search for: meheff

Displaying 8 results from an estimated 8 matches for "meheff".

2015 Mar 16
2
[LLVMdev] Question about shouldMergeGEPs in InstructionCombining
----- Original Message ----- > From: "Jingyue Wu" <jingyue at google.com> > To: "Daniel Berlin" <dberlin at dberlin.org>, "Mark Heffernan" <meheff at google.com>, "Hal Finkel" <hfinkel at anl.gov> > Cc: "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu> > Sent: Friday, March 13, 2015 1:31:59 PM > Subject: Re: [LLVMdev] Question about shouldMergeGEPs in InstructionCombining > > > Hi D...
2015 Mar 13
3
[LLVMdev] Question about shouldMergeGEPs in InstructionCombining
On Fri, Mar 13, 2015 at 10:16 AM Mark Heffernan <meheff at google.com> wrote: > On Thu, Mar 12, 2015 at 2:34 PM, Hal Finkel <hfinkel at anl.gov> wrote: > >> It is not clear to me at all that preventing the merging is the right >> solution. There are a large number of analysis, including alias analysis, >> and optimizati...
2015 Mar 12
2
[LLVMdev] Question about shouldMergeGEPs in InstructionCombining
...ld, however, pull these apart somewhere, and probably in some way that is address-mode aware. I'd recommend trying to split non-free (via the addressing-mode) loop-invariant parts of GEPs out of loops in CodeGenPrep. -Hal ----- Original Message ----- > From: "Mark Heffernan" <meheff at google.com> > To: "Francois Pichet" <pichet2000 at gmail.com> > Cc: "Hal Finkel" <hfinkel at anl.gov>, "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu> > Sent: Thursday, March 12, 2015 4:19:56 PM > Subject: Re: [LLVMdev] Quest...
2015 Mar 12
3
[LLVMdev] Question about shouldMergeGEPs in InstructionCombining
...return Src.hasAllConstantIndices(); // was return false; Following that change, I noticed some performance gain for a few specific tests and no regression at all in our (admittedly limited) benchmarks suite. Regards, Francois Pichet, Octasic. On Thu, Mar 12, 2015 at 4:14 PM, Mark Heffernan <meheff at google.com> wrote: > Coincidentally, I just ran into this same issue on some of our benchmarks > for the NVPTX backend. You have something like this before instcombine: > > %tmp = getelementptr inbounds i32, i32* %input, i64 %offset > loop: > %loop_variant = ... >...
2014 Jun 22
2
[LLVMdev] Failed to Unroll a Seemingly Simple Loop
Hi, I found LLVM cannot unroll the loop in the example below, while gcc can. Before I dig more about this issue, is this behavior as designed? bool bar(int i); void foo(int *a, int x, int y) { for (int i = 0; i < 4; ++i) { if (bar(i)) { break; } a[i] = i; } } Btw, if s/break/continue, LLVM is able to unroll it. Thanks, Jingyue -------------- next part --------------
2014 Jul 23
2
[LLVMdev] Adding custom #pragma for clang
I'd like to add a custom #pragma directive in clang for research purposes. I'm familiar with the LLVM pass-writing interface but new to the rest of LLVM and clang. I've looked into Simone Pellegrini's work on a #pragma interface (https://github.com/motonacciu/clomp and http://llvm.org/devmtg/2013-04/pellegrini-slides.pdf), but I'm in no position to determine if this approach
2014 Jul 17
4
[LLVMdev] Removing metadata in a pass
Is it OK to remove metadata in an optimization pass? The context is patch http://reviews.llvm.org/D4571 which removes loop unrolling hint metadata after using it to avoid unrolling more than the hint suggests. This is a potential problem because loop unrolling can be run more than once. Example: a loop annotated with "#pragma clang loop unroll_count(2)" which adds hint metadata to the
2015 Feb 25
2
[LLVMdev] Question about shouldMergeGEPs in InstructionCombining
----- Original Message ----- > From: "Hal Finkel" <hfinkel at anl.gov> > To: "Francois Pichet" <pichet2000 at gmail.com> > Cc: "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu>, "chandlerc" <chandlerc at gmail.com> > Sent: Tuesday, February 24, 2015 11:27:43 PM > Subject: Re: [LLVMdev] Question about