gcc, as, AVX, binutils and MacOS X 10.7

[vincent habchi]

Ok, finally I figured out a way to compile AVX instructions. But it is somewhat crooked. The old ‘as’ assembler in /usr/bin/as must be discarded and replaced by this script, that uses the clang assembler:

#!/bin/sh
HAS_INPUT_FILE=0
ARGS=$@
while [ $# -ne 0 ]; do
        ARG=$1
        # Skip options
        if [ $ARG == "-arch" ] || [ $ARG == "-o" ]; then
                # Skip next token
                shift
                shift
                continue
        fi

        if [ `echo $ARG | head -c1` == "-" ]; then
                shift
                continue
        fi

        HAS_INPUT_FILE=1
        break
done

if [ $HAS_INPUT_FILE -eq 1 ]; then
        clang -c -x assembler $ARGS
else
        clang -c -x assembler $ARGS -
fi

Obviously, since this is a shell script, the assembly phase is slowed down. But it seems to work, at least it compiles AVX assembly properly (gcc-mp-4.5 avx.s works, and I have even recompiled gcc45 with the script as assembler). 

Well, I have filed a RADAR asking Apple to give us an assembler that supports AVX. We’ll see.

Cheers
Vincent