similar to: [LLVMdev] Where is liveness analysis pass?

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Jin-Gu Thanks for your suggestion. Using liveness information for virtual register is a good idea, but what I am working on is a source-to-source compiler, so I prefer to use FunctionPass instead of MachineFunctionPass. Interestingly I found a FunctionPass example for classic liveness data flow equation. http://cs.pub.ro/~cpl/wiki/images/1/15/Hello.txt

I've read that LiveValues has been removed from trunk. Did it bitrot or was simply removed because a replacement is available? If it's the former, what caused the bitrotting? If it's the latter, what's the replacement? (I've found LiveVariables but I'm not sure it can be used in a ModulePass). b.r. -- Carlo Alberto Ferraris <cafxx at strayorange.com <mailto:cafxx

LiveVariables is the optimized and tested way to get variable liveness information (it's used by register allocation). Unfortunately it requires a MachineFunction to work - so you'll either need to lower to one of the built-in targets or add your own target to acquire access to this pass. Andrew On 03/31/2011 12:28 PM, Carlo Alberto Ferraris wrote: > I've read that LiveValues

On Jul 11, 2007, at 11:39 AM, David Greene wrote: > On Wednesday 11 July 2007 12:41, Tanya M. Lattner wrote: > >> I think the coalescer should be flexible enough to be run >> independent of >> the register allocator. For example, you may want to expose the >> copies >> induced by transforming out of SSA to the scheduler. If the >> scheduler is

Hi all, At some points of my program, I would like to know if some LLVM values are live or not. For that, I'm using the LiveValues pass, which gives me methods such as : isLiveThroughBlock(Value * v, BasicBlock * b) isKilledInBlock(Value * v, BasicBlock * b) * If I understand well the code, dominator trees are used to compute the LiveThrough blocks. The definition of dominator in graph

Hi, I am combining 16-bit registers to a 32 bit register in order to make a wide store, as per below: 732 %reg16506:hi16<def,dead> = COPY %reg16445<kill>; 740 %reg16506:lo16<def> = COPY %reg16468<kill>; 748 %r3<def,dead> = store %reg16506<kill>, %r3, As you can see, LiveVariables has marked the high part dead, even though the super-register is used at

On May 19, 2011, at 7:47 AM, Jonas Paulsson wrote: > Hi, > > I am combining 16-bit registers to a 32 bit register in order to make a wide store, as per below: > > 732 %reg16506:hi16<def,dead> = COPY %reg16445<kill>; > 740 %reg16506:lo16<def> = COPY %reg16468<kill>; > 748 %r3<def,dead> = store %reg16506<kill>, %r3, > > As you can

Hi, I tried to use the LiveValues pass without success. I did exactly as you wrote me but no luck for me. I am getting this error : [rotem at localhost ~]$ opt -load /home/rotem/Desktop/install/Release/lib/BBPass.so -BBPass < /home/rotem/Desktop/tmp/BBtry.bc > /dev/null Error opening '/home/rotem/Desktop/install/Release/lib/BBPass.so':

Hi (Jakob), in reference to the prior message below, I have the following follow-up questions, as I also need a scheduling pass prior to regalloc. I need to do this in order to set VLIW-flags, so that the RA is aware of several MI's per cycle with a redefined LiveRange::overlap-function. On a multiple-issue cycle, a register that gets killed can be reused by another MI - these live ranges do

Hi, I need the Instructions live out, so i will be able to run my pass. One option that i already discussed is to compute it myself. Second option, use the LiveValues Pass(include/llvm/Analysis/LiveValues). This questions are on the LiveValues pass: Do i need to set the "LiveValues" pass in the PassManager as a prerequisite? if so how do i get the results ?How do i get/use the results

Hi, I wonder when the preRASched pass is planned to be available? I wonder how one would best try to implement a pass in between RegCoalescer and RA. After RegCoalescer, the LiveVariables information seems broken (there are no Kills anywhere), and LiveVariables can't be rerun after SSA form is left. So, how could one rebuild LiveIntevals? For register allocation purposes - what would be the

On Jun 2, 2009, at 5:54 AM, Rotem Varon wrote: > > This questions are on the LiveValues pass: > Do i need to set the "LiveValues" pass in the PassManager as a > prerequisite? if so how do i get the results ? Yes; it's a standard analysis pass. See http://llvm.org/docs/WritingAnLLVMPass.html for information about interactions between passes. > How do i get/use the

At 2014-01-01 04:36:21,"Andrew Trick" <atrick at apple.com> wrote: On Dec 31, 2013, at 3:52 AM, Haishan <hndxvon at 163.com> wrote: Hi, I insert a new machine basic block(MBB) before Greedy Register Allocation, after Simple Register Coalescing. But I encounter a fatal error "regalloc = ... not currently supported with -O0". I use command line with opt level

Hi, I insert a new machine basic block(MBB) before Greedy Register Allocation, after Simple Register Coalescing. But I encounter a fatal error "regalloc = ... not currently supported with -O0". I use command line with opt level O2, not O0. The probable reason of this error is that no LiveInterval information for newly MBB which is used by Register Allocation. And, LiveIntervals depend

On Jan 3, 2014, at 1:06 PM, Andrew Trick <atrick at apple.com> wrote: > > On Jan 3, 2014, at 12:10 PM, Jakob Stoklund Olesen <stoklund at 2pi.dk> wrote: > >> >> On Jan 3, 2014, at 11:01 AM, Andrew Trick <atrick at apple.com> wrote: >> >>> >>> On Jan 3, 2014, at 4:58 AM, Haishan <hndxvon at 163.com> wrote: >>>

On May 24, 2011, at 8:22 AM, Jonas Paulsson wrote: > Hi (Jakob), > > in reference to the prior message below, I have the following follow-up questions, as I also need a scheduling pass > prior to regalloc. I need to do this in order to set VLIW-flags, so that the RA is aware of several MI's > per cycle with a redefined LiveRange::overlap-function. On a multiple-issue cycle, a

The pass you're referring to is in include/llvm/Analysis/LiveValues.h and lib/Analysis/LiveValues.cpp. It computes conservative approximations for specific liveness queries, rather than full livein/liveout information. It's intended to be used as a heuristic. Dan On May 30, 2009, at 3:51 PM, Evan Cheng wrote: > I believe Dan has added a pass to compute livein / liveout values. >

Hello, I am interested to to know live variables at LLVM IR. There is LiveVariables implementation but it requires a MachineFunction to work. There used to be LiveValues implementation which was LLVM IR Value liveness analysis pass, but it has been removed from the trunk back in 2011. Is there any replacement to get liveness information for LLVM IR Values that could work on Module or function

So what is the status about LiveVariables. Is there a plan to remove it? After searching in old lvm-dev-mails it is mentioned that LiveVariable still exists due to one pass needing it. And a comment in TargetPassConfig.cpp indicates that the pass in question is TwoAddressInstruction: // FIXME: Once TwoAddressInstruction pass no longer uses kill flags, // LiveVariables can be removed