similar to: [LLVMdev] -O4 limitations in llvm/llvm-gcc-4.2 2.5?

Displaying 20 results from an estimated 3000 matches similar to: "[LLVMdev] -O4 limitations in llvm/llvm-gcc-4.2 2.5?"

2009 Jan 25
0
[LLVMdev] -O4 limitations in llvm/llvm-gcc-4.2 2.5?
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
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. >
2011 Dec 30
1
[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
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
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
2007 May 18
0
[LLVMdev] API changes (was Antw.: 2.0 Pre-release tarballs online)
On Sat, 19 May 2007, Anton Korobeynikov wrote: >> * It seems that a C-call like printf("---\n") is transformed to puts >> ("---") in the LLVM IR instead of keeping it a printf. What are the >> circumstances in which this happens? Do other similar conversions >> occur? Can this be turned off (lower optimisation level?)? Manually >> replacing the
2015 May 09
2
[LLVMdev] about MemoryDependenceAnalysis usage
Hi, I try to use MemoryDependenceAnalysis in a pass to analyse a simple function: void fct (int *restrict*restrict M, int *restrict*restrict L) { S1: M[1][1] = 1; S2: L[2][2] = 2; } When I iterate over MemoryDependenceAnalysis on the S2 statement, I get the load instruction for the first depth of the array, that’s ok. But I get also the load and store for the S1 statement. I assume the
2007 May 23
1
[LLVMdev] API changes (was Antw.: 2.0 Pre-release tarballs online)
On Tue, 22 May 2007 23:52:46 -0700 (PDT) Chris Lattner <sabre at nondot.org> wrote: >On Sun, 20 May 2007, Bram Adams wrote: >> On a related note: while using llvmc I have some test cases where the >> following error now pops up on Linux X86 (not on OSX): >> >> <premain>: CommandLine Error: Argument 'debug' defined more than once! >> llvmc:
2007 May 18
1
[LLVMdev] API changes (was Antw.: 2.0 Pre-release tarballs online)
Hello, Bram > * It seems that a C-call like printf("---\n") is transformed to puts > ("---") in the LLVM IR instead of keeping it a printf. What are the > circumstances in which this happens? Do other similar conversions > occur? Can this be turned off (lower optimisation level?)? Manually > replacing the puts-calls by a printf-call is not
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 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
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
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
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
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
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
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 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 >>
2015 May 02
5
[LLVMdev] Modifying LoopUnrollingPass
Hi Zhoulai, I am trying to modify "LoopUnrollPass" in llvm which produces multiple copies of loop equal to the loop unroll factor.Currently, using multicore architecture, say 3 for example and the execution goes like: for 3 cores if there are 9 iterations of loop core instruction 1 0,3,6 2 1,4,7 3 2,5,8 But I want to to
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