similar to: [LLVMdev] subregisters, def-kill

On May 19, 2011, at 7:47 AM, Jonas Paulsson wrote: > Hi, > > I am combining 16-bit registers to a 32 bit register in order to make a wide store, as per below: > > 732 %reg16506:hi16<def,dead> = COPY %reg16445<kill>; > 740 %reg16506:lo16<def> = COPY %reg16468<kill>; > 748 %r3<def,dead> = store %reg16506<kill>, %r3, > > As you can

If I write %reg16506<def> = INSERT_SUBREG %reg16506, %reg16445, hi16; #1 %reg16506<def> = INSERT_SUBREG %reg16506, %reg16468, lo16; #2 store %reg16506 #3 it will not coalesce, as LiveVariables: on #2: %16506 gets #2 as a kill #3: %16506 gets #3 as an additional kill LiveIntervalAnalysis:

On May 9, 2011, at 9:00 AM, Jonas Paulsson wrote: > Hi, > > I am trying to take 16 bit memory reads and combine them to a single 32 bit read. I am having trouble to make the code simply read 32 bytes and the use the subregisters accordingly, without unnecessary copying. > > I have tried two techniques, in the MachineFunction: > > 1. replace the MachineOperands in the users

Hi, I am trying to take 16 bit memory reads and combine them to a single 32 bit read. I am having trouble to make the code simply read 32 bytes and the use the subregisters accordingly, without unnecessary copying. I have tried two techniques, in the MachineFunction: 1. replace the MachineOperands in the users of the data with the new register/subregister index. This yields an assert failure

I see, thanks. I used to work with GCC, which has an SSA-property verification run after each pass. It is surprising to find that LLVM does not check this! Jonas > Subject: Re: [LLVMdev] subregisters, def-kill > From: stoklund at 2pi.dk > Date: Thu, 19 May 2011 15:39:40 -0700 > CC: llvmdev at cs.uiuc.edu > To: jnspaulsson at hotmail.com > > > On May 19, 2011, at 7:47

On Sun, Nov 22, 2015 at 1:28 AM, Rui Ueyama <ruiu at google.com> wrote: > I'm not sure if I understand the semantics of HI16 and LO16 relocations. If > my understanding is correct, a pair of HI16 and LO16 represents an addend > AHL. AHL is computed by (AHI<<16) | (ALO&0xFFFF). Can't we apply HI16 and > LO16 relocations separately and produce the same relocation

Hi, I have a problem regarding sub-register definitions and LiveIntervals on our target. When a subregister is defined, other parts of the register are always left untouched - they are neither read or def:ed. It however seems that Codegen treats subregister definitions as somehow clobbering the whole register. The SSA-code looks like this after isel: (Reg0 and Reg1 are 16bit registers. Reg2,

Hi Quentin, On 08/15/14 19:01, Quentin Colombet wrote: [...] >> The question is: How should true subregister definitions be >> expressed so that they do not interfere with each other? See the >> detailed problem description below. > > We do have a limitation in our current liveness tracking for > sub-register. Therefore, I am not sure that is possible. > >

On Sat, Nov 21, 2015 at 10:08 AM, Rui Ueyama <ruiu at google.com> wrote: > On Fri, Nov 20, 2015 at 11:02 PM, Simon Atanasyan <simon at atanasyan.com> > wrote: >> >> On Sat, Nov 21, 2015 at 9:28 AM, Rui Ueyama <ruiu at google.com> wrote: >> > On Fri, Nov 20, 2015 at 10:13 PM, Simon Atanasyan <simon at atanasyan.com> >> > wrote: >>

On Sat, Nov 21, 2015 at 9:28 AM, Rui Ueyama <ruiu at google.com> wrote: > On Fri, Nov 20, 2015 at 10:13 PM, Simon Atanasyan <simon at atanasyan.com> > wrote: >> >> In case of MIPS O32 ABI we have to find a matching R_MIPS_LO16 >> relocation to calculate R_MIPS_HI16 one because R_MIPS_HI16 uses >> combined addend (AHI << 16) + (short)ALO where AHI is

Hi, I'm having an issue with subregisters on my target. With a pseudo that writes to a 32 bit reg: %vreg20<def> = toHi16_low0_pseudo %vreg2; reg32:%vreg20 hi16:%vreg2 expands to %vreg2<def> = COPY %a2h; hi16:%vreg2 %vreg43<def> = mov 0, pred:0, pred:%noreg, %ac0<imp-use>, %ac1<imp-use>; lo16:%vreg43 %vreg20<def> =

Hi, I am working on support R_MIPS_HI16 / R_MIPS_LO16 in the new LLD and have a couple of questions. == Q1 In case of MIPS O32 ABI we have to find a matching R_MIPS_LO16 relocation to calculate R_MIPS_HI16 one because R_MIPS_HI16 uses combined addend (AHI << 16) + (short)ALO where AHI is original R_MIPS_HI16 addend and ALO is addend of the matching R_MIPS_LO16 relocation [1]. There are two

On Tue, 9 Jan 2007, Evan Cheng wrote: >> - How does one deal with multiple instruction sequences in a pattern? >> To load a constant is a two instruction sequence, but both >> instructions only take two operands (assume that r3 is a 32-bit >> register): >> >> ilhu $3, 45 # r3 = (45 << 16) >> iohl $3, 5 # r3 |= 5

+llvmdev -llvmcommits On Fri, Nov 12, 2010 at 8:03 AM, Jim Grosbach <grosbach at apple.com> wrote: > Sorta. getBinaryCodeForInst() is auto-generated by tablegen, so shouldn't be modified directly. The target can register hooks for instruction operands for any special encoding needs, including registering fixups, using the EncoderMethod string. For an example, have a look at the

Hi Quentin, On 08/19/14 18:58, Quentin Colombet wrote: [...] > It seems that you will have to debug further the *** Bad machine code: Instruction loads from dead spill slot *** before we can be of any help. Yes, I've done some more digging. Sorry for the long mail... I get: Inline spilling aN40_0_7:%vreg1954 [5000r,5056r:0)[5056r,5348r:1) 0 at 5000r 1 at 5056r At this point I have

Are there any examples of using tablegen to generate multiple machine instructions from a single pattern? Or do these cases always have to be manually expanded? -Dave

Hi all, This seems like a dumb question but while setting up a pattern in TD file, I got stuck on trying to get each half of an immediate as the half-sized type (ie. i64 imm -> pair of i32 imm's). Is there an existing way to do it? I've tried the 'EXTRACT_SUBREG' but that seems to error at the end of scheduling. Looking at Target.td, I'm not sure which opcode is meant

Sadly the latest optimization broke completely everything. The asm code isn't gas compliant. the libFLAC linker script has a typo, disabling the asm optimization and/or altivec won't let a correct build anyway. Instant fixes for the asm stuff: sed -i -e"s:;:\#:" on the lpc_asm.s to load address instead of addis+ori you could use lis and la and PLEASE use the @l(register)

Hi there, I am doing relocation in my backend by calling my function getAddrNonPic: SDValue getAddrNonPIC(NodeTy *N, SDLoc DL, EVT Ty, SelectionDAG &DAG)const{ SValue Hi=getTarget(N,Ty,DAG, MyBackend::Hi16); SValue Lo=getTarget(N,Ty,DAG, MyBackend::Lo16); return DAG.getNode(ISD::ADD, DL, Ty, DAG.getNode(MyBackend::Hi16, DL, Ty, Hi), DAG.getNode(MyBackend::Lo16, DL, Ty, Ho)); }

Chris Lattner wrote: >>It is possible to write multi-instruction pattern, e.g. >>X86InstrSSE.td line 1911. But how are you defining HI16 and LO16? >>Sounds like you want to define them as SDNodeXform that returns upper >>and lower 16 bits respectively. Take a look at PSxLDQ_imm in >>X86InstrSSE.td as an example. > > > Another good example is the PPC