4 Commits

Author	SHA1	Message	Date
Emmanuel Marty	668204d953	Merge optimizations by Pavel Zagrebin ... Manually merge PR #44	2020-04-04 13:29:25 +02:00
mobygamer	30192238ea	Rewrite 8088 jumptable decompressor for maximum speed ... This is a rewrite of LZSA1JMP.ASM to use a 256-element jumptable, which allows the code to handle all of the hot paths (common cases) without any branching. This not only reduces branches (which are very costly on x86) to a bare minimum, but also grants us foreknowledge in a decode path of what steps can be skipped. The new code is 12.7% faster than the old code, and assembles to less than 3K of object code and data.	2019-10-26 23:34:24 -05:00
mobygamer	c38b582e73	Time-efficient LZSA2 decompressor ... This commit provides a time-effecient LZSA2 decompressor for the 8088 (and higher) CPU. Decompression speed is roughly 50% faster than ZX7 on the same hardware.	2019-07-13 22:35:28 -05:00
mobygamer	f123a6d9df	Submit 8086-optimized decompressor using jump tables ... Because the 8086's BIU is more efficient and can read a word in a single operation, we can skew LZSA1 decompression faster on 8086 by using a jump table to eliminate 2 comparions.	2019-07-11 17:22:29 -05:00