diff options
Diffstat (limited to 'src/cmd/compile/internal/walk/assign.go')
| -rw-r--r-- | src/cmd/compile/internal/walk/assign.go | 55 |
1 files changed, 18 insertions, 37 deletions
diff --git a/src/cmd/compile/internal/walk/assign.go b/src/cmd/compile/internal/walk/assign.go index 3fe810ac4e..6e8075a35f 100644 --- a/src/cmd/compile/internal/walk/assign.go +++ b/src/cmd/compile/internal/walk/assign.go @@ -248,18 +248,6 @@ func walkReturn(n *ir.ReturnStmt) ir.Node { return n } -// fncall reports whether assigning an rvalue of type rt to an lvalue l might involve a function call. -func fncall(l ir.Node, rt *types.Type) bool { - if l.HasCall() || l.Op() == ir.OINDEXMAP { - return true - } - if types.Identical(l.Type(), rt) { - return false - } - // There might be a conversion required, which might involve a runtime call. - return true -} - // check assign type list to // an expression list. called in // expr-list = func() @@ -268,21 +256,17 @@ func ascompatet(nl ir.Nodes, nr *types.Type) []ir.Node { base.Fatalf("ascompatet: assignment count mismatch: %d = %d", len(nl), nr.NumFields()) } - var nn, mm ir.Nodes + var nn ir.Nodes for i, l := range nl { if ir.IsBlank(l) { continue } r := nr.Field(i) - // Any assignment to an lvalue that might cause a function call must be - // deferred until all the returned values have been read. - if fncall(l, r.Type) { - tmp := ir.Node(typecheck.Temp(r.Type)) - tmp = typecheck.Expr(tmp) - a := convas(ir.NewAssignStmt(base.Pos, l, tmp), &mm) - mm.Append(a) - l = tmp + // Order should have created autotemps of the appropriate type for + // us to store results into. + if tmp, ok := l.(*ir.Name); !ok || !tmp.AutoTemp() || !types.Identical(tmp.Type(), r.Type) { + base.FatalfAt(l.Pos(), "assigning %v to %+v", r.Type, l) } res := ir.NewResultExpr(base.Pos, nil, types.BADWIDTH) @@ -290,16 +274,9 @@ func ascompatet(nl ir.Nodes, nr *types.Type) []ir.Node { res.SetType(r.Type) res.SetTypecheck(1) - a := convas(ir.NewAssignStmt(base.Pos, l, res), &nn) - updateHasCall(a) - if a.HasCall() { - ir.Dump("ascompatet ucount", a) - base.Fatalf("ascompatet: too many function calls evaluating parameters") - } - - nn.Append(a) + nn.Append(ir.NewAssignStmt(base.Pos, l, res)) } - return append(nn, mm...) + return nn } // check assign expression list to @@ -392,11 +369,7 @@ func ascompatee(op ir.Op, nl, nr []ir.Node) []ir.Node { appendWalkStmt(&late, convas(ir.NewAssignStmt(base.Pos, lorig, r), &late)) - if name == nil || name.Addrtaken() || name.Class == ir.PEXTERN || name.Class == ir.PAUTOHEAP { - memWrite = true - continue - } - if ir.IsBlank(name) { + if name != nil && ir.IsBlank(name) { // We can ignore assignments to blank. continue } @@ -405,7 +378,12 @@ func ascompatee(op ir.Op, nl, nr []ir.Node) []ir.Node { // parameters. These can't appear in expressions anyway. continue } - assigned.Add(name) + + if name != nil && name.OnStack() && !name.Addrtaken() { + assigned.Add(name) + } else { + memWrite = true + } } early.Append(late.Take()...) @@ -418,7 +396,10 @@ func readsMemory(n ir.Node) bool { switch n.Op() { case ir.ONAME: n := n.(*ir.Name) - return n.Class == ir.PEXTERN || n.Class == ir.PAUTOHEAP || n.Addrtaken() + if n.Class == ir.PFUNC { + return false + } + return n.Addrtaken() || !n.OnStack() case ir.OADD, ir.OAND, |