See: http://builds.linaro.org/toolchain/gcc-4.7~svn178154
The problem is -Werror triggering on:
../../../gcc-4.7~/gcc/config/arm/arm.c: In function 'int optimal_immediate_sequence_1(rtx_code, long long unsigned int, four_ints*, int)': ../../../gcc-4.7~/gcc/config/arm/arm.c:2690:46: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare] ../../../gcc-4.7~/gcc/config/arm/arm.c:2690:60: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare] ../../../gcc-4.7~/gcc/config/arm/arm.c:2691:20: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare] ../../../gcc-4.7~/gcc/config/arm/arm.c:2691:34: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare] ../../../gcc-4.7~/gcc/config/arm/arm.c:2701:16: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare] ../../../gcc-4.7~/gcc/config/arm/arm.c:2702:18: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare] ../../../gcc-4.7~/gcc/config/arm/arm.c:2703:18: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
-- Michael