similar to: [LLVMdev] Performing my own pass with a single command line?

Hi John, Are there any documents about how to add a pass into LTO? Cheers, Zheng On 19 April 2010 15:11, John Criswell <criswell at uiuc.edu> wrote: > Dear Zheng Wang, > > You have a few options: > > 1) You can add your pass to the set of passes that llvm-gcc runs when it > optimizes code.  This requires re-compiling llvm-gcc; it also means that > your pass must be

Dear Zheng Wang, You have a few options: 1) You can add your pass to the set of passes that llvm-gcc runs when it optimizes code. This requires re-compiling llvm-gcc; it also means that your pass must be able to run on incomplete programs and be run multiple times over the same code (i.e., it cannot do whole-program analysis). 2) You can change the build system of the program you're

Hi, How to compile a large project (such as Apache) by using llvm-gcc? I tried to replace CC with llvm-gcc and CFLAGS with -emit-llvm while running configure, but it didn't work. Thank you for your help. -Wink

Dear John, Thanks for your reply. I want to do whole program analysis, all what I need are just the separate .bc files. What instructions should I follow? I run the configure on apache in this way: CC=clang CFLAGS=-emit-llvm ./configure while I get the error message like: checking for gcc... clang checking for C compiler default output file name... configure: error: C compiler cannot

Hi All, I am using clang to compile Mysql source code. Because I want to do some inter-procedural analysis, hopefully, I want to get a .o(bitcode) file(a module) containing all possible function declarations and definitions. Is it possible to do that ? Or you guys have some suggestions? To be clear, like Mysql, there is a mysqld routine, which is a major routine. I want to mysqld.o(which is

Wink zhang wrote: > Hi, > > How to compile a large project (such as Apache) by using llvm-gcc? > I tried to replace CC with llvm-gcc and CFLAGS with -emit-llvm while > running configure, but it didn't work. > If you just want to compile the program with llvm-gcc, then Diego's instructions are fine. If, however, you want to do inter-procedural optimization or whole

Wink zhang wrote: > Dear John, > > Thanks for your reply. I want to do whole program analysis, all what I > need are just the separate .bc files. What instructions should I follow? > I'm a little confused. Whole-program analysis requires that you link all of the individual bitcode files from different compilation unit (i.e., individual .c files) together into a single

On Friday 21 September 2007, Chris Lattner wrote: > On Sep 21, 2007, at 9:42 AM, Maarten ter Huurne wrote: > > However, it is not possible to let the zlib Makefile issue that > > command > > without patching the Makefile, because the fragment that does the > > linking is > > hardcoded to use the compiler command for linking: > > > > example$(EXE):

Hello, I followed the instruction given at: http://llvm.org/docs/LinkTimeOptimization.html#design, but got an error. Why it was that? Should I enable anything when configuring LLVM? I am using LLVM v2.6. $ llvm-gcc --emit-llvm -c a.c -o a.o $ llvm-gcc -c main.c -o main.o $ llvm-gcc a.o main.o -o main a.o: file not recognized: File format not recognized collect2: ld returned 1 exit status

It appears that llvm-ld can handle bitcode files but llvm-gcc complains that when I pass bitcode files to it. I assume that means that llvm-gcc does not use llvm-ld by default. Is there a way to force it to use llvm-ld? Bill Wendling wrote: > You do it by using the -flto flag. But you will need a linker that's able to handle the bitcode files. The Apple linker can and so can the

On 26.01.2011, at 04:39, John McCall wrote: > On Jan 24, 2011, at 10:36 AM, Hendrix_ at gmx.net wrote: >> I was using "clang -O3 -S -emit-llvm" got some very optimized output. >> >> Then I did "clang -S -emit-llvm" (without optimization) and wanted to optimized the code in a >> separate pass. The llvm program "opt" did not do anything.

On Jan 27, 2011, at 12:02 PM, Hendrix_ at gmx.net wrote: > OK, I am looking for "LTO"/global optimization. So the function definition will remain "somewhere else" (externally), and the optimizer will find in some other module to possibly inline it later on. > > I am planning to concat all the *.ll (eg "link" the files) and pass them to the

Hi, Is there a tutorial on how to get started with writing link-time optimization passes? The documentation at http://www.llvm.org/docs/LinkTimeOptimization.html explains the design of the LTO interface, but does not explain where to start writing code. Would my pass go inside libLTO.a or is it separate from libLTO.a? What I would like to be able to do is traverse through the entire

On Sep 23, 2007, at 3:27 AM, Maarten ter Huurne wrote: > On Friday 21 September 2007, Chris Lattner wrote: >> On Sep 21, 2007, at 9:42 AM, Maarten ter Huurne wrote: >>> However, it is not possible to let the zlib Makefile issue that >>> command >>> without patching the Makefile, because the fragment that does the >>> linking is >>> hardcoded

> > > Is there a reason why LLVM's link-time optimization won't work for you? > > http://llvm.org/docs/GoldPlugin.html > http://llvm.org/docs/LinkTimeOptimization.html > > Well the primary motivation to move to LLVM is licensing which is why we also ditched binutils since we can't package gcc for iOS due to the GPL. So in the end the gold plugin wouldn't

On May 26, 2009, at 10:52 AM, Rafael Espindola wrote: > Today support for plugins has been committed to BFD. That is the file > format abstraction library used by binutils. This now works Very nice Rafael! Can you please update the web page to mention this, e.g. in the LinkTimeOptimization.html document and wherever else relevant? -Chris > > $ llvm-gcc -emit-llvm -O2 -c a.c

On 27.01.2011, at 21:12, Devang Patel wrote: > > On Jan 27, 2011, at 12:02 PM, Hendrix_ at gmx.net wrote: > >> OK, I am looking for "LTO"/global optimization. So the function definition will remain "somewhere else" (externally), and the optimizer will find in some other module to possibly inline it later on. >> >> I am planning to concat all the

Hi, I need advice in instrumenting programs using liblto and gold plugin. Specifically, I added my pass in tools/lto/LTOCodeGenerator.cpp. My pass inserts functions (myLoad and myStore) for some load and store instructions. The functions exist in a library file. I found that the approach works for the example in the link: http://llvm.org/docs/GoldPlugin.html $ llvm-gcc -flto a.c -c -o a.o $ ar q

Hi All, After the initial learning curve, we're excited to have put together a completely gcc/binutils-free toolchain based on LLVM. Now that we have things working, we desperately need to optimize the resulting binaries. Our bin files are up to 10x their fully optimized gcc equivalent (1.5k vs 16k). This is for a bare metal ARM based system so this is significant. We're using lld for

I have been trying to enable the gold linker on FreeBSD to use the link time optimizations. I made gold from the binutils under /usr/ports. After building binutils using make -k install clean i got ld under /usr/bin and in the directory /usr/local/bin i got ld, ld.gold and ld.bfd. Now while trying to use link time optimization for the simple example programs