search for: selectionddag

I'm still working on SSP support in LLVM. We have code that is in an IR pass StackProtector, SelectionDAG, FastISel, and some MachineFunction passes. Even in SelectiondDAG we have different code paths. I wonder if we can at least have only two code paths, one for SelectionDAG and the other for FastISel. IR pass may generate two forms of IR: 1) Almost pure IR, which contains only llvm.stackprotector that can be lowered. 2) An IR skeleton which contains llvm.stackprot...

On Thursday 03 April 2008 22:00:34 Dan Gohman wrote: > However, for people just interested in post-regalloc scheduling and > VLIW packing and similar things, MemOperands aren't the only approach. > A potentially better way to do this would be to extend MachineInstrs > to preserve the chain dependencies from the SelectionDAG. the selection dag may already contain unnecessary

There have been a few queries about this recently, and I've done some work in this area recently, so I'm posting a summary of what the major outstanding issues are. * BasicAliasAnalysis, the default AliasAnalysis implementation, doesn't understand lowered GEPs, integer arithmetic, or PHIs, and the regular codegen process involves passes that lower GEPs. One way to solve this is