// operation not covered above then we probably need to keep it.
		// We also need to keep autos if they reach Phis (issue #26153).
		if v.Type.IsMemory() || v.Type.IsFlags() || v.Op == OpPhi || v.MemoryArg() != nil {
			for _, a := range args {
				if n, ok := addr[a]; ok {
					if !used.Has(n) {
						used.Add(n)
						changed = true
					}
				}
			}
			return
		}

			if v.Op != OpPhi && v.Op != OpInitMem && v.Type.IsMemory() {
				nextMem[v.MemoryArg().ID] = v
			}
		}

		// Add edges to enforce that any load must come before the following store.
		for _, v := range b.Values {
			if v.Op == OpPhi || v.Type.IsMemory() {
				continue
			}
			w := v.MemoryArg()
			if w == nil {
				continue
			}
			if s := nextMem[w.ID]; s != nil && s.Block == b {

	}
	return reg.(*Register).name
}

// MemoryArg returns the memory argument for the Value.
// The returned value, if non-nil, will be memory-typed (or a tuple with a memory-typed second part).
// Otherwise, nil is returned.
func (v *Value) MemoryArg() *Value {
	if v.Op == OpPhi {
		v.Fatalf("MemoryArg on Phi")
	}
	na := len(v.Args)
	if na == 0 {
		return nil
	}

		// ops that generate memory values.
		ss.clear()
		for _, v := range b.Values {
			if v.Op == OpPhi || !v.Type.IsMemory() {
				continue
			}
			if m := v.MemoryArg(); m != nil {
				ss.add(m.ID)
			}
		}
		// There should be at most one remaining unoverwritten memory value.
		for _, v := range b.Values {
			if !v.Type.IsMemory() {
				continue
			}

			//    m2 = store operation ... m1
			//    m3 = store operation ... m2
			//    m4 = WBend m3

			// Find first memory op in the block, which should be a Phi.
			m := v
			for {
				m = m.MemoryArg()
				if m.Block != b {
					lv.f.Fatalf("can't find Phi before write barrier end mark %v", v)
				}
				if m.Op == ssa.OpPhi {
					break
				}
			}

		return false
	}

	// We can't merge the load into the target if the load
	// has more than one use.
	if load.Uses != 1 {
		return false
	}

	mem := load.MemoryArg()

	// We need the load's memory arg to still be alive at target. That
	// can't be the case if one of target's args depends on a memory
	// state that is a successor of load's memory arg.
	//