diff options
| -rw-r--r-- | src/cmd/compile/internal/gc/order.go | 40 | ||||
| -rw-r--r-- | src/cmd/compile/internal/gc/ssa.go | 24 | ||||
| -rw-r--r-- | test/checkbce.go | 4 | ||||
| -rw-r--r-- | test/fixedbugs/issue30566a.go | 23 | ||||
| -rw-r--r-- | test/fixedbugs/issue30566b.go | 27 | ||||
| -rw-r--r-- | test/live.go | 9 |
6 files changed, 104 insertions, 23 deletions
diff --git a/src/cmd/compile/internal/gc/order.go b/src/cmd/compile/internal/gc/order.go index 4848a02bb6..0098242c79 100644 --- a/src/cmd/compile/internal/gc/order.go +++ b/src/cmd/compile/internal/gc/order.go @@ -1130,14 +1130,40 @@ func (o *Order) expr(n, lhs *Node) *Node { } case OANDAND, OOROR: - mark := o.markTemp() - n.Left = o.expr(n.Left, nil) + // ... = LHS && RHS + // + // var r bool + // r = LHS + // if r { // or !r, for OROR + // r = RHS + // } + // ... = r + + r := o.newTemp(n.Type, false) + + // Evaluate left-hand side. + lhs := o.expr(n.Left, nil) + o.out = append(o.out, typecheck(nod(OAS, r, lhs), ctxStmt)) + + // Evaluate right-hand side, save generated code. + saveout := o.out + o.out = nil + t := o.markTemp() + rhs := o.expr(n.Right, nil) + o.out = append(o.out, typecheck(nod(OAS, r, rhs), ctxStmt)) + o.cleanTemp(t) + gen := o.out + o.out = saveout - // Clean temporaries from first branch at beginning of second. - // Leave them on the stack so that they can be killed in the outer - // context in case the short circuit is taken. - n.Right = addinit(n.Right, o.cleanTempNoPop(mark)) - n.Right = o.exprInPlace(n.Right) + // If left-hand side doesn't cause a short-circuit, issue right-hand side. + nif := nod(OIF, r, nil) + if n.Op == OANDAND { + nif.Nbody.Set(gen) + } else { + nif.Rlist.Set(gen) + } + o.out = append(o.out, nif) + n = r case OCALLFUNC, OCALLINTER, diff --git a/src/cmd/compile/internal/gc/ssa.go b/src/cmd/compile/internal/gc/ssa.go index 95904edd6a..e03988dac2 100644 --- a/src/cmd/compile/internal/gc/ssa.go +++ b/src/cmd/compile/internal/gc/ssa.go @@ -994,26 +994,32 @@ func (s *state) stmt(n *Node) { s.assign(n.Left, r, deref, skip) case OIF: - bThen := s.f.NewBlock(ssa.BlockPlain) bEnd := s.f.NewBlock(ssa.BlockPlain) - var bElse *ssa.Block var likely int8 if n.Likely() { likely = 1 } + var bThen *ssa.Block + if n.Nbody.Len() != 0 { + bThen = s.f.NewBlock(ssa.BlockPlain) + } else { + bThen = bEnd + } + var bElse *ssa.Block if n.Rlist.Len() != 0 { bElse = s.f.NewBlock(ssa.BlockPlain) - s.condBranch(n.Left, bThen, bElse, likely) } else { - s.condBranch(n.Left, bThen, bEnd, likely) + bElse = bEnd } + s.condBranch(n.Left, bThen, bElse, likely) - s.startBlock(bThen) - s.stmtList(n.Nbody) - if b := s.endBlock(); b != nil { - b.AddEdgeTo(bEnd) + if n.Nbody.Len() != 0 { + s.startBlock(bThen) + s.stmtList(n.Nbody) + if b := s.endBlock(); b != nil { + b.AddEdgeTo(bEnd) + } } - if n.Rlist.Len() != 0 { s.startBlock(bElse) s.stmtList(n.Rlist) diff --git a/test/checkbce.go b/test/checkbce.go index a8f060aa72..6a126099bc 100644 --- a/test/checkbce.go +++ b/test/checkbce.go @@ -33,9 +33,7 @@ func f1(a [256]int, i int) { if 4 <= i && i < len(a) { useInt(a[i]) - useInt(a[i-1]) // ERROR "Found IsInBounds$" - // TODO: 'if 4 <= i && i < len(a)' gets rewritten to 'if uint(i - 4) < 256 - 4', - // which the bounds checker cannot yet use to infer that the next line doesn't need a bounds check. + useInt(a[i-1]) useInt(a[i-4]) } } diff --git a/test/fixedbugs/issue30566a.go b/test/fixedbugs/issue30566a.go new file mode 100644 index 0000000000..5d736ccd0d --- /dev/null +++ b/test/fixedbugs/issue30566a.go @@ -0,0 +1,23 @@ +// run + +// Copyright 2019 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 main + +import "fmt" + +//go:noinline +func ident(s string) string { return s } + +func returnSecond(x bool, s string) string { return s } + +func identWrapper(s string) string { return ident(s) } + +func main() { + got := returnSecond((false || identWrapper("bad") != ""), ident("good")) + if got != "good" { + panic(fmt.Sprintf("wanted \"good\", got \"%s\"", got)) + } +} diff --git a/test/fixedbugs/issue30566b.go b/test/fixedbugs/issue30566b.go new file mode 100644 index 0000000000..92e064436d --- /dev/null +++ b/test/fixedbugs/issue30566b.go @@ -0,0 +1,27 @@ +// run + +// Copyright 2019 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 main + +import ( + "bytes" + "fmt" +) + +func main() { + _, _ = false || g(1), g(2) + if !bytes.Equal(x, []byte{1, 2}) { + panic(fmt.Sprintf("wanted [1,2], got %v", x)) + } +} + +var x []byte + +//go:noinline +func g(b byte) bool { + x = append(x, b) + return false +} diff --git a/test/live.go b/test/live.go index a508947afc..e7134eca0c 100644 --- a/test/live.go +++ b/test/live.go @@ -572,7 +572,7 @@ func f36() { func f37() { if (m33[byteptr()] == 0 || // ERROR "stack object .autotmp_[0-9]+ interface \{\}" m33[byteptr()] == 0) && // ERROR "stack object .autotmp_[0-9]+ interface \{\}" - m33[byteptr()] == 0 { // ERROR "stack object .autotmp_[0-9]+ interface \{\}" + m33[byteptr()] == 0 { printnl() return } @@ -697,9 +697,10 @@ func f41(p, q *int) (r *int) { // ERROR "live at entry to f41: p q$" func f42() { var p, q, r int - f43([]*int{&p,&q,&r}) // ERROR "stack object .autotmp_[0-9]+ \[3\]\*int$" - f43([]*int{&p,&r,&q}) - f43([]*int{&q,&p,&r}) + f43([]*int{&p, &q, &r}) // ERROR "stack object .autotmp_[0-9]+ \[3\]\*int$" + f43([]*int{&p, &r, &q}) + f43([]*int{&q, &p, &r}) } + //go:noescape func f43(a []*int) |