Compiler Speed Trials

[boriel]

Finally got a quick chance to test this. Yes, -O3 does improve BM7 - but the 0.16 seconds value isn't really fair. -O3 reports that variables are not used and optimizes out all the loops!

I don't remember that optimization. Which code snippet are you using? BM7 above?

Putting a print M(1),k,i,var at the end of the program makes it actually do the work rather than skip it (but putting the print AFTER the time is recorded doesn't extend the time), and it duly recorded a time of 2.12 seconds.

Did you also run this modified version on the other compilers? (they might also be doing some optimizations: so just to be sure). Please paste the benchmark code here, or tell me witch one are you using.

If you made some modifications to BM7 and or BM8, please paste them there. Also, the code MUST be the same (e.g. no function calls for any compiler, of function calls for any of them, etc...).

This is a noticeable improvement, but still a long way behind the code that Hisoft Basic and other integer compilers make. It still looks as though the array handling is somewhat behind other implementations.

Do the other compilers allow multidimensional arrays of float / string / Integers?

Incidentally, also tested BM 8, with -O3, which shows about a 16% improvement!

It's clear that things like Tobos use very highly optimized FP math structures. Changing out sin for the fSin function listed in the library (which breaks with -O3 btw) ran in 17 seconds instead - showing 7 seconds of speed up (41%). There might be a very strong case, at some point, for looking into optional faster FP functions.

As told before, we could use add a --fast-floating-point option to include Fast FP routines instead of ROM ones (most compilers do). This will eat memory for sure (in fact, z88dk uses ROM calc routines too). FP routines aren't used in games. The most common technique is to use precomputed table values (mostly in demos).