search for: pointstoconstantmemori

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

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'

I was reading the code in AliasAnalysis.cpp and happened to notice what looks like a bug. See the line marked by '*' below: AliasAnalysis::ModRefResult AliasAnalysis::getModRefInfo(const VAArgInst *V, const Location &Loc) { // If the va_arg address cannot alias the pointer in question, then the // specified memory cannot be accessed by the va_arg. if (!alias(getLocation(V),

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 during the calling of any given function in the module. There seem to

Hi, I am looking at the Type Based Alias Analysis and I am trying to understand why, from what I see, pointsToConstantMemory() never returns true. It seems that this information should come from the TBAA metadata, in which the Access Tag has an optional 4th field to specify this information. "Access tags are represented as MDNode s with either 3 or 4 operands. The first operand is an

> On Dec 1, 2014, at 3:44 PM, Philip Reames <listmail at philipreames.com> wrote: > > (Spawning a separate subthread off the 'Optimization hints for "constant" loads' discussion for a related question. ) > > Looking at TBAA again, I was reminded that TBAA also contains a third field which indicates that "meaning pointsToConstantMemory should return

I'm looking at how to optimize IR which contains reads from a field which is known to be initialized exactly once. I've got an idea on how to approach this, but wanted to see if others have alternate ideas or similar problems which might spark discussion. It feels like there's a potentially generally useful optimization hint here if we can generalize it sufficiently without

----- Original Message ----- > From: "Daniel Berlin" <dberlin at dberlin.org> > To: "Jingyue Wu" <jingyue at google.com> > Cc: "Hal Finkel" <hfinkel at anl.gov>, llvm-dev at lists.llvm.org, "Justin Holewinski" <jholewinski at nvidia.com> > Sent: Wednesday, August 12, 2015 2:03:34 PM > Subject: Re: [llvm-dev] [RFC]

----- Original Message ----- > From: "James Molloy via llvm-dev" <llvm-dev at lists.llvm.org> > To: "Vaivaswatha Nagaraj" <vn at compilertree.com> > Cc: "LLVM Dev" <llvm-dev at lists.llvm.org> > Sent: Thursday, December 3, 2015 4:41:46 AM > Subject: Re: [llvm-dev] Function attributes for LibFunc and its impact on GlobalsAA > >