similar to: [LLVMdev] Some questions on SelectionDAG

Thanks for all replies, they have been very helpful! Note: Sorry, i forgot to group reply.... ---------- Forwarded message ---------- From: Duncan Sands <baldrick at free.fr> Date: 2011/9/4 Subject: Re: [LLVMdev] Some questions on SelectionDAG To: Zakk <zakk0610 at gmail.com> Hi Zak, Therefore, after the LegalizeType phase, maybe SelectionDAG have > unsupported > type

Index: llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp =================================================================== --- llvm.orig/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp 2007-07-14 16:59:23.000000000 +0200 +++ llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp 2007-07-14 16:59:52.000000000 +0200 @@ -696,7 +696,7 @@ } } break; - case ISD::EH_RETURN: + case ISD::EH_RETURN: {

Hi, For my research, I need to reshape the current ARM backend to support armv2a. Zero-extend half word load (ldrh) is not supported by armv2a, so I need to make the code generation to not generate ldrh instructions. I want to replace all those instances with a 32-bit load (ldr) and then and the result with 0xffff to mask out the upper bits. These are the modifications that I have made to

I'm curious about this code in ReduceLoadWidth (and in DAGCombiner in general): if (LegalOperations && !TLI.isLoadExtLegal(ExtType, ExtVT)) return SDValue <http://llvm.org/docs/doxygen/html/classllvm_1_1SDValue.html>(); LegalOperations is false for the first pre-legalize pass and true for the post-legalize pass. The first pass is target-independent yes? So that makes sense.

On Jun 8, 2009, at 2:42 PM, robert muth wrote: > On Sun, Jun 7, 2009 at 11:53 PM, Evan Cheng <evan.cheng at apple.com> > wrote: >> >> On Jun 7, 2009, at 6:59 AM, robert muth wrote: >> >>> On Sat, Jun 6, 2009 at 4:51 PM, Evan Cheng<evan.cheng at apple.com> >>> wrote: >>>> +cl::opt<std::string>

On Sun, Jun 7, 2009 at 11:53 PM, Evan Cheng <evan.cheng at apple.com> wrote: > > On Jun 7, 2009, at 6:59 AM, robert muth wrote: > >> On Sat, Jun 6, 2009 at 4:51 PM, Evan Cheng<evan.cheng at apple.com> >> wrote: >>> +cl::opt<std::string> FlagJumpTableSection("jumptable-section", >>> +                                          

Hi, >> DAGCombiner::visitBRCOND() has code: >> >> SDValue N1 = N->getOperand(1); >> SDValue N2 = N->getOperand(2); >> >> ... >> >> SDNode *Trunc = 0; >> if (N1.getOpcode() == ISD::TRUNCATE&& N1.hasOneUse()) { >> // Look past truncate. >> Trunc = N1.getNode(); >> N1 = N1.getOperand(0);

Per subject, this patch adding an additional pass to handle vector operations; the idea is that this allows removing the code from LegalizeDAG that handles illegal types, which should be a significant simplification. There are still some issues with this patch, but does the approach look sane? -Eli -------------- next part -------------- Index: lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp

Is there a way to define a register class that is storage-only? I want to have an i8 register class that I can use for loads/stores/converts, but that does not support arithmetic. It seems addOperationAction(ISD::ADD, MVT::i8, Promote) and SetPromotedToType(ISD::ADD, MVT::i8, MVT::i16) are not sufficient, as the legalizer just looks at whether or not the underlying type is legal (which it is).

Bill Wendling wrote: > On Sep 29, 2010, at 12:36 AM, Heikki Kultala wrote: > >> On 29 Sep 2010, at 06:25, Heikki Kultala wrote: >> >>> Our architecture has 1-bit boolean predicate registers. >>> >>> I've defined comparison >>> >>> def NErrb : InstTCE<(outs I1Regs:$op3), (ins I32Regs:$op1,I32Regs:$op2), "", [(set

Hi All, I'm working on a back end for an architecture that makes use of multi- typed register classes. def MR: RegisterClass<"namespace", [type1, type2, ... ], ... > When running some preliminary tests I found that the instruction selector refused to select certain ops (specifically stores) for some instructions when the operand type wasn't the first type for the

1) It's crashing because LD1 is produced due to LegalOperations=false in pre-legalize pass. Then Legalization does not know how to handle it so it asserts on a default case. I don't know if it's a reasonable expectation or not but we do not have support for it. I have not tried overriding shouldReduceLoadWidth. 2) I see, that makes sense to some degree, I'm curious if you can

> -----Original Message----- > From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] > On Behalf Of Fabian Scheler > Sent: Wednesday, August 15, 2012 9:12 AM > To: LLVM Developers Mailing List > Subject: [LLVMdev] More Back-End Porting Troubles > > Hi LLVM-Folks, > > as mentioned in an earlier post >

In the 2.3 release, we included a list of the major LLVM API changes. If you are working on upgrading your code from 2.3 to 2.4, I'd appreciate it if you could compile a list of the major stumbling blocks you have, so that others can benefit from your experience. Please send any info to the list, thanks! -Chris

Hello. I fixed the bug reported in the previous post on this thread (<<llvm::MemSDNode::MemSDNode(unsigned int, unsigned int, const llvm::DebugLoc&, llvm::SDVTList, llvm::EVT, llvm::MachineMemOperand*): Assertion `memvt.getStoreSize() <= MMO->getSize() && "Size mismatch!"' failed.>>) The problem with this strange error reported comes from

On Feb 12, 2007, at 1:41 AM, Christopher Lamb wrote: > > selector refused to select certain ops (specifically stores) for some > instructions when the operand type wasn't the first type for the > register class. After some digging around I seem to have solved the > problem by creating bitconvert patterns between the types in the > register class like the following: > >

Hi LLVM-Folks, as mentioned in an earlier post (http://lists.cs.uiuc.edu/pipermail/llvmdev/2012-July/051677.html) I am currently working on a Back-End for the TriCore processor. Currently, I am struggling as LLVM could not select zext and load, for instance, so some of the testcases in test/CodeGen/Generic are not successfully compiled by my back-end. Furthermore, I am completely puzzled by the

On Sep 30, 2010, at 2:13 AM, Heikki Kultala wrote: > Bill Wendling wrote: >> On Sep 29, 2010, at 12:36 AM, Heikki Kultala wrote: >> >>> On 29 Sep 2010, at 06:25, Heikki Kultala wrote: >>> >>>> Our architecture has 1-bit boolean predicate registers. >>>> >>>> I've defined comparison >>>> >>>> def

Sorry to ask again, but I still can't get it right. The following code compiles and runs, but produces no instructions: Ops.push_back(DAG.getRegister(X86::EAX, MVT::i32)); Ops.push_back(DAG.getConstant(1, MVT::i32)); DAG.getNode(ISD::ADD, DAG.getVTList(MVT::i32), &Ops[0], Ops.size()); I reckon that has something to do with the fact that I am not using the Chain object. But as soon

Hello. I'm having problems at instruction selection with my back end with the following basic-block due to a vector add with immediate constant vector (obtained by vectorizing a simple C program doing vector sum map): vector.ph: ; preds = %vector.memcheck50 %.splatinsert = insertelement <8 x i64> undef, i64 %i.07.unr, i32 0