Function predefinedFSEInputs

zstd/fse_decoder_bench_test.go:9–35

predefinedFSEInputs returns the three RFC default distributions (litLength, offset, matchLength) as fseDecoders, ready for buildDtable. Defined without build constraints so the benchmark can run under both the asm and -tags noasm (pure-Go) builds for an apples-to-apples comparison.

()

// Defined without build constraints so the benchmark can run under both the
// asm and -tags noasm (pure-Go) builds for an apples-to-apples comparison.
func predefinedFSEInputs() map[string]func() *fseDecoder {
	return map[string]func() *fseDecoder{
		"litLength": func() *fseDecoder {
			s := &fseDecoder{actualTableLog: 6, symbolLen: 36}
			copy(s.norm[:], []int16{4, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1,
				2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 1, 1, 1, 1, 1,
				-1, -1, -1, -1})
			return s
		},
		"offset": func() *fseDecoder {
			s := &fseDecoder{actualTableLog: 5, symbolLen: 29}
			copy(s.norm[:], []int16{
				1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1,
				1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1})
			return s
		},
		"matchLength": func() *fseDecoder {
			s := &fseDecoder{actualTableLog: 6, symbolLen: 53}
			copy(s.norm[:], []int16{
				1, 4, 3, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1,
				1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
				1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1,
				-1, -1, -1, -1, -1})
			return s
		},
	}
}

func BenchmarkBuildDtable(b *testing.B) {
	for name, mk := range predefinedFSEInputs() {