similar to: Accessing list names in lapply

There is PostDominatorTree for determining post-dominance. Even if A post-dominates B and B is executed, that doesn't guarantee that A will be executed. For example, there could be an infinite loop in-between. Strong post-dominance makes the stronger guarantee that there will be no infinite loop from B to A. Do we have anything in LLVM for determining strong post-dominance and in general for

Hello all! I have a problem to extract values greater that for example 1820. I try this code: x[x[,1]>1820,]->x1 Please help me! Thank you! The data structure is: structure(c(2.576, 1.728, 3.434, 2.187, 1.928, 1.886, 1.2425, 1.23, 1.075, 1.1785, 1.186, 1.165, 1.732, 1.517, 1.4095, 1.074, 1.618, 1.677, 1.845, 1.594, 1.6655, 1.1605, 1.425, 1.099, 1.007, 1.1795, 1.3855, 1.4065, 1.138, 1.514,

Hi Adam, Indvar widening can sometimes be harmful for architectures (e.g. NVPTX and AMDGPU) where wider integer operations are more expensive ( https://llvm.org/bugs/show_bug.cgi?id=21148). For this reason, we disabled indvar widening in NVPTX in http://reviews.llvm.org/D6196. Hope it helps. Jingyue On Mon, Jun 29, 2015 at 11:59 AM Adam Nemet <anemet at apple.com> wrote: > > >

Hi Johannes, Sanjoy has given you great information already. On Sun, Apr 10, 2016 at 5:19 PM, Sanjoy Das <sanjoy at playingwithpointers.com> wrote: > Johannes Doerfert wrote: > > Is there any plan to use e.g., post-dominance information to > > propagate wrapping flags? > > None that I'm aware of. > > > If x +nsw y post-dominates the entry block > >

----- Original Message ----- > From: "Bjarke Roune" <broune at google.com> > To: "Jingyue Wu" <jingyue at google.com> > Cc: llvmdev at cs.uiuc.edu > Sent: Tuesday, June 30, 2015 8:16:13 PM > Subject: Re: [LLVMdev] Deriving undefined behavior from nsw/inbounds/poison for scalar evolution > > Hi Adam, > > Jingyue is right. We need to keep

----- Original Message ----- > From: "Bjarke Roune" <broune at google.com> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: llvmdev at cs.uiuc.edu, "Jingyue Wu" <jingyue at google.com> > Sent: Wednesday, July 1, 2015 2:27:59 PM > Subject: Re: [LLVMdev] Deriving undefined behavior from nsw/inbounds/poison for scalar evolution > >

*** Summary I'd like to propose (and implement) functionality in LLVM to determine when a poison value from an instruction is guaranteed to produce undefined behavior. I want to use that to improve handling of nsw, inbounds etc. flags in scalar evolution and LSR. I imagine that there would be other uses for it. I'd like feedback on this idea before I proceed with it. *** Details Poison

Hi Nicolas, On Tue, Mar 3, 2009 at 11:38 AM, Nicolas Geoffray <nicolas.geoffray at lip6.fr> wrote: > > Duncan Sands wrote: >> >> Another possibility, very close you yours and currently used by the vmkit >> project, is to modify all functions so they return two values, the usual >> return value and an additional boolean value indicating whether an >>

Hi Bjarke, Bjarke Walling wrote: > I see. So you check this value stored in a thread-local variable after > each call? And you lower invoke to a call and branch with regard to > this value? > Yes, that's correct. > What are these sophisticated techniques you are talking about? My time > frame for implementing this is, not unlimited, but fairly long. Less > than a

Hi Duncan, Hi Bjarke, Duncan Sands wrote: > Take a look at libunwind (http://www.hpl.hp.com/research/linux/libunwind/). > Another possibility, very close you yours and currently used by the vmkit > project, is to modify all functions so they return two values, the usual > return value and an additional boolean value indicating whether an exception > was thrown during the call or

Dear forum members, How can I force a negative slope in a linear regression even though the slope might be positive? I will need it for the purpose of determining the trend due reasons other than biological because the biological (genetic) trend is not positive for these data. Thanks. Julia Example of the data: [1] 1.254 1.235 1.261 0.952 1.202 1.152 0.801 0.424 0.330 0.251 0.229

Hello all! I have a problem to arrange data in another form. My initial data is like this: 'data.frame': 421 obs. of 58 variables: $ 01A: num NA NA NA NA NA NA NA NA NA NA ... $ 01B: num NA NA NA NA NA NA NA NA NA NA ... $ 03A: num NA NA NA NA NA NA NA NA NA NA ... $ 03B: num NA NA NA NA NA NA NA NA NA NA ... $ 05A: num NA NA NA NA NA NA NA NA NA NA ... $ 05B: num NA NA NA NA

Hi, I want to support the unwind instruction on x86. Specifically I want to: * Provide an efficient runtime implementation that does not depend on reading the DWARF EH information. * It should be self hosted, meaning the runtime is static linked in. I want to use it kernel mode. * Unwinding should be a read-only operation regarding the stack, so I can create a stack dump in the

Hi Jingyue, I consider it a very important element of the design of convergent that it does not require baseline LLVM to contain a definition of uniformity, which would itself pull in a definition of SIMT/SPMD, warps, threads, etc. The intention is that it should be a conservative (but hopefully not too conservative) approximation, and that implementations of specific GPU programming models

Bjarke Walling wrote: > Another option I'm thinking about is creating a runtime that, when > initialized, compiles the DWARF information to native code. It could > create an Instruction Pointer lookup hash table associated with unwind > actions. JIT-compiling the unwinder data, yes. Given that the unwinder data is, basically, the source for a specialized bytecode interpreter I

Hi Bjarke, > * Provide an efficient runtime implementation that does not > depend on reading the DWARF EH information. why? The DWARF EH info encodes two things: (1) how to restore registers; and (2) matching rules for exception objects, and what to do with them. You will need something along the lines of (1) if you unwind out of the middle of functions. As for (2), if you

Hello, I was wondering under which circumstances ScalarEvolution will propagate the no wrap flags from binary operators. In particular I looked at non-loop carried code, e.g., as in the following function: int add(int x, int y) { return x + y; } for which clang uses an "add nsw" instruction but ScalarEvolution does not propagate this information. The -analyze output looks like this:

Hi Sanjoy, thanks for your thoughts on this. On Sat, Jun 27, 2015 at 12:16 AM, Sanjoy Das <sanjoy at playingwithpointers.com > wrote: > > First of all, going by the "poison causes UB only when observed", SCEV > does not do the right thing currently: [...] > > That seems like a bug? There's also bug 23527 for GEP. Sounds like there might be more such bugs. One

Hello, Bjarke > * Provide a pass that raises C++ exception handling to just > unwind instructions and thread-local data. Are you familiar with C++ EH? How would you handle catches? Cleanups? > Other call frames might be more complex to handle. It depends on the > moves needed to restore the registers of the previous call frame (the > caller) and to remove the current frame.

Hello, > still don't see the complexities in stack unwinding: Restore caller > registers, remove the frame, lookup next frame, etc. This is not enough for C++, for example. You would need to run destructors, be able to propagate exception object upper, do a type- based catch, etc. You might want to read http://www.codesourcery.com/public/cxx-abi/abi-eh.html Also, studying libgcc