mpint) Neg() { - a.Val.Neg(&a.Val) -} - -func (a *Mpint) Int64() int64 { - if a.Ovf { - if nsavederrors+nerrors == 0 { - Fatalf("constant overflow") - } - return 0 - } - - return a.Val.Int64() -} - -func (a *Mpint) SetInt64(c int64) { - a.Val.SetInt64(c) -} - -func (a *Mpint) SetString(as string) { - _, ok := a.Val.SetString(as, 0) - if !ok { - // The lexer checks for correct syntax of the literal - // and reports detailed errors. Thus SetString should - // never fail (in theory it might run out of memory, - // but that wouldn't be reported as an error here). - Fatalf("malformed integer constant: %s", as) - return - } - if a.checkOverflow(0) { - yyerror("constant too large: %s", as) - } -} - -func (a *Mpint) GoString() string { - return a.Val.String() -} - -func (a *Mpint) String() string { - return fmt.Sprintf("%#x", &a.Val) -} |