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

package ld

import "cmd/link/internal/loader"

// Min-heap implementation, for the deadcode pass.
// Specialized for loader.Sym elements.

type heap []loader.Sym

func (h *heap) push(s loader.Sym) {
	*h = append(*h, s)
	// sift up
	n := len(*h) - 1
	for n > 0 {
		p := (n - 1) / 2 // parent

// license that can be found in the LICENSE file.

package ssa

// combine copyelim and phielim into a single pass.
// copyelim removes all uses of OpCopy values from f.
// A subsequent deadcode pass is needed to actually remove the copies.
func copyelim(f *Func) {
	phielim(f)

	// loop of copyelimValue(v) process has been done in phielim() pass.
	// Update block control values.
	for _, b := range f.Blocks {

		addlibpath(ctxt, "command line", "command line", flag.Arg(0), "main", "", zerofp)
	}
	bench.Start("loadlib")
	ctxt.loadlib()

	bench.Start("inittasks")
	ctxt.inittasks()

	bench.Start("deadcode")
	deadcode(ctxt)

	bench.Start("linksetup")
	ctxt.linksetup()

	bench.Start("dostrdata")
	ctxt.dostrdata()
	if buildcfg.Experiment.FieldTrack {
		bench.Start("fieldtrack")

	}
}

// TestMemProfileCheck tests that cmd/link sets
// runtime.disableMemoryProfiling if the runtime.MemProfile
// symbol is unreachable after deadcode (and not dynlinking).
// The runtime then uses that to set the default value of
// runtime.MemProfileRate, which this test checks.
func TestMemProfileCheck(t *testing.T) {
	testenv.MustHaveGoBuild(t)
	t.Parallel()

//    iff tpose(x) or tpose(y) has one use and have same permutation.
//
// Proof:
// WLOG, let tpose(x) have 1 use. Then ewise is the only user, and removing
// its use of tpose(x) will render tpose(x) deadcode. So in this case
// we both remove 1 and add 1 transpose to the graph thus the number remains
// unchanged.
class CommuteBothInputsTransposedWithEwiseOps : public RewritePattern {
 public:

	// the following optimization will do this.
	b.removeEdge(0)
	if s0 != b && len(s0.Preds) == 0 {
		s0.removeEdge(0)
		// Move any (dead) values in s0 to b,
		// where they will be eliminated by the next deadcode pass.
		for _, v := range s0.Values {
			v.Block = b
		}
		b.Values = append(b.Values, s0.Values...)
		// Clear s0.
		s0.Kind = BlockInvalid
		s0.Values = nil
		s0.Succs = nil
		s0.Preds = nil

				nerrors++
				return
			}

			// Mark exported symbols and also add them to
			// the lists used for roots in the deadcode pass.
			if f[0] == "cgo_export_static" {
				if ctxt.LinkMode == LinkExternal && !l.AttrCgoExportStatic(s) {
					// Static cgo exports appear
					// in the exported symbol table.

{"Action":"pass","Test":"TestVet/1"}
{"Action":"output","Test":"TestVet/7","Output":"    --- PASS: TestVet/7 (0.19s)\n"}
{"Action":"output","Test":"TestVet/7","Output":"        vet_test.go:114: files: [\"testdata/deadcode.go\" \"testdata/shift.go\"]\n"}
{"Action":"pass","Test":"TestVet/7"}
{"Action":"pass","Test":"TestVet"}
{"Action":"output","Test":"TestVetDirs","Output":"--- PASS: TestVetDirs (0.01s)\n"}

package ssa

import (
	"cmd/compile/internal/types"
	"cmd/internal/src"
	"fmt"
	"sort"
)

// cse does common-subexpression elimination on the Function.
// Values are just relinked, nothing is deleted. A subsequent deadcode
// pass is required to actually remove duplicate expressions.
func cse(f *Func) {
	// Two values are equivalent if they satisfy the following definition:
	// equivalent(v, w):
	//   v.op == w.op
	//   v.type == w.type

}

func TestVet(t *testing.T) {
	t.Parallel()
	for _, pkg := range []string{
		"appends",
		"asm",
		"assign",
		"atomic",
		"bool",
		"buildtag",
		"cgo",
		"composite",
		"copylock",
		"deadcode",
		"directive",
		"httpresponse",
		"lostcancel",
		"method",
		"nilfunc",
		"print",
		"shift",
		"slog",
		"structtag",
		"testingpkg",
		// "testtag" has its own test
		"unmarshal",