similar to: [LLVMdev] Original data type after DAG legalization

Hello everybody, During the past week I've kept looking for a solution to this but i couldn't find one, is there really a way to get this type of information or some workaround? Thanks. 2010/12/22 Borja Ferrer <borja.ferav at gmail.com> > Hello, > > Is there a way to determine before register allocation if a virtual reg is > mapped to the lo or hi part of a piece of a

Hello everbody, This is my first email to the list, and hope to write more as i get more involved in LLVM. I'm currently writing a backend for a 8 bit microcontroller, and i have arrived to a point where i need to take a design decision in order to continue the development. Some background information: The microcontroller only has 8bit registers, however it has some special instructions that

Hello Jakob, I'm still getting the error, I can give you any other debug info you need. I haven't pasted the regalloc debug info here because it is quite huge, but if you tell me what specific details you need I will include them. Thanks for your help! 2012/7/14 Jakob Stoklund Olesen <stoklund at 2pi.dk> > > On Jul 14, 2012, at 10:09 AM, Borja Ferrer <borja.ferav at

Hello Jakob, Did you get a chance to take a look into this, and if not, can you do it when you get some spare time? Thanks! 2012/12/19 Borja Ferrer <borja.ferav at gmail.com> > We did something like this back when the register allocator couldn't split >> live ranges. >> > > Yes, I remember the isWinToJoinCrossClass() function, removed here: > >

Hello, some months ago i wrote to the mailing list asking some questions about register pairing, i've been experimenting several things with the help i got back then. Some background first: this issue is for a backend for an 8bit microcontroller with only 8bit regs, however it has a few 16bit instructions that only work with fixed register pairs, so it doesnt allow all combinations of regs.

Hi, I don't know if anyone else has responded to your question, but I am currently in development of a register allocator. Thank you for bringing up the fact that sub-register classes may be larger than their super-register. If this remains the case, I for one will write a transform for my allocator which will make the 16 bit register the super-register with the 8bit as the sub. At least for

Jakob, one more hint, I've placed some asserts around the code you added and noticed that the InlineSpiller::insertReload() function is not being called. 2012/7/14 Borja Ferrer <borja.ferav at gmail.com> > Hello Jakob, > > I'm still getting the error, I can give you any other debug info you need. > I haven't pasted the regalloc debug info here because it is quite

On Jan 7, 2013, at 4:58 AM, Borja Ferrer <borja.ferav at gmail.com> wrote: > Hello Jakob, > > Did you get a chance to take a look into this, and if not, can you do it when you get some spare time? It's not likely I'll have time to look at this in the near future. I'd recommend you do it yourself. /jakob > 2012/12/19 Borja Ferrer <borja.ferav at gmail.com>

Hello, I'm getting a machine verifier error after introducing the earlyclobber constraint to some instructions where the src and dest regs can't be the same. The offending instruction pattern is this one: let canFoldAsLoad = 1, isReMaterializable = 1, Constraints = "@earlyclobber $dst" in def LDDWRdPtrQ : Inst<(outs DREGS:$dst), (ins memri:$src),

Ok, I've found that marking tiny live intervals as not spillable inside VirtRegAuxInfo::CalculateWeightAndHint is not playing nicely with very constrained regclasses, in my case a regclass composed of only one register. As a workaround, instead of marking them as not spillable, I've marked them with a very high spill cost and the regalloc is able to compile the function with good code

Hello, I would like to know if there's a way of setting the callee-saved register list inside getCalleeSavedRegs() to make the PEI pass save/restore only one half of a register pair if the other half is not being used, instead of saving the whole pair. Here is an example of what I try to explain to make things more clear: Suppose this situation where we have a register file of 8bit regs, and

Hello, while testing trivial functions in my backend i noticed a suboptimal way of assigning regs that had the following pattern, consider the following function: typedef unsigned short t; t foo(t a, t b) { t a4 = b^a^18; return a4; } Argument "a" is passed in R15:R14 and argument "b" is passed in R13:R12, the return value is stored in R15:R14. Producing the

Hello Jakob, > Those are some severe constraints on register allocation, but it ought to > be possible anyway. > Indeed, these constraints aren't playing very well with the register allocator :\ > > You may wan't to investigate how RAGreedy::canEvictInterference() is > behaving. > Ok, this is what I've noticed, not sure if it makes sense at all but, regalloc

On Jul 14, 2012, at 10:09 AM, Borja Ferrer <borja.ferav at gmail.com> wrote: > Hello, > > I'm getting a machine verifier error after introducing the earlyclobber constraint to some instructions where the src and dest regs can't be the same. The offending instruction pattern is this one: > > let canFoldAsLoad = 1, > isReMaterializable = 1, > Constraints =

Hello, I noticed that the following code could be improved a little bit further. If the optimization is too tricky for the compiler or something and it's done this way by design forgive me, but in any case i just wanted to point it out. Consider the following C code: extern int mcos(int a); extern int msin(int a); extern int mdiv(int a, int b); int foo(int a, int b) { int a4 =

On Jan 9, 2013, at 10:46 AM, Borja Ferrer <borja.ferav at gmail.com> wrote: > Ok, I've found that marking tiny live intervals as not spillable inside VirtRegAuxInfo::CalculateWeightAndHint is not playing nicely with very constrained regclasses, in my case a regclass composed of only one register. > As a workaround, instead of marking them as not spillable, I've marked them

Hi Borja, On Jul 10, 2012, at 6:26 PM, Borja Ferrer wrote: > Hello, > > I would like to know if there's a way of setting the callee-saved register list inside getCalleeSavedRegs() to make the PEI pass save/restore only one half of a register pair if the other half is not being used, instead of saving the whole pair. Here is an example of what I try to explain to make things more

Hello, I would like to reserve a register or make it available to the register allocator depending if the stack is used inside a function or not. By using the stack i mean the following: if all regs are spilled so that frame space has to be allocated, arguments passed through the stack and allocas. I know how to get the last two options when the register allocator is run since that info is

On Dec 19, 2012, at 8:58 AM, Borja Ferrer <borja.ferav at gmail.com> wrote: > Hello Jakob, > > I think I've found something interesting that may help you get a better idea of what's going on. > > While looking at the debug info I noticed that the coalescer was removing lots of copies that could help the allocator make more cross class copies. As a test, I disabled

On Jul 15, 2012, at 9:20 AM, Borja Ferrer <borja.ferav at gmail.com> wrote: > Jakob, one more hint, I've placed some asserts around the code you added and noticed that the InlineSpiller::insertReload() function is not being called. > > 2012/7/14 Borja Ferrer <borja.ferav at gmail.com> > Hello Jakob, > > I'm still getting the error, I can give you any other