similar to: [LLVMdev] Immediate dominator

Hi, guys, what is the interface for finding the immediate dominator of a machine basic block in LLVM 2.1? I found some methods to check if a node dominates other in llvm::MachineDominatorTree, but I was looking for something like: MachineBasicBlock * mbb = ... MachineBasicBlock * iDom = XXX->getImmediateDominator(mbb); is there something similar? best, Fernando

Dear LLVMers, I need help with one error in my register allocator. I am getting errors when folding instructions for the x86 (it does not happen when I use the PowerPC as target). The problem is that, when I execute something like: mi = mbb->insert(mbb->erase(mi), fmi), where mbb is a MachineBasicBlock, valgrind gives this error message: Address 0x42C62B0 is 24 bytes inside a block

Dear llvmers, I am trying to insert a move instruction where both source and destination registers are physical registers. How is the code for this? I tried this one here: void PhiDeconstruction_Fer::add_move ( MachineFunction & mf, MachineBasicBlock & mbb, unsigned

On Aug 13, 2006, at 11:16 PM, Fernando Magno Quintao Pereira wrote: > > Dear LLVMers, > > I am trying to fold memory operands in the way that is done in > RegAllocLocal.cpp, or in LiveIntervalAnalysis.cpp, but I am getting > errors > that > I don't know how to fix. Could someone tell me which steps should I > take > in order > to correctly fold memory

Fernando, The code there should be more or less functional, though it's not currently used by anything. Eventually it should probably be moved to a method on MachineBasicBlock. The API breakage you're seeing is because some methods moved around. Feel free to fix it. :-) --Owen On Jan 26, 2008, at 6:31 PM, Fernando Magno Quintao Pereira wrote: > > Hi LLVMers, > >

Dear LLVMers, I am trying to fold memory operands in the way that is done in RegAllocLocal.cpp, or in LiveIntervalAnalysis.cpp, but I am getting errors that I don't know how to fix. Could someone tell me which steps should I take in order to correctly fold memory operands? The code that I am using is: const TargetMachine & target_machine = this->machine_function->getTarget();

copyRegToReg() always insert the move instruction before "iter". Just use prior(iter) after the insertion to reference the newly created move instruction. Evan On Feb 21, 2007, at 11:17 PM, Fernando Magno Quintao Pereira wrote: > > Hey, guys, I am creating some move instructions with > MRegisterInfo::copyRegToReg. How do I get a pointer to the instruction > that I just

On Thu, 21 Jun 2007, Fernando Magno Quintao Pereira wrote: > I would like to make a suggestion. In the LiveIntervalAnalysis class, > instead of numbering the instructions in the order in which basic blocks > are stored in the machine function, use the df_ext_iterator. It will order > the instruction according to the dominance tree (or it seems to be doing > so). There are many

Hi, Just my two cents: If I recall correctly, in some papers on the linear scan register allocation people described that they tried different orderings for instruction numbering, e.g. including DFS or based on the loop nesting levels, etc. There was no clear winner though. But let's see the numbers anyway. May be it really brings some improvements. -Roman Chris Lattner wrote: > On

Nice idea. Please also try using SmallPtrSet (with a sufficiently large size) instead of std::set for traversal after everything is working. Using std::set can really hurt compile time in case of large basic block numbers. Is there a way to dynamically adjust "SmallSize" based on number of basic blocks in the function? Evan On Jun 21, 2007, at 10:20 PM, Fernando Magno Quintao

Hi LLVMers, what is the status of breaking critical edges in machine functions? I just compiled the top of the LLVM tree, and I found llvm/CodeGen/BreakCriticalMachineEdge.h. But this file seems not to be up-to-date with the other classes in the top of the tree. For instance, it calls isTerminatorInstr on llvm::TargetInstrInfo, but this method is no longer there. If I want to break

Hey, guys, I am creating some move instructions with MRegisterInfo::copyRegToReg. How do I get a pointer to the instruction that I just created? Is there a way to do something like: // mbb is MachineBasicBlock, reg_info is MRegisterInfo MachineBasicBlock::iterator iter = mbb.getFirstTerminator(); reg_info->copyRegToReg(mbb, iter, dst, src, rc); iter--; (???) MachineInstr *

I would like to make a suggestion. In the LiveIntervalAnalysis class, instead of numbering the instructions in the order in which basic blocks are stored in the machine function, use the df_ext_iterator. It will order the instruction according to the dominance tree (or it seems to be doing so). There are many advantages in doing this. One of them is that, once you traverse the dominance tree

On Sun, 2 Jul 2006, Fernando Magno Quintao Pereira wrote: > Thank you, chris. But I still do not understand how to insert this move > instruction :) You call copyRegToReg, like you are already doing. What you really aren't understanding is how to pick a regclass, which is a different issue. > I have the machine function, the basic block, and the > unsigned descriptors of the

On Sun, 2 Jul 2006, Fernando Magno Quintao Pereira wrote: > MachineBasicBlock::iterator iter = mbb.getFirstTerminator(); > const TargetRegisterClass *rc = mf.getSSARegMap()->getRegClass(dst); > const MRegisterInfo * reg_info = mf.getTarget().getRegisterInfo(); > reg_info->copyRegToReg(mbb, iter, dst, src, rc); > } > > But the getRegClass method seems to

Hi Fernando, On Jul 18, 2007, at 10:57 AM, Fernando Magno Quintao Pereira wrote: > > Dear LLVMers, > > we here in the UCLA compiler's lab have an implementation of a > very > cool register allocator in LLVM. It finds an optimal register > assignment > for the x86 machine, via live range splitting, that is, if it is > possible > to have a register

Dear guys, what is the best way to implement a swap of floating point registers in X86? For the integer registers, I am using xchg. Is there a similar instruction for floating point? My function to insert swaps is like: void X86RegisterInfo::swapRegs( MachineBasicBlock & mbb, MachineBasicBlock::iterator mi, unsigned r1, unsigned r2, const TargetRegisterClass

> On Sun, 2 Jul 2006, Fernando Magno Quintao Pereira wrote: > > > MachineBasicBlock::iterator iter = mbb.getFirstTerminator(); > > const TargetRegisterClass *rc = mf.getSSARegMap()->getRegClass(dst); > > const MRegisterInfo * reg_info = mf.getTarget().getRegisterInfo(); > > reg_info->copyRegToReg(mbb, iter, dst, src, rc); > > } > > >

Hi Florian, we though about using UIUC, like in LLVM. Do you guys know if that could be a problem, given that we are mining the functions from github? > Have you thought about integrating the benchmarks as external tests into LLVM’s test-suite? That would make it very easy to play around with. We did not think about it actually. But we would be happy to do it, if the community accepts

>> I am in need of a no-op instruction: an instruction that does not do >> anything, and has no operands. Does LLVM predefine such an instruction? I >> want to transform the program so that there is no empty basic block. > > You can never have an empty basic block. All BBs must have a TerminatorInst. > I've built a pass to split critical edges of machine