Users of tcg_gen_atomic_cmpxchg and do_atomic_op rightfully utilize
the output. Even though this code is dead, it gets translated, and
without the initialization we encounter a tcg_error.
Reported-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Tested-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Tested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
---
tcg/tcg-op.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c
index 95a39b7..6b1f415 100644
--- a/tcg/tcg-op.c
+++ b/tcg/tcg-op.c
@@ -2861,6 +2861,9 @@ void tcg_gen_atomic_cmpxchg_i64(TCGv_i64 retv, TCGv addr, TCGv_i64 cmpv,
#endif
#else
gen_helper_exit_atomic(tcg_ctx.tcg_env);
+ /* Produce a result, so that we have a well-formed opcode stream
+ with respect to uses of the result in the (dead) code following. */
+ tcg_gen_movi_i64(retv, 0);
#endif /* CONFIG_ATOMIC64 */
} else {
TCGv_i32 c32 = tcg_temp_new_i32();
@@ -2966,6 +2969,9 @@ static void do_atomic_op_i64(TCGv_i64 ret, TCGv addr, TCGv_i64 val,
#endif
#else
gen_helper_exit_atomic(tcg_ctx.tcg_env);
+ /* Produce a result, so that we have a well-formed opcode stream
+ with respect to uses of the result in the (dead) code following. */
+ tcg_gen_movi_i64(ret, 0);
#endif /* CONFIG_ATOMIC64 */
} else {
TCGv_i32 v32 = tcg_temp_new_i32();
--
2.9.3