similar to: Build a Interference Graph

Ok, just to clarify, RegUnits, as far I understand, are Physical registers or alias to Physical registers. They exist because some instructions use physical registers directly rather than virtual register. It's right? And why this RegUnits should be present in the Interference Graph? I thought were only the Live Intervals would be the nodes of the graph. Sorry about the trouble to

I'm working on my project for completion undergraduate courses, consisting of an experimental analysis of registers allocation algorithms. For this task, I am using the set of tools from the LLVM project. However, I have read the documentation of the LLVM project and not yet found a way to put the pieces of the puzzle together. So far I know: - As passes work as engage them to LLVM and

Hello to all LLVM developers. I'm developing a register allocator using LLVM, my allocator has a local search phase: given a solution (assignment of virtual registers to physical registers or memory) generated in the first phase of the algorithm, some movements are applied to this solution in order to find a better solution. To apply such movements, I need to unassign a virtual register from

Hello to all. I'm trying to implement a simple register allocator using graph colouring (I know, everyone has already done that :-)) and I'm also using LLVM 3.4 from master branch. The algorithm I'm using is based on the one described on the "Modern Compiler Implementation in C". My implementation is totally experimental and doesn't aim to be fast, eficient or even

On Sep 17, 2013, at 5:15 AM, Leandro Santiago <leandrosansilva at gmail.com> wrote: > Hello to all. I'm trying to implement a simple register allocator using graph colouring (I know, everyone has already done that :-)) and I'm also using LLVM 3.4 from master branch. > > The algorithm I'm using is based on the one described on the "Modern Compiler Implementation in

Hi Jakob, I've got a good test case that I'm working on at the moment. I noticed something odd though: Is '0' a valid register unit? I'm seeing a LiveInterval with li->reg == 0 show up, which previously wasn't valid. We have a few checks around the place to disregard the '0' physreg - could these trigger on interaction with a '0' interval? That could

Jakob Stoklund Olesen <stoklund at 2pi.dk> writes: >> A MachineOperand has both a getReg() and a getSubReg() interface. >> For a physical register operand, is getReg() guaranteed to be the >> "most super" register with getSubReg() providing the specific >> subregister information for the operand? If so then for my current >> purposes it seems I

Hello, I have an R script that I use as a template to perform a task for multiple files (in this case, multiple chromosomes). What I would like to do is to utilize a simple loop to parse through each chromosome number so that I don't have to type the same code over and over again in the R console. I've tried using: for(i in 1:22){ etc.. } and replacing each chromosome number with

Good Afternoon. I am a Computer Science undergraduate student in Brazil and as completion of course work, I am developing an register allocator, using the infrastructure of the LLVM. To accomplish this task, I have based my implementation in allocators already implemented in LLVM. But a question came to me while I was researching in books and articles of compiler theory and own documentation of

Hello to all LLVM Developers. The LLVM IR is in strict SSA form (i.e. every variable is defined before it is used along every path from the entry to exit point)? According to the documentation, currently the LLVM IR is in the SSA form, but I don't see additional information about *strict* SSA form. The strict SSA form provide opportunities of optimization in register allocation, because is

On Apr 19, 2013, at 7:18 AM, <dag at cray.com> wrote: > Jakob Stoklund Olesen <stoklund at 2pi.dk> writes: > >>> A MachineOperand has both a getReg() and a getSubReg() interface. >>> For a physical register operand, is getReg() guaranteed to be the >>> "most super" register with getSubReg() providing the specific >>> subregister

Patch for review. On Mon, Aug 21, 2017 at 11:45 PM Puyan Lotfi <puyan.lotfi.llvm at gmail.com> wrote: > Ping. > > Still working on preparing code for review. Will have a patch for review > ready in the coming days. > > PL > > On Tue, Aug 15, 2017 at 12:06 PM Puyan Lotfi <puyan.lotfi.llvm at gmail.com> > wrote: > >> Hi, >> >> >>

> On 29 Sep 2020, at 09:28, Quentin Colombet <qcolombet at apple.com> wrote: > > + Daniel who added the MCRegister class. > > Ah sorry, I replied too fast. > I mixed up MCPhysReg with MCRegister. > > I was not aware we had such class. > > From a look at it, MCRegister are essentially the same thing as Register. I am guessing that the difference is Register

Thanks Lang! Here's another question: I'm trying to process this input: int main() { return 0; } but I'm getting an error Assertion `!Fn.getRegInfo().getNumVirtRegs() && "Regalloc must assign all vregs"' failed. At the start of runOnMachineFunction I call Fn.getRegInfo().getNumVirtRegs(); and find that there is 1 virtual register. However,

When we discussed this our line of thought was like this: - LLVM IR already uses %name for SSA values which is closer to what a vreg is than to what a physreg is. It would be neat to draw that parallel to llvm IR. - We wanted another sigil for physregs so they are easy to differentiate from vregs to allow people to differentiate vregs/physregs even if they don't know all the physreg names of

Yes so long as you're including the invalid space too (IIRC it matters for DBG_VALUE in particular) the reason I didn't do that is that there's a lot more ctors than consumers of MCRegister. It seemed cheaper to do the checks when they're consumed and pretty much every consumer I encountered started with `assert(Reg.isPhysicalRegister() && ...)`. > On 29 Sep 2020, at

Hi, My name is Puyan and I've been exploring ways to improve the state of instruction level diffing using llvm and MIR. Below is a proposal for a new llvm tool meant to address issues encountered when diffing at the machine level. I'm eager to hear the community's feedback. Thanks PL mir-canon: A new tool for canonicalizing MIR for cleaner diffing. Problem Statement and

On Jun 12, 2007, at 10:53 AM, Chris Lattner wrote: > On Tue, 12 Jun 2007, Christopher Lamb wrote: >>>> What's the best way to get an SDNode through to DAG scheduling >>>> without getting mangled during Lowering/ISel? >>> >>> What do you mean by "mangled"? Please clarify. >> >> My mangled I mean the nodes shouldn't be

Hi Susan, In x86-64 the REX prefix must be used to access an extended register (r8-r15 and their aliases), but cannot be used when accessing the high byte of the ABCD regs (AH, BH, CH, DH). In your test case you have hardcoded %vreg1 to R8B, and %vreg15 to AH, and the test case contains a copy between these registers. The copy simultaneously must have a REX prefix, and cannot have a REX prefix,

> On 29 Sep 2020, at 11:13, Mircea Trofin <mtrofin at google.com> wrote: > > > > On Tue, Sep 29, 2020 at 11:09 AM Daniel Sanders <daniel_l_sanders at apple.com <mailto:daniel_l_sanders at apple.com>> wrote: > Yes so long as you're including the invalid space too (IIRC it matters for DBG_VALUE in particular) the reason I didn't do that is that