similar to: [LLVMdev] LICM/store-aliasing of global loads

On 22-Jul-08, at 1:22 PM, Dan Gohman wrote: > On Jul 21, 2008, at 3:51 PM, Stefanus Du Toit wrote: >> - build a custom alias analysis pass that indicates that these loads >> never alias with any stores in a given function >> - declare these globals as external constants within the module > > If you can convince yourself that no interprocedural optimization > will ever

On Jul 21, 2008, at 3:51 PM, Stefanus Du Toit wrote: > Our frontend can guarantee that loads from globals are > rematerializable and do not alias with any stores in any function in > the given module. We'd like the optimization passes (and ideally the > register allocator as well) to be able to use this fact. The globals > are not constant "forever" but are constant

Hello, I'm working on using the LLVM JIT for a little project of mine, amazing work first off! I have a question about optimization passes. I initially have this function I've created, in python it looks like this: OS_end = 50OS_start = 0OS_timestep = 1birth_rate = .3population = 30.0for time in range(OS_start, OS_end, OS_timestep): births = birth_rate * population deaths = 0.1

On Jul 22, 2008, at 2:51 PM, Stefanus Du Toit wrote: > On 22-Jul-08, at 1:22 PM, Dan Gohman wrote: >>> If I apply the patch found further down, LICM moves the loads out >>> (as >>> expected), but of course this is a fairly specific fix. >> >> Slightly better than checking for GlobalVariabls directly >> is to call the AliasAnalysis'

The frontend code is a pretty simple for loop, that counts from i = 0; i != 10; i += 1 It gets optimized into and endless loop. export fn entry() void { var array: [10]Bar = undefined; var x = for (array) |elem, i| { if (i == 1) break elem; } else bar2(); } Here's the generated IR: ; ModuleID = 'test' source_filename = "test" target datalayout =

Hello, We've run across the following missed optimization: in the attached loop (addind.c/addind-opt.ll) there's a lookup into an array (V) using an indirect index (coming from another array, WI[k]) offset by a loop- invariant base (l). The full addressing expression can be reassociated so that we add the offset l to V's base first, and then add the indirect part. This makes

On 30-Jan-09, at 6:14 PM, Eli Friedman wrote: > On Fri, Jan 30, 2009 at 3:03 PM, Stefanus Du Toit > <stefanus.dutoit at rapidmind.com> wrote: >> The computation of %base then becomes loop-invariant and can be >> lifted out. >> >> What's the best way to add this optimization to LLVM? > > Probably the best place is LICM itself... only loop

On Fri, Jan 30, 2009 at 3:03 PM, Stefanus Du Toit <stefanus.dutoit at rapidmind.com> wrote: > The computation of %base then becomes loop-invariant and can be lifted out. > > What's the best way to add this optimization to LLVM? Probably the best place is LICM itself... only loop transformations are aware whether something is loop-invariant. Although, I'm not completely

Hello LLVM Developers, We are working on extending currently available register rematerialization to include cases where sequence of multiple instructions is required to rematerialize a value. We had a discussion on this in community mailing list and link is here: http://lists.llvm.org/pipermail/llvm-dev/2016-September/subject.html#104777 >From the above discussion and studying the code we

Hi Stefanus, Thanks for verifying this. Could you patch this or should I open a new bug report and find a generic solution first? Cheers, Nicolas From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On Behalf Of Stefanus Du Toit Sent: woensdag 1 april 2009 18:59 To: LLVM Developers Mailing List Subject: Re: [LLVMdev] Shuffle combine On 1-Apr-09, at 12:42

Hi Nicolas, On 2-Apr-09, at 6:04 PM, Nicolas Capens wrote: > Thanks for verifying this. Could you patch this or should I open a > new bug report and find a generic solution first? I don't have write access so the best I could do would be to submit a patch, and I'm crazy busy at the moment. I actually think the check I described below is fine and would fix this bug (but

For those curious about uses of LLVM, we just officially announced our adoption of LLVM in our products: http://www.rapidmind.com/News-Nov10-08-LLVM-OpenCL.php Thanks for all the support so far on here, we look forward to continuing to work with LLVM! -- Stefanus Du Toit <stefanus.dutoit at rapidmind.com> RapidMind Inc. phone: +1 519 885 5455 x116 -- fax: +1 519 885 1463

Hi Stefanus, Thanks for the info. I still think it's a bug though. Take for example a case where the vectors each have four elements. The values in Mask[] can range from 0 to 7, while HLSMask only has 4 elements. So LHSMask[Mask[i]] can go out of bounds, no? Cheers, Nicolas From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On Behalf Of Stefanus Du

The llvm-dev archives (and other llvm/clang mailing list archives) on the web don't seem to have any new messages since some time Monday night. Stefanus -- Stefanus Du Toit <stefanus.dutoit at rapidmind.com> RapidMind Inc. phone: +1 519 885 5455 x116 -- fax: +1 519 885 1463

On 1-Apr-09, at 12:42 PM, Nicolas Capens wrote: > Hi Stefanus, > > Thanks for the info. I still think it’s a bug though. Take for > example a case where the vectors each have four elements. The values > in Mask[] can range from 0 to 7, while HLSMask only has 4 elements. > So LHSMask[Mask[i]] can go out of bounds, no? Good point! One easy way to fix this would be to use:

On Nov 10, 2008, at 12:01 PM, Stefanus Du Toit wrote: > For those curious about uses of LLVM, we just officially announced our > adoption of LLVM in our products: > > http://www.rapidmind.com/News-Nov10-08-LLVM-OpenCL.php I'm thrilled to read an official announcement of that! Do you use LLVM only for static code generation or are you also doing any late (e.g.,

Hello, I'm having some trouble with getTripCount() ... again. In particular it fails in the first of the following two examples, although it works for the second. By fails, I mean it returns NULL. ---------- example 1 ---------- test1(int *a, const int *ip) { int k; for (k = 0; k < ip[2]; ++k) { a[k] = (k+11)/(k+2); } } ---------- example 2 ---------- test2(int

On 21-Jul-08, at 7:33 PM, Eli Friedman wrote: > On Mon, Jul 21, 2008 at 1:21 PM, Stefanus Du Toit > <stefanus.dutoit at rapidmind.com> wrote: >> 1) Vector shl, lshr, ashr >> > I have a rough draft of a patch for this that works reasonably well > for simple cases... I don't think I really have the time to finish it > properly, but I'll clean it up a bit and

On 31-Jul-08, at 2:38 PM, Dan Gohman wrote: > On Jul 31, 2008, at 7:22 AM, Nicolas Capens wrote: >> In the same breath I’d also like to kindly ask if someone could have >> a look at the reverse operations, namely trunk from 128 to 64 bit >> using movdq2q, and 128 to 32 and 64 to 32 using movd. This also >> seems related to Bug 2585. Thanks again. > > The operations

Hi all, I've located a regression that causes my project to crash. It's in revision 67979, where PointerIntPair is changed from storing the integer in the upper bits instead of the lower bits. My project is an experimental JIT-compiler in Windows. So I was wondering if anyone had any clue why the new PointerIntPair implementation might fail. It doesn't seem very safe to me to