[LLVMdev] O3 passes
baldrick at free.fr
Tue Apr 28 02:26:39 PDT 2009
> Thanks for the help. When I run the following (where $llvm is the path
> to my llvm installation):
> $llvm/bin/llvm-gcc -c -o - -O1 tmp.c -emit-llvm -mllvm
> --disable-llvm-optzns | $llvm/bin/opt -raiseallocs
> I get the following error:
> cc1: error: unrecognized command line option "-fdisable-llvm-optzns"
I think this is a bug in 2.5 that was fixed in svn. Try running
at -O0 and emit the -mllvm --disable-llvm-optzns part.
> I am running llvm 2.5. I performed a
> $llvm/libexec/gcc/i686-pc-linux-gnu/4.2.1/cc1 --help and didn't see
> -fdisable-llvm-optzns or anything similar. Do you know what might be
> going on?
> Duncan Sands wrote:
> > On Tuesday 28 April 2009 09:19:19 am Ryan M. Lefever wrote:
> >> Can I specify passes that I want run directly to llvm-gcc? I don't want
> >> all of -O3, for example. I tried llvm-gcc -raiseallocs ..., but that
> >> didn't work. I also tried running cc1 directly and it didn't take
> >> -raiseallocs as a parameter either.
> > You are better off run passes explicitly using opt. Try this:
> > llvm-gcc -c -o - -O1 my_proc.c -emit-llvm -mllvm --disable-llvm-optzns | opt list_of_passes
> > Passing -O1 to llvm-gcc means that gcc will perform constant folding and
> > some other small optimizations. Passing -emit-llvm means that LLVM bitcode
> > is produced, suitable for piping to opt. -mllvm --disable-llvm-optzns means
> > that the LLVM optimizers will not be run.
> > Ciao,
> > Duncan.
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu
More information about the llvm-dev