Re: [Qemu-devel] [PATCH v3 13/34] tcg: Add atomic helpers

[Leon Alrae <leon.alrae@imgtec.com>]

> +#define GEN_ATOMIC_HELPER(NAME, OP, NEW)                                \
> +static void * const table_##NAME[16] = {                                \
> +    [MO_8] = gen_helper_atomic_##NAME##b,                               \
> +    [MO_16 | MO_LE] = gen_helper_atomic_##NAME##w_le,                   \
> +    [MO_16 | MO_BE] = gen_helper_atomic_##NAME##w_be,                   \
> +    [MO_32 | MO_LE] = gen_helper_atomic_##NAME##l_le,                   \
> +    [MO_32 | MO_BE] = gen_helper_atomic_##NAME##l_be,                   \
> +    [MO_64 | MO_LE] = gen_helper_atomic_##NAME##q_le,                   \
> +    [MO_64 | MO_BE] = gen_helper_atomic_##NAME##q_be,                   \
> +};                                                                      \
> +void tcg_gen_atomic_##NAME##_i32                                        \
> +    (TCGv_i32 ret, TCGv addr, TCGv_i32 val, TCGArg idx, TCGMemOp memop) \
> +{                                                                       \
> +    if (parallel_cpus) {                                                \
> +        do_atomic_op_i32(ret, addr, val, idx, memop, table_##NAME);     \
> +    } else {                                                            \
> +        do_nonatomic_op_i32(ret, addr, val, idx, memop, NEW,            \
> +                            tcg_gen_##OP##_i32);                        \
> +    }                                                                   \
> +}                                                                       \
> +void tcg_gen_atomic_##NAME##_i64                                        \
> +    (TCGv_i64 ret, TCGv addr, TCGv_i64 val, TCGArg idx, TCGMemOp memop) \
> +{                                                                       \
> +    if (parallel_cpus) {                                                \
> +        do_atomic_op_i64(ret, addr, val, idx, memop, table_##NAME);     \
> +    } else {                                                            \
> +        do_nonatomic_op_i64(ret, addr, val, idx, memop, NEW,            \
> +                            tcg_gen_##OP##_i64);                        \
> +    }                                                                   \
> +}
> +
> +GEN_ATOMIC_HELPER(fetch_add, add, 0)
> +GEN_ATOMIC_HELPER(fetch_and, and, 0)
> +GEN_ATOMIC_HELPER(fetch_or, or, 0)
> +GEN_ATOMIC_HELPER(fetch_xor, xor, 0)
> +
> +GEN_ATOMIC_HELPER(add_fetch, add, 1)
> +GEN_ATOMIC_HELPER(and_fetch, and, 1)
> +GEN_ATOMIC_HELPER(or_fetch, or, 1)
> +GEN_ATOMIC_HELPER(xor_fetch, xor, 1)

This causes build errors on CentOS6.5 (where __ATOMIC_RELAXED is undefined):
/user/lea/dev/qemu/tcg/tcg-op.c:2280: error: ‘gen_helper_atomic_fetch_addb’ undeclared here (not in a function)
/user/lea/dev/qemu/tcg/tcg-op.c:2280: error: ‘gen_helper_atomic_fetch_addw_le’ undeclared here (not in a function)
/user/lea/dev/qemu/tcg/tcg-op.c:2280: error: ‘gen_helper_atomic_fetch_addw_be’ undeclared here (not in a function)
(...)


The fix I've been using locally while working on enabling MTTCG for MIPS:

diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h
index 5542416..818a5a4 100644
--- a/include/qemu/atomic.h
+++ b/include/qemu/atomic.h
@@ -409,22 +409,22 @@
 /* Provide shorter names for GCC atomic builtins.  */
 #define atomic_fetch_inc(ptr)  __sync_fetch_and_add(ptr, 1)
 #define atomic_fetch_dec(ptr)  __sync_fetch_and_add(ptr, -1)
-#define atomic_fetch_add       __sync_fetch_and_add
-#define atomic_fetch_sub       __sync_fetch_and_sub
-#define atomic_fetch_and       __sync_fetch_and_and
-#define atomic_fetch_or        __sync_fetch_and_or
-#define atomic_fetch_xor       __sync_fetch_and_xor
+#define atomic_fetch_add(ptr, n)  __sync_fetch_and_add(ptr, n)
+#define atomic_fetch_sub(ptr, n)  __sync_fetch_and_sub(ptr, n)
+#define atomic_fetch_and(ptr, n)  __sync_fetch_and_and(ptr, n)
+#define atomic_fetch_or(ptr, n)  __sync_fetch_and_or(ptr, n)
+#define atomic_fetch_xor(ptr, n)  __sync_fetch_and_xor(ptr, n)

 #define atomic_inc_fetch(ptr)  __sync_add_and_fetch(ptr, 1)
 #define atomic_dec_fetch(ptr)  __sync_add_and_fetch(ptr, -1)
-#define atomic_add_fetch       __sync_add_and_fetch
-#define atomic_sub_fetch       __sync_sub_and_fetch
-#define atomic_and_fetch       __sync_and_and_fetch
-#define atomic_or_fetch        __sync_or_and_fetch
-#define atomic_xor_fetch       __sync_xor_and_fetch
-
-#define atomic_cmpxchg         __sync_val_compare_and_swap
-#define atomic_cmpxchg__nocheck  atomic_cmpxchg
+#define atomic_add_fetch(ptr, n)  __sync_add_and_fetch(ptr, n)
+#define atomic_sub_fetch(ptr, n)  __sync_sub_and_fetch(ptr, n)
+#define atomic_and_fetch(ptr, n)  __sync_and_and_fetch(ptr, n)
+#define atomic_or_fetch(ptr, n)  __sync_or_and_fetch(ptr, n)
+#define atomic_xor_fetch(ptr, n)  __sync_xor_and_fetch(ptr, n)
+
+#define atomic_cmpxchg(ptr, old, new) __sync_val_compare_and_swap(ptr, old, new)
+#define atomic_cmpxchg__nocheck(ptr, old, new)  atomic_cmpxchg(ptr, old, new)

 /* And even shorter names that return void.  */
 #define atomic_inc(ptr)        ((void) __sync_fetch_and_add(ptr, 1))