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Hi all, Unfortunately, all my Hunks are failed when I apply : patch -p1 < da.patch command. The problem might be due to the fact that da.patch file was created against revision 167549, but I am on revision 167719 (I believe the most recent one). I am not sure if this cause the problem ? But Preston may I ask you to generate the patch file against revison 167719 ? Thanks in advance. On Tue, Nov 13, 2012 at 9:41 AM, Arnaldo <arnaldo.cruz at upr.edu> wrote: > Preston, thanks for the explanation and patch. Now it's printing the > direction and distance values. > > &gt...

Erkan, you're right. Sorry about that. Attached is the most recent version. Preston Hi Preston, > I am trying to use DA as well. I used your example and commands that you > wrote in order to get DA information. > However, it does not report any dependence info. > I am wondering whether your local copy differs from the one on the > repository ? > Thanks. > E...

Preston, thanks for the explanation and patch. Now it's printing the direction and distance values. On Tue, Nov 13, 2012 at 12:22 PM, Preston Briggs <preston.briggs at gmail.com>wrote: > Erkan, you're right. Sorry about that. > Attached is the most recent version. > > Preston &...

...: Hi all, Unfortunately, all my Hunks are failed when I apply : patch -p1 < da.patch command. The problem might be due to the fact that da.patch file was created against revision 167549, but I am on revision 167719 (I believe the most recent one). I am not sure if this cause the problem ? But Preston may I ask you to generate the patch file against revison 167719 ? Thanks in advance. The patch to print all dependences is in trunk, you don't need the patch for it anymore. Related thread: http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20121112/155651.html - Ben On Tue, N...

...he general case, we can't coalesce without a notion of interference. My worry is that looking at interference by ranges of instruction numbers leads to inaccuracies when a range is introduced by a copy. But perhaps I should focus on the links and, as you suggested, the debugging info. Thanks, Preston On Mon, Sep 10, 2018 at 5:02 PM, Matthias Braun <mbraun at apple.com> wrote: > > > On Sep 10, 2018, at 4:53 PM, Preston Briggs <preston.briggs at gmail.com> > wrote: > > > > The underlying liveness datastructure is a list of ranges where each > vreg is al...

On 11/02/2012 11:02 AM, Hal Finkel wrote: > ----- Original Message ----- >> From: "Tobias Grosser" <tobias at grosser.es> >> To: "preston briggs" <preston.briggs at gmail.com> >> Cc: "Benjamin Kramer" <benny.kra at gmail.com>, "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu> >> Sent: Friday, November 2, 2012 12:56:53 PM >> Subject: Re: [LLVMdev] DependenceAnalysis an...

...o replace the function call with an ISD::FSQRT SDNode. If I remove the above test, then the compiler will emit a sqrtsd instruction. I am hoping that someone might be able to comment on what onlyReadsMemory is supposed to do be doing in general and why it is returning false in this case. Thanks! Preston -- Preston Gurd <preston.gurd at intel.com> Intel Waterloo -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20130517/051b48de/attachment.html>

On Wed, Oct 3, 2012 at 10:15 AM, Matthieu Moy <Matthieu.Moy at grenoble-inp.fr> wrote: > Preston Briggs <preston.briggs at gmail.com> writes: >> Think about costs asymptotically; that's what matters. Calls and >> returns require constant time, just like addition and multiplication. > > Constant time, but not necessarily constant memory. > > Deep recursion will...

...falling back on "average code" is a little disingenuous. People looking for performance don't care about average code; they care about their own personal code, their important loop, and wonder why there are unnecessary copies right *there* and wasn't this problem solved ages ago? Preston On Tue, Sep 11, 2018 at 11:00 AM, Quentin Colombet < quentin.colombet at gmail.com> wrote: > Le mar. 11 sept. 2018 à 10:23, Preston Briggs > <preston.briggs at gmail.com> a écrit : > > > > Hi, > > > > Using Chaitin's approach, removing a copy via co...

> On Sep 10, 2018, at 5:25 PM, Matthias Braun <mbraun at apple.com> wrote: > > > >> On Sep 10, 2018, at 5:11 PM, Preston Briggs <preston.briggs at gmail.com <mailto:preston.briggs at gmail.com>> wrote: >> >> The phi instruction is irrelevant; just the way I think about things. >> The question is if the allocator believes that t0 and t2 interfere. >> >> Perhaps the coalescin...

...me spent rebuilding the interference graph and attempting to coalesce can add up, but I hate that we (apparently) give up on quality results to maybe save some compile time. Our machines are really fast these days; lets spend their speed on something useful! Thanks for the pointer and explanation, Preston On Tue, Sep 11, 2018 at 9:40 AM, Quentin Colombet < quentin.colombet at gmail.com> wrote: > Hi Preston, > > To summarize what Matthias said, LLVM approach to regalloc is split in > two main phases: > 1. Aggressive coalescing based on the "interference graph" of the...

...ap(unsigned NumInitBuckets = 0) { init(NumInitBuckets); } if given an explicit argument, requires that the argument be a power of 2. It's checked by an assert in init(), but for some reason my code didn't trip the assertion. Is there a special way I must make to enable asserts? Thanks, Preston On Wed, Jan 25, 2012 at 9:44 PM, Preston Briggs <preston.briggs at gmail.com>wrote: > Reading the LLVM Programmer's Manual, the description of DenseSet mentions: > > *Note that DenseSet has the same requirements for the value type that > DenseMap <http://llvm.org/docs/Pr...

...that t2 and t0 shouldn't interfere, but some folks might say the ranges overlap. Similarly, t6 = mumble t7 = t6 t8 = t6 + 5 t9 = t7 + 10 print t8, t9 Chaitin points out that t6 and t7 shouldn't interfere, even though the live ranges overlap. Anyway, I'll look at the links. Thanks, Preston > > We have separate aggressive coalescing pass before allocation. The > register allocator will later perform live range splitting inside the main > allocation loop as it seems fit. > > > I ask these questions because we (guys I work with) see loops > where there's...

...the memory store by the movl. If you are familiar with the Post-RA scheduler works, then I would appreciate any suggestions you might have as to how I could fix this problem, such as by treating inline assembly code as a barrier or by including memory references in scheduling decisions. Thanks, Preston G -- Preston Gurd <preston.gurd at intel.com> Intel Waterloo -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20121017/0ef31365/attachment.html> -------------- next part -------------- A non-text at...

...POperator>(DstPtr); After that, most everything is done by disassembling the SrcGEP and DstGEP. The conservative approach would be to make sure SrcPtr and DstPtr are both loop invariant. I'm not sure what you're suggesting. How to I pass one (both?) of these pointers to SCEV? Thanks, Preston On Fri, Nov 2, 2012 at 11:08 AM, Tobias Grosser <tobias at grosser.es> wrote: > On 11/02/2012 11:02 AM, Hal Finkel wrote: > >> ----- Original Message ----- >> >>> From: "Tobias Grosser" <tobias at grosser.es> >>> To: "preston brig...

On 11/02/2012 10:21 AM, Preston Briggs wrote: > > My initial guess is that a conservative fix is quick and small (make > sure the underlying pointers are loop invariant, otherwise give up). A > better approach would be to somehow turn code like the example into > array references that can be analyzed. I'll need...

...tried replacing the declaration of frontier with DenseMap<BasicBlock *, Frontier *> frontier(blocks*3/2); but trip over the same problem in the same place. I've used the DenseMap successfully in several other places, so I'm not sure that's gone wrong here. Any ideas? Thanks, Preston -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20120125/854da6bb/attachment.html>

...st paper (Section 1.3) and the 1st printing of Allen & Kennedy (Definition 2.10) are similarly incorrect. See http://www.elsevierdirect.com/companion.jsp?ISBN=9781558602861 particularly the replacement for page 46. I'm also confused about the math, but I'll keep working on it. Thanks, Preston On Sun, Mar 25, 2012 at 9:49 PM, Sanjoy Das <sanjoy at playingwithpointers.com> wrote: > Hi Hal, Preston! > > Sorry for the delay! Got busy with some offline work. > > I've worked on my previous code to calculate direction and distance > vectors whenever possible (st...

...my mind, a great weakness of linear scan)? Is there way to do coalescing (the great strength of coloring)? I ask these questions because we (guys I work with) see loops where there's a little register juggling that seems unnecessary. Is there a paper that describes what y'all do? Thanks, Preston On Mon, Sep 10, 2018 at 9:57 AM, Matthias Braun <mbraun at apple.com> wrote: > I would not describe LLVMs register allocator as linear scan, it's closer > to graph coloring than linear scan IMO (though doesn't really matcher > either approach). > > RegAllocGreedy ass...

...tive enough, 'cause I can't get it to work. I tried a couple of variations (one seemed straightforward; in the other, I went through looking for every example of Sparc to see how they did it and making the appropriate changes). I tried configuring like this ./configure --enable-target=preston --disable-optimized --enable-assertions=yes --prefix=/path-to-install and it chunked along for a while, but ultimately failed, complaining configure: error: Unrecognized target preston configure: error: ./configure failed for projects/sample Any ideas? Thanks, Preston -------------- nex...