similar to: [LLVMdev] Re: Loops

On 8/29/07, Domagoj Babic <babic.domagoj at gmail.com> wrote: > Seung, > > On 8/25/07, Chris Lattner <sabre at nondot.org> wrote: > > Ok. Note that LLVM can represent irreducible loops. You can handle > > this through code duplication. > > -Chris > > > If you are willing to invest more effort into a more complicated analysis, > in many cases you

Daniel, On 8/30/07, Daniel Berlin <dberlin at dberlin.org> wrote: > On 8/29/07, Domagoj Babic <babic.domagoj at gmail.com> wrote: > > Seung, > > > > On 8/25/07, Chris Lattner <sabre at nondot.org> wrote: > > > Ok. Note that LLVM can represent irreducible loops. You can handle > > > this through code duplication. > > > -Chris >

Seung, On 8/25/07, Chris Lattner <sabre at nondot.org> wrote: > Ok. Note that LLVM can represent irreducible loops. You can handle > this through code duplication. > -Chris If you are willing to invest more effort into a more complicated analysis, in many cases you can even avoid code duplication. See this paper for details: @inproceedings{erosa94taming, author = {Ana M.

I am also trying to build llvm-gcc4 and llvm as you are on amd64 linux. I am currently running into the error "Did not get a target machine!" on the first file compiled by xgcc. Did you encounter this error at all? Also, what distribution did you use? GCC version, and target triple? Thanks, -Chandler Carruth On 12/10/06, Domagoj Babic <babic.domagoj at gmail.com> wrote: >

On 4/9/07, Domagoj Babic <babic.domagoj at gmail.com> wrote: > > > Traditionally, such analyses have been considered too expensive to be > practical, and were mostly an academic curiosity. The core of the > problem is the lack of adequate automated decision procedures which > could quickly determine whether a set of constraints is satisfiable or > not, and if it is

Unless I'm missing something, the problem lies directly with the fact that you are trying to do a link-stage operation with the GCC frontend. GCC, by default, probably runs "ld" or another system linker, which grabs the executable from binutils. This linker hasn't been modified (yet) to include support for .bc files, but you're compiler is emitting byte code to the *.o files.

Hi all, I have the same problem. My guess is that when a structure is passed as a parameter, you cast it into an array for optimization reasons (less parameters, less stack space). This is, certainly, a reasonable optimization, but makes inter-procedural static analysis more complex. Is there a way to disable it (my guess is that this should be doable by passing some parameter to llvm-gcc)? If

Hi, I've ran my static checker Calysto on openssh and found the following bug: Possible NULL-ptr deref (vc536): @/work/benchmarks/SOURCES/openssh-4.6p1/moduli.c:173 + ptr gtm returned from gmtime dereferenced without checking (gmtime can return NULL). There are probably more possible NULL-ptr dereferences, but Calysto currently does not check the usage of library functions (for instance, if

New version of Calysto reports a warning that looks like a bug to me: ------------------------------------------ Possible NULL-ptr deref (vc27053): @/work/projects/llvm/tools/Calysto/IfaceSpecs/clib.c:1823 Bug: ?? Explanation: choose_dh (dh.c:111) calls fopen twice (@120). If the first call to fopen fails (returns NULL), but the second one succeeds, fgets (@129) is called with f==NULL.

On Sep 29, 2006, at 2:05 PM, Domagoj Babic wrote: > > Check out scc_* iterators. Also note that the call graph > is not aware of the indirect calls, so you will need to write your > own CG implementation if you need to handle function pointers > soundly. > Chris, is this true? If so, it seems like a bad property for the CallGraphSCCPass framework. --Vikram

Hi all, On 11/28/06, Reid Spencer <rspencer at reidspencer.com> wrote: > * Venue: West Coast, USA. Probably either San Francisco Bay Area or > Seattle > * Time Frame: Post 2.0 release, summer 2007 > * Topics: Anything related to use or development of LLVM I'd vote for Seattle. The costs of organization should be lower than in the Bay Area. > * An indication of how

Dear LLVMers, This email is intended for those interested in path-sensitive analysis, integer overflow analysis, static analysis, and (perhaps) loop invariant computation. Traditionally, such analyses have been considered too expensive to be practical, and were mostly an academic curiosity. The core of the problem is the lack of adequate automated decision procedures which could quickly

On Sep 28, 2009, at 2:28 AM, Ralf Karrenberg wrote: > Hello everybody, > > I just started implementing a part of my algorithm that deals with > irreducible control-flow. > Apparently, the LoopInfo analysis does not recognize loops with > multiple > incoming edges (as of LLVM 2.5). > On the mailing list archives I found a few discussions related to > irreducible

Chandler/Domagoj, On Sun, 2006-12-10 at 10:53 -0500, Chandler Carruth wrote: > Unless I'm missing something, the problem lies directly with the fact > that you are trying to do a link-stage operation with the GCC > frontend. GCC, by default, probably runs "ld" or another system > linker, which grabs the executable from binutils. This linker hasn't > been modified

Hey, Thank you for your replies, Chris and Dan. Chris Lattner wrote: >> I am considering writing a patch for LoopInfo instead of creating my own >> data structure for irreducible loops. >> Is such an enhancement desired or even already implemented by someone >> (e.g. in the 2.6 branch)? > I'm not sure that this is a good idea. LoopInfo is clearly defined to >

On Oct 2, 2007, at 1:03 AM, Domagoj Babic wrote: > Hi all, > > I have the same problem. My guess is that when a structure > is passed as a parameter, you cast it into an array for optimization > reasons (less parameters, less stack space). This is not an optimization. This behavior is to be ABI complaint when emitting code for your OS. That said, this is not a very good way to

I will try to reduce a test case for the regression I found and will update. Thanks, Balaram From: Friedman, Eli [mailto:efriedma at codeaurora.org] Sent: Friday, June 30, 2017 2:54 PM To: Balaram Makam <bmakam at codeaurora.org>; llvm-dev at lists.llvm.org Subject: Re: [llvm-dev] LoopSimplify pass prevents loop unrolling On 6/30/2017 11:38 AM, Balaram Makam wrote: Thanks Eli,

On Fri, 29 Sep 2006, Vikram Adve wrote: > On Sep 29, 2006, at 2:05 PM, Domagoj Babic wrote: >> Check out scc_* iterators. Also note that the call graph >> is not aware of the indirect calls, so you will need to write your >> own CG implementation if you need to handle function pointers >> soundly. > Chris, is this true? If so, it seems like a bad property for the

Hello everybody, I just started implementing a part of my algorithm that deals with irreducible control-flow. Apparently, the LoopInfo analysis does not recognize loops with multiple incoming edges (as of LLVM 2.5). On the mailing list archives I found a few discussions related to irreducible control-flow, but it was never mentioned if it is planned to enhance LoopInfo to also represent such

Hi, Dear Boissinot: 1. When I have irreducible CFG, I travel its nodes by DFS. search backedge for every node. After I finish one node, push it into a stack. [0, 1, 2, M] <---push. [0, 1, 2, M,...N] <---push. When resolving node M, find a edge from node N to node M, N is not in stack(M < N), It is a backedge. N is in stack(M > N), It is NOT a backedge.