func decomposeSlicePhi(v *Value) {
	types := &v.Block.Func.Config.Types
	ptrType := v.Type.Elem().PtrTo()
	lenType := types.Int

	ptr := v.Block.NewValue0(v.Pos, OpPhi, ptrType)
	len := v.Block.NewValue0(v.Pos, OpPhi, lenType)
	cap := v.Block.NewValue0(v.Pos, OpPhi, lenType)
	for _, a := range v.Args {
		ptr.AddArg(a.Block.NewValue1(v.Pos, OpSlicePtr, ptrType, a))
		len.AddArg(a.Block.NewValue1(v.Pos, OpSliceLen, lenType, a))

		if ctl.Op == OpNot {
			swap = 1 ^ swap
		}
		ctl = ctl.Args[0]
		nval++ // wrapper around control value
	}
	if ctl.Op != OpPhi || ctl.Block != b || ctl.Uses != 1 {
		return false
	}
	nOtherPhi := 0
	for _, w := range b.Values {
		if w.Op == OpPhi && w != ctl {
			nOtherPhi++
		}
	}
	if nOtherPhi > 0 && len(b.Preds) != 2 {
		// We rely on b having exactly two preds in shortcircuitPhiPlan

		// the calculated store chain is good only for this block.
		for _, v := range b.Values {
			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

			}

			for i, arg := range v.Args {
				if arg == nil {
					f.Fatalf("value %s has nil arg", v.LongString())
				}
				if v.Op != OpPhi {
					// For non-Phi ops, memory args must be last, if present
					if arg.Type.IsMemory() && i != len(v.Args)-1 {
						f.Fatalf("value %s has non-final memory arg (%d < %d)", v.LongString(), i, len(v.Args)-1)
					}

	// looks profitable.

	// Check that there are Phis, and that all of them
	// can be safely rewritten to CondSelect.
	hasphis := false
	for _, v := range post.Values {
		if v.Op == OpPhi {
			hasphis = true
			if !canCondSelect(v, f.Config.arch, loadAddr) {
				return false
			}
		}
	}
	if !hasphis {
		return false
	}

	// Pick some upper bound for the number of instructions

		e := emc.e
		h := e.b

		// find the phi function for the memory input at "h", if there is one.
		var headerMemPhi *Value // look for header mem phi

		for _, v := range h.Values {
			if v.Op == OpPhi && v.Type.IsMemory() {
				headerMemPhi = v
			}
		}

		if headerMemPhi == nil {
			// if the header is nil, make a trivial phi from the dominator
			mem0 := memDefsAtBlockEnds[idom[h.ID].ID]

	s.resolveFwdRefs()

	// Erase variable numbers stored in AuxInt fields of phi ops. They are no longer needed.
	for _, b := range s.f.Blocks {
		for _, v := range b.Values {
			if v.Op == ssa.OpPhi {
				v.AuxInt = 0
			}
			// Any remaining FwdRefs are dead code.
			if v.Op == ssa.OpFwdRef {
				v.Op = ssa.OpUnknown
				v.Aux = nil
			}
		}
	}
}

		for k := range localAddrs {
			delete(localAddrs, k)
		}
		stores = stores[:0]
		for _, v := range b.Values {
			if v.Op == OpPhi {
				// Ignore phis - they will always be first and can't be eliminated
				continue
			}
			if v.Type.IsMemory() {
				stores = append(stores, v)
				for _, a := range v.Args {

				dest := edge.b
				destVisited := t.visitedBlock[dest.ID]

				// mark edge as visited
				t.visited[edge] = true
				t.visitedBlock[dest.ID] = true
				for _, val := range dest.Values {
					if val.Op == OpPhi || !destVisited {
						t.visitValue(val)
					}
				}
				// propagates constants facts through CFG, taking condition test
				// into account
				if !destVisited {
					t.propagate(dest)
				}
			}

			Goto("checkPtr")),
		Bloc("b2",
			Valu("ptr2", OpAddr, ptrType, 0, nil, "sb"),
			Goto("checkPtr")),
		// both ptr1 and ptr2 are guaranteed non-nil here
		Bloc("checkPtr",
			Valu("phi", OpPhi, ptrType, 0, nil, "ptr1", "ptr2"),
			Valu("bool2", OpIsNonNil, c.config.Types.Bool, 0, nil, "phi"),
			If("bool2", "extra", "exit")),
		Bloc("extra",
			Goto("exit")),
		Bloc("exit",
			Exit("mem")))