[Bug rtl-optimization/85745] variable with asm register assignment allocated in wrong reg

[bernd.edlinger at hotmail dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85745

--- Comment #3 from Bernd Edlinger <bernd.edlinger at hotmail dot de> ---
just in case someone runs into the same issue, this would
be the linux patch that Jakub suggested:

commit 20dfb4d2eb648bd947adbb729d963f78df75ffee
Author: Bernd Edlinger <bernd.edlinger@hotmail.de>
Date:   Fri May 11 18:51:03 2018 +0200

    Fix compilation with gcc-8

diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
index 74b17d0..dc64fa2 100644
--- a/arch/arm/include/asm/uaccess.h
+++ b/arch/arm/include/asm/uaccess.h
@@ -220,7 +220,7 @@ extern int __put_user_8(void *, unsigned long long);
        ({                                                              \
                unsigned long __limit = current_thread_info()->addr_limit - 1;
\
                const typeof(*(p)) __user *__tmp_p = (p);               \
-               register const typeof(*(p)) __r2 asm("r2") = (x);       \
+               register typeof(*(p)) __r2 asm("r2") = (x);             \
                register const typeof(*(p)) __user *__p asm("r0") = __tmp_p; \
                register unsigned long __l asm("r1") = __limit;         \
                register int __e asm("r0");                             \