testlog, err := os.ReadFile(a.Objdir + "testlog.txt")
	if err != nil || !bytes.HasPrefix(testlog, testlogMagic) || testlog[len(testlog)-1] != '\n' {
		if cache.DebugTest {
			if err != nil {
				fmt.Fprintf(os.Stderr, "testcache: %s: reading testlog: %v\n", a.Package.ImportPath, err)
			} else {
				fmt.Fprintf(os.Stderr, "testcache: %s: reading testlog: malformed\n", a.Package.ImportPath)
			}

		os.Exit(2)
	}
	if *testlog != "" {
		// Note: Not using toOutputDir.
		// This file is for use by cmd/go, not users.
		var f *os.File
		var err error
		if m.numRun == 1 {
			f, err = os.Create(*testlog)
		} else {
			f, err = os.OpenFile(*testlog, os.O_WRONLY, 0)
			if err == nil {
				f.Seek(0, io.SeekEnd)
			}
		}

		if f, s := Lgamma(vflgammaSC[i]); !alike(lgammaSC[i].f, f) || lgammaSC[i].i != s {
			t.Errorf("Lgamma(%g) = %g, %d, want %g, %d", vflgammaSC[i], f, s, lgammaSC[i].f, lgammaSC[i].i)
		}
	}
}

func TestLog(t *testing.T) {
	for i := 0; i < len(vf); i++ {
		a := Abs(vf[i])
		if f := Log(a); log[i] != f {
			t.Errorf("Log(%g) = %g, want %g", a, f, log[i])
		}
	}
	if f := Log(10); f != Ln10 {