Compiler optimization breaks multi-threaded code

[Kagamin]

Sean Kelly Wrote:

> > shared uint cnt;
> > void atomicInc  ( ) { uint o; while ( !cas( &cnt, o, o + 1 ) ) o = cnt; }
> > 
> > is compiled with dmd -O to something like:
> > 
> > shared uint cnt;
> > void atomicInc  ( ) { while ( !cas( &cnt, cnt, cnt + 1 ) ) { } }
> What a mess.  DMD isn't supposed to optimize across asm blocks.

There're no asm blocks in the code. It's a violated contract of shared data access.