similar to: [LLVMdev] LazyValueInfo.getPredicateAt

I am primarily interested in phi nodes and their induction variables, in ValueTracking file there is an analysis of them, but if the upper bound is inf, it is not working? 2017-08-07 11:41 GMT+02:00 Anastasiya Ruzhanskaya < anastasiya.ruzhanskaya at frtk.ru>: > So, it is not supported to determine by this instruction : %cmp = icmp slt > i32 %i.03, 99, > that %i.03 = phi i32 [ 0,

On 2016-09-27 02:28, Philip Reames wrote: > On 09/20/2016 12:05 PM, Matti Niemenmaa via llvm-dev wrote: >> I posted some questions related to implementing inference of nsw/nuw >> flags based on known icmp results to Bug 30428 ( >> https://llvm.org/bugs/show_bug.cgi?id=30428 ) and it was recommended >> that I engage a wider audience by coming here. The minimal context is

Hello, I am trying to modify my LLVM-based compiler to perform an initial, no-optimization compilation synchronously on startup and then perform an asynchronous, optimized recompilation in the background, and I am getting in one of the optimization passes. - I am using the official release of LLVM 2.8 - I have compiled LLVM with threading enabled; I am running llvm::llvm_start_multithreaded() on

Hi, in a recent review [0], Florian Hahn helped me to realize something that was rather surprising to me: The widely popular and very useful function llvm::Value::stripPointerCasts() can return a value with a different bit pattern than the input. Now, I think this should not be the case but I want the hear other opinions. Before I go on, please not that there is at least one location in

On Sun, Apr 5, 2020 at 6:34 PM Stefanos Baziotis < stefanos.baziotis at gmail.com> wrote: > Hi Craig, > > > Adding a nuw to the add -8 is incorrect. > Yeah, I didn't mean to say it was correct. It was just an observation that > with nuw the optimization was happened and I asked if someone thought it > was somehow connected. > > > From the perspective of the

Adding a nuw to the add -8 is incorrect. From the perspective of the unsigned math, -8 is treated a very large positive number. The input to the add is [8,13) and adding a large positive number to it wraps around past 0. So that is guaranteed unsigned wrap. On the other hand, a sub nuw 8 would be correct. ~Craig On Sun, Apr 5, 2020 at 3:27 PM Stefanos Baziotis via llvm-dev < llvm-dev at

Hi everyone, I posted some questions related to implementing inference of nsw/nuw flags based on known icmp results to Bug 30428 ( https://llvm.org/bugs/show_bug.cgi?id=30428 ) and it was recommended that I engage a wider audience by coming here. The minimal context is the following, please see the bug report for more detail: > 1. If (X s< Y), then both X + 1 and Y - 1 are nsw. > 2.

Dear all, I am searching for a possibility to view large data sets (e.g. stored in ffdf objects) in a GUI window in a memory-efficient way. So far I looked at gtkDfEdit (package RGtk2Extras) and gdf (package gWidgets). Both operate (as far as I can see) on data frames stored in memory. gtkDfEdit accepts an ff data frame as input, but there is a long delay before it shows up, so I presume the

Thanks for the pointers. Looks like LazyValueInfo has the sort of infrastructure I had in mind. LVILatticeVal could be extended to floating point. (The comment "this can be made a lot more rich in the future" is an invitation :-). I'm thinking a simple lattice would address most cases of interest for floating-point checks. The lattice points for floating-point could be all

On Mon, May 18, 2015 at 8:40 PM, Joseph Tremoulet <jotrem at microsoft.com> wrote: > > I want to have separate normal and exceptional codepaths > > I assume you at least mean that's what you'll be doing in Clang's initial > IR generation. Do you also mean to impose this as a restriction on other > IR generators, and as a property that IR transformations must

> Checks against 1.0 are also common. Why not just add a FP range class, like our constant range, and go from there? That's certainly another way to go. My worry is that a more complicated lattice gets us deeper into rounding-mode issues and considerably more work for smaller gain. I like the idea of creating an FPRange class. We could start with a simple one and extend it as experience

Hi, Is there any easiest way to display only names of disks taking part from a Zpool : zpool status |awk ''/c.t./{print $1}'' I am wondering if it''s enought while disks can be named differently as cXtY ! Thank''s for your help. @del. This message posted from opensolaris.org

I think adding transitions to cleanupblocks on the normal execution path would be an optimization barrier. Most passes would see the cleanupblock instruction and run the other way. It's definitely appealing from the perspective of getting the smallest possible code, but I'm OK with having no more than two copies of everything in the finally block. I think with the addition of the

With floating point, won't you need to model a partial order for the end points? I thought there were pairs of floating point values which are incomparable. Not sure if partial order is the right abstraction, but I'm pretty sure a total order isn't. This may make implementing the range comparisons (which are themselves partially ordered) a bit tricky... Philip (Who knows just

This example is pretty compelling, but I still think I want to limit the scope of this change to not include this feature. It's probably reasonable to hold onto the idea as future work, though. In the meantime, frontends can decide for themselves whether they want code size or stronger optimization of cleanups by doing early outlining or not. The only way we can hit the quadratic growth from

The Julia language implements sqrt(x) with conditional branch taken if x<0. Alas this prevents vectorization of loops with sqrt. Often the argument can be proven to be non-negative. E.g., sqrt(x*x+y*y). Is there an existing LLVM pass or analysis that does floating-point range propagation to eliminate such unnecessary checks? Arch D. Robison Intel Corporation -------------- next part

Yes, the modeling of floating-point is trickier. The wrap-around trick used by ConstantRange seems less applicable, and there are the unordered NaNs. Though in all cases, the key abstraction is a lattice of values, so an instance of FPRange should be thought of as a point on a lattice, not an interval. The lattice needs to be complicated enough the cover the cases of interest, but not so

On Mon, May 18, 2015 at 12:03 PM, Joseph Tremoulet <jotrem at microsoft.com> wrote: > Hi, > > > > Thanks for sending this out. We're looking forward to seeing this come > about, since we need funclet separation for LLILC as well (and I have > cycles to spend on it, if that would be helpful). > > > > Some questions about the new proposal: > > >

Hi, I found that after moving to Clang pre-3.6 (git 65d8b4c4998b3a0c20934ea72ede72ef4838a004) and trunk (git 718825a8666acd9ceaab70fc7868332f20e2758f) our internal build machines started going offline in Jenkins. Clang after 3.5 release is consuming extreme amounts of memory in some cases. I have uploaded [1] one of affected files. $ g++ -std=c++11 -c -O1 -fPIC vpp_generated.ii -o