search for: gobalisel

...lobal-isel The Recommended way will issue a warning if it falls back to SelectionDAG, the OkToFallBack will silently fallback to SDISel if it needs to, and the AbortOnFallBack will kill the compiler if GlobalISel cannot handle the input completely. *** What Is Next? *** We would like to turn on GobalISel by default in the next couple of weeks. Please help identify any critical issue that needs to be resolved before that can happen. We expect that minor hiccups and outliers in any metrics can be fixed quickly, but are worried about harmful run-time (miscompile) or compile-time crashes. Many thanks...

Hi , Currently GobalIsel like FastIsel designed to use fallback to DAGIsel in case of failure. You can use -global-isel-abort=2 option. llc -global-isel -pass-remarks-missed="gisel-*" -global-isel-abort=2 simple_foo.ll Regards, Igor From: S. Bharadwaj Yadavalli [mailto:bharadwajy at gmail.com] Sent: Thurs...

Hi all, The DAGCombiner pass actually runs even if the optimize level is set to None. This can result in incorrect debug information or unexpected stepping/debugging experience. Not to mention that having good stepping/debugging experience is the major reason to compile at /O0. I recently suggested a patch to disable one specific DAG combine at /O0 that broke stepping on a particular case

...sm for each optimization and this is a matter of classifying them. Anyhow, what are other people thoughts? Note: I understand this is a big refactoring and maybe not one that we want to do now, but I believe we could reuse some of the ideas we are discussing here when we eventually do combines in GobalISel. Cheers, -Quentin > On May 13, 2016, at 12:51 PM, Robinson, Paul via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > (Remembering to re-add llvm-dev again…) > Yes, this would be too aggressive. DAG combiner does more than just optimization (which I discovered as part of D7181...

I believe if you pass(iirc) -pass-remarks-missed=“gisel-*”, it’ll print the instruction it failed to legalize. Sent from my iPhone > On Oct 11, 2017, at 6:44 PM, S. Bharadwaj Yadavalli via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > Thanks for your quick reply. > > Here its is: > > =========== > > ; ModuleID = 'simple_foo.c' > source_filename

I may be wrong here, but legalizing early seems like something that is more likely to prevent optimizations than it is to encourage them. But I guess I don't follow why things like TTI, TII and TLI queries don't suffice for this. CodeGenPrepare will break this sequence up. I would imagine that if the target returns false for isCheapToSpeculateCtlz() and false for canInsertSelect(), the