search for: liveintervals

Displaying 20 results from an estimated 526 matches for "liveintervals".

2013 Dec 31
2
[LLVMdev] How to update LiveInterval information of newly inserted machine basic block
...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 LiveVariables which require the machine function to be in SSA form. However, in this case, the modified machine function(including newly inserted MBB) is not SSA form any more. So, how to update LiveInterval information of newly MBB? Could someone help me with that? Thank you very much in...
2012 Aug 17
0
[LLVMdev] Assert in LiveInterval update
...#39; failed. has this following call stack: #3 in llvm::LiveInterval::addRangeFrom (this=0x46e99a0, LR=..., From=0x46ee4b0) at lib/CodeGen/LiveInterval.cpp:266 #4 in llvm::LiveInterval::addRange (this=0x46e99a0, LR=...) at include/llvm/CodeGen/LiveInterval.h:384 #5 in llvm::LiveIntervals::HMEditor::moveInternalFrom (this=0x7fffffff8010, OldIdx=..., P=...) at lib/CodeGen/LiveIntervalAnalysis.cpp:1220 #6 in llvm::LiveIntervals::HMEditor::moveAllInternalFrom (this=0x7fffffff8010, OldIdx=..., Internal=...) at lib/CodeGen/LiveIntervalAnalysis.cpp:1226 #7 in llvm::Li...
2014 Jan 03
2
[LLVMdev] How to update LiveInterval information of newly inserted machine basic block
...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 LiveVariables which require the machine function to be in SSA form. However, in this case, the modified machine function(including newly inserted MBB) is not SSA form any more. So, how to update LiveInterval information of newly MBB? Could someone help me with that? Thank you very much in...
2008 Jan 17
1
[LLVMdev] LiveInterval Questions
...t understanding what a "value number" is. When I think of "value number" I think of a web -- an intersection of def-use chains that relate to each other (mutliple defs reaching the same use, for example). Is this the LLVM definition of "value number" in the context of LiveIntervals? There's also the concept of "value number" in, for example, Global Value Numbering but that's not the same thing as LiveInterval "value numbers" as I understand things. -Dave
2011 May 24
0
[LLVMdev] Need advice on writing scheduling pass
...9;t have any VLIW support, so nobody has thought about how best to do it. > Well, I would like to schedule the VLIW code after SimpleRegisterCoalescer, so that I get more or less the > final code to work with. As the instructions are rearrange, I suppose I must run the SlotIndexes and > LiveIntervals again. LiveVariables should also be refreshed as a register might get killed with a different > MI if two users change place, etc, I suppose. > > I would like to just rerun these passes, but you said below that LiveIntervals do not work after SSA form is > abandoned. > > I wonde...
2011 May 24
4
[LLVMdev] Need advice on writing scheduling pass
...er that gets killed can be reused by another MI - these live ranges do not then overlap. Well, I would like to schedule the VLIW code after SimpleRegisterCoalescer, so that I get more or less the final code to work with. As the instructions are rearrange, I suppose I must run the SlotIndexes and LiveIntervals again. LiveVariables should also be refreshed as a register might get killed with a different MI if two users change place, etc, I suppose. I would like to just rerun these passes, but you said below that LiveIntervals do not work after SSA form is abandoned. I wonder how you mean to update the l...
2015 Sep 04
2
LiveInterval and Loop Info
Thanks Matthias I can also use the method intervalIsInOneMBB() from LiveIntervals class to relate a LiveInterval to a MachineBasicBlock, right? Em 04/09/2015 2:26 PM, "Matthias Braun" <mbraun at apple.com> escreveu: > There is no direct support for this, but you can use > LiveIntervalAnalysis::getMBBStartIndex()/getMBBEndIndex()/getMBBFromI...
2005 Sep 07
3
[LLVMdev] LiveIntervals invalidates LiveVariables?
I though LiveVariables may be invalidated by LiveIntervals, but it's declared not: void LiveIntervals::getAnalysisUsage(AnalysisUsage &AU) const { AU.addPreserved<LiveVariables>(); AU.addRequired<LiveVariables>(); ... LiveInterval may coalesce virtual registers and remove identity moves instructions: bool LiveIntervals::runOnMa...
2014 Jan 04
2
[LLVMdev] How to update LiveInterval information of newly inserted machine basic block
On Jan 4, 2014, at 4:38 AM, Haishan <hndxvon at 163.com> wrote: > At 2014-01-04 06:11:38,"Jakob Stoklund Olesen" <stoklund at 2pi.dk> wrote: > > On Jan 3, 2014, at 1:52 PM, Andrew Trick <atrick at apple.com> wrote: > >> He really just wants to rerun LiveIntervals analysis, but LiveVariables is no longer available. Would it work just to clear all the intervals rerun LiveIntervals::computeVirtRegs after all the CFG transforms are complete? > > Yes, I should think so. > > /jakob > > > Thank you very much for your talk. > I think...
2009 Feb 27
2
[LLVMdev] Easiest way to rewrite machine instructions when each live range of a LiveInterval may be assigned a different physical register
...replace all virtual registers by assigned physical registers. I see different options for doing it: a) Normally, I'd use the spiller provided by the VirtRegMap class. But currently, it assumes that live register has only one physical register assigned to it. b) It could be possible to change LiveIntervalsAnalysis so that it creates a new LiveInterval for each live range. But this will probably have a negative impact on performance and also reduce coalescing possibilities. c) May be LiveIntervals could be split after register allocation, just before rewriting? How this could be easily done? May be P...
2008 Jan 17
0
[LLVMdev] LiveInterval Questions
On Jan 16, 2008, at 11:49 AM, David Greene wrote: > I had been assuming that give a LiveRange a, a.valno->def, if > valid, would be the same as a.start. But this is apparently not > always the case. For example: > > Predecessors according to CFG: 0x839d130 (#3) 0x8462780 (#35) > 308 %reg1051 = MOV64rr %reg1227<kill> > 312 %reg1052 = MOV64rr %reg1228<kill>
2014 Jan 03
2
[LLVMdev] How to update LiveInterval information of newly inserted machine basic block
On Jan 3, 2014, at 1:52 PM, Andrew Trick <atrick at apple.com> wrote: > He really just wants to rerun LiveIntervals analysis, but LiveVariables is no longer available. Would it work just to clear all the intervals rerun LiveIntervals::computeVirtRegs after all the CFG transforms are complete? Yes, I should think so. /jakob -------------- next part -------------- An HTML attachment was scrubbed... URL: &lt...
2018 Nov 07
3
How to invoke the print method in MachineFunctionPass
...have a 'usual' pass, which can be used by the 'opt' tool, we can just pass the '-analyze' command line argument but what about the 'llc' compiler? As I can see, there is an implementation of the 'print(raw_ostream &OS, const Module*)' method in the 'LiveIntervals.cpp'. void LiveIntervals::print(raw_ostream &OS, const Module* ) const { OS << "********** INTERVALS **********\n"; // Dump the regunits. ... The method also is implemented in 'RegisterCoalescer.cpp' (in fact, this method just invokes one from LiveInt...
2014 Jan 03
2
[LLVMdev] How to update LiveInterval information of newly inserted machine basic block
...>>>> >>>> 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: >>>> My update steps are shown following: >>>> LiveIntervals *LIS = &getAnalysis<LiveIntervals>(); >>>> 1. LIS->insertMBBInMaps(NewMBB) >>>> 2. LIS->InsertMachineInstrRangeInMaps(NewMBB->begin(), NewMBB->end()) >>>> 3. Due to some machine instructions of NewMBB copy from OldMBB, I have to...
2009 Feb 27
0
[LLVMdev] Easiest way to rewrite machine instructions when each live range of a LiveInterval may be assigned a different physical register
...ical registers. I > see different options for doing it: > > a) Normally, I'd use the spiller provided by the VirtRegMap class. But > currently, it assumes that live register has only one physical > register assigned to it. Right. > > > b) It could be possible to change LiveIntervalsAnalysis so that it > creates a new LiveInterval for each live range. But this will probably > have a negative impact on performance and also reduce coalescing > possibilities. Not to mention it will significantly increase memory usage. > > > c) May be LiveIntervals could be spli...
2008 Jan 16
4
[LLVMdev] LiveInterval Questions
I had been assuming that give a LiveRange a, a.valno->def, if valid, would be the same as a.start. But this is apparently not always the case. For example: Predecessors according to CFG: 0x839d130 (#3) 0x8462780 (#35) 308 %reg1051 = MOV64rr %reg1227<kill> 312 %reg1052 = MOV64rr %reg1228<kill> 316 %reg1053 = MOV64rr %reg1229<kill> 320 %reg1054 = MOV64rr
2010 May 08
0
[LLVMdev] Regarding LLVM Compiler
...llocator (-regalloc=pbqp), whereas LLVM uses linear scan by default (-regalloc=linscan). That's why you're not seeing it called. LLVM does not currently have an interference graph as such, because we do not have a graph coloring register allocator. You can get the same information from the LiveIntervals pass though. The LiveIntervals pass holds a set of LiveInterval objects, one for each register (both virtual and physical) that is live in the function. Each LiveInterval object describes the set of instructions for which its register is live. The LiveInterval::overlaps method will tell you whether...
2014 Apr 04
2
[LLVMdev] How should I update LiveIntervals after removing a use of a register?
...ant to transform: ... %vreg1 = V_MOV_B32 1 %vreg2 = V_ADD_I32 %vreg1, %vreg0 ... into: %vreg1 = V_MOV_B32 1 ; <- Only delete this if it is dead %vreg2 = V_ADD_I32 1, %vreg0 For best results, I am trying to run this pass after the TwoAddressInstruction pass, which means I need to preserve the LiveIntervals analysis. My question is: How do I update the LiveIntervals to reflect the fact that V_ADD_I32 no longer uses %vreg0? Thanks, Tom
2015 Sep 03
2
LiveInterval and Loop Info
Hello to all LLVM Developers. Given a object from a LiveInterval class, is there any way to know if this Live Interval is part or is inside a loop? Att -- Natanael Ramos Membro do corpo discente de Ciência da Computação pelo Instituto Federal de Minas Gerais - Campus Formiga -------------- next part -------------- An HTML attachment was scrubbed... URL:
2012 Aug 15
3
[LLVMdev] MI bundle liveness attributes
On Aug 13, 2012, at 8:34 AM, Sergei Larin <slarin at codeaurora.org> wrote: > Andy, > > Yes, this is what Arnold has suggested also, and from this point it looks > like it should work, but it will require parsing the bundle every time we > care to know whether this is a real use or a conditional def. This might > become awkward... but I guess I should provide a better