similar to: [LLVMdev] Is InstructionSimplify still a good place to contribute?

There's some interest in my "auto-simplifier", which is nice :), so let me explain a bit about it. On 19/01/11 19:35, Sandeep Patel wrote: > You've mentioned your auto-simplifier a few times now and curiosity is > getting the better of me. Can you explain it a bit more? On 20/01/11 00:32, Nuno Lopes wrote: > Just out of curiosity, what's this auto-simplifier?

Dear all, If possible, I would like to contribute to LLVM. First of all, I would like to say that I'm a newbie in LLVM, and my experience in compilers implementation is only in simples and academics "toy projects". My main interesting are focused in try to improve the code generated by LLVM, where "improve" I mean "better performance". I'm interested, for

<cc'ing llvmdev> On Nov 10, 2010, at 6:38 AM, Duncan Sands wrote: > Hi Chris, in commit 12800 you introduced the following transform: > > Implement select.ll:test12* > > This transforms code like this: > > %C = or %A, %B > %D = select %cond, %C, %A > into: > %C = select %cond, %B, 0 > %D = or %A, %C > > Since B is often a

Sure. David, what do you think about merging this to 3.9? Sanjay: are you saying I'd just apply that diff to InstructionSimplify.cpp, not InstCombineSelect.cpp? On Fri, Jul 22, 2016 at 7:08 AM, Sanjay Patel <spatel at rotateright.com> wrote: > Hi Hans - > > Yes, I think this is a good patch for 3.9 (cc'ing David Majnemer as code > owner). The functional change was

Sanjay: let me know if this is something that will apply to 3.9. Thanks, Hans On Wed, Jul 20, 2016 at 5:59 PM, Sanjay Patel via llvm-dev <llvm-dev at lists.llvm.org> wrote: > Quick update - the bug existed before I refactored that chunk in > InstSimplify with: > https://reviews.llvm.org/rL275911 > > In fact, as discussed in https://reviews.llvm.org/D22537 - because we have a

David, Sanjay: ping? On Mon, Jul 25, 2016 at 11:07 AM, Hans Wennborg <hans at chromium.org> wrote: > Sure. David, what do you think about merging this to 3.9? > > Sanjay: are you saying I'd just apply that diff to > InstructionSimplify.cpp, not InstCombineSelect.cpp? > > On Fri, Jul 22, 2016 at 7:08 AM, Sanjay Patel <spatel at rotateright.com> wrote: >> Hi

On Wed, Dec 12, 2012 at 01:59:55PM -0800, Dan Gohman wrote: > The bug here isn't in clang's use of noalias or in BasicAliasAnalysis' > implementation of noalias; it's in the code that's optimizing the > icmp. Let's come back to this. The attached patch decouples InstSimplify from the alias analysis and provides the conservative logic for when pointers are not

LGTM On Wednesday, July 27, 2016, Hans Wennborg <hans at chromium.org> wrote: > David, Sanjay: ping? > > On Mon, Jul 25, 2016 at 11:07 AM, Hans Wennborg <hans at chromium.org > <javascript:;>> wrote: > > Sure. David, what do you think about merging this to 3.9? > > > > Sanjay: are you saying I'd just apply that diff to > >

Thanks for notifying me. Yes, this was a recent change. Taking a look now. On Wed, Jul 20, 2016 at 1:49 PM, Michael Kuperstein <mkuper at google.com> wrote: > +Sanjay, who touched this last. :-) > > On Wed, Jul 20, 2016 at 12:44 PM, Ismail Badawi (ibadawi) via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > >> Hi folks, >> >> I'm hitting the

Hello, My name is Siddharth. I’m a student studying math and computer science at the University of Toronto. I’m interested in learning more about the LLVM compiler through GSoC. I have no prior experience with LLVM, but I have a strong interest in compilers, and I look forward to learning more. I would like to pursue one of two potential projects: rewriting bugpoint, and moving optimizations

As Sanjay noted in D31426<https://reviews.llvm.org/D31426#712701>, InstructionSimplify is missing the following simplification: This function: define <4 x i32> @splat_operand(<4 x i32> %x) { %splat = shufflevector <4 x i32> %x, <4 x i32> undef, <4 x i32> zeroinitializer %shuf = shufflevector <4 x i32> %splat, <4 x i32> undef, <4 x i32>

> I wouldn't be surprised if InstSimplify were relying on (1) to implement > some of its optimizations: > http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/InstructionSimplify.cpp?revision=233938&view=markup#l2298 Yup! It looks like LLVM really implements (1) and (2) is just a misleading anecdote. So I'll change my vote from "remove (1)" to "remove

Eli Friedman <eli.friedman <at> gmail.com> writes: > > Empirically the OSR optimization is compile-time faster than LSR. I have > > also noticed that OSR has more "analysis" requirements: Induction Variable > > User, Natural Loop Information, Canonicalize natural loops, and Scalar > > Evolution Analysis. Both OSR and LSR require the Dominator Tree

On Wed, Jan 16, 2013 at 12:53:55AM +0100, Joerg Sonnenberger wrote: > Let's come back to this. The attached patch decouples InstSimplify from > the alias analysis and provides the conservative logic for when pointers > are not equal. Let's take the version with the cleanup from IRC. *sigh* Dealing with too many copies. Joerg -------------- next part -------------- Index:

Thanks, Sanjay, that makes sense. The opportunity for improving instcombining splat sounds promising. Another question about shuffle simplification. This is a testcase from test/Transforms/InstCombine/vec_shuffle.ll: define <4 x i32> @test10(<4 x i32> %tmp5) nounwind { %tmp6 = shufflevector <4 x i32> %tmp5, <4 x i32> undef, <4 x i32> <i32 1, i32 undef, i32

On Wed, Dec 12, 2012 at 1:26 PM, Joerg Sonnenberger <joerg at britannica.bec.de> wrote: > On Wed, Dec 12, 2012 at 11:01:01AM -0800, Dan Gohman wrote: >> > Is that >> > assumption violated if I explicitly cast away const and pass the result >> > to a function with NoAlias argument? >> >> Not immediately, no. It means that you can't access the

Eli Friedman <eli.friedman <at> gmail.com> writes: > >> > I did not mention in the original email (and should have) that OSR needs > >> > -instcombine to be run after it for cleanup. Also -licm, -reassociate, -gvn > >> > and -sccp can be enabling optimizations for OSR. > >> > >> Hmm... perhaps that could be partially fixed

On Wed, Dec 12, 2012 at 11:01:01AM -0800, Dan Gohman wrote: > > Is that > > assumption violated if I explicitly cast away const and pass the result > > to a function with NoAlias argument? > > Not immediately, no. It means that you can't access the constant > pointer's pointee directly within the noalias argument's scope. Access > to that object must go

The LangRef says this for left shifts: "If the nsw keyword is present, then the shift produces a poison value if it shifts out any bits that disagree with the resultant sign bit." ... (1) followed by "As such, NUW/NSW have the same semantics as they would if the shift were expressed as a mul instruction with the same nsw/nuw bits in (mul %op1, (shl 1, %op2))." ... (2) But

Greetings, I've been using LLVM and Clang for a while now, primarily targeting x86 and ARM. Recently, I read the list of open LLVM projects, one of them being "Add JIT support to the SPARC port." Looking further, I saw a May 2010 post from Chris Lattner [2], which basically stated that a future-proof implementation should use LLVM-MC. Is anybody currently working on this project?