search for: getvaarg

...upport targets with a more complex va_list struct featuring separate save areas for GPRs and FPRs, splitting a va_arg in to multiple operations (one per element of an aggregate) doesn't seem like it could work without heroic gymnastics in the backend. Converting the va_arg instruction to a new GETVAARG SelectionDAG node plus a series of LOADs seems like it may provide a straight-forward path to supporting aggregates on targets that use a pointer for va_list. Of course this ends up exposing loads plus offset generation in the SelectionDAG, just hiding the va_list increment behind GETVAARG. For suc...

# The future of the va_arg instruction ## Summary LLVM IR currently defines a va_arg instruction, which can be used to access a vararg. Few Clang targets make use of it, and it has a number of limitations. This RFC hopes to promote discussion on its future - how 'smart' should va_arg be? Should we be aiming to transition all targets and LLVM frontends to using it? ## Background on va_arg

Hi everyone, I'm interested in variadic functions and how llvm handles them. I discovered that the Clang frontend is doing a great job at lowering the va_arg (precisely __builtin_va_arg) function into target dependent code. I have also seen the va_arg function that exist at IR level. I found some information about va_arg (IR one) that currently does not support all platform. But since 2009,

On Wed, May 20, 2009 at 4:55 PM, Dan Gohman <gohman at apple.com> wrote: > Can you explain why you chose the approach of using a new pass? > I pictured removing LegalizeDAG's type legalization code would > mostly consist of finding all the places that use TLI.getTypeAction > and just deleting code for handling its Expand and Promote. Are you > anticipating something more

On May 20, 2009, at 1:34 PM, Eli Friedman wrote: > On Wed, May 20, 2009 at 1:19 PM, Eli Friedman > <eli.friedman at gmail.com> wrote: > >> Per subject, this patch adding an additional pass to handle vector >> >> operations; the idea is that this allows removing the code from >> >> LegalizeDAG that handles illegal types, which should be a significant

...etNode(ISD::SRL, dl, NVT, Tmp1, Node->getOperand(1)); - break; - - case ISD::VAARG: - Tmp1 = Node->getOperand(0); // Get the chain. - Tmp2 = Node->getOperand(1); // Get the pointer. - if (TLI.getOperationAction(ISD::VAARG, VT) == TargetLowering::Custom) { - Tmp3 = DAG.getVAArg(VT, dl, Tmp1, Tmp2, Node->getOperand(2)); - Result = TLI.LowerOperation(Tmp3, DAG); - } else { - const Value *V = cast<SrcValueSDNode>(Node->getOperand(2))->getValue(); - SDValue VAList = DAG.getLoad(TLI.getPointerTy(), dl, Tmp1, Tmp2, V, 0); - // Increment the...