"runtime.wasmTruncS":      {Params: []byte{F64}, Results: []byte{I64}},                // x -> int(x)
	"runtime.wasmTruncU":      {Params: []byte{F64}, Results: []byte{I64}},                // x -> uint(x)
	"gcWriteBarrier":          {Params: []byte{I64}, Results: []byte{I64}},                // #bytes -> bufptr
	"runtime.gcWriteBarrier1": {Results: []byte{I64}},                                     // -> bufptr

		}

	case ssa.OpWasmLoweredWB:
		p := s.Prog(wasm.ACall)
		// AuxInt encodes how many buffer entries we need.
		p.To = obj.Addr{Type: obj.TYPE_MEM, Name: obj.NAME_EXTERN, Sym: ir.Syms.GCWriteBarrier[v.AuxInt-1]}
		setReg(s, v.Reg0()) // move result from wasm stack to register local

	case ssa.OpWasmI64Store8, ssa.OpWasmI64Store16, ssa.OpWasmI64Store32, ssa.OpWasmI64Store, ssa.OpWasmF32Store, ssa.OpWasmF64Store:

		// the result should be the PC within f that g will return to.
		// See runtime/stubs.go for a more detailed discussion.
		{name: "LoweredGetCallerPC", reg: gp01, rematerializeable: true},

		// LoweredWB invokes runtime.gcWriteBarrier. arg0=mem, auxint=# of buffer entries needed
		// It saves all GP registers if necessary,
		// but clobbers R31 (LR) because it's a call
		// and R23 (REGTMP).
		// Returns a pointer to a write barrier buffer in R25.

		// the result should be the PC within f that g will return to.
		// See runtime/stubs.go for a more detailed discussion.
		{name: "LoweredGetCallerPC", reg: gp01, rematerializeable: true},

		// LoweredWB invokes runtime.gcWriteBarrier. arg0=mem, auxint=# of buffer entries needed
		// It saves all GP registers if necessary,
		// but clobbers R1 (LR) because it's a call
		// and R30 (REGTMP).
		// Returns a pointer to a write barrier buffer in R29.

		// the result should be the PC within f that g will return to.
		// See runtime/stubs.go for a more detailed discussion.
		{name: "LoweredGetCallerPC", reg: gp01, rematerializeable: true},

		// LoweredWB invokes runtime.gcWriteBarrier. arg0=mem, auxint=# of buffer entries needed
		// It saves all GP registers if necessary,
		// but clobbers R31 (LR) because it's a call
		// and R23 (REGTMP).
		// Returns a pointer to a write barrier buffer in R25.

		return
	}

	// Number of write buffer entries we can request at once.
	// Must match runtime/mwbbuf.go:wbMaxEntriesPerCall.
	// It must also match the number of instances of runtime.gcWriteBarrier{X}.
	const maxEntries = 8

	var sb, sp, wbaddr, const0 *Value
	var cgoCheckPtrWrite, cgoCheckMemmove *obj.LSym
	var wbZero, wbMove *obj.LSym
	var stores, after []*Value
	var sset, sset2 *sparseSet

		// the result should be the PC within f that g will return to.
		// See runtime/stubs.go for a more detailed discussion.
		{name: "LoweredGetCallerPC", reg: gp01, rematerializeable: true},

		// LoweredWB invokes runtime.gcWriteBarrier. arg0=mem, auxint=# of buffer entries needed
		// It saves all GP registers if necessary,
		// but clobbers RA (LR) because it's a call
		// and T6 (REG_TMP).
		// Returns a pointer to a write barrier buffer in X24.

		p.To.Reg = v.Reg()

	case ssa.Op386LoweredWB:
		p := s.Prog(obj.ACALL)
		p.To.Type = obj.TYPE_MEM
		p.To.Name = obj.NAME_EXTERN
		// AuxInt encodes how many buffer entries we need.
		p.To.Sym = ir.Syms.GCWriteBarrier[v.AuxInt-1]

	case ssa.Op386LoweredPanicBoundsA, ssa.Op386LoweredPanicBoundsB, ssa.Op386LoweredPanicBoundsC:
		p := s.Prog(obj.ACALL)
		p.To.Type = obj.TYPE_MEM
		p.To.Name = obj.NAME_EXTERN

		s.TailCall(v)
	case ssa.OpS390XLoweredWB:
		p := s.Prog(obj.ACALL)
		p.To.Type = obj.TYPE_MEM
		p.To.Name = obj.NAME_EXTERN
		// AuxInt encodes how many buffer entries we need.
		p.To.Sym = ir.Syms.GCWriteBarrier[v.AuxInt-1]
	case ssa.OpS390XLoweredPanicBoundsA, ssa.OpS390XLoweredPanicBoundsB, ssa.OpS390XLoweredPanicBoundsC:
		p := s.Prog(obj.ACALL)
		p.To.Type = obj.TYPE_MEM
		p.To.Name = obj.NAME_EXTERN

	ir.Syms.Duffzero = typecheck.LookupRuntimeFunc("duffzero")
	ir.Syms.GCWriteBarrier[0] = typecheck.LookupRuntimeFunc("gcWriteBarrier1")
	ir.Syms.GCWriteBarrier[1] = typecheck.LookupRuntimeFunc("gcWriteBarrier2")
	ir.Syms.GCWriteBarrier[2] = typecheck.LookupRuntimeFunc("gcWriteBarrier3")
	ir.Syms.GCWriteBarrier[3] = typecheck.LookupRuntimeFunc("gcWriteBarrier4")
	ir.Syms.GCWriteBarrier[4] = typecheck.LookupRuntimeFunc("gcWriteBarrier5")