Displaying 20 results from an estimated 10000 matches similar to: "Is there a way to pass Optimization passes to clang?"
2015 Jan 17
3
[LLVMdev] loop multiversioning
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
2015 May 11
2
[LLVMdev] about MemoryDependenceAnalysis usage
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.
>
2013 Aug 19
1
[LLVMdev] How to disbale loop-rotate in opt -O3 ?
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
2012 Jun 08
2
[LLVMdev] How to use LLVM optimizations with clang
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"
2012 Jun 08
0
[LLVMdev] How to use LLVM optimizations with clang
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
2012 Jun 12
2
[LLVMdev] How to use LLVM optimizations with clang
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
2011 Oct 22
5
[LLVMdev] How to make Polly ignore some non-affine memory accesses
I was trying the new feature you introduce about printing out the
graphs, so I updated my version of llvm/clang/polly synchronizing them
to the last version, but I get this error launching clang (also , I
recently switched to MacOS X for development):
$ clang not_so_simple_loop.c -O3 -Xclang -load -Xclang
${PATH_TO_POLLY_LIB}/LLVMPolly.dylib -mllvm -enable-polly-viewer
-mllvm -enable-iv-rewrite
2012 Jun 08
0
[LLVMdev] How to use LLVM optimizations with clang
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
>>
2012 Jun 12
2
[LLVMdev] How to use LLVM optimizations with clang
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
2016 May 09
4
Some questions about phase ordering in OPT and LLC
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
2012 Jun 12
0
[LLVMdev] How to use LLVM optimizations with clang
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
2011 Oct 08
0
[LLVMdev] How to make Polly ignore some non-affine memory accesses
On 10/07/2011 03:43 PM, Marcello Maggioni wrote:
> 2011/10/7 Marcello Maggioni<hayarms at gmail.com>:
>> Hi,
>>
>> for example this loop:
>>
>> #include<stdio.h>
>>
>> int main()
>> {
>> int A[1024];
>> int j, k=10;
>> for (j = 1; j< 1024; j++)
>> A[j] =
2012 Jun 12
0
[LLVMdev] How to use LLVM optimizations with clang
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
2016 May 09
2
Some questions about phase ordering in OPT and LLC
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
2011 Nov 15
1
[LLVMdev] opt -O2 optimization passes
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
2011 Oct 23
0
[LLVMdev] How to make Polly ignore some non-affine memory accesses
On 10/22/2011 08:41 AM, Marcello Maggioni wrote:
> I was trying the new feature you introduce about printing out the
> graphs, so I updated my version of llvm/clang/polly synchronizing them
> to the last version, but I get this error launching clang (also , I
> recently switched to MacOS X for development):
>
> $ clang not_so_simple_loop.c -O3 -Xclang -load -Xclang
>
2009 Feb 02
1
[LLVMdev] Proposal: Debug information improvement - keep the line number with optimizations
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
2015 Jan 05
2
[LLVMdev] LTO v. opt
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
2010 Jan 13
2
[LLVMdev] Cross-module function inlining
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)
2012 Jun 08
2
[LLVMdev] How to use LLVM optimizations with clang
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