search for: mappbqptoregalloc

Hi All, I finally had a chance to get back to my pbqp trials, now using the 3.0 release. I still hit the same assert : "Attempting to spill already spilled value." This is triggered because in RegAllocPBQP::mapPBQPToRegAlloc, a vreg node is either : - a physical register (problem.isPRegOption(vreg, alloc)), - or a spill (problem.isSpillOption(vreg, alloc)) The problem is that pass CalcSpillWeights can 'hint' that it is a poor idea to spill this specific register with : CalcSpillWeights.cpp / VirtRegAuxInfo:...

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.

...int would be welcome. > > The data structure you want to keep your eye on is the set vregsToAlloc to RegAllocPBQP. This set holds the virtual registers which PBQP must allocate for on its next round. Once a virtual register has been spilled it should be erased from this set (see RegAllocPBQP::mapPBQPToRegAlloc), and it should never re-enter it, and thus never be considered again by the PBQP allocator. At a guess it sounds like one of your vregs may be being added to this set a 2nd time, but I'm not sure how that could be happening. Is your backend public? Are you able to share a test case with me? I...

...5000e-02) Selected 0 for node 5 (cost = inf) Selected 1 for node 3 (cost = 0.000000e+00) Selected 1 for node 2 (cost = 0.000000e+00) Selected 1 for node 1 (cost = 0.000000e+00) llc: /home/lhames/Projects/llvm/llvm-broken-pbqp/llvm/lib/CodeGen/RegAllocPBQP.cpp:701: bool<unnamed>::PBQPRegAlloc::mapPBQPToRegAlloc(const PBQP::Solution&): Assertion `solution.getCost() != std::numeric_limits<PBQP::PBQPNum>::infinity() && "Invalid (infinite cost) solution for PBQP problem."' failed. The problem is that node 5 is being allocated an infinite cost option (which implies that all its...

Attached is a small patch to allow users of the PBQP allocator to optionally insert a custom pass. I believe it can be usefull to other users of the pbqp. I used it to undo some of the coalescer work, and make sure that I have different virtual registers, inserting a copy if necessary, to build a pair. I noticed an unexpected --- to me at least --- behaviour of the allocator. I have some

...larddegrandmaison at parrot.com> wrote: > > Hi All, > > I finally had a chance to get back to my pbqp trials, now using the 3.0 > release. I still hit the same assert : "Attempting to spill already spilled > value." > > This is triggered because in RegAllocPBQP::mapPBQPToRegAlloc, a vreg node is > either : >  - a physical register (problem.isPRegOption(vreg, alloc)), >  - or a spill (problem.isSpillOption(vreg, alloc)) > > The problem is that pass CalcSpillWeights can 'hint' that it is a poor > idea to spill this specific register with : > >...

...node 5 (cost = inf) > Selected 1 for node 3 (cost = 0.000000e+00) > Selected 1 for node 2 (cost = 0.000000e+00) > Selected 1 for node 1 (cost = 0.000000e+00) > llc: /home/lhames/Projects/llvm/llvm-broken-pbqp/llvm/lib/CodeGen/RegAllocPBQP.cpp:701: > bool<unnamed>::PBQPRegAlloc::mapPBQPToRegAlloc(const PBQP::Solution&): > Assertion `solution.getCost() != > std::numeric_limits<PBQP::PBQPNum>::infinity() && "Invalid (infinite > cost) solution for PBQP problem."' failed. > > The problem is that node 5 is being allocated an infinite cost option &g...

...ng. Any hint would be welcome. The data structure you want to keep your eye on is the set vregsToAlloc to RegAllocPBQP. This set holds the virtual registers which PBQP must allocate for on its next round. Once a virtual register has been spilled it should be erased from this set (see RegAllocPBQP::mapPBQPToRegAlloc), and it should never re-enter it, and thus never be considered again by the PBQP allocator. At a guess it sounds like one of your vregs may be being added to this set a 2nd time, but I'm not sure how that could be happening. Is your backend public? Are you able to share a test case with me? I...

Hi Lang, I'm surprised about the fact that you omit R1/R2 reductions in some cases. Can you give a more detailed description of the bug (e.g. a PBQP dump)? Best regards, Sebastian Lang Hames wrote: > Hi Sachin, llvm-dev, > > I've just committed a new PBQP solver which, among other things, > should take care of this bug. > > Please let me know how it works out for you.

Hi Sachin, llvm-dev, I've just committed a new PBQP solver which, among other things, should take care of this bug. Please let me know how it works out for you. Cheers, Lang. On Tue, Dec 15, 2009 at 5:54 PM, Lang Hames <lhames at gmail.com> wrote: > Hi Sachin, > > Yes. Bernhard Scholz and I have just discussed a fix for this. I hope to > commit it in the next few days. I