similar to: ISelDAGToDAG breaks node ordering

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()); >

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

Hi, I'd like to define a pseudo-instruction whose expansion will, as a side-effect, overwrite an input register's value: the pseudo-instruction ldw r1:r2, P to load 2 bytes from memory address P is to be expaneded to ld r1, P+ ld r2, P where "ld _, P+" is an instruction that loads a single byte from P, and post-increments P by one. How can I represent this behaviour in

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))]>, >>

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).

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

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

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

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 } ==================================

I am currently working on DAGToDAGISel class for MIPS and am trying to figure out a way to use INTRINSIC_W_CHAIN for an intrinsic which can return a value. My intrinsic is defined as: Intrinsic<[llvm_i32_ty],[llvm_i32_ty,llvm_i32_ty,llvm_i32_ty,llvm_i32_ty],[IntrReadWriteArgMem]>; i.e. it has four arguments and one return value In DAGToDAGISel when I try to pass it with four arguments and

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

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

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)

Hi I am looking at some of the existing targets to try to understand more about writing a backend. I was a little puzzled by the use of a method ReplaceUses in *ISelDAGToDAG.cpp (*= most targets, e.g. ARM, X86..). I found its definition in the *GenDAGISel.inc file that is autogenerated from the target description. I can only assume TableGen emits this method definition for every traget.

On Mar 26, 2011, at 4:09 PM, Borja Ferrer wrote: > You can look at the output of -debug-only=regcoalescing to see what is going on. > > This is the debug output i've got, some information is a bit cryptic for me so next is what i understood: > > ********** SIMPLE REGISTER COALESCING ********** > ********** Function: foo > ********** JOINING INTERVALS *********** >

> > You can look at the output of -debug-only=regcoalescing to see what is > going on. > > This is the debug output i've got, some information is a bit cryptic for me so next is what i understood: ********** SIMPLE REGISTER COALESCING ********** ********** Function: foo ********** JOINING INTERVALS *********** entry: 16L %vreg0<def> = COPY %R25R24<kill>;

The parts of klibc specific to the parisc architecture. Signed-off-by: H. Peter Anvin <hpa at zytor.com> --- commit 078d6614054391efe17093f8d70340e2c0644ffb tree 63a4bf899e5ca2ef3c0a8e9ef3098273012f7a33 parent ebd2860ad3dc19cb11fd5b9cc235cab54e9165f4 author H. Peter Anvin <hpa at zytor.com> Sun, 25 Jun 2006 16:58:36 -0700 committer H. Peter Anvin <hpa at zytor.com> Sun, 25 Jun

Hello all, I am working on adding atomics support to the AVR backend. Because the target can only have one core, it is sufficient to: - Save the status register - Disable interrupts - Do the nonatomic LOAD/STORE/SWAP/ADD - Restore the status register I’d really like to be able to do this at the IR level. What I want to do is write a custom lowering hook to convert ISD::ATOMIC_LOAD

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.

On Friday 26 February 2010 10:34:41 David Greene wrote: > On Friday 26 February 2010 09:55:32 David Greene wrote: > > In the continuing quest to try to track down problems we're seeing in > > SelectionDAG, I added the following assert > > toSelectionDAG::ReplaceAllUsesOfValuesWith: > > Here's a patch to add more of these deleted node asserts. They fire > tons