search for: idempotence

Hi all, Just a quick question about the idempotence of an intrinsic function. Is there a way to specify that an intrinsic function is idempotent? I am trying to give as much information about the intrinsic function I added to LLVM so that LLVM can do optimizations otherwise disabled. Thanks a lot in advance. Bin

The LLVM projects page says this: "We need some way to reason about errno. Consider a loop like this: for () x += sqrt(loopinvariant);" and: "The hard part of this project is figuring out how to describe errno in the optimizer" The important property here is the idempotence of sqrt(): it is potentially side-effecting, but that side effect is independent of the number of times it is called (with the same argument). Thus the solution to the errno problem seems to be an idempotence analysis pass, an idempotent function attribute, and a handful of passes (LICM, maybe...

...t moment to do this. There are no bugs that I'm aware of, though there are unaddressed optimization opportunities with respect to, among other things, (a) better register-pressure awareness, (b) employing transformations (particularly loop transformations) to increase the "degree" of idempotence and/or improve code generator performance, and (c) better alias analysis... if anyone is interested; I personally am moving on to other things for now... Lastly, thank you to all of the LLVM community for effectively enabling this research. Marc [1] M. de Kruijf, K. Sankaralingam, and S. Jha. *S...

At least I think the word I want "idempotent" - it has been a long debugging session and my brain is fried so I am not sure. What I mean is that as.name applied to a name gives an error. > as.name("foo") foo > as.name(as.name("foo")) Error in as.name(x) : character argument required It might help if it were a bit more flexible about the arguments it

Our code calls del_vqs multiple times, assuming it's idempotent. commit 3ec7a77bb3089bb01032fdbd958eb5c29da58b49 virtio_pci: free up vq->priv broke this assumption, by adding kfree there, so multiple calls cause double free. Fix it up. Fixes: 3ec7a77bb3089bb01032fdbd958eb5c29da58b49 Reported-by: Sasha Levin <sasha.levin at oracle.com> Signed-off-by: Michael S. Tsirkin <mst

Our code calls del_vqs multiple times, assuming it's idempotent. commit 3ec7a77bb3089bb01032fdbd958eb5c29da58b49 virtio_pci: free up vq->priv broke this assumption, by adding kfree there, so multiple calls cause double free. Fix it up. Fixes: 3ec7a77bb3089bb01032fdbd958eb5c29da58b49 Reported-by: Sasha Levin <sasha.levin at oracle.com> Signed-off-by: Michael S. Tsirkin <mst

Hi All, I have running puppet client and server on solaris 10 x86. Now days some of puppet client behaviors is something weird !!! or May be i am missing something... for ex. I created class to add one line in /etc/vfstab . but puppet client did it successfully 1st time ...But .. After few days , i saw there are same line has been added more than 250 times.. [ see same line is added so many

Dear all, I have been working on an idempotent version of apply, such that applying a function f(x) = x (ie. force) returns the same array (or a permutation of it depending on the order of the margins): a <- array(1:27, c(2,3,4)) all.equal(a, iapply(a, 1, force)) all.equal(a, iapply(a, 1:2, force)) all.equal(a, iapply(a, 1:3, force)) all.equal(aperm(a, c(2,1,3)), iapply(a, 2, force))

as.name(as.name("ss")) gives an error in R (0.90 and earlier) but should of course give the same as simply as.name("ss") This reminds me of similar bug/problem... which I don't recall. Yes, I should build tests like these into "make test-Specific" .. Martin --please do not edit the information below-- Version: platform = sparc-sun-solaris2.5.1 arch =

I noticed a change in LLVM's behavior between 3.2 and 3.3/ToT, but I'm not sure if it qualifies as a bug/regression or not. The change is that in 3.3 and tip of trunk, calling ConstantFoldConstantExpression on i64 and (i64 add (i64 add (i64 ptrtoint (i64* getelementptr (i64* null, i32 1) to i64), i64 ptrtoint (i64* getelementptr (i64* null, i32 1) to i64)), i64 15), i64 -16)

Thanks for your reply, Philip. You are right, when I use LLVM-3.8, the 'argmemonly' shows up. Previously, I use LLVM-3.7. I think idempotent is what I want. Can you tell me how to add idempotent attribute to the function? Thanks. Regards, Xiangyang 2016-03-24 14:30 GMT-07:00 Philip Reames <listmail at philipreames.com>: > > > On 03/24/2016 12:45 PM, Xiangyang Guo via

On 29 June 2015 at 07:37, John R Pierce <pierce at hogranch.com> wrote: > so a regex looking for "system:" vs "system {" should nicely delineate > these. I dunno, I might even put that into the conversion utility and > have it just quit if the file is already in the new format, and always run > it. > ?+1 for the idempotent approach. IMHO much more

Hi folks, I am just getting into rails again after a multi-year stint of mod_perl jobs, which might grant me some newbie-indemnity for the time being - but I''ve found an issue I think warrants discussion. As discussed here - http://api.rubyonrails.org/classes/ActionController/RequestForgeryProtection/ClassMethods.html - the CSRF protection feature does not kick in for GET requests. This

On 29/06/15 01:07, Kahlil Hodgson wrote: > On 29 June 2015 at 07:37, John R Pierce <pierce at hogranch.com> wrote: > >> so a regex looking for "system:" vs "system {" should nicely delineate >> these. I dunno, I might even put that into the conversion utility and >> have it just quit if the file is already in the new format, and always run

Beyond any more general questions of whether pam sessions *should* be run as root, is there an immediate security concern with moving the pam_open_session (and pam_setcred) stuff to the parent (root) process? (E.g., via the patch below.) -- Mike Stone diff -u -r1.4 auth-pam.c --- auth-pam.c 25 Jun 2002 00:45:33 -0000 1.4 +++ auth-pam.c 25 Jun 2002 20:33:41 -0000 @@ -286,6 +286,8 @@

On 03/24/2016 12:45 PM, Xiangyang Guo via llvm-dev wrote: > Hi, > > When I define an intrinsic function with memory write permission, my > assumption is that we can either attach [IntrReadWriteArgMem] or [] to > the intrinsic function. Based on the comment of the source code , > "IntrReadWriteArgMem - This intrinsic reads and writes only from > memory that one of its

Hello, fencing enthusiasts! *TL;DR:* We'd like to propose an addition to the LLVM memory model requiring non-temporal accesses be surrounded by non-temporal load barriers and non-temporal store barriers, and we'd like to add such orderings to the fence IR opcode. We are open to different approaches, hence this email instead of a patch. *Who's "we"?* Philip Reames brought

The common case is wanting LICM to hoist a loop-invariant function call into the pre-header of a loop where the trip count is unknown - and, in particular, not known to be > 0. -----Original Message----- From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On Behalf Of Hal Finkel Sent: Thursday, July 16, 2015 08:38 To: Raoux, Thomas F Cc: llvmdev at cs.uiuc.edu Subject:

On Fri, May 15, 2015 at 11:50 AM, David Chisnall < David.Chisnall at cl.cam.ac.uk> wrote: > On 15 May 2015, at 17:53, Chris Bieneman <beanz at apple.com> wrote: > > > > +1 to lib/Target/SPIRV/(Reader|Writer) > > > > I really like this idea. I’ve talked with some people on both the LLVM > and Khronos sides and I really think adding SPIR-V support to LLVM

This is almost ideal for SLP vectorization, except for two problems: 1. We have 4 stores to consecutive locations, but the last element is the constant zero, and not an additional SUB. At the moment we don’t have support for idempotence operations, but this is something that we should add. 2. The values that we are subtracting come from 3 loads. We usually load 4 elements from memory, or scalarize the inputs (we don’t support masked loads on AVX512). Do you know if the GCC SLP Vectorizer vectorizes this, or is it their Loop...