[Libre-soc-dev] v3.1B prefix

[Alexandre Oliva]

On Dec 20, 2020, Luke Kenneth Casson Leighton <lkcl at lkcl.net> wrote:

>> Compressed/original ratio: 0.933947

> are you *sure* that's right?

Well, yeah, I was comparing apples to apples.  The numbers from my Dec
13 post that I quoted and compared were from before your cregs* changes,
so the comparison with the alternate mode-switching logic used the same
cregs* from before your change.


With those changes (merged and pushed last night), the comparison is
about just as favorable to the alternate mode-switching logic:


aoliva at livre$ unxz < ppc-gcc.raw.xz | python3 ./comp16-v1-skel.py | tail -n 12
Summary
32-bit uncompressed instructions: 106490
16-bit compressed instructions: 8119
16-imm compressed-mode instructions: 16795
10-bit compressed instructions: 4063
10-bit mode-switching nops: 3336
10-bit mode-switching nops for imm-16: 11523
16-bit mode-switching nops after imm-16: 2915
10-bit nop+16-imm pairs above, backtracked to 32-bit: 9589
Compressed size estimate: 519462
Original size: 541868
Compressed/original ratio: 0.958650
aoliva at livre$ unxz < ppc-gcc.raw.xz | python3 ./comp16-v1alt-skel.py | tail -n 7
Summary
32-bit uncompressed instructions: 106490
16-bit compressed instructions: 28977
16-bit mode-switching nops: 8684
Compressed size estimate: 501282
Original size: 541868
Compressed/original ratio: 0.925100
aoliva at livre$ git log --oneline | head -n 1
7fbefca9 merge luke's cregs improvements

-- 
Alexandre Oliva, happy hacker  https://FSFLA.org/blogs/lxo/
   Free Software Activist         GNU Toolchain Engineer
        Vim, Vi, Voltei pro Emacs -- GNUlius Caesar