testRemaining{6, 3},
			testReadFrom{fileOps{int64(3), "cde"}, 6, nil},
			testRemaining{0, 0},
		},
	}, {
		maker: makeSparse{makeReg{5, "abcde"}, sparseHoles{{2, 3}}, 8},
		tests: []testFnc{
			testReadFrom{fileOps{"ab", int64(3), "cde"}, 8, nil},
			testRemaining{0, 0},
		},
	}, {
		maker: makeSparse{makeReg{5, "abcde"}, sparseHoles{{2, 3}}, 8},
		tests: []testFnc{

	{name: "dead auto elim", fn: elimDeadAutosGeneric},
	{name: "sccp", fn: sccp},
	{name: "generic deadcode", fn: deadcode, required: true}, // remove dead stores, which otherwise mess up store chain
	{name: "check bce", fn: checkbce},
	{name: "branchelim", fn: branchelim},
	{name: "late fuse", fn: fuseLate},
	{name: "dse", fn: dse},
	{name: "memcombine", fn: memcombine},

	s   string
	sep string
	n   int
	a   []string
}

var splittests = []SplitTest{
	{"", "", -1, []string{}},
	{abcd, "a", 0, nil},
	{abcd, "", 2, []string{"a", "bcd"}},
	{abcd, "a", -1, []string{"", "bcd"}},
	{abcd, "z", -1, []string{"abcd"}},
	{abcd, "", -1, []string{"a", "b", "c", "d"}},
	{commas, ",", -1, []string{"1", "2", "3", "4"}},
	{dots, "...", -1, []string{"1", ".2", ".3", ".4"}},

//		{Offset: 21, Length: 4},  // Hole fragment for 21..24
//	}
//
// Then the content of the resulting sparse file with a Header.Size of 25 is:
//
//	var sparseFile = "\x00"*2 + "abcde" + "\x00"*11 + "fgh" + "\x00"*4
type (
	sparseDatas []sparseEntry
	sparseHoles []sparseEntry
)

// validateSparseEntries reports whether sp is a valid sparse map.