search for: d12494

On Wed, Sep 23, 2015 at 12:00 PM, Hal Finkel <hfinkel at anl.gov> wrote: >> >> Should we try the patch in it's current location, namely after LSR? > > Sure; post the patch as you have it so we can look at what's going on. > http://reviews.llvm.org/D12494 One particular point: The algorithm checks that SCEV's are equal when their raw pointers are equal. Is that a future-proof feature of SCEVs?

...M 2.9 and we've been using it ever since. I've done some light refactoring and modernization. This pass broke 4 existing tests that were sensitive to generated code. I've corrected all these, but please give them special scrutiny. The patch is available here: http://reviews.llvm.org/D12494 Please advise. Regards, -steve

I've noticed that there was an attempt to mitigate ExitValues problem in https://reviews.llvm.org/D12494 that went nowhere. Were there particular issues with that approach? -- Danila From: Philip Reames [mailto:listmail at philipreames.com] Sent: Saturday, August 10, 2019 02:05 To: Danila Malyutin <Danila.Malyutin at synopsys.com>; Finkel, Hal J. <hfinkel at anl.gov> Cc: llvm-dev at list...

...able Induction Variable Simplification? Wasn't aware of this patch. No, I don't see an obvious reason why it wasn't followed up on. Philip On 8/13/19 8:25 AM, Danila Malyutin wrote: I've noticed that there was an attempt to mitigate ExitValues problem in https://reviews.llvm.org/D12494<https://urldefense.proofpoint.com/v2/url?u=https-3A__reviews.llvm.org_D12494&d=DwMD-g&c=DPL6_X_6JkXFx7AXWqB0tg&r=VEV8gWVf26SDOqiMtTxnBloZmItAauQlSqznsCc0KxY&m=dG9EWNnpejxa8ub7_ajgnN50pG20wvSyA7WI9jWEv2Q&s=XRJmqJsGpSvBiRcYTKFYc_m94KMv3dQ6FFLsfF7GR1Y&e=> that went nowher...

On Mon, Sep 21, 2015 at 11:13 AM, Wei Mi <wmi at google.com> wrote: > Maybe it can follow the "Delete dead loops" pass which is after > Induction Variable Simplification pass, so it will not affect existing > exitvalue rewriting optimization in Induction Variable Simplification > to find out and delete dead loops? > > Existing pass pipeline: >

Hi Hal, I see. So LSR could theoretically counteract undesirable Ind Var transformations but it's not implemented at the moment? I think I've managed to come up with a small reproducer that can also exhibit similar problem on x86, here it is: https://godbolt.org/z/_wxzut As you can see, when rewriteLoopExitValues is not disabled Clang generates worse code due to additional spills,