On Tue, Mar 30, 2010 at 10:05 AM, Luca Barbieri <luca.barbi...@gmail.com> wrote: > DDX/DDY could cause miscompilation, but I think that only happens if > LLVM clones or causes some paths to net execute them. > > Someone proposed some time ago on llvmdev to add a flag to tell llvm > to never duplicate an intrinsic, not sure if that went through (iirc, > it was for a barrier instruction that relied on the instruction > pointer). > Alternatively, it should be possible to just disable any passes that > clone basic blocks if those instructions are present. > > The non-execution problem should be fixable by declaring DDX/DDY to > have global-write-like side effects (this will prevent dead code > elimination of them if they are totally unused, but hopefully shaders > are not written so badly they need that).
We're talking about a HW-specific issue here, not anything that needs global changes. I'm really not sure where you're going with this. -- When the facts change, I change my mind. What do you do, sir? ~ Keynes Corbin Simpson <mostawesomed...@gmail.com> ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Mesa3d-dev mailing list Mesa3d-dev@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mesa3d-dev
