for i, a := range v.Args {
				if !a.rematerializeable() {
					continue // not a constant we can move around
				}
				if a.Block == b.Preds[i].b {
					continue // already in the right place
				}
				// Make a copy of a, put in predecessor block.
				v.SetArg(i, a.copyInto(b.Preds[i].b))
			}
		}
	}
}

// memState computes the memory state at the beginning and end of each block of

				v.Pos = firstPos.WithDefaultStmt() // default to default
				break
			}
		}

		if firstPosIndex == -1 { // Effectively empty block, check block's own Pos, consider preds.
			line := src.NoXPos
			for _, p := range b.Preds {
				pbi := p.Block().ID
				if !endlines[pbi].SameFileAndLine(line) {
					if line == src.NoXPos {
						line = endlines[pbi]
						continue
					} else {
						line = src.NoXPos

		}
	}

	// Initialize indegree of each block
	for _, b := range f.Blocks {
		if exit.contains(b.ID) {
			// exit blocks are always scheduled last
			continue
		}
		indegree[b.ID] = len(b.Preds)
		if len(b.Preds) == 0 {
			// Push an element to the tail of the queue.
			zerodegree = append(zerodegree, b.ID)
		} else {
			posdegree.add(b.ID)
		}
	}

	bid := f.Entry.ID
blockloop:
	for {

		// blocks.  Therefore remove unchanged blocks from the
		// predecessor list.
		for i := len(preds) - 1; i >= 0; i-- {
			pred := preds[i]
			if blockLocs[pred.ID].lastChangedTime > locs.lastCheckedTime {
				continue // keep this predecessor
			}
			preds[i] = preds[len(preds)-1]
			preds = preds[:len(preds)-1]
			if state.loggingLevel > 2 {

	return order
}

type linkedBlocks func(*Block) []Edge

func dominators(f *Func) []*Block {
	preds := func(b *Block) []Edge { return b.Preds }
	succs := func(b *Block) []Edge { return b.Succs }

	//TODO: benchmark and try to find criteria for swapping between
	// dominatorsSimple and dominatorsLT
	return f.dominatorsLTOrig(f.Entry, preds, succs)
}

// dominatorsLTOrig runs Lengauer-Tarjan to compute a dominator tree starting at

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package j

func f(try func() int, shouldInc func() bool, N func(int) int) {
	var n int
loop: // we want to have 3 preds here, the function entry and both gotos
	if v := try(); v == 42 || v == 1337 { // the two || are to trick findIndVar
		if n < 30 { // this aims to be the matched block
			if shouldInc() {
				n++
				goto loop
			}

		mem1 := sched.NewValue1I(bb.Pos, OpSelectN, types.TypeMem, 0, call)
		sched.AddEdgeTo(h)
		headerMemPhi.AddArg(mem1)

		bb.Succs[p.i] = Edge{test, 0}
		test.Preds = append(test.Preds, Edge{bb, p.i})

		// Must correct all the other phi functions in the header for new incoming edge.
		// Except for mem phis, it will be the same value seen on the original
		// backedge at index i.

}

func (p stringFuncPrinter) startBlock(b *Block, reachable bool) {
	if !p.printDead && !reachable {
		return
	}
	fmt.Fprintf(p.w, "  b%d:", b.ID)
	if len(b.Preds) > 0 {
		io.WriteString(p.w, " <-")
		for _, e := range b.Preds {
			pred := e.b
			fmt.Fprintf(p.w, " b%d", pred.ID)
		}
	}
	if !reachable {
		fmt.Fprint(p.w, " DEAD")
	}
	io.WriteString(p.w, "\n")
}

//	 \
//	  b
//	 / \
//	s0 s1
//
// where b has the combined control value 'unsigned(x-1) < 4'.
// Later passes will then fuse p and b.
func fuseIntegerComparisons(b *Block) bool {
	if len(b.Preds) != 1 {
		return false
	}
	p := b.Preds[0].Block()
	if b.Kind != BlockIf || p.Kind != BlockIf {
		return false
	}

	// Don't merge control values if b is likely to be bypassed anyway.

		for _, v := range b.Values {
			if v.Op != ssa.OpFwdRef {
				continue
			}
			var_ := v.Aux.(fwdRefAux).N

			// Optimization: look back 1 block for the definition.
			if len(b.Preds) == 1 {
				c := b.Preds[0].Block()
				if w := s.defvars[c.ID][var_]; w != nil {
					v.Op = ssa.OpCopy
					v.Aux = nil
					v.AddArg(w)
					continue
				}
			}

			if _, ok := s.varnum[var_]; ok {