similar to: Dereferenceable load semantics & LICM

On Fri, Mar 31, 2017 at 10:23 AM, Sanjoy Das <sanjoy at playingwithpointers.com > wrote: > Hi Piotr, > > On March 31, 2017 at 9:07:42 AM, Piotr Padlewski > (piotr.padlewski at gmail.com) wrote: > > Hi all, > > I have a question about dereferenceable metadata on load instruction. I > > have a patch (https://reviews.llvm.org/D31539) for LICM that hoists >

2017-04-01 15:59 GMT+02:00 Piotr Padlewski <piotr.padlewski at gmail.com>: > > > 2017-03-31 23:20 GMT+02:00 Sanjoy Das <sanjoy at playingwithpointers.com>: > >> Hi Piotr, >> >> On March 31, 2017 at 1:07:12 PM, Piotr Padlewski >> (piotr.padlewski at gmail.com) wrote: >> > [snip] >> > Do I understand it correctly, that it is legal to

2017-04-05 18:30 GMT+02:00 Sanjoy Das <sanjoy at playingwithpointers.com>: > Hi Piotr, > > On Mon, Apr 3, 2017 at 2:01 PM, Piotr Padlewski > <piotr.padlewski at gmail.com> wrote: > >> I don't see any way to model it right now in LLVM, but I see a one > simple > >> solution: > >> add extra information to the metadata nodes indicating that

2017-04-06 17:57 GMT+02:00 Sanjoy Das <sanjoy at playingwithpointers.com>: > Hi Piotr, > > On April 6, 2017 at 2:36:53 AM, Piotr Padlewski > (piotr.padlewski at gmail.com) wrote: > > I disagree, I find it different than the patch you mentioned. We don't > have > > any problems with code like this: > > > > ptr = load i8*, i8** %ptrptr,

I left a comment on https://reviews.llvm.org/D18738 earlier which I feel is related to this discussion, so I'm reproducing it here: I wonder though if what we want to express isn't some sort of "type-based dereferencability annotations". For example the semantics I care about are essentially, "if you know you have a defereferencable pointer, you can go and dereference any

Hi Piotr, I think makes sense. Modulo bitcasts, the invariant is identified by a particular pointer SSA value. Given that you can't sensibly have two nonequivalent invariants associated with the same pointer SSA value simultaneously, there's no need to also identify the invariant with a metadata string as well. When we need a new "identifier" for the pointed-to value, we

2017-01-26 3:28 GMT+01:00 Richard Smith <richard at metafoo.co.uk>: > On 25 January 2017 at 15:03, Hal Finkel via cfe-dev < > cfe-dev at lists.llvm.org> wrote: > >> Hi Piotr, >> >> I think makes sense. Modulo bitcasts, the invariant is identified by a >> particular pointer SSA value. Given that you can't sensibly have two >> nonequivalent

2017-01-26 15:41 GMT+01:00 Hal Finkel <hfinkel at anl.gov>: > > On 01/26/2017 06:44 AM, Piotr Padlewski wrote: > > > > 2017-01-26 3:28 GMT+01:00 Richard Smith <richard at metafoo.co.uk>: > >> On 25 January 2017 at 15:03, Hal Finkel via cfe-dev < >> cfe-dev at lists.llvm.org> wrote: >> >>> Hi Piotr, >>> >>> I think

Hi Piotr, On March 31, 2017 at 1:07:12 PM, Piotr Padlewski (piotr.padlewski at gmail.com) wrote: > [snip] > Do I understand it correctly, that it is legal to do the hoist because all > of the instructions above %vtable does not throw? Yes, I think you're right.  HeaderMayThrow is a conservative approximation, and the conservativeness is biting us here. > Are there any plans to

On 01/28/2017 10:36 AM, Piotr Padlewski wrote: > > > 2017-01-26 15:41 GMT+01:00 Hal Finkel <hfinkel at anl.gov > <mailto:hfinkel at anl.gov>>: > > > On 01/26/2017 06:44 AM, Piotr Padlewski wrote: >> >> >> 2017-01-26 3:28 GMT+01:00 Richard Smith <richard at metafoo.co.uk >> <mailto:richard at metafoo.co.uk>>: >>

On Sat, Jul 25, 2015 at 12:39 PM, Hal Finkel <hfinkel at anl.gov> wrote: > Hi Piotr, > > Thanks for posting this! First, a question. When you say, regarding i8* > @llvm.invariant.group.barrier(i8*): > > "Required to handle destructors, placement new and std::launder. Call of > this function will be put on the end of each of this functions" > > I

Bugs item #27425, was opened at 2009-11-11 21:15 You can respond by visiting: http://rubyforge.org/tracker/?func=detail&atid=411&aid=27425&group_id=85 Category: win32-open3 Group: Code Status: Open Resolution: None Priority: 3 Submitted By: Daniel Berger (djberg96) Assigned to: Nobody (None) Summary: win32-open3 doesn''t build with 1.9.1 Initial Comment: Windows XP VC++ 9

Hi, Sorry I fat fingered an earlier send in the previous email. I was trying to say: On Mon, Jan 9, 2017 at 2:52 PM, Sanjoy Das <sanjoy at playingwithpointers.com> wrote: >> +1 Exactly this. >> I don't think C programmer will not understand using. The "=" makes it much >> simpler to read, even if it is the first time you see it, which is not the >>

2017-01-10 0:06 GMT+01:00 David Blaikie <dblaikie at gmail.com>: > > > On Mon, Jan 9, 2017 at 2:59 PM Sanjoy Das via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > >> Hi, >> >> Sorry I fat fingered an earlier send in the previous email. I was >> trying to say: >> >> On Mon, Jan 9, 2017 at 2:52 PM, Sanjoy Das >> <sanjoy at

Hello, While instrumenting LLVM IR in ThreadSanitizer (race detector), I need to distinguish between a store to vtable pointer (vptr) and any other regular store. This special treatment should be limited to class DTORs, so I should also know when a function is a DTOR. Rationale: need to distinguish benign and harmful races on vptr (

Hi Sanjay, > Am 02.08.2016 um 21:39 schrieb Sanjay Patel <spatel at rotateright.com>: > > Hi Matthias - > > Sorry for the delayed reply. I think you're on the right path with D22864. No problem, thank you for your answer! > If I'm understanding it correctly, my foo() example and zext_or_icmp_icmp() will be equivalent after your patch is added to InstCombine.

On Feb 19, 2013, at 7:46 AM, Krzysztof Parzyszek <kparzysz at codeaurora.org> wrote: > On 2/19/2013 12:31 AM, Bill Wendling wrote: >> >> Yeah, that was in the one that I committed. I basically want something like this: >> >> define void @foo() "no-builtin" { >> call void @printf() >> } >> >> And then the `call' to

On Mar 19, 2012, at 2:52 PM, Kostya Serebryany wrote: > Hello, > > While instrumenting LLVM IR in ThreadSanitizer (race detector), I need to distinguish between a store to vtable pointer (vptr) and any other regular store. > This special treatment should be limited to class DTORs, so I should also know when a function is a DTOR. > Rationale: need to distinguish benign and

Hi, While working on PR21780, I used "dereferenceable_or_null" metadata and I realized now that it is not correct for my solution to use this metadata type since it might point to an address that it is not dereferenceable but null. I think that we need another new metadata type, something like "dereferenceable" with that we could annotate any load (not just pointer type like

Dear rsync people, Today I tried to back up my computer using rsnapshot with the RPM version of rsync-acl 2.6.9pre1 that I built. I tried twice, and both times, rsync encountered some kind of assertion failure. I was trying to reproduce the crash with rsync-acl 2.6.9pre2 and noticed a different bug (described below); when I have a chance, I will go back and investigate the crash further. Rsync