similar to: Pseudo-instruction that overwrites its input register

On Sun, 28 May 2017, David Chisnall wrote: >> let Constraints = "@earlyclobber $reg" in >> def LDWRdPtr : Pseudo<(outs DREGS:$reg), >> (ins PTRREGS:$ptrreg), >> "ldw\t$reg, $ptrreg", >> [(set i16:$reg, (load i16:$ptrreg))]>, >>

Thanks. I saw the header comments but it wasn’t clear to me what the difference between those concepts is? My slightly vague understanding is IsDef means that the register specified by this operand is set by the machine instruction. So I understand that to mean the MO will override that register? Also things like early clobber, perhaps there is another document that clarifies some of these

Hi, During instruction selection, I have the following code for certain LOAD instructions: const LoadSDNode *LD = cast<LoadSDNode>(N); SDNode* LDW = CurDAG->getMachineNode(AVR::LDWRdPtr, SDLoc(N), VT, PtrVT, MVT::Other, LD->getBasePtr(), LD->getChain()); // Honestly, I have no idea what this does, but other memory // accessing instructions

On 7/29/2017 1:28 AM, Dr. ERDI Gergo via llvm-dev wrote: > Hi, > > During instruction selection, I have the following code for certain > LOAD instructions: > > const LoadSDNode *LD = cast<LoadSDNode>(N); > SDNode* LDW = CurDAG->getMachineNode(AVR::LDWRdPtr, SDLoc(N), > VT, PtrVT, MVT::Other, > LD->getBasePtr(), LD->getChain()); >

Hello, I've noticed the following issue while testing some codegen tests, i would like to know if it's a missed optimization or i missed something out here. This is for an out of tree backend im writing. I managed to reduce it to the following C function: void foo(int *a) // int here is 16bits { *a &= 0xFF; } This is the code before regalloc: Live Ins: %R25R24

The reason the ones in PPCInstrInfo.td don't have the patterns to match is the reason they are more analogous to your problem. Namely, tblgen does not have a way to produce nodes with more than one result. The load-with-update instructions do exactly that - one of the inputs is also an output, but the other output is independent (and necessarily a separate register). The FMA variants have

On Tue, 30 May 2017, Nemanja Ivanovic wrote: > This is typically accomplished with something like PPC's `RegConstraint` and > `NoEncode`. You can see examples of it that are very similar to what you're after in > PPC's load/store with update forms (i.e. load a value and update the base register > with the effective address - these are used for pre-increment loads/stores).

I can't get it to work with pattern matching. My operand is defined like so: def LDSTPtrReg : Operand<i16> { let MIOperandInfo = (ops PTRREGS); let EncoderMethod = "encodeLDSTPtrReg"; } I am able to use it in the place of PTRREGS in the definition of the LD instruction, but if I use it in an instruction matching pattern, compilation fails with the error "Unknown

On 7 April 2013 14:54, Sam Parker <S.Parker3 at lboro.ac.uk> wrote: > Hi Anitha, > > memri is just describing that the address contains two components, an > immediate and a register, and how to handle them in the instruction printer. > The STWU expects a memri operand, and that is what is passed from the Pat. > My confusion is how operands of STWU from "Pat

On Mar 24, 2011, at 5:42 PM, Borja Ferrer wrote: > The last copy instruction should be removed as pointed out above, but since R27R26 is killed in the load instruction it has to be emitted. About the insane amount of regclasses there, the load/store and the andi instructions take subsets of regs from the main register class, they cant work with all registers, that's why STW and LDW needs

Hi, How do "Pat" operands get matched? I am trying to follow the example given in http://llvm.org/docs/CodeGenerator.html#selectiondag-process In the latest trunk of ppcintrinfo.td following pattern is defined: def : Pat<(pre_store i32:$rS, iPTR:$ptrreg, iaddroff:$ptroff), (STWU $rS, iaddroff:$ptroff, $ptrreg)>; I understand that input operand list i.e. ins of

Hi Anitha, memri is just describing that the address contains two components, an immediate and a register, and how to handle them in the instruction printer. The STWU expects a memri operand, and that is what is passed from the Pat. Hope that helps, Sam On 07/04/2013 10:19, Anitha B Gollamudi wrote: > Hi, > > > How do "Pat" operands get matched? I am trying to follow

I am trying to prototype a back end for a new processor. It has a 64-bit datapath, so all registers are 64 bits and load instructions always extend to 64 bits. But the type 'int' is 32 bits, and arithmetic instructions have variants that operate on only the lower 32 bits of each register. So for a basic 'a = b + c' example, we get %0 = load i32, i32* @b, align 4, !tbaa !1 %1

Hello! I have the following simple IR: ================================== @l = common global i64 0, align 8 define void @hello() nounwind { entry: store i64 -4919131755279862989, i64* @l ret void } define i32 @main(i32 %argc, i8** %argv) nounwind { entry: call void @hello() %tmp = load i64* @l %conv = trunc i64 %tmp to i32 ret i32 %conv } ==================================

Hello, I'm new to LLVM and I'm using it to translate from LLVM to another language rather than emitting actual machine code. The target language has instructions that operate on pointers which aren't naturally exposed in LLVM. Here's what I've done to add pointer support for an instruction called PADD that takes a pointers and an offset and returns the new pointer value:

Christian Sayer wrote: > Hi, > my target architecture has a kind of "16bit addressing mode", i.e. one address does not address 8 bit but a 16bit chunk. Consequently, every constant used to calculate effective addresses must be divided by two. > So far this is not such a problem for stack objects since FrameIndexes, function arguments etc. have a lot of custom lowering code where

----- Original Message ----- > Hi Hal, > > > Our Architecture has indirect move instruction which increments > the > pointer implicitly and the target only has i8 type values. So the > load > of i16 will be converted to two i8 target loads wherein after the > first > load instruction, the pointer to the first i8 address will > automatically >

Hi Johannes, what processor are you targeting? Is it little-endian or big-endian? Ciao, Duncan. > I have the following simple IR: > > ================================== > @l = common global i64 0, align 8 > > define void @hello() nounwind { > entry: > store i64 -4919131755279862989, i64* @l > ret void > } > > define i32 @main(i32 %argc, i8** %argv)

Are there any other patterns in your TD file? If so, then one of the ones before this pattern will match everything, and this pattern will never be matched. -bw On Jul 3, 2009, at 8:27 PM, Javier Martinez wrote: > Hello, > > I'm new to LLVM and I'm using it to translate from LLVM to another > language rather than emitting actual machine code. The target language > has

Hi Hal, On Tuesday 01 October 2013 06:22 PM, Hal Finkel wrote: > ----- Original Message ----- >> Hi Hal, >> >> >> Our Architecture has indirect move instruction which increments >> the >> pointer implicitly and the target only has i8 type values. So the >> load >> of i16 will be converted to two i8 target loads wherein after the