similar to: [LLVMdev] [PATCH] RegScavenger::scavengeRegister

On Mar 25, 2013, at 12:04 PM, Akira Hatanaka <ahatanak at gmail.com> wrote: > This patch adds parameter "EliminateFI" to RegScavenger::scavengeRegister, which tells register scavenger not to eliminate frame index of the emergency spill slot if set to false. > > I have pseudo load, store and copy instructions which are generated during register allocation and expanded

Hi Jakob, I believe Hal is trying to enable register scavenger to find two (or more) registers that can be used as temporaries. One problem I see with this approach is that, if you use register scavenger during PEI, you will have to pessimistically set aside two emergency spill slots before you call scavengeRegister, even if it turns out you only need one. Having an extra stack slot might not be

On Mar 25, 2013, at 1:41 PM, Akira Hatanaka <ahatanak at gmail.com> wrote: > Hi Jakob, > > I believe Hal is trying to enable register scavenger to find two (or more) registers that can be used as temporaries. > > One problem I see with this approach is that, if you use register scavenger during PEI, you will have to pessimistically set aside two emergency spill slots before

On Apr 6, 2013, at 12:42 AM, Hal Finkel <hfinkel at anl.gov> wrote: > ----- Original Message ----- >> From: "Jakob Stoklund Olesen" <stoklund at 2pi.dk> >> To: "Akira Hatanaka" <ahatanak at gmail.com> >> Cc: "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu>, "Hal Finkel" <hfinkel at anl.gov> >>

----- Original Message ----- > From: "Jakob Stoklund Olesen" <stoklund at 2pi.dk> > To: "Akira Hatanaka" <ahatanak at gmail.com> > Cc: "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu>, "Hal Finkel" <hfinkel at anl.gov> > Sent: Tuesday, March 26, 2013 12:40:44 PM > Subject: Re: [LLVMdev] [PATCH]

On Mar 26, 2013, at 10:29 AM, Akira Hatanaka <ahatanak at gmail.com> wrote: > The size of general purpose integer registers for mips32 is 32-bit and accumulators are 64-bit registers consisting of 32-bit hi/lo register pairs. So you will need two instructions to copy two 32-bit GPR registers to a 64-bit accumulator register. If spilling to multiple registers is unsupported, perhaps I can

On Mon, Mar 25, 2013 at 4:02 PM, Jakob Stoklund Olesen <stoklund at 2pi.dk>wrote: > > On Mar 25, 2013, at 2:51 PM, Akira Hatanaka <ahatanak at gmail.com> wrote: > > > Yes, it sounds like it will solve the problem. > > > > Using the following example where live ranges of accumulators $vreg_acc0 > and $vreg_acc1 conflict, > > > > MULT

On Mon, Mar 25, 2013 at 2:07 PM, Jakob Stoklund Olesen <stoklund at 2pi.dk>wrote: > > On Mar 25, 2013, at 1:41 PM, Akira Hatanaka <ahatanak at gmail.com> wrote: > > > Hi Jakob, > > > > I believe Hal is trying to enable register scavenger to find two (or > more) registers that can be used as temporaries. > > > > One problem I see with this

Hello all, For my custom processor backend I am trying add some instruction using BuildMI() inside eliminateFrameIndex(). I tried RegScavenger like this: unsigned RegUnused0 = RS->FindUnusedReg(&LASER::GNPRegsRegClass); if (!RegUnused0) RegUnused0 = RS->scavengeRegister(&LASER::GNPRegsRegClass, II, SPAdj); assert(RegUnused0 && "Register scavenger failed");

On Oct 8, 2013, at 2:06 PM, Akira Hatanaka <ahatanak at gmail.com> wrote: > What I didn't mention in r192119 is that mthi/lo clobbers the other sub-register only if the contents of hi and lo are produced by mult or other arithmetic instructions (div, madd, etc.) It doesn't have this side-effect if it is produced by another mthi/lo. So I don't think making mthi/lo clobber the

Currently it will always spill / restore the whole vreg but only spilling the parts that are actually live would be a nice addition in the future. Looking at r192119': if "mtlo" writes to $LO and sets $HI to an unpredictable value, then it should just have an additional (dead) def operand for $hi, shouldn't it? Greetings Matthias Am 10/8/13, 11:03 AM, schrieb Akira

What I didn't mention in r192119 is that mthi/lo clobbers the other sub-register only if the contents of hi and lo are produced by mult or other arithmetic instructions (div, madd, etc.) It doesn't have this side-effect if it is produced by another mthi/lo. So I don't think making mthi/lo clobber the other half would work. For example, this is an illegal sequence of instructions,

Is there a way to force or increase the likelihood of rematerialization of condition registers, instead of copying or spilling? mips isa doesn't have a handy instruction which enables reading or writing condition registers in one or two cycles (you need several shift and masking operations), so it makes more sense to rematerialize, if that's possible. On Sat, Apr 6, 2013 at 9:56 AM,

On Mar 25, 2013, at 2:51 PM, Akira Hatanaka <ahatanak at gmail.com> wrote: > Yes, it sounds like it will solve the problem. > > Using the following example where live ranges of accumulators $vreg_acc0 and $vreg_acc1 conflict, > > MULT $vreg_acc0, $vreg_gpr0, $vreg_gpr1 > MULT $vreg_acc1, $vreg_gpr2, $vreg_gpr3 > > (consumer of $vreg_acc1) > (consumer of

----- Original Message ----- > From: "Jakob Stoklund Olesen" <stoklund at 2pi.dk> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu>, "Akira Hatanaka" <ahatanak at gmail.com> > Sent: Saturday, April 6, 2013 11:56:28 AM > Subject: Re: [LLVMdev] [PATCH]

So what I realized is that you can't use the simple scavenger trick where you create the virtual register and use the more advanced features. This is because you can't call forward() in any form if there are virtual registers being used by any of the instructions in the basic block. This will cause forward to fail. Maybe this is a bug in forward() On 02/05/2013 02:51 PM, Reed Kotler

I ran into a case in Mips16 where I need two registers. The problem arises from the fact that SP is not a mips16 register. You can implicitly use it in load/store and, move it to/from a mips16 register and add small immediate values to it but that's it. It's not in general a problem for me because there are a bunch of mips32 registers that are hard to use in mips16 so at this time, I

No. forward() is working correctly. All virtual register references must be resolved before calling it. -Jim On Feb 5, 2013, at 4:05 PM, Reed Kotler <rkotler at mips.com> wrote: > So what I realized is that you can't use the simple scavenger trick where you create the virtual register and use the more advanced features. > > This is because you can't call forward() in any

Chris Lattner skrev: > On Feb 22, 2010, at 6:08 AM, Kalle.Raiskila at nokia.com wrote: >> currently the SPU backend does not handle big stack frames (>16*511 >> bytes) nicely. llc asserts on malformed machine instructions. >> (Assertion `MI->getOperand(OpNo).isImm() && "printDFormAddr first >> operand is not immediate") > > Sounds fine

Does not seem that anyone is using the more advanced features of RegScavenger On 02/05/2013 01:09 PM, reed kotler wrote: > I ran into a case in Mips16 where I need two registers. > > The problem arises from the fact that SP is not a mips16 register. > You can implicitly use it in load/store and, move it to/from a mips16 > register and add small immediate values to it but