Error: non-constant expression in ".if" statement

Hi,

I've stumbled across an assembler error message that I don't understand.

bl1/aarch64/bl1_exceptions.S: Assembler messages: bl1/aarch64/bl1_exceptions.S:53: Error: non-constant expression in ".if" statement

It occurs when building ARM Trusted Firmware with aarch64-linux-gnu-gcc that ships with Ubuntu 16.04. It does _not_ occur with an older Linaro toolchain. More details in [1].

The .align directives in the vector_base and vector_entry macros _do_ make a difference. Are they the cause of the problem? Would you recommend writing the code differently? Or is it a compiler bug?

[1] https://github.com/ARM-software/tf-issues/issues/401

Thanks,