func countNewCoverageBits(base, snapshot []byte) int {
	n := 0
	for i := range snapshot {
		n += bits.OnesCount8(snapshot[i] &^ base[i])
	}
	return n
}

// isCoverageSubset returns true if all the base coverage bits are set in
// snapshot.
func isCoverageSubset(base, snapshot []byte) bool {
	for i, v := range base {
		if v&snapshot[i] != v {
			return false
		}
	}
	return true
}

				// keepCoverage to only minimize the crash going forward.
				keepCoverage = nil
			}
			return true
		}
		// Minimization should preserve coverage bits.
		if keepCoverage != nil && isCoverageSubset(keepCoverage, coverageSnapshot) {
			return true
		}
		vals[args.Index] = prev
		return false
	}
	switch v := vals[args.Index].(type) {
	case string: