similar to: [LLVMdev] [LLVMDev] Profile guided information?

Bump: Does profiling / run time information exist when dealing with machine basic blocks? Thanks, Jeff Kunkel On Tue, Sep 28, 2010 at 9:51 AM, Jeff Kunkel <jdkunk3 at gmail.com> wrote: > How do I find the profiling or run time information for machine basic > blocks from a machine function? There are quite a few optimization > that may be preformed with this information, when it

How do I find the profiling or run time information for machine basic blocks from a machine function? There are quite a few optimization that may be preformed with this information, when it exists. Thanks, Jeff Kunkel

Hi Jeff, There is an algorithm to build the dominator tree that is O(n2), where n is the number of nodes on the control flow graph. I believe exists another that is linear, but I don't which one of them is implemented in LLVM. The problem is that the branch predictor requires post dominance information. None of the LLVM basic passes require post dominance information (AFAIK), hence it is

You said it was expensive, but if you had to put a big-o estimate on it, what would it be? -Thanks Jeff Kunkel On Tue, Nov 2, 2010 at 8:54 PM, Andrei Alvares <logytech at gmail.com> wrote: > Hello Jeff, > > On Tue, Nov 2, 2010 at 9:17 PM, Jeff Kunkel <jdkunk3 at gmail.com> wrote: > > My god! I would love a branch predictor! It would simplify many aspects > of >

Hello Jeff, On Tue, Nov 2, 2010 at 9:17 PM, Jeff Kunkel <jdkunk3 at gmail.com> wrote: > My god! I would love a branch predictor! It would simplify many aspects of > my register allocator. The branch predictor of the implementation is not as accurate as the one from the paper, but it is close enough. Unfortunately, the branch predictor is a very expensive pass, because it relies on

My god! I would love a branch predictor! It would simplify many aspects of my register allocator. Second, I am surprised it did not make it into the tree. Since more is being done with register allocation as a while "RegAllocBasic" was just put in, I hope this is looked at again. Do you have a working svn copy? Also, could you send me a copy/link to that '94 paper off the list

I am looking for the slot index of a register around the given slot index Min. Is there a better way than the linear search: ... findDefUsesAroundIndex( LiveInterval* li, SlotIndex Min ) ... for( MachineOperand * mo = MRI->getRegUseDefListHead(li->reg); mo; mo = mo->getNextOperandForReg() ) { SlotIndex si = SI->getInstructionIndex( use.getOperand().getParent() ); if(

I forgot to cc the list. On Sat, Oct 9, 2010 at 10:47 AM, Jeff Kunkel <jdkunk3 at gmail.com> wrote: > On Sat, Oct 9, 2010 at 10:37 AM, Michael Spencer <bigcheesegs at gmail.com> wrote: >>> On Sat, Oct 9, 2010 at 1:10 AM, Jeff Kunkel <jdkunk3 at gmail.com> wrote: >>>> Hello, does LLVM already have a Random Number Generator built into >>>>

I am plugging this into my code. If someone wants to take it out and add it to the llvm library, it's a simple Linear Congruential Generator, but here it is: typedef struct random_number_gen { unsigned a, c, seed, m; random_number_gen( unsigned seed, unsigned modulo ) : seed(seed), m(modulo) { unsigned primes[] = { 2, 3, 5, 7, 11, 13, 17, 19, 23, 29 };

I'm just running VS 10 in debug mode. In a step by step set up: 1. I download the svn 2. I make my changes 3. I compile the libraries 4. I make changes to the code within my project 5. I compile my code, and I re-link llc with my changed files. 6. I repeat 4,5, and 6 until it finally works. - Jeff Kunkel On Tue, Nov 2, 2010 at 1:21 PM, Óscar Fuentes <ofv at wanadoo.es> wrote: >

I forgot to CC the forum. I found what was happening. The BranchFolder documentation says: // Note that this pass must be run after register allocation, it cannot handle // SSA form. > On Wed, Oct 6, 2010 at 8:05 PM, Jeff Kunkel <jdkunk3 at gmail.com> wrote: >> No, I just noticed that blocks were separated. >> >> >> On Wed, Oct 6, 2010 at 8:04 PM, Bob Wilson

- I placed my code in the the existing CodeGen library. - No, it is not in the CMakeLists.txt. The code is separate from the rest of the CodeGen code, but it is linked into the code gen library automatically through the visual studio linker. Perhaps something funny is going on here. I will try placing the code directly in the library, and I will include it to the CMakeLists.txt. - Thanks - Jeff

Also note: there may be multiple MachineBasicBlock's for a single BasicBlock. - David M On Fri, Oct 15, 2010 at 4:59 AM, Jeff Kunkel <jdkunk3 at gmail.com> wrote: > I don't think you can. > > The BasicBlock is a member of MachineBasicBlock. It is not inherited, > so it cannot be cast. The number of the MachineBasicBlock is not the > same as any BasicBlock values.

1. Summary I will implement two optimizations in the LLVM compiler, both based on runtime profile information: an inlining mechanism that takes the call frequency into consideration, and a better basic block placement algorithm. 2. The project LLVM now includes an efficient framework [1] for instrumenting an application and collecting edge and path profile information. Profile-guided

Thank you! The pieces are starting to fall into place finally. I need to track which MachineBasicBlocks branch into other MachineBasicBlocks. How do I do it? I see a MachineOperand can hold a MachineBasicBlock*. Does this mean the instruction may branch to the MachineBasicBlock, or can it be something like an object reference? - Thanks, Jeff Kunkel On Thu, Sep 2, 2010 at 1:56 PM, Jeff Kunkel

Let me rephrase my question. The live intervals have a weight associated with them. What does this weight exactly represent? Thanks Jeff Kunkel On Thu, Oct 28, 2010 at 7:41 PM, Jeff Kunkel <jdkunk3 at gmail.com> wrote: > I understand the mechanics. I don't know why a lesser weight is better > than a greater weight. > > > On Thu, Oct 28, 2010 at 7:22 PM, Jakob Stoklund

Would I be correct in assuming that the alias set is defined as the registers which may reside in the same space as the register? In other words the register is either a super or sub register which holds the same physical location in the register set? Could someone please explain what the Alias set is if it is not what I described above? TargetRegisterInfo::getAliasSet( unsigned reg ) Thanks

Hi! My name is Gratian and I would like to participate to GSOC 2011. I'm interested in profile-guided optimizations, and I want to implement two optimizations that can bring tangible benefits for most applications: profile-guided function inlining and basic block positioning. Inlining can be greatly improved if we take into consideration how many times the function we want to inline was

hello,everyone recently, I analyze the compiler optimization level, so I have searched the usage of profile-guided optimization of LLVM, but little result in google, therefore, could you please list detailed usage of profile-guided optimization? LLVM must be install with flags '--enable-profile'? A example will be pleasure. thanks von -------------- next part -------------- An HTML

I ran cmake to build the visual studio projects. Then I included my code under the Visual Studio interface, but I placed my code separate from the CodeGen code. Visual studio was smart enough to compile and link in my code into the CodeGen library. Thus, I did not need to add my code into the same directory as the CodeGen files, and I did not need to change the CMakeList.txt. The offical name is