}
	}

	// Force benchmarks to run in serial.
	if !testC && (testBench != "") {
		// The first run must wait for all builds.
		// Later runs must wait for the previous run's print.
		for i, run := range runs {
			if i == 0 {
				run.Deps = append(run.Deps, builds...)
			} else {
				run.Deps = append(run.Deps, prints[i-1])
			}
		}
	}

	b.Do(ctx, root)
}

func isGitRepo() bool {
	// NB: simply checking the exit code of `git rev-parse --git-dir` would
	// suffice here, but that requires deviating from the infrastructure
	// provided by `run`.
	gitDir := chomp(run(goroot, 0, "git", "rev-parse", "--git-dir"))
	if !filepath.IsAbs(gitDir) {
		gitDir = filepath.Join(goroot, gitDir)
	}
	return isdir(gitDir)
}

/*
 * Initial tree setup.
 */

	}
}

func BenchmarkEqual(b *testing.B) {
	b.Run("0", func(b *testing.B) {
		var buf [4]byte
		buf1 := buf[0:0]
		buf2 := buf[1:1]
		for i := 0; i < b.N; i++ {
			eq := Equal(buf1, buf2)
			if !eq {
				b.Fatal("bad equal")
			}
		}
	})

	sizes := []int{1, 6, 9, 15, 16, 20, 32, 4 << 10, 4 << 20, 64 << 20}

	b.Run("same", func(b *testing.B) {

	// modules may be disabled (GO111MODULE=auto) or commands may run in a
	// limited module mode.
	AutoRoot Root = iota

	// NoRoot is used for commands that run in module mode and ignore any go.mod
	// file the current directory or in parent directories.
	NoRoot

	// NeedRoot is used for commands that must run in module mode and don't
	// make sense without a main module.
	NeedRoot
)

	tg.run("env", "GCCGO")
	tg.grepStdout(".", "GCCGO unexpectedly empty")

	tg.run("env", "CGO_CFLAGS")
	tg.grepStdout(".", "default CGO_CFLAGS unexpectedly empty")

	tg.setenv("CGO_CFLAGS", "-foobar")
	tg.run("env", "CGO_CFLAGS")
	tg.grepStdout("^-foobar$", "CGO_CFLAGS not honored")

	tg.setenv("CC", "gcc -fmust -fgo -ffaster")
	tg.run("env", "CC")
	tg.grepStdout("gcc", "CC not found")
	tg.run("env", "GOGCCFLAGS")

			if err != nil && (pkg == nil || pkg.Name() != "issue51803") {
				t.Fatal(err)
			}
			imports[pkg.Name()] = pkg
			return pkg
		}
		makePkg(lib)
		pkg := makePkg(test.src)

		t.Run(pkg.Name(), func(t *testing.T) {
			// Sort instances in source order for stability.
			instances := sortedInstances(instMap)
			if got, want := len(instances), len(test.instances); got != want {

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

// Register allocation.
//
// We use a version of a linear scan register allocator. We treat the
// whole function as a single long basic block and run through
// it using a greedy register allocator. Then all merge edges
// (those targeting a block with len(Preds)>1) are processed to
// shuffle data into the place that the target of the edge expects.
//

		fmt.Fprint(os.Stderr, "EOF\n")
	}
	stdout, stderr, _ := run(stdin, nargs)
	if *debugGcc {
		os.Stderr.Write(stdout)
		os.Stderr.Write(stderr)
	}
	return string(stderr)
}

// runGcc runs the gcc command line args with stdin on standard input.
// If the command exits with a non-zero exit status, runGcc prints
// details about what was run and exits.

(StaticCall ...) => (CALLstatic ...)
(ClosureCall ...) => (CALLclosure ...)
(InterCall ...) => (CALLinter ...)
(TailCall ...) => (CALLtail ...)

// Lowering conditional moves
// If the condition is a SETxx, we can just run a CMOV from the comparison that was
// setting the flags.
// Legend: HI=unsigned ABOVE, CS=unsigned BELOW, CC=unsigned ABOVE EQUAL, LS=unsigned BELOW EQUAL

		t.Errorf("wrote %v bytes with ReadFrom, want %v", got, want)
	}
}

func TestReadZero(t *testing.T) {
	for _, size := range []int{100, 2} {
		t.Run(fmt.Sprintf("bufsize=%d", size), func(t *testing.T) {
			r := io.MultiReader(strings.NewReader("abc"), &emptyThenNonEmptyReader{r: strings.NewReader("def"), n: 1})
			br := NewReaderSize(r, size)