On Mon, Jan 26, 2015 at 05:55:52PM +0800, Hale Wang wrote:
> The GCC combine pass combines the insns even though they contain volatile
> registers. This doesn't make sence.
>
> The test case listed in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=46164
> shows the expected asm command "mov r1, r1" is not generated."r1" is defined
> as a volatile register, and there are three insns related to r1:
There is nothing volatile on reg/v, that is just a flag that the
corresponding variable has been declared by the user. Preventing that to be
combined would be a serious regression on code quality.
Jakub
