similar to: [LLVMdev] Potential SimplifyCFG optimization; hammock to diamond transformation

Message: 6 Date: Tue, 6 Aug 2013 10:46:19 -0400 From: Chad Rosier <chad.rosier at gmail.com<mailto:chad.rosier at gmail.com>> To: llvmdev <llvmdev at cs.uiuc.edu<mailto:llvmdev at cs.uiuc.edu>> Subject: [LLVMdev] Potential SimplifyCFG optimization; hammock to diamond transformation Message-ID: <CAMo3wbR6x1wBzb17=GrkERV7kvzx2RdpuheFzyxkQEs3BBvKaw at

Thanks, Mark. I will give the paper a look. On Tue, Aug 6, 2013 at 1:42 PM, Mark Lacey <mark.lacey at apple.com> wrote: > Hi Chad, > > On Aug 6, 2013, at 7:46 AM, Chad Rosier <chad.rosier at gmail.com> wrote: > > > All, > > I have some code that looks like the following: > > > > { > > double a, b, c; > > for (...) { > >

Hi Chad, On Aug 6, 2013, at 7:46 AM, Chad Rosier <chad.rosier at gmail.com> wrote: > All, > I have some code that looks like the following: > > { > double a, b, c; > for (...) { > ... > a = lots of FP math; > b = lots of FP math; > c = lots of FP math; > if (cond) { > a = 0.0; > b = 0.1; > c = 0.2; >

All, I have some code that looks like the following: { double a, b, c; for (...) { ... a = lots of FP math; b = lots of FP math; c = lots of FP math; if (cond) { a = 0.0; b = 0.1; c = 0.2; } ... } } Could we not convert the hammock into a diamond and move the initial computation of a, b, and c into the else block. Something like this: {

Hello Duncan Sorry for the mistake. Actually that error occurred when I was compiling all the files at once, NOT in for loop. The for loop is working perfectly as it is dealing with individual files. I have now one new issue. Let me specify it briefly. If I compile the program using the following command line i.e. $ clang -O3 -lm *.c then $ time ./a.out real 0m2.606s user 0m2.584s sys

Sure. The comb.ll and data files are attached and can be invoked as the following $ lli comb.ll data -c Regards Shahzad On Tue, Jun 12, 2012 at 12:28 PM, Duncan Sands <baldrick at free.fr> wrote: > Hi, > > >> Yes, they both are exactly the same. > > > then I don't know what is going on.  I suggest you send a copy of comb.ll to > the > list so that we can

Thanks Duncan It was really helpful. Regards Abdul On Fri, Jun 8, 2012 at 7:23 PM, Duncan Sands <baldrick at free.fr> wrote: > Hi, > > >> If I compile the program using the following command line i.e. >> >> $ clang -O3 -lm *.c > > > this may be doing link time optimization. > > >> >> then >> >> $ time ./a.out >>

Hi, is the comb.ll used here: > $ time lli ./comb.ll > > then the runtime is > > real 0m2.671s > user 0m2.640s > sys 0m0.020s > > But, if I convert this same file comb,ll in to native binary the same as the comb.ll used here: > $ clang comb.ll ? Ciao, Duncan. > > and execute it, then the runtime increases alot > > $ time ./a.out > > real

Hi, > Yes, they both are exactly the same. then I don't know what is going on. I suggest you send a copy of comb.ll to the list so that we can see for ourselves. Ciao, Duncan. > > Regards > > Shahzad > > On Tue, Jun 12, 2012 at 9:38 AM, Duncan Sands<baldrick at free.fr> wrote: >> Hi, is the comb.ll used here: >> >> >>> $ time lli

Hi, > If I compile the program using the following command line i.e. > > $ clang -O3 -lm *.c this may be doing link time optimization. > > then > > $ time ./a.out > > real 0m2.606s > user 0m2.584s > sys 0m0.012s > > BUT, if I use all the optimizations enabled with -O3 but specify them > explicity i.e. you can just use "opt -O3"

Hello I need some help here please. If we compile source files directly in to native code: $ clang -O3 -lm *.c then the runtime is like following real 0m2.807s user 0m2.784s sys 0m0.012s and If we emit LLVM bytcode and apply optimizations $ clang -O3 -c -emit-llvm *.c $ llvm-link *.o -o comb.ll $ time lli ./comb.ll then the runtime is real 0m2.671s user 0m2.640s sys 0m0.020s But, if I

Hi Yes, they both are exactly the same. Regards Shahzad On Tue, Jun 12, 2012 at 9:38 AM, Duncan Sands <baldrick at free.fr> wrote: > Hi, is the comb.ll used here: > > >> $ time lli ./comb.ll >> >> then the runtime is >> >> real    0m2.671s >> user    0m2.640s >> sys     0m0.020s >> >> But, if I convert this same file comb,ll

Hello, in the description of SimplifyCFG, it says that it can "Eliminates PHI nodes for basic blocks with a single predecessor." I tested this pass with a program that has phi nodes with a single predecessor and it did not remove it. I also looked in the code and found nothing to remove it. I'm I missing something, or it does not remove phis with a single predecessor? My

Some time ago I was allowed to discuss "Diamond Graphs", and whether they would be useful in R, in this mailing list. The August 2003 issue of The American Statistician has finally arrived here and I have been able to read the article. A number of points of interest arise. 1. The article is "A Diamond-Shaped Equiponderant Graphical Display of the Effects of Two

I apologise for starting a new thread, but we had a mail problem and I don't have the original message to refer to. Someone mentioned the new "Diamond Graphs" invented at Johns Hopkins. I haven't see the August 2003 issue of The American Statistician yet, but I _have_ read the press release. The press release is a bit of a stunner. I quote: "Who would have thought we

I am looking to replicate the functionality of the JMP diamond plot in R. I have found the following enhancement and no other references(see below). I have tried to contact the author via email and I have had no luck. Does any know if this functionality exists in R? If it does not does anyone know how to contact the author of the enhancement request? "Hi, I experimented with a set of S

This looks like a bug in simplifycfg. We should preserve lifetime intrinsics due to the reasons I described. The code in //lib/Transforms/Utils/Local.cpp: if (Succ->getSinglePredecessor()) { // BB is the only predecessor of Succ, so Succ will end up with exactly // the same predecessors BB had. // Copy over any phi, debug or lifetime instruction.

Hi, > I tried it with -o - but its producing an error > > gcc: fatal error: cannot specify -o with -c, -S or -E with multiple files > > What you suggest? what I wrote: >> for F in *.c ; do B=`basename $F .c` ; gcc -fplugin=/path/to/dragonegg.so >> -S -o - $F -fplugin-arg-dragonegg-emit-ir | opt -adce -o $B.ll ; done >> clang *.ll Thanks to the for loop and

Hi, I haven't found in R a possibility to draw a boxplot with a diamond shape (means and CI). Does anyone know how to plot it ? thanks,

Hi all, I am noticing a significant degradation in execution performance in loops with just one backedge than loops with two backedges. Unifying the backedges into one will also cause the slowdown. To replicate this problem, I used the C code in https://gist.github.com/sklam/11f11a410258ca191e6f263262a4ea65 and checked against clang-3.8 and clang-4.0 nightly. Depending on where I put the