r275242 - in /trunk/gcc: ChangeLog config/or1k/...

[shorne@gcc.gnu.org]

Author: shorne
Date: Sat Aug 31 06:00:56 2019
New Revision: 275242

URL: https://gcc.gnu.org/viewcvs?rev=275242&root=gcc&view=rev
Log:
or1k: Fix issue with set_got clobbering LR (r9)

When compiling glibc we found that the GOT register was being allocated
r9 when the instruction was still set_got_tmp.  That is a problem
because r9 is the Link Register (LR) in OpenRISC which is used/clobbered
in set_got.  We cannot use r9 as the GOT register.  Also, we cannot
simply say set_got_tmp clobbers r9 as this is the reason for having the
temporary set_got_tmp.

Fix by using a register class constraint that does not allow r9 during
register allocation.

gcc/ChangeLog:

        * config/or1k/constraints.md (t): New constraint.
        * config/or1k/or1k.h (GOT_REGS): New register class.
        * config/or1k/or1k.md (set_got_tmp, set_got): Use t contraint.


Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/or1k/constraints.md
    trunk/gcc/config/or1k/or1k.h
    trunk/gcc/config/or1k/or1k.md