diff options
Diffstat (limited to 'src/cmd/compile/internal/ssagen/ssa.go')
| -rw-r--r-- | src/cmd/compile/internal/ssagen/ssa.go | 29 |
1 files changed, 22 insertions, 7 deletions
diff --git a/src/cmd/compile/internal/ssagen/ssa.go b/src/cmd/compile/internal/ssagen/ssa.go index 1e7eda94fc..346a801508 100644 --- a/src/cmd/compile/internal/ssagen/ssa.go +++ b/src/cmd/compile/internal/ssagen/ssa.go @@ -1696,9 +1696,11 @@ func (s *state) stmt(n ir.Node) { case ir.OTAILCALL: n := n.(*ir.TailCallStmt) - b := s.exit() - b.Kind = ssa.BlockRetJmp // override BlockRet - b.Aux = callTargetLSym(n.Target) + s.callResult(n.Call, callTail) + call := s.mem() + b := s.endBlock() + b.Kind = ssa.BlockRetJmp // could use BlockExit. BlockRetJmp is mostly for clarity. + b.SetControl(call) case ir.OCONTINUE, ir.OBREAK: n := n.(*ir.BranchStmt) @@ -3645,6 +3647,7 @@ const ( callDefer callDeferStack callGo + callTail ) type sfRtCallDef struct { @@ -4911,13 +4914,13 @@ func (s *state) call(n *ir.CallExpr, k callKind, returnResultAddr bool) *ssa.Val } } - if k != callNormal && (len(n.Args) != 0 || n.Op() == ir.OCALLINTER || n.X.Type().NumResults() != 0) { + if k != callNormal && k != callTail && (len(n.Args) != 0 || n.Op() == ir.OCALLINTER || n.X.Type().NumResults() != 0) { s.Fatalf("go/defer call with arguments: %v", n) } switch n.Op() { case ir.OCALLFUNC: - if k == callNormal && fn.Op() == ir.ONAME && fn.(*ir.Name).Class == ir.PFUNC { + if (k == callNormal || k == callTail) && fn.Op() == ir.ONAME && fn.(*ir.Name).Class == ir.PFUNC { fn := fn.(*ir.Name) callee = fn if buildcfg.Experiment.RegabiArgs { @@ -4971,7 +4974,7 @@ func (s *state) call(n *ir.CallExpr, k callKind, returnResultAddr bool) *ssa.Val stksize := params.ArgWidth() // includes receiver, args, and results res := n.X.Type().Results() - if k == callNormal { + if k == callNormal || k == callTail { for _, p := range params.OutParams() { ACResults = append(ACResults, p.Type) } @@ -5018,7 +5021,7 @@ func (s *state) call(n *ir.CallExpr, k callKind, returnResultAddr bool) *ssa.Val // These are written in SP-offset order. argStart := base.Ctxt.FixedFrameSize() // Defer/go args. - if k != callNormal { + if k != callNormal && k != callTail { // Write closure (arg to newproc/deferproc). ACArgs = append(ACArgs, types.Types[types.TUINTPTR]) // not argExtra callArgs = append(callArgs, closure) @@ -5068,6 +5071,10 @@ func (s *state) call(n *ir.CallExpr, k callKind, returnResultAddr bool) *ssa.Val case callee != nil: aux := ssa.StaticAuxCall(callTargetLSym(callee), params) call = s.newValue0A(ssa.OpStaticLECall, aux.LateExpansionResultType(), aux) + if k == callTail { + call.Op = ssa.OpTailLECall + stksize = 0 // Tail call does not use stack. We reuse caller's frame. + } default: s.Fatalf("bad call type %v %v", n.Op(), n) } @@ -7399,6 +7406,14 @@ func (s *State) Call(v *ssa.Value) *obj.Prog { return p } +// TailCall returns a new tail call instruction for the SSA value v. +// It is like Call, but for a tail call. +func (s *State) TailCall(v *ssa.Value) *obj.Prog { + p := s.Call(v) + p.As = obj.ARET + return p +} + // PrepareCall prepares to emit a CALL instruction for v and does call-related bookkeeping. // It must be called immediately before emitting the actual CALL instruction, // since it emits PCDATA for the stack map at the call (calls are safe points). |