[fpc-devel] The 15k bounty: Optimizing executable speed for Linux x86 / LLVM

[Michael Van Canneyt]

On Sat, 27 Oct 2018, Florian Klämpfl wrote:

> If you read the whole thread, LLVM needs a rewritten exception handling as well. Further, a quick test
> of table based exception handling on bansi1 (which is mainly a memory manager test) gives:
>
> standard exception handling:
>
> fpctrunk\tests\bench>pp11 bansi1 -O3
>
> fpctrunk\tests\bench>bansi1
> Test 1: 1000000 done in 0.537 sec
> Test 2: 1000000 done in 0.535 sec
> Test 3: 1000000 done in 0.587 sec
>
> SEH based exception handling:
>
> fpctrunk\tests\bench>pp11 bansi1 -O3
>
> fpctrunk\tests\bench>bansi1
> Test 1: 1000000 done in 0.456 sec
> Test 2: 1000000 done in 0.457 sec
> Test 3: 1000000 done in 0.446 sec

Florian, I am not sure what this is supposed to prove ?

It's 15% off the elapsed time (almost 1/6th), that seems worth spending some time on...

Michael.