On Fri, Feb 19, 2016 at 11:03 PM, Bernd Schmidt <bschm...@redhat.com> wrote: > In this PR, we generate unnecessarily bad code for code that declares a > global register var. Since global regs get added to fixed_regs, IRA never > considers them as candidates. However, we do seem to have proper data flow > information for them. In the testcase, the global reg dies, some operations > are done on temporary results, and the final result stored back in the > global reg. We can achieve the desired code generation by reusing the global > reg for those temporaries. > > Bootstrapped and tested on x86_64-linux. Ok? An argument could be made not > to use this for gcc-6 since global register vars are both not very important > and not very well represented in the testsuite.
Do calls properly clobber them even if they are not in the set of call-clobbered regs? Are asm()s properly using/clobbering them? I think you are allowed to use them in asm()s without adding constraints for them? I'd say this is sth for GCC 7. Thanks, Richard. > > Bernd
