Re: [HACKERS] Any interest in buildfarm a member using Apple's llvm-gcc-4.2 or clang?

[Robert Creager]

On Sep 8, 2009, at 4:18 PM, Tom Lane wrote:

Robert Creager <rob...@logicalchaos.org> writes:

I'll set up one or  two more 'machines' if there is interest (Snow
Leopard)

LLVM, perhaps, though are you sure that llvm and gcc aren't the
same thing under the hood on SL?  I thought I'd read somewhere that
Apple had turned gcc into a wrapper around the llvm code generator.

Well, the versions reported are definitely different.

% gcc --version
i686-apple-darwin10-gcc-4.2.1 (GCC) 4.2.1 (Apple Inc. build 5646)

rob...@dhcp-ubrm05-218-133:/usr/local/src/build-farm-3.2_llvm
% /Developer/usr/llvm-gcc-4.2/bin/llvm-gcc-4.2 --version




And, the llvm version takes the -flto, where the normal one doesn't:

/Developer/usr/llvm-gcc-4.2/bin/llvm-gcc-4.2 -flto main.c -o main_llvm
/usr/bin/gcc-4.2 -flto main.c -o main_gcc
cc1: error: unrecognized command line option "-flto"
make: *** [main_gcc] Error 1

       -flto
           Enable LLVM Link Time Optimization.

And, the binaries are different for the same simple program.

So, I'm convinced they are different (where I wasn't sure before).

Later,
Rob

i686-apple-darwin10-llvm-gcc-4.2 (GCC) 4.2.1 (Based on Apple Inc. build 5646) (LLVM build 2118) And the llvm tools you only get with the Xcode install, and the sizes of the two gcc compilers are very different.

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