similar to: How to finalize instruction lowering after register allocation.

On Mon, Jun 24, 2019 at 4:08 PM Tim Northover <t.p.northover at gmail.com> wrote: > On Mon, 24 Jun 2019 at 12:16, Gleb Popov via llvm-dev > <llvm-dev at lists.llvm.org> wrote: > > 1. Where does it come from? Can I do anything to make it not appear? > > It comes from something like: > > %ptr = alloca i8 > %var = alloca i8* > store i8* %ptr, i8**

Hello. After "Initial selection DAG" stage I get a DAG with node t14: ch = store<(store 4 into %ir.p45, align 8, addrspace 1)> t10, FrameIndex:i32<2>, FrameIndex:i32<3>, undef:i32 1. Where does it come from? Can I do anything to make it not appear? 2. If not, how do I change it so that the operand being stored would be first loaded into a register, and that register

Hi all, this is my first post in this mailing group. I hope that anyboby could help me parsing a xml file. I found this website http://www.omegahat.org/RSXML/gettingStarted.html but unfortunately my XML file is not as easy as the one in the example. Example: <?xml version="1.0" encoding="UTF-8"?> <?xml-stylesheet

Hi, I am trying to parse XML files and read them into R as a data frame, but have been unable to find examples which I could apply successfully. I'm afraid I don't know much about XML, which makes this all the more difficult. If someone could point me in the right direction to a resource (preferably with an example or two), it would be greatly appreciated. Here is a snippet from one of

On Tue, Jun 25, 2019 at 9:59 AM Tim Northover <t.p.northover at gmail.com> wrote: > On Tue, 25 Jun 2019 at 06:26, Gleb Popov via llvm-dev > <llvm-dev at lists.llvm.org> wrote: > >> While the store is being selected LLVM will just treat the value being > >> stored as a generic pointer-width integer unless you have written a > >> specific pattern for

Hi, In the context of MachineCode custom inserter, I'm trying to enforce the mapping of virtual register to a physical one. According to the documentation https://llvm.org/docs/CodeGenerator.html#mapping-virtual-registers-to-physical-registers There are two ways: the direct one and the indirect ones. The indirect ones refer VirtRegMap class that I've never found. So I tried the direct

Hi, For the development of a new micro-controller backend, I try to lowering the following store SDNode: t5: ch = store<ST2[%ptr2](align=4)> t0, Constant:i16<3>, FrameIndex:i16<1>, undef:i16 I have defined the following instruction and associated DAG pattern. def MOVSUTO_A_i32o : CLPFPU_A_i32o_Inst<0b1000001101,

Hi, I'm writing a backend for a proprietary microcontroller. I'm facing a limitation related to Live Interval Analysis. Some FPU instructions, most notably the FDIV, requires a few cycles to complete. There is a pipeline and, during the execution of the FDIV, others instructions could be executed in parallel, provided they don't use the same registers. This pipeline has been modeled

Hi, I'm try to lower the store LLVM-IR instruction as per the following LLVM IR program: *** IR Dump After Module Verifier *** define void @storeloadi32() { %ptr = alloca i32 store volatile i32 12, i32* %ptr ret void } The target instruction is associated to the store like this: def MOVSUTO_A_iSLr : CLPFPU_A_iSLr<0b1000001101,

Hi again, After further investigation, I've found that the private PhysRegUseDefLists array ("head of use/def list for physical register") from MachineRegisterInfo class seems to be empty. But I didn't found any methods for updating such data structure. How/where this "use/def list" should be managed ? Is the documentation

Hi, I'm trying to complete the lowering for a new microcontroller. I'm using LLVM 3.8. For now this lowering crashes on 'Store' node, which is actually not yet defined. I've tried to map the ISel 'Store' node to architecture specific instructions. I've define the following semantic to my architecture specific instructions: def MOVSUTO_SU_rr :

Hi, Is there a kind of scope mechanism in the instruction lowering pattern language in order to control where instructions are inserted or how they are later reordered during the SelectionDiag linearization? I know the glue chain that stick instructions together. But such mechanism in not provided in instruction lowering pattern. I'm facing many situations where some patterns are lowered into

Hi Krzysztof, Thanks for your response. I was trying to map function input parameters to machine specific registers. My solution I found is based to the RegInfo.setSimpleHint() API. Here is the body of the parameters loop of TargetLowering::LowerFormalArguments VReg = RegInfo.createVirtualRegister(RC); RegInfo.setSimpleHint(VReg,CLP::FA_ROFF1+i);

Hi Dominique, From your description it is not really clear what you are trying to do here. It may be the case that the goal you are trying to accomplish can be better reached using a different approach. In general, optimizations don't try to assign physical registers, that's done by the register allocation passes. There are some cases when target-specific passes use physical

Hi, As a first step to port the LLVM chain on an in-house big-endian processor, I'm integrating the native assembler as a new '-assemble -arch=' in llvm-mc. All work quite well, I have a correct output ELF format except that generated code is little-endian. I've understood that the endianess of the LLVM chain is controlled by the DataLayout class, but it appear to me that llvm-mc

The DAG dumping will try to print some of the nodes "inline" (i.e. where they are used) to make the output more readable, so the dump of the DAG may not strictly reflect the node ordering. -Krzysztof On 5/4/2018 8:18 AM, Dominique Torette via llvm-dev wrote: > Here is a last example to illustrate my concern. > > The problem is about the lowering of node t13. > >

Hi, I've instruction scheduling problem that I cannot further investigate by myself... Could someone give me some clues? After Instruction selection, here is part of the generated instruction. NOP MOV_AB_ro @s1, %fab_roff0 %6:fpuaoffsetclass = COPY %fab_roff0; FPUaOffsetClass:%6 MOV_A_oo %6, def %5; FPUaOffsetClass:%6,%5 MOVSUTO_A_iSLo 24575, def %7;

Krzysztof, Thanks for your interest to my questions. In order to clarify the context, here is the C source file of my test case. The 3 builtins initialize some stack pointers. They have to be executed before any other instruction. extern float fdivfaddfmul_a(float a, float b, float c, float d); volatile static float x1,x2,x3,x4; void _start(void) { float res;

Hi, I have a question related to pre-RA scheduling and spill of registers. I'm writing a backend for two operands instructions set, so FPU operations result have implicit destination. For example, the result of FMUL_A_oo is implicitly the register FA_ROUTMUL. I have defined FPUaROUTMULRegisterClass containing only FA_ROUTMUL. During the instruction lowering, in order to avoid frequent spill

Hi, My backend (based on version 3.8) was hanging in an infinite loop in the Prolog/Epilog Inserter. After investigation, it appears that it was looping in the first level loop of the PEI::replaceFrameIndices() method: processing the second instruction of the block again and again... This loop never exits because the iterator is 'skipped backward' under some condition in the middle of