search for: cfgsimplifi

Hi, The phase of instruction combine cannot handle the instruction %4 = select i1 %tobool.i, metadata !12, metadata !10 generated by the phase of CFG simplification and the compiler generates an assertion failure. I wonder whether this is valid LLVM IR: %4 = select i1 %tobool.i, metadata !12, metadata !10 Before CFGSimplify cond.true.i: ; preds = %entry

To reproduce the issue, please use the command line "opt -simplifycfg filename". target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" target triple = "x86_64-unknown-linux-gnu" %struct.G = type { %struct.ordered_index_node*, i32 } %struct.ordered_index_node = type { %struct.B, %struct.F } %struct.B = type { i32 } %struct.F = type { i32*, i32* }

Thanks for sharing this background information :). If you've got the time, I think it'd be great to check this bulleted list into docs/. I see that we don't have a Canonicalizations.rst or a LoopOptimizations.rst -- your notes look like a good starting point. Given that the pass seems to be doing the right thing from a design perspective, should it stay in tree? Since it's been

We're not actively using this, but from a design perspective I'm wondering if we should be using this or something like it.  At the moment, our various loop optimization assume mostly canonical input.  Some of the passes have been taught to deal with limited amounts of non-canonical-ism, but there's a strong code simplicity argument in favor of only handling canonical input and

Hi, I think we should remove the LoopInstSimplify pass, as it has no test coverage and no users (afaik). If you are using the pass, or think that it should stay in tree for some other reason, please let me know. Here's the patch: https://reviews.llvm.org/D44053 <https://reviews.llvm.org/D44053> vedant -------------- next part -------------- An HTML attachment was scrubbed... URL:

The code is simple enough that I'd vote to delete and reintroduce later if needed.  :) Philip On 03/05/2018 01:23 PM, Vedant Kumar wrote: > Thanks for sharing this background information :). If you've got the > time, I think it'd be great to check this bulleted list into docs/. I > see that we don't have a Canonicalizations.rst or a > LoopOptimizations.rst --

On Mon, Jul 17, 2017 at 5:11 PM, Wei Mi <wmi at google.com> wrote: > On Mon, Jul 17, 2017 at 2:09 PM, Sanjoy Das > <sanjoy at playingwithpointers.com> wrote: >> Hi, >> >> On Mon, Jul 17, 2017 at 1:56 PM, Daniel Berlin via llvm-dev >> <llvm-dev at lists.llvm.org> wrote: >>> >>> >>> On Mon, Jul 17, 2017 at 1:53 PM, Wei Mi

Hello, Recently I've come across two instances where Induction Variable Simplification lead to noticable performance regressions. In one case, the removal of extra IV lead to the inability to reschedule instructions in a tight loop to reduce stalls. In that case, there were enough registers to spare, so using extra register for extra induction variable was preferable since it reduced

On 07/18/2017 06:03 PM, David Majnemer via llvm-dev wrote: > I doubt it is possible for us to try and make any fix which is > predicated on eagerly treating undef in a particular way, refinement > will always cause these problems to come about... > > Given what I've seen in LLVM (and what I've learned from other > compilers), we probably have two choices: > 1.

Hi, On Mon, Jul 17, 2017 at 1:56 PM, Daniel Berlin via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > > On Mon, Jul 17, 2017 at 1:53 PM, Wei Mi <wmi at google.com> wrote: >> >> It seems MemorySSA.cpp is the only real code where we found the >> problem happening. > > > This is doubtful, ¸FWIW :) > >> >> Is it possible to change the

Hi Danny, Thanks for that :) However I've just updated the prototype patch to NewGVN and it didn't need any API changes - all I rely on is GVNExpression. Hongbin, I wanted to explain a little about what GVNSink can currently do, what it was designed for and hopefully how to make it handle your testcase. *Background* Common code sinking is more difficult to efficently do than one might