similar to: Should intrinsics llvm.eh.sjlj.setjmp be with isBarrier flag?

> On Oct 13, 2017, at 1:46 PM, Matthias Braun <matze at braunis.de> wrote: > > Yes, I've run into the problem myself that the Pending queue isn't even checked with the tryCandidate() logic and so takes priority over all other scheduling decisions. > > I personally would be open to changes in this area. To start the brainstorming I could imagine that we move nodes

Hi, I've been looking at the Machine Scheduler on Power PC. I am looking only at the pre-RA machine scheduler and I am running it in the default bi-directional mode (so, both top down and bottom up queues are considered). I've come across an example where the scheduler picks a poor ordering for the instructions which results in very high register pressure which results in spills.

isBarrier is not defined in BX_RET and tBX_RET instructions and the Machine Instructions Verifier (-verify-machineinstrs) give errors about that. Is it normal that isBarrier is not defined on these instructions ?

Hi, this is a small patch of ARM Instructions description because "-verify-machineinstrs" complains about that. This doesn't break the tests on my machine. Regards -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: patch_barrier URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20090929/84aca914/attachment.ksh>

Hi, >> from the exist llvm-ir it seems there are some common info for sjlj-eh >> and dwarf-eh! >> are there possible use the exist llvm-ir to generate exception table > >for sjlj-eh ? >No. There should be support from llvm-gcc. sjlj eh and dwarf eh have >different semantics different semantics ? ! I think llvm-gcc generate the IR should not include the exception

On Wed, Feb 8, 2017 at 6:21 PM, Wei Mi <wmi at google.com> wrote: > I have an issue that I've been wrestling with for quite some time and I'm > hoping that someone with a deeper understanding of the register allocator > can help me with. > > Namely, I am trying to teach RA to split a live range rather than > allocating a CSR. I've attempted a very large number

Hi, >There's definitely more to it than the current intrinsics, which are >there to support dwarf. that's to say we need modify the llvm-gcc so the front end can generate the sjlj-style IR, >SJLJ exceptions rely on runtime library >functions to register and unregister call frames which require >unwinding, so we need to modify LLVM to handle generating those call my

Hi, >There's definitely more to it than the current intrinsics, which are >there to support dwarf. from the exist llvm-ir it seems there are some common info for sjlj-eh and dwarf-eh! are there possible use the exist llvm-ir to generate exception table for sjlj-eh ? zhangzw

Hi, many people suggest that if we want llvm to support sjlj-eh, we should modify the llvm-gcc to generate sjlj-style IR. yeah, I'm digging into the llvm-gcc now. there are some functions, at the llvm-gcc e.g TreeToLLVM::CreateExceptionValues() , BasicBlock *TreeToLLVM::getPostPad(unsigned RegionNo), void TreeToLLVM::EmitLandingPads(), void TreeToLLVM::EmitPostPads() , void

Hello, Can setjmp-longjmp excaption handling be mixed with invoke/landingpad? Can LLVM treat a call to @llvm.eh.sjlj.longjmp as a thrown exception and go to matching landingpad? Does any reference implementation of SJLJ EH exists? - Paweł -------------- next part -------------- An HTML attachment was scrubbed... URL:

I have an issue that I've been wrestling with for quite some time and I'm hoping that someone with a deeper understanding of the register allocator can help me with. Namely, I am trying to teach RA to split a live range rather than allocating a CSR. I've attempted a very large number of tweaks to the costs (both existing and experimental ones that I've added). However, despite all

Hello all, I want to add a custom intrinsic to the LLVM IR which would be lowered into a pseudo instruction since it doesn't correspond to any real instruction defined by the architecture. The speciality of this intrinsic/pseudo instruction that it should behave like a scheduling barrier: every instruction before the intrinsic has to be emitted before the intrinsic, the same goes for all

Hi, I've been experimenting with writing a backend for LLVM (3.2) (having already written a frontend http://savourysnax.github.com/EDL), everything was going reasonably ok ( calls/returns, epilogue, prologue, etc are all working), up until I tried to place support for conditional branches. Given this simple program : int test(int c,int d) { if (c) { return

Hi, guys, I compiled a subroutine with -O2, and llvm backend produced codes like: ################################################################## LBB0_32: ... R31 = -1 R20 = R31 * R20; .... bnz R2, LBB0_34 LBB0_31: ... b LBB0_34 LBB0_33: # weird basic block? R20 = R5 LBB0_34: ....

Hello, I have an intrinsic that matches to a asm instruction directly. This intrinsic starts a coprocessor that can do anything. If I put another instruction next to it (a multiplication for example), the "llc" reorders and puts the intrinsic after the multiplication. I have tried all: - Setting the instruction like if it takes 256 cycles or 0 cycles. - Setting the instruction with

I am working on a back end for an architecture whose jump via table instruction includes the range check. If the index is out of range, the jump table instruction just falls through. I implemented a pass to remove the range check generated before the jump table instruction because it is superfluous. This causes as assertion in MachineBlockPlacement.cpp:

Hello, Julio > These later things are ignored, I don't know if when the intrinsic is > lowered, then it doesn't matter (or perhaps the reorder is made > before). What is the description of the instruction you're lowering intrinsic into? Have you looked for the instruction flags defined in Target.td file? You instruction should definitely have "isBarrier" flag set.

Hi Yang, > bnz R2, LBB0_34 > > I do not have any clue what happens when compiling with -O2. > Can someone make a suggestion? Is the "bnz" instruction marked "isBarrier" in your TableGen files? If so, that would mean LLVM considers fallthrough impossible and decides it can move LBB0_33 around at will. It's still very odd that it thinks it can put it

Nothing... I'll show you all the info related to: The intrinsic: def int_soru_sre : Intrinsic<[llvm_void_ty, llvm_i32_ty], [IntrWriteMem]>; The lower instruction (in MIPS): class SORUI<bits<6> op, dag outs, dag ins, string asmstr, list<dag> pattern, InstrItinClass itin>: FI<op, outs, ins, asmstr, pattern, itin> { let isBarrier = 1; // or call,

The Sparc, Microblaze, and Mips code generators implement branch delay slots. They all seem to exhibit the same bug, which is not surprising since the code is very similar. If I compile code with this snippit: while (n--) *s++ = (char) c; I get this (for the Microblaze): swi r19, r1, 0 add r3, r0, r0 cmp r3, r3, r7 beqid r3,