gcc-4.4 fails to build some files with this constraint, which was added to help out with gcc-4.6 and higher:
fs/btrfs/delayed-ref.c: In function 'add_delayed_tree_ref': arch/arm/include/asm/atomic.h:280: error: 'asm' operand requires impossible reload
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=44492 Signed-off-by: Arnd Bergmann arnd@arndb.de --- arch/arm/include/asm/atomic.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h index 66d0e215a773..65d5b843831a 100644 --- a/arch/arm/include/asm/atomic.h +++ b/arch/arm/include/asm/atomic.h @@ -280,7 +280,10 @@ static inline long long atomic64_read(const atomic64_t *v) __asm__ __volatile__("@ atomic64_read\n" " ldrd %0, %H0, [%1]" : "=&r" (result) - : "r" (&v->counter), "Qo" (v->counter) + : "r" (&v->counter) +#if GCC_VERSION >= 40600 + , "Qo" (v->counter) +#endif );
return result; @@ -302,7 +305,10 @@ static inline long long atomic64_read(const atomic64_t *v) __asm__ __volatile__("@ atomic64_read\n" " ldrexd %0, %H0, [%1]" : "=&r" (result) - : "r" (&v->counter), "Qo" (v->counter) + : "r" (&v->counter) +#if GCC_VERSION >= 40600 + , "Qo" (v->counter) +#endif );
return result;