similar to: [LLVMdev] Safe Passes

Which transformation passes are 'safe', meaning it does not worsens the effectiveness of a later pass or the generated code? I imagine all passes which either removes data or add attributes are included in this list, plus some simplification passes: -adce -argpromotion -constmerge -constprop -deadargelim -dse -functionattrs -globaldce -globalopt -gvn -instcombine -internalize

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

Jack Howarth wrote: > I've had better luck compiling all of pymol 1.1r2 with > -O4 on darwin9. Everythink links and there appears to be > no regressions in the resulting code. I take it that LTO > in llvm 2.5 is still limited to dead code elimination, > correct? No. libLTO does the equivalent to opt -internalize -ipsccp -globalopt -constmerge -deadargelim -instcombine

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

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

The project that I use to test LLVM against showed that currently llvm-ld doesn't honor the -Ox switch. $ /usr/src/llvm/dist/bin/llvm-ld \ -v -stats -native -O1 -strip-all \ -o main \ -L/usr/share/qt3/lib -L/usr/X11R6/lib \ -lcrypto -lusb -lutil -lqt-mt -lXext -lX11 -lm -lpthread ... $ size main text data bss dec hex filename 1128271 71980 8392 1208643 127143

On Fri, Apr 22, 2005 at 02:32:25AM +0200, Markus F.X.J. Oberhumer wrote: > Ok, after pasting the output from "gccas -debug-pass=Arguments > </dev/null -o - >/dev/null" I get the following: > > bugpoint -verify -lowersetjmp -funcresolve -raiseallocs -simplifycfg > -mem2reg -globalopt -globaldce -ipconstprop -deadargelim -instcombine > -simplifycfg -prune-eh

I've developed a working LLVM back-end (based on LLVM 2.6) for a custom architecture with its own tool chain. This tool chain creates stand-alone programs from a single assembly. We used to use GCC, which supported producing a single machine assembly from multiple source files. I modified Clang to accept the architecture, but discovered that clang-cc (or the Clang Tool subclass inside Clang)

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

Hi, I've been thinking about how to keep the line number with the llvm transform/Analysis passes. Basically, I agree with Chris's notes ( http://www.nondot.org/sabre/LLVMNotes/DebugInfoImprovements.txt), and I will follow his way to turn on the line number information when optimization enabled. Here is a detailed proposal: 1. Introduction At the time of this writing, LLVM's

Mark Muir wrote: > I've developed a working LLVM back-end (based on LLVM 2.6) for a custom architecture with its own tool chain. This tool chain creates stand-alone programs from a single assembly. We used to use GCC, which supported producing a single machine assembly from multiple source files. > > I modified Clang to accept the architecture, but discovered that clang-cc (or the

Hi, Op 19-mei-07, om 00:39 heeft Chris Lattner het volgende geschreven: > Anton is right. You should be able to use -fno-builtins to disable > this. Thanks, that did the trick. Some final remarks (my app works again :-)): * llvm.va_start and similar intrinsics now have an i8* arg instead of an sbyte** * For some reason the Arguments of a Function are now circularly linked,

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. >

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

instcombine doesn't seem to be doing it. From my testing it seems to only occur when I use -indvars after a long string of commands. For example: llvm-as < test_fc_27.ll | opt -preverify -domtree -verify -lowersetjmp -raiseallocs -simplifycfg -domtree -domfrontier -mem2reg -globalopt -globaldce -ipconstprop -deadargelim -instcombine -simplifycfg -ba siccg -prune-eh -inline

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

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 >>

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

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