Comment 4 for bug 677360

The thing is that there's a plethora of defines, and even GCC itself doesn't get it right all the times.

see libffi/src/arm/sysv.S. This is error prone, and maybe Linaro should push something better upstream.

/* We need a better way of testing for this, but for now, this is all
   we can do. */
@ This selects the minimum architecture level required.
#define __ARM_ARCH__ 3

#if defined(__ARM_ARCH_4__) || defined(__ARM_ARCH_4T__)
# undef __ARM_ARCH__
# define __ARM_ARCH__ 4
#endif

#if defined(__ARM_ARCH_5__) || defined(__ARM_ARCH_5T__) \
        || defined(__ARM_ARCH_5E__) || defined(__ARM_ARCH_5TE__) \
        || defined(__ARM_ARCH_5TEJ__)
# undef __ARM_ARCH__
# define __ARM_ARCH__ 5
#endif

#if defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) \
        || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) \
        || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) \
        || defined(__ARM_ARCH_6M__)
# undef __ARM_ARCH__
# define __ARM_ARCH__ 6
#endif

#if defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) \
        || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) \
        || defined(__ARM_ARCH_7EM__)
# undef __ARM_ARCH__
# define __ARM_ARCH__ 7
#endif