search for: fixpoint

...out of instcombine, >>>>> ​open questions for me would be >>>>> ​​: >>>>> >>>>> >>>>> 1. Since -reassociate isn't a fixed point pass, >>>>> >>>> >>>> This is fixable, fwiw, without fixpointing it. >>>> >>> >>> How? >>> >> >> Depends on specifically which part you would like to know about ;) >> > > ​Maybe I misunderstood what you meant by "This is fixable". Did you mean > that we won't somehow need to fixpo...

...gt;>> ​,​ >>>> out of instcombine, >>>> ​open questions for me would be >>>> ​​: >>>> >>>> >>>> 1. Since -reassociate isn't a fixed point pass, >>>> >>> >>> This is fixable, fwiw, without fixpointing it. >>> >> >> How? >> > > Depends on specifically which part you would like to know about ;) > ​Maybe I misunderstood what you meant by "This is fixable". Did you mean that we won't somehow need to fixpoint between instcombine and reassociate, o...

...t;>> or keep additional ones >>> ​,​ >>> out of instcombine, >>> ​open questions for me would be >>> ​​: >>> >>> >>> 1. Since -reassociate isn't a fixed point pass, >>> >> >> This is fixable, fwiw, without fixpointing it. >> > > How? > Depends on specifically which part you would like to know about ;) > > >> >>> we might need to repeat "-instcombine -reassociate" multiple times to >>> ​fold >>> down to what we want (relating to my comment her...

...;>>> ​open questions for me would be >>>>>> ​​: >>>>>> >>>>>> >>>>>> 1. Since -reassociate isn't a fixed point pass, >>>>>> >>>>> >>>>> This is fixable, fwiw, without fixpointing it. >>>>> >>>> >>>> How? >>>> >>> >>> Depends on specifically which part you would like to know about ;) >>> >> >> ​Maybe I misunderstood what you meant by "This is fixable". Did you mean >>...

...s for me would be >>>>>>> ​​: >>>>>>> >>>>>>> >>>>>>> 1. Since -reassociate isn't a fixed point pass, >>>>>>> >>>>>> >>>>>> This is fixable, fwiw, without fixpointing it. >>>>>> >>>>> >>>>> How? >>>>> >>>> >>>> Depends on specifically which part you would like to know about ;) >>>> >>> >>> ​Maybe I misunderstood what you meant by "This is...

...> ​open questions for me would be > ​​: > > > 1. Since -reassociate isn't a fixed point > pass, > > > This is fixable, fwiw, without fixpointing it. > > > How? > > > Depends on specifically which part you would like to > know about ;) > > > ​Maybe I misunderstood what you meant by "This is > fixable". Did you mean that w...

...t;>>>>> ​​: >>>>>>>> >>>>>>>> >>>>>>>> 1. Since -reassociate isn't a fixed point pass, >>>>>>>> >>>>>>> >>>>>>> This is fixable, fwiw, without fixpointing it. >>>>>>> >>>>>> >>>>>> How? >>>>>> >>>>> >>>>> Depends on specifically which part you would like to know about ;) >>>>> >>>> >>>> ​Maybe I misunderst...

R gurus, Every so often(*) someone asks how to suppress scientific notation in printing, so I thought I'd give it a shot, but I need some help. The formatting decision is made(**) on line 286 of src/main/format.c : if (mF <= *m) { /* IFF it needs less space : "F" (Fixpoint) format */ where mF is the number of characters for "normal" printing and *m is the number of characters for scientific notation. If mf <= *m, then parameters are set that cause "normal" printing. My idea was to introduce a "penalty" for scientific notation, whic...

...​: >>>>>>>>> >>>>>>>>> >>>>>>>>> 1. Since -reassociate isn't a fixed point pass, >>>>>>>>> >>>>>>>> >>>>>>>> This is fixable, fwiw, without fixpointing it. >>>>>>>> >>>>>>> >>>>>>> How? >>>>>>> >>>>>> >>>>>> Depends on specifically which part you would like to know about ;) >>>>>> >>>>> >...

...starting this discussion.) > > If > ​we will > move > ​reassociation, > or keep additional ones > ​,​ > out of instcombine, > ​open questions for me would be > ​​: > > > 1. Since -reassociate isn't a fixed point pass, > This is fixable, fwiw, without fixpointing it. > we might need to repeat "-instcombine -reassociate" multiple times to > ​fold > down to what we want (relating to my comment here > <https://reviews.llvm.org/D46336#1087082>). I assumed this isn't not what > we want to do > ​? My impression is we do...

...l >> move >> ​reassociation, >> or keep additional ones >> ​,​ >> out of instcombine, >> ​open questions for me would be >> ​​: >> >> >> 1. Since -reassociate isn't a fixed point pass, >> > > This is fixable, fwiw, without fixpointing it. > How? > >> we might need to repeat "-instcombine -reassociate" multiple times to >> ​fold >> down to what we want (relating to my comment here >> <https://reviews.llvm.org/D46336#1087082>). I assumed this isn't not >> what we want...

....com/gp/book/9783540654100> [2] Data Flow Analysis: Theory and Practice. <https://dl.acm.org/doi/book/10.5555/1592955> [3] Static Program Analysis. <https://cs.au.dk/~amoeller/spa/spa.pdf> [4] 2019 LLVM Developers’ Meeting: J. Doerfert “The Attributor: A Versatile Inter-procedural Fixpoint.." <https://www.youtube.com/watch?v=HVvvCSSLiTw> [5] Soot - A Java optimization framework <https://github.com/Sable/soot> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20200314/5beb64c2/attac...

...ddress is resolved and erroneously applies branch relaxation to the > jump. I don't know why a linker private symbol would make a difference. > Relaxation is the process of *shortening* jumps that can be shortened, and then re-running instruction layout to discover more relaxations until fixpoint. Removing the -relax-all flag in clang won't help here, it would hurt. I'm not exactly sure what the semantics of linker private symbols are, but using a normal assembler temporary label is probably the way to go anyway. -------------- next part -------------- An HTML attachment was scrubb...

...on > (i.e. constant folding / propagation etc.) might have folded that (%v) > into the constant null. So, the former can ask him. > These connections give the power and the complexity. > > The attributes have a state, that changes. When the state stops changing, > it has reached a fixpoint, at which point > the deduction of it stops. From the initialization of the attribute until > a fixpoint is reached, the state changes > in updates (called updateImpl() in the source code). This is where > attributes try to deduce new things, ask one another > and eventually try to r...

...to propose a "proper" organization***. Why? Because we do not derive nearly as many attributes as we could****, while we do maintain various (separate and diffently organized) "data-flow-like analyses" to do so. What else? I propose a single optimistic data-flow (fixpoint) loop to perform the deduction (similar to [2,3] but for all propagation forms and not only call sites -> callee). Given that a pessimistic initialization allows to terminate early, we can then also vary the compile time investment. Where is the catch? It will require a substantial r...

...'s true, we continue to the next instruction, otherwise we stop. If we make it through all of them, checkForAllInstructions() returns true. Otherwise false. The predicate checks if any instruction breaks our assumption (we'll see shortly how). If it does, we immediately indicate pessimistic fixpoint. What about TEST 2 and 3 ? Those 2 functions have a call inside but if you put a print inside the predicate, you'll see again nothing. The reason for that brings us to an important part of the Attributor and that is that "deadness" (and the relative attribute) is very important. check...

I thought jumps start short and relaxation widens them as needed until fixpoint. So relax-all causes them all to be widened unconditionally. On Wed, Jun 29, 2016 at 9:27 AM, Reid Kleckner via llvm-dev < llvm-dev at lists.llvm.org> wrote: > On Wed, Jun 22, 2016 at 9:36 AM, Nirav Davé <llvm-dev at lists.llvm.org> > wrote: > >> In any case, the issue...

( ​I came across this issue in the context of D46336 <https://reviews.llvm.org/D46336>. ​ ​ Thanks, Sanjay, for starting this discussion.) If ​we will move ​reassociation, or keep additional ones ​,​ out of instcombine, ​open questions for me would be ​​: 1. Since -reassociate isn't a fixed point pass, we might need to repeat "-instcombine -reassociate" multiple times to

...nificant performance impact. However it might be useful. What is your opinion about this analysis and transformation? Am I right regarding the usefulness and the effort? What level of precision would be reasonable (e.g. the depth of a calling context or no context sensitivity at all)? What kind of fixpoint solver would be the best choice for this purpose? Are their any reasons against my proposal? Kind regards, Gordon

On Wed, Jun 29, 2016 at 10:05 AM, Craig Topper <craig.topper at gmail.com> wrote: > I thought jumps start short and relaxation widens them as needed until > fixpoint. So relax-all causes them all to be widened unconditionally. > My mistake, you're right. I've been reading that code for years and assuming that it goes large-to-small, but I guess the process is the same regardless of which direction you go. :) -------------- next part --------------...