On 11/3/20 2:52 AM, Chen Qun wrote:
> The compiler cannot determine whether the return values of the
> xtensa_operand_is_register(isa, opc, opnd)
> and xtensa_operand_is_visible(isa, opc, opnd) functions are the same.
> So,it assumes that 'rf' is not assigned, but it's used.
>
> The compiler showed warning:
> target/xtensa/translate.c: In function ‘disas_xtensa_insn’:
> target/xtensa/translate.c:985:43: warning: ‘rf’ may be used uninitialized in
> this function [-Wmaybe-uninitialized]
> 985 | arg[vopnd].num_bits =
> xtensa_regfile_num_bits(isa, rf);
> |
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Add a default value for 'rf' to prevented the warning.
>
> Reported-by: Euler Robot <euler.ro...@huawei.com>
> Signed-off-by: Chen Qun <kuhn.chen...@huawei.com>
> ---
> Cc: Max Filippov <jcmvb...@gmail.com>
> ---
> target/xtensa/translate.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/target/xtensa/translate.c b/target/xtensa/translate.c
> index 944a157747..eea851bbe7 100644
> --- a/target/xtensa/translate.c
> +++ b/target/xtensa/translate.c
> @@ -953,7 +953,7 @@ static void disas_xtensa_insn(CPUXtensaState *env,
> DisasContext *dc)
>
> for (opnd = vopnd = 0; opnd < opnds; ++opnd) {
> void **register_file = NULL;
> - xtensa_regfile rf;
> + xtensa_regfile rf = -1;
NAck (code smells).
Deferring to Max, but possible fix:
-- >8 --
@@ -953,10 +953,9 @@ static void disas_xtensa_insn(CPUXtensaState *env,
DisasContext *dc)
for (opnd = vopnd = 0; opnd < opnds; ++opnd) {
void **register_file = NULL;
- xtensa_regfile rf;
+ xtensa_regfile rf = xtensa_operand_regfile(isa, opc, opnd);
if (xtensa_operand_is_register(isa, opc, opnd)) {
- rf = xtensa_operand_regfile(isa, opc, opnd);
register_file = dc->config->regfile[rf];
if (rf == dc->config->a_regfile) {
---
