similar to: [LLVMdev] Opt ...the pass manager utility

Hello, I am trying to simplify the CFG of a given code and eliminate the conditionals, even though I will obtain codes that are not semantically equivalent. For example, given a simple loop: for(i=0; i<N; i++){    a[i] = i;     if (i%2==0)       a[i] += 12; } I would keep only the loop, without the if statement: for(i=0; i<N; i++){    a[i] = i; } I can eliminate such conditionals on

Hi all, I would like to know which optimization passes are performed at -O2 by opt. So I used following command: llvm-as < /dev/null | opt -O2 -std-compile-opts -disable-output -debug-pass=Arguments I've got following output for LLVM opt 2.9: Pass Arguments: -no-aa -tbaa -basicaa -simplifycfg -domtree -scalarrepl -early-cse Pass Arguments: -targetlibinfo -no-aa -tbaa -basicaa

0 down vote favorite <http://stackoverflow.com/questions/34049511/how-to-pass-optimization-passes-to-clang#> I'm trying to debug an issue for a new target where a testcase fails with -O1 optimization and passes with -O0 optimization. I got a list of optimization passes being performed when 'clang -O1' is called like this: llvm-as < /dev/null | opt -O1 -disable-output

On Mon, May 09, 2016 at 01:07:07PM -0700, Mehdi Amini via llvm-dev wrote: > > > On May 9, 2016, at 10:43 AM, Ricardo Nobre via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > > > Hi, > > > > I'm a PhD student doing phase ordering as part of my PhD topic and I would like to ask some questions about LLVM. > > > > Executing the following

Hi, I'm a PhD student doing phase ordering as part of my PhD topic and I would like to ask some questions about LLVM. Executing the following command to see what passes does OPT execute when targeting a SPARC V8 processor: /opt/clang+llvm-3.7.1-x86_64-linux-gnu-ubuntu-15.10/bin/llvm-as < /dev/null | /opt/clang+llvm-3.7.1-x86_64-linux-gnu-ubuntu-15.10/bin/opt -O3 -march=sparc -mcpu=v8

add -basicaa to your command line :) On Mon, May 11, 2015 at 7:15 AM, Willy WOLFF <willy.mh.wolff at gmail.com> wrote: > I play a bit more with MemoryDependenceAnalysis by wrapping my pass, and > call explicitely BasicAliasAnalysis. Its still using No Alias Analysis. > > How can I let MemoryDependenceAnalysis use BasicAliasAnalysis? > > Please, find attached my pass. >

Does LLVM have loop multiversioning ? it seems it does not with clang++ -O3 -mllvm -debug-pass=Arguments program.c -c bash-4.1$ clang++ -O3 -mllvm -debug-pass=Arguments fast_algorithms.c -c clang-3.6: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated Pass Arguments: -datalayout -notti -basictti -x86tti -targetlibinfo -no-aa -tbaa -scoped-noalias

Liu Xin <navy.xliu at gmail.com> writes: > Your decompose vector patch works perfect on my site. Unfortunately, I > still get stupid code because llvm '-dse' fails followed by > 'decompose-vector' . > I read the DSE code and it is definitely capable of eliminating unused > memory stores if its AA works. I don't think basic AA works for me. I > found

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

Hi Mark, It is not clear to me at all that preventing the merging is the right solution. There are a large number of analysis, including alias analysis, and optimizations that use GetUnderlyingObject, and related routines to search back through GEPs. They only do this up to some small finite depth (six, IIRC). So reducing the GEP depth is likely the right solution for InstCombine (which has the

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 >>

Optimization passes running before LoopVectorizer should be able to combine the two statements (this should be happening in O1. Pls check) arr[i] = a + i sum += arr[i] to sum += a + i Not sure, why are you using the array there. - Suyog On 4 May 2015 23:11, "Michael Zolotukhin" <mzolotukhin at apple.com> wrote: > Hi Yaduveer, > > Vectorizer probably fails because it

Hi, Richard, Your decompose vector patch works perfect on my site. Unfortunately, I still get stupid code because llvm '-dse' fails followed by 'decompose-vector' . I read the DSE code and it is definitely capable of eliminating unused memory stores if its AA works. I don't think basic AA works for me. I found my program have complex memory accesses, such as bi-dimentional

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"

Thanks to you both. On my Linux (centos6) system, I have reproduce a variant of the bug and learned about -plugin-opt=-debug-pass=Arguments which I infer from comments is intended to built arguments to “opt” however I found that some of the arguments don’t seem to be quite correct. I assume this just minor bit rot. bin/opt -o pass1.bc -datalayout -notti -basictti -x86tti -targetlibinfo

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