search for: superregisters

Displaying 20 results from an estimated 30 matches for "superregisters".

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2008 Feb 21
2
[LLVMdev] Bug? Coalescing & Updating Subreg Intervals
On Feb 20, 2008, at 12:25 PM, David Greene wrote: > On Wednesday 20 February 2008 14:14, David Greene wrote: > >> I discovered this through an assert I put into some of my own >> code. I want >> to know if that assert is bogus or if there's a bug here. > > A little more information: the assert checks that after coalescing > two nodes, > all subregister
2008 Jan 23
1
[LLVMdev] LiveInterval Splitting & SubRegisters
On Wednesday 23 January 2008 02:01, Evan Cheng wrote: > > Can you explain the basic mechanics of the live interval splitting > > code? > It's splitting live intervals that span multiple basic blocks. That > is, when an interval is spilled, it introduce a single reload per > basic block and retarget all the uses to use the result of the single > reload. It does not
2008 Feb 20
0
[LLVMdev] Bug? Coalescing & Updating Subreg Intervals
On Wednesday 20 February 2008 14:14, David Greene wrote: > I discovered this through an assert I put into some of my own code. I want > to know if that assert is bogus or if there's a bug here. A little more information: the assert checks that after coalescing two nodes, all subregister live intervals for the register coaelsced to now interfere with whatever the eliminated live
2008 Feb 21
0
[LLVMdev] Bug? Coalescing & Updating Subreg Intervals
On Wednesday 20 February 2008 07:00:28 pm Evan Cheng wrote: > > In other words, after coalescing, should it be the case that > > subregister > > intervals contain at least all of the range information that was > > contained > > in any eliminated intervals when those eliminated intervals were > > coalesced > > to the subregister's superregister? >
2008 Jan 22
4
[LLVMdev] LiveInterval Splitting & SubRegisters
Evan, Can you explain the basic mechanics of the live interval splitting code? Is it all in LiveIntervalAnalysis.cpp under addIntervalsForSpills and child routines? What is it trying to do? Also, in the ancient subregister coalescing code, there used to be an update of the SSARegMap to point subregisters to the superregister they were coalesced to (IIRC). That has since gone away. I used to
2008 Feb 20
3
[LLVMdev] Bug? Coalescing & Updating Subreg Intervals
I have a question about what is going on at line 754 of SimpleRegisterCoalescing.cpp. The comment says we are updating the live intervals for subregisters. This happens when we coalesce to a physical register. Now, I read that as, "merge in the range information from the eliminated live interval to the subregister live interval," but that appears to not be what happens. In my case,
2008 Jan 23
0
[LLVMdev] LiveInterval Splitting & SubRegisters
On Jan 22, 2008, at 12:23 PM, David Greene wrote: > Evan, > > Can you explain the basic mechanics of the live interval splitting > code? > Is it all in LiveIntervalAnalysis.cpp under addIntervalsForSpills > and child > routines? What is it trying to do? It's splitting live intervals that span multiple basic blocks. That is, when an interval is spilled, it
2008 Feb 21
2
[LLVMdev] Bug? Coalescing & Updating Subreg Intervals
On Feb 20, 2008, at 7:36 PM, David A. Greene wrote: > On Wednesday 20 February 2008 07:00:28 pm Evan Cheng wrote: > >>> In other words, after coalescing, should it be the case that >>> subregister >>> intervals contain at least all of the range information that was >>> contained >>> in any eliminated intervals when those eliminated intervals were
2011 Apr 07
1
[LLVMdev] IMPLICIT_DEF?
Hi, I have a MachineInstr that writes to a subreg, but clobbers the superreg. How should I BuildMI this instruction? I try to do a IMPLICIT_DEF super_reg and then write to a subreg of that super register , but it gets DCE:ed. Is there a way to express this clobbering of a superregister? thanks, Jonas -------------- next part -------------- An HTML attachment was
2015 Dec 04
2
analyzePhysReg question
>-----Original Message----- >From: Quentin Colombet [mailto:qcolombet at apple.com] >Sent: Thursday, December 03, 2015 4:43 PM >To: Smith, Kevin B <kevin.b.smith at intel.com> >Cc: llvm-dev at lists.llvm.org >Subject: Re: [llvm-dev] analyzePhysReg question > > >> On Dec 3, 2015, at 4:35 PM, Smith, Kevin B via llvm-dev <llvm- >dev at lists.llvm.org>
2015 Dec 04
2
analyzePhysReg question
> On Dec 3, 2015, at 5:36 PM, Quentin Colombet via llvm-dev <llvm-dev at lists.llvm.org> wrote: > >> >> On Dec 3, 2015, at 5:11 PM, Smith, Kevin B <kevin.b.smith at intel.com <mailto:kevin.b.smith at intel.com>> wrote: >> >> >> >>> -----Original Message----- >>> From: Quentin Colombet [mailto:qcolombet at apple.com
2010 Sep 02
0
[LLVMdev] [LLVMDev] [Modeling] About the structure of my allocator
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
2018 Jan 23
1
MachineVerifier and undef
I'm working on getting an out of tree target machine verifier clean. This has found some nasty bugs so I'd like to continue with it. One instance of bad machine code is "Using an undefined physical register". This arises whenever undef propagates to a machine instruction. Usually this means the input was meaningless - e.g. call an undefined address. Other times it's a
2015 Dec 04
2
analyzePhysReg question
I am looking at results from analyzePhysReg, and am getting results a little different than I expected for x86. The call to this is coming from this code in llvm::MachineBasicBlock::computeRegisterLiveness 1163 MachineOperandIteratorBase::PhysRegInfo Analysis = 1164 ConstMIOperands(I).analyzePhysReg(Reg, TRI); The instruction I being analyzed is: %BX<def> = MOV16rm
2010 Sep 02
5
[LLVMdev] [LLVMDev] [Modeling] About the structure of my allocator
I need to model my registers for my allocator. I need to identify the super-register and the sub-register conflicts. Something like: For each set of registers R in the set of aligned registers defined by the input request virtual register alpha. Now each register block r in R can have zero, one, or more registers defined in the block started at the aligned size and ending at the aligned size plus
2010 Aug 31
2
[LLVMdev] Register design decision for backend
Hello Jeff, you're the first one to reply to my question :) I got a bit confused with the fact you said that the subregister class is larger than the superregister class. As far as i understood or what i tried to do with my code is to define a register pair composed of two 8 bit registers the way i described in my previous message. So R1R0 in WDREGS is directly mapped into R0 and R1 of GPR8.
2012 Oct 09
0
[LLVMdev] Pairing Registers on a Target Similar to Mips?
Ryan, I don't think I fully understand the problem you described, but please see the comments below. Hope this helps you solve the problem. On Sat, Oct 6, 2012 at 3:18 PM, ryan baird <ryanrbaird at gmail.com> wrote: > I'm working on a target based on the MIPS target, and when I copy f64 > values into 32 bit registers for calling functions, I need the operation to > work
2010 Aug 31
0
[LLVMdev] Register design decision for backend
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
2015 Dec 04
2
analyzePhysReg question
>-----Original Message----- >From: llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org] On Behalf Of >Sanjoy Das via llvm-dev >Sent: Thursday, December 03, 2015 11:16 PM >To: Quentin Colombet <qcolombet at apple.com> >Cc: llvm-dev at lists.llvm.org >Subject: Re: [llvm-dev] analyzePhysReg question > >I think this is related to PR25033:
2012 Oct 06
2
[LLVMdev] Pairing Registers on a Target Similar to Mips?
I'm working on a target based on the MIPS target, and when I copy f64 values into 32 bit registers for calling functions, I need the operation to work on a of 32 bit registers (because the language I'm translating to isn't actually mips). I've been looking at how to do this, but I haven't been able to figure it out. Since the Mips target code is still really close to mine,