search for: vrm

I've been playing around with spillers and found that the SimpleSpiller fails badly on a particular code. The problem arises because SimpleSpiller does the test VRM.isAssignedReg(virtReg) which is implemented as: 00183 bool isAssignedReg(unsigned virtReg) const { 00184 if (getStackSlot(virtReg) == NO_STACK_SLOT && 00185 getReMatId(virtReg) == NO_STACK_SLOT) 00186 return true; 00187 // Split register can be assigned a...

...ain the theory behind the spillers in VirtRegMap.cpp? It seems as though the spillers do triple duty: - Insert load/store operations and/or fold instructions as necessary to carry out spills - Rewrite the spilled virtual registers to use machine registers (mapping given by the caller in the VRM). - Rewrite machine code to change virtual registers to physical registers (mapping given by the caller in the VRM, presumably the caller is regalloc). My question concerns duty #2. There is code in the spiller that assumes intervals created to spill a virtual register have been mapped to phy...

On May 27, 2008, at 5:36 PM, David Greene wrote: > I've been playing around with spillers and found that the > SimpleSpiller fails > badly on a particular code. > > The problem arises because SimpleSpiller does the test > VRM.isAssignedReg(virtReg) which is implemented as: > > 00183 bool isAssignedReg(unsigned virtReg) const { > 00184 if (getStackSlot(virtReg) == NO_STACK_SLOT && > 00185 getReMatId(virtReg) == NO_STACK_SLOT) > 00186 return true; > 00187 // Spli...

...to fold the load / store. The spiller doesn't actually perform the "folding". It needs to know that they have happened to keep track of reuse information. > > - Rewrite the spilled virtual registers to use machine registers > (mapping > given by the caller in the VRM). > > - Rewrite machine code to change virtual registers to physical > registers > (mapping given by the caller in the VRM, presumably the caller is > regalloc). Right. > > My question concerns duty #2. There is code in the spiller that > assumes > intervals cr...

...------------------------------------------------------------- void RegAllocChordal_Fer::spill( unsigned v_reg, KillingSites_Fer & ks, const MachineBasicBlock & mbb ) { // First, find a place to store this register. Of course, this will be done // by the implementation of vrm. We just have to ask it. int slot = vrm->assignVirt2StackSlot(v_reg); unsigned p_reg = this->reg_mapping->get_physical_location(v_reg); // Now, it is necessary to break the live range of the spilled register. // This is done by creating new virtual registers, and substitut...

..., the error does not happen. But I realized something important: I am not mapping virtuals to physicals strait on VirtRegMap during the scan. I use my own data structures to record the register assignment, and write on VirtRegMap after I am done, on a single step. When I remove the command this->vrm->virtFolded(v_reg, mi, u, fmi) from my code, the error does not happen. So, I think I am not using VirtRegMap properly. It seems to me that I don't have to call this method during the scan, because instruction operands still contain virtuals, not physical registers, as it would be expected....

Hey all, I've found a bug in either the PBQP register allocator or in VirtRegRewriter. I'm observing this assertion in VirtRegRewriter::rewrite() fail: unsigned VirtReg = MO.getReg(); unsigned PhysReg = VRM->getPhys(VirtReg); ... assert(!MRI->isReserved(PhysReg) && "Reserved register assignment"); Indeed there is a case where PhysReg may be a reserved physical register. Specificially, RegAllocPBQP::finalizeAlloc() may select a physical register thusly:...

...der MIB = BuildMI(*RMBB, RMI, RMI->getDebugLoc(), tii_->get(TargetInstrInfo::IMPLICIT_DEF), NewVReg); (*MIB).getOperand(0).setIsUndef(); RMO.setReg(NewVReg); RMO.setIsUndef(); RMO.setIsKill(); } Souldn't there be a call to vrm.grow() after each call to mri->createVirtualRegister()? -Dave

So what addIntervalsToSpills returns are new intervals to allocate with infinite weights, right? And I need not to allocate the old interval. Should hasStackSlot return true on its register then? On 8/21/06, Fernando Magno Quintao Pereira <fernando at cs.ucla.edu> wrote: > > > Well, someone correct me if am wrong, but, you still have to allocate > physical registers to them,

..., RMI, RMI->getDebugLoc(), > tii_->get(TargetInstrInfo::IMPLICIT_DEF), NewVReg); > (*MIB).getOperand(0).setIsUndef(); > RMO.setReg(NewVReg); > RMO.setIsUndef(); > RMO.setIsKill(); > } > > Souldn't there be a call to vrm.grow() after each call to > mri->createVirtualRegister()? No. This function is run during the analysis stage. vrm is actually owned by the register allocator which then passed it into liveintervals. Is there an actual problem that you run into? Evan > >...

...g is: const TargetMachine & target_machine = this->machine_function->getTarget(); const MRegisterInfo *ri = target_machine.getRegisterInfo(); MachineInstr * fmi = ri->foldMemoryOperand(mi, u, slot); if(fmi) { numFolded++; MachineBasicBlock * mbb = mi->getParent(); this->vrm->virtFolded(v_reg, mi, u, fmi); //std::cerr << "Folding " << NeatPrint::mi2string(*mi, *this->machine_function) << "\n"; // TODO: see if it is not necessary to iterate // again on the instruction. return mbb->insert(mbb->erase(mi), fmi);...

...rget_machine = > this->machine_function->getTarget(); > const MRegisterInfo *ri = target_machine.getRegisterInfo(); > MachineInstr * fmi = ri->foldMemoryOperand(mi, u, slot); > if(fmi) { > numFolded++; > MachineBasicBlock * mbb = mi->getParent(); > this->vrm->virtFolded(v_reg, mi, u, fmi); > //std::cerr << "Folding " << NeatPrint::mi2string(*mi, > *this->machine_function) << "\n"; > // TODO: see if it is not necessary to iterate > // again on the instruction. > return mbb->insert...

I need to remove certain interactions and keep only the one between the second level of the factor and the continuous var t2 bin4 <- glm(resp2~ t*t2+c5.vrm,data=dfa,family="quasibinomial") > summary(bin4) Call: glm(formula = resp2 ~ t * t2 + c5.vrm, family = "quasibinomial", data = dfa) Deviance Residuals: Min 1Q Median 3Q Max -6.5464 -3.0720 -1.8135 0.4896 28.9207 Coefficients: Es...

Dear list, I am using the hurdle model for modelling the habitat of rare fish species. However I do get an error message when I try to model my data: > test_new1<-hurdle(GALUMEL~ depth + sal + slope + vrm + lat:long + offset(log(haul_numb)), dist = "negbin", data = datafit_elasmo) Error in hurdle(GALUMEL ~ depth + sal + slope + vrm + lat:long + offset(log(haul_numb)), : invalid dependent variable, non-integer values When I do fit the same model with round(my dependent variable) the mo...

On Mon, 14 Aug 2006, Fernando Magno Quintao Pereira wrote: > I reload spilled code. If I am doing something evidently wrong, I would > appreciate if someone tells me. With the comment on vrm->virtFolded, I am > passing all the tests that I have. I haven't had a chance to look at the code you have below, but I would guess that you are leaving a dangling pointer in some map somewhere. "foldMemoryOperand", if successful, leaves the original instruction in the progr...

...gt;> in MBB#0 define the LR? It should be enough, or? > > Every machine basic block must list physical register livein's. One question, just to be sure I understand you correctly. You mean that after the RegAlloc has assigned physical registers to LiveIntervals and before it calls the VRM to rewrite the function, it should explicitly add lives-ins for each MBB, just like LinearScan does it at the end of the RALinScan::linearScan() function??? E.g. like this: // Add live-ins to every BB except for entry. Also perform trivial coalescing. MachineFunction::iterator EntryMBB = mf_-...

...after the spill code handling inside selectOrSplit() (ignoring some control logic): for (LiveIntervals::const_iterator I = LIS->begin(), E = LIS->end(); I != E; ++I) { unsigned VirtReg = I->first; if ((TargetRegisterInfo::isVirtualRegister(VirtReg)) && (VRM->getPhys(VirtReg) == REG_Y)) { LiveInterval &LI = LIS->getInterval(VirtReg); unassign(LI, REG_Y); enqueue(&LI); } } RegClassInfo.runOnMachineFunction(VRM->getMachineFunction()); // update reserve reglist So similar to what's done in LRE_WillShrinkVi...

Hi again Lang, I decided to try the approach you proposed to see whether it makes the assembly-code problem go away. Again, I tried a very simple register allocator (attached) that just calls vrm.assignVirt2Phys for every vreg in each function, mapping the vreg to the first preg in the register class. I tried two versions: one maps *every* vreg, and the other only maps those for which MRI->reg_empty(vreg) returns false. In both cases I get a core dump somewhere after my reg-allocat...

Hello, I have worked on LLVM for my project related to Register Allocation. Bernhard Scholz suggested that Implementing Branch and Bound Heuristic for Reduce N in PBQP register Allocation for LLVM would be to great project to work on. I'm looking forward to implement it in LLVM system. How should i get start about it ? I would also like to know about some of the other projects in LLVM.

...te the virtual register mapping (VirtRegMap pass) with your allocation, rather than rewriting the registers directly through MachineRegisterInfo. Have your allocator require and preserve the VirtRegMap pass, then in your runOnMachineFunction pass grab a reference to the pass with: VirtRegMap &vrm = getAnalysis<VirtRegMap>(); You can then describe your register allocations with: vrm.assignVirt2Phys(<virtreg>, <physreg>) The VirtRegRewriter pass (in VirtRegMap.cpp) will run after your allocator and apply the mapping that you described in the VirtRegMap. I hope this helps...