Hi!
On Thu, Apr 08, 2021 at 03:33:45PM +0000, Christophe Leroy wrote:
+#define ATOMIC_OP(op, asm_op, dot, sign) \
static __inline__ void atomic_##op(int a, atomic_t *v) \
{ \
int t; \
\
__asm__ __volatile__( \
"1: lwarx %0,0,%3 # atomic_" #op "\n" \
- #asm_op " %0,%2,%0\n" \
+ #asm_op "%I2" dot " %0,%0,%2\n" \
" stwcx. %0,0,%3 \n" \
" bne- 1b\n" \
- : "=&r" (t), "+m" (v->counter) \
- : "r" (a), "r" (&v->counter) \
+ : "=&b" (t), "+m" (v->counter) \
+ : "r"#sign (a), "r" (&v->counter) \
: "cc"); \
} \
You need "b" (instead of "r") only for "addi". You can use "addic"
instead, which clobbers XER[CA], but *all* inline asm does, so that is
not a downside here (it is also not slower on any CPU that matters).
@@ -238,14 +238,14 @@ static __inline__ int atomic_fetch_add_unless(atomic_t *v, int a, int u)
"1: lwarx %0,0,%1 # atomic_fetch_add_unless\n\
cmpw 0,%0,%3 \n\
beq 2f \n\
- add %0,%2,%0 \n"
+ add%I2 %0,%0,%2 \n"
" stwcx. %0,0,%1 \n\
bne- 1b \n"
PPC_ATOMIC_EXIT_BARRIER
-" subf %0,%2,%0 \n\
+" sub%I2 %0,%0,%2 \n\
2:"
- : "=&r" (t)
- : "r" (&v->counter), "r" (a), "r" (u)
+ : "=&b" (t)
+ : "r" (&v->counter), "rI" (a), "r" (u)
: "cc", "memory");
Same here.
Nice patches!
Acked-by: Segher Boessenkool <segher@xxxxxxxxxxxxxxxxxxx>