similar to: Nested instruction patterns rejected by GlobalISel when having registers in Defs

Hi Dominik, Thanks for your reply. In my case, the Defs is the cause of the problem. Or rather, it is part of the problem, because when I remove it from the instruction TableGen gives me a different error message which concerns a part which is deeper into the pattern tree, so at least it is able to proceed beyond that part of the pattern. I have also stepped TableGen inside gdb and

Hi Daniel, Thanks for replying; I was hoping to get in touch with you on this issue. I had a look at how SelectionIDAG does it when generating the matcher table, and it does consider the implicit defs as additional output. Here is the match table generated for the pattern: /* 0*/ OPC_CheckOpcode, TARGET_VAL(ISD::SIGN_EXTEND), /* 3*/ OPC_MoveChild0, /* 4*/ OPC_CheckOpcode,

Hi all, After a recent upstream merge into our downstream sources we are suddenly encountering the freeze instruction in LLVM IR for div/rem pairs. This seems to be related to [1]. Our downstream target is GlobalISel only and unfortunately GlobalISel doesn't support this instruction yet, so most of our internal test-suite is now breaking due to GlobalISel not being able to translate this

Hi Matt, thanks for responding. I left a couple of comments down below. Am 24.03.20 um 18:26 schrieb Matt Arsenault: > >> On Mar 24, 2020, at 12:24, Dominik Montada via llvm-dev <llvm-dev at lists.llvm.org> wrote: >> >> Hi all, >> >> recently when working with GlobalISel we have often encountered cases in the legalizer where instructions could not be

Hi all, recently when working with GlobalISel we have often encountered cases in the legalizer where instructions could not be narrowed because the narrowing code relies on G_UNMERGE_VALUES and therefore requires the source type to be a multiple of the narrow type. Often times these instructions can be widened without any problem to a fitting type. This has us writing legalization rules like

Hi Quentin, Am 08.10.20 um 21:17 schrieb Quentin Colombet: > Hi Dominik, > >> On Oct 8, 2020, at 5:03 AM, Dominik Montada >> <dominik.montada at hightec-rt.com >> <mailto:dominik.montada at hightec-rt.com>> wrote: >> >> Hi Quentin, >> >> thanks for picking up the conversation! >> >> > I think we should step back and

Hi Quentin, thanks for picking up the conversation! > I think we should step back and check what we want before investing any time in some rewrite. That is a very fair point and I might have been getting ahead of myself in my last email. What I would like to see from RegBankSelect is to produce the mapping with the overall lowest cost. Keeping track of all different combinations of

Hi Quentin, thank you for the reply! This clears up a lot of the questions I was having. It seems like we should definitely invest some time in rewriting some of our legalization rules then! I also posted some questions further down below. I would appreciate getting your opinion on them. > Hi Dominik, > > I’ll do a brief reply here and if you want more information we can talk further

Hi Quentin, Hi Amara, I was following your discussion on D75086 regarding declaring types as legal even if they are smaller than the actual register class (e.g. s16 and gpr32). We are working on a backend which only has 32 and 64-bit registers and we recently had a problem regarding exactly this where we had to declare G_UNMERGE_VALUES and G_MERGE_VALUES with a smaller type of <s32 as

Hi Quentin, thank you for the reply! I have a couple more questions that came up when I tried to implement this today. I hope you can help me out with this again! Am 09.03.20 um 23:31 schrieb Quentin Colombet: > I would expect that you could create a register class and register > bank for the special register. That way you have something to map to > when you do register bank select.

Hi, We're working on adding exception handling support for a downstream bare-metal target. I read through the LLVM exception handling docs [1] and went through some patches from other backends to understand what parts we need to implement. We're now at a point were it feels like it should work, but unfortunately exceptions are still not getting caught. Our target uses DWARF

I just landed these patches: commit c55051eea5d3cd57abfd9727f519b670517704d9 Author: Louis Dionne <ldionne at apple.com> Date: Thu Jun 25 12:02:43 2020 -0400 [libunwind] Allow specifying custom Lit config files This is the libunwind counterpart of 0c66af970c80. commit 33c9c10d183371edc95fa936705bef56f55ab611 Author: Louis Dionne <ldionne at

Hi all, first of all thanks to Matt for hosting the round table yesterday and to everyone else for their time and the valuable discussions. As promised in the chat yesterday, here is the email regarding the legalizer / artifact combiner issue we talked about. I will send a separate email regarding the regbankselect discussion. In case someone on the list didn't attend the round table

Hi Louis, sorry for bothering you once more about the libcxx test suite! I was wondering whether you could help with some of my problems again. After the recent discussion on the mailing list and your diff, I was able to set up cross-compilation and remote-execution of the libcxx test suite, so thank you for that! We have split up the build of the libraries into different stages, so libcxx,

Hi all, this is the second email for the round table follow-up, this time regarding the issues around the greedy RegBankSelect and alternative mappings. The issue I brought up was that because RegBankSelect goes top-down, it never looks at all available mappings for the operands when considering which of the mappings to apply to the current instruction. In our architecture we have one

A question for those of you who have developed complex TableGen files: Do you think a trace facility would be useful during debugging? The idea is to add a new statement to TableGen along these lines: trace tag : value1, value2, ... ; When encountered, the TableGen parser would display the tag along with the values of the specified value1, value2, etc. The tag is an identifier that makes it

I find the one-dimensional "integrate" very helpful, but often enough I stumble into problems that require two (or more)-dimensional integrals. I suppose there are no R functions that can do this for me, "directly"? The ideal thing would be to be able to define say f <- function(x) { x1 <- x[1] x2 <- x[2] sin(x1*x2)*exp(x1-x2) } and then write say integrate(f,

Sorry if I wasn't clear about my use case. In my daily dev work, I do many local "ninja check"s, or "llvm-lit" on a subdirectory as a quick(er) smoke test if I am making changes in that area (e.g. "llvm-lit ../llvm/test/CodeGen"). Nothing wrong here, as indeed nothing changed here. But in case of a test failure, I want to run just that test: bin/llvm-lit

Hi, I get strange code when using regalloc=greedy. A value spill is redundant and cleared, as another spill of same value is inserted. The former spill is however not NOP:ed, but KILL:ed, thus the operands get a kill status. The code becomes: %vreg301<def> = mv32Imm 200000000, pred:0, pred:%noreg, %CCReg<imp-def,dead>, %ac0<imp-use>, %ac1<imp-use>; aN32_0_7:%vreg301

I'm with Matt on this one. I much prefer the approach of ALWAYS use braces for ifs and for loops, even if they're not needed, for basically the same reasons as he put. The number of times I've added a statement inside an if without braces and forget to add them is annoyingly high, especially as it's not always an obvious error upfront. Similarly, being involved in a downstream