similar to: [LLVMdev] Proposal: Loads/stores with deterministic trap/unwind behavior

On Sat, Apr 05, 2014 at 12:21:17AM -0700, Andrew Trick wrote: > > On Mar 31, 2014, at 6:58 PM, Peter Collingbourne <peter at pcc.me.uk> wrote: > > > Hi, > > > > I wanted to propose an IR extension that would allow us to support zero-cost > > exception handling for non-call operations that may trap. I wanted to start > > with loads and stores through

Moving this month old RFC to llvmdev. Not sure why I sent this to cfe-dev in the first place... --- Based on code review discussion from John, he thinks filter expressions should be emitted into the body of the function with the try, rather than being outlined by the frontend. Instead of having the frontend create filter functions, we would use labels in place of typeinfo. The IR would look

Hi all, I'm trying to figure out a weird bug I'm seeing. I'm hoping it's something simple in my IR but I can't see anything wrong so I'm hoping someone here can see something. I'm using LLVM to compile Java bytecode into native functions. My code keeps track of the Java local variables in an array of llvm::Value pointers which get phi'd up at various points. The

Hi Reid, Is this design supposed to be able to cope with asynchronous exceptions? I am having trouble imagining how this would work without adding the ability to associate landing pads with scopes in LLVM IR. Vadim On Tue, Nov 25, 2014 at 5:27 PM, Reid Kleckner <rnk at google.com> wrote: > On Tue, Nov 25, 2014 at 3:09 PM, Kaylor, Andrew <andrew.kaylor at intel.com> > wrote:

On Sun, May 11, 2014 at 8:19 AM, Stephan Tolksdorf <st at quanttec.com> wrote: > Hi, > > When clang/LLVM can't prove that a noexcept function only contains > non-throwing code, it seems to insert an explicit exception handler that > calls std::terminate. Why doesn't clang leave it to the eh personality > function to call std::terminate when an exception is thrown

On Apr 25, 2014, at 2:21 PM, Eric Christopher <echristo at gmail.com> wrote: >> In short, I agree with your observations that these intrinsics are not an >> obvious slam-dunk compared to making the explicit control flow, but I think >> that the intrinsics do give enough flexibility on the LLVM side that it >> would be great if front-ends used them rather than rolling

What? Yet another EH proposal?! This one is different from the others in that I'm planning to start implementing this shortly. But I want your feedback! I've all ready gotten a lot of feedback from Chris, John, Jim, Eric, and many others. Now is your turn! Please read this proposal and send me your comments, suggestions, and concerns. -bw

I'd love to hear more details. Are you saying that this infinite loop is a limitation of EHABI table format, and not something that can be fixed in the compiler? Meanwhile, please notice that gcc behavior matches current clang behavior that I described above. We would not want to create an incompatibility. On Fri, Feb 14, 2014 at 8:42 PM, Logan Chien <tzuhsiang.chien at gmail.com>

I was thinking about this last night, and I came up with a third alternative which I think looks very promising. It’s basically a re-working of the previous alternative to use the landingpad concept rather than arbitrary fake logic, but it uses a single landing pad for the entire function that mimics the logic of the personality function to dispatch unwinding calls and catch handlers. I believe

On April 25, 2014 at 1:44:37 PM, Reid Kleckner (rnk at google.com) wrote: Thanks for the writeup! It's very helpful. On Fri, Apr 25, 2014 at 11:49 AM, Filip Pizlo <fpizlo at apple.com> wrote: On April 25, 2014 at 10:48:18 AM, Reid Kleckner (rnk at google.com) wrote: On Fri, Apr 25, 2014 at 10:19 AM, Filip Pizlo <fpizlo at apple.com> wrote: The sdiv operation in LLVM IR only

Hi all, I feel that there are two problems with the existing infrastructure: * The nounwind attribute is ambiguous for (1) not throwing exceptions and (2) not performing stack unwinding. I feel that it will be better to separate this in two different attributes * There is some problem when the function has both uwtable and nounwind. Although, I think it fine to keep the current definition of

I am very much in favor of having a div instruction with well defined div-by-zero and overflow behavior. The undefined behavior on certain values for LLVM intrinsics has been a major pain point for us in Julia, because adding the extra branches just kills performance and we know that there is an X86 instruction that just does what we want. Anyway, this was brought up briefly above, but want to

This is a revision of the second exception handling proposal I sent out. You can see it here: http://lists.cs.uiuc.edu/pipermail/llvmdev/2010-November/036484.html After much discussion, there are some changes to the proposal – some significant and some minor. One major point, this proposal does not address the issue of catching an exception thrown from a non-invoke instruction. However if done

On 2008-06-11, at 13:16, Gary Benson wrote: > Duncan Sands wrote: > >> Can you please attach IR which can be compiled to an executable >> (and shows the problem). > > I've been generating functions using a builder and then compiling > them with ExecutionEngine::getPointerToFunction(). Is there some way > I can get compilable IR from that?

Hi, I have a question about the IR model for SEH filters (as I want to use the same model for CLR filters). In particular, when an outer filter is invoked before entering an inner finally, which piece of IR reflects the filter's side-effects? To take a concrete example, consider this C code: void foo() { int x; __try { x = 0; __try { x = 2; may_throw(); }

On 09/02/2011 05:58 PM, Duncan Sands wrote: > Hi Yiannis, > >> I have been using llvm 2.8 (i know ancient history!) for a backend that i was >> implementing. I have been trying to port my patches to latest llvm (svn build) >> lately but i have one problem as far as the Exception Handling mechanism is >> concerned. It seems that there are no Exception Tables generated

Duncan Sands wrote: > Can you please attach IR which can be compiled > to an executable (and shows the problem). I've been generating functions using a builder and then compiling them with ExecutionEngine::getPointerToFunction(). Is there some way I can get compilable IR from that? Cheers, Gary -- http://gbenson.net/

Hi Yiannis, >>> I have been using llvm 2.8 (i know ancient history!) for a backend that i was >>> implementing. I have been trying to port my patches to latest llvm (svn build) >>> lately but i have one problem as far as the Exception Handling mechanism is >>> concerned. It seems that there are no Exception Tables generated any more such >>> as the one

Hi, This is a spin-off of previous Windows SEH RFC below. This RFC only focus on supporting HW Exception Handling. A detailed implementation can be seen in here: https://github.com/tentzen/llvm-project/commit/8a2421c274b683051e456cbe12c177e3b934fb5e It passes all MSVC SEH suite (excluding those with “Jumping out of _finally” ( _Local_Unwind)). Thanks, --Ten **** The rules for C code: ****

On Dec 10, 2007, at 11:38 AM, Duncan Sands wrote: >>> ... If you force a "cleanup" by changing the selector call to: >>> %eh_select8.i = tail call i32 (i8*, i8*, ...)* >>> @llvm.eh.selector.i32( i8* %eh_ptr.i, i8* bitcast (i32 (...)* >>> @__gxx_personality_v0 to i8*), i32 0) >>> then it doesn't work either: the unwinder observes that