On Tue, 1 Apr 2025, Jeremy Drake via Cygwin-patches wrote: > On Tue, 1 Apr 2025, Corinna Vinschen wrote: > > > And btw., I checked the file size again, and it turns out that after > > stripping the debug symbols the DLL takes ~30 pages or 120 K more memory > > than before udis86. I hope that's ok. But if you see ways to shave a > > few pages off by dropping code from udis86, I wouldn't be too unhappy :} > > Hmm, I only tested on top of msys2 (which is on gcc 13.3.0), but here's > what I see: > > $ ls -l > total 47952 > -rwxr-xr-x 1 XXX None 24682293 Apr 1 10:14 postmsys-2.0.dll > -rwxr-xr-x 1 XXX None 24417887 Apr 1 10:12 premsys-2.0.dll > > $ echo $(( $(stat -c %s postmsys-2.0.dll) - $(stat -c %s premsys-2.0.dll) )) > 264406 > > $ strip premsys-2.0.dll > $ strip postmsys-2.0.dll > > $ ls -l > total 6428 > -rwxr-xr-x 1 XXX None 3330598 Apr 1 10:15 postmsys-2.0.dll > -rwxr-xr-x 1 XXX None 3246118 Apr 1 10:15 premsys-2.0.dll > > $ echo $(( $(stat -c %s postmsys-2.0.dll) - $(stat -c %s premsys-2.0.dll) )) > 84480 > > One thing I noticed that could make the code using udis86 smaller and > faster is to use members of the ud_t struct directly instead of calling > accessor functions. I don't know for sure if these members are intended > to be public or not (but they do seem to know how to declare members as > non-public: in ud_operand_t, they have an "internal use only" comment > followed by members named with leading underscores). I don't think it > would make a large dent in the size of the code relative to the size of > udis86 itself though.
I changed the code to use the struct directly, and amazingly the dll was the exact same size after stripping. I then tried building the udis86/*.c with -ffunction-sections -fdata-sections, and that resulted in a *larger* dll. Building just udis86.c with -ffunction-sections (in addition to the struct access change) resulted in a 1k savings. Instead #ifdef'ing out the unused functions (including those now unused because the struct members are read directly) in udis86.c resulted in a 2k savings. In addition to ifdef'ing out functions, building all 3 udis86/*.c files with -Os resulted in an overall 4608 byte savings in stripped dll size.
