On 10/23/2015 05:07 AM, Eduardo Habkost wrote:
On Thu, Oct 01, 2015 at 02:06:36PM -0300, Eduardo Habkost wrote:
On Thu, Oct 01, 2015 at 11:35:52AM +1000, Richard Henderson wrote:
On 09/30/2015 06:34 AM, Eduardo Habkost wrote:
Left shift of negative values is undefined behavior. Detected by clang:
qemu/target-i386/translate.c:2423:26: runtime error:
left shift of negative value -8
This changes the code to reverse the sign after the left shift.
Signed-off-by: Eduardo Habkost <ehabk...@redhat.com>
---
target-i386/translate.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/target-i386/translate.c b/target-i386/translate.c
index 8b35de1..cc59b7e 100644
--- a/target-i386/translate.c
+++ b/target-i386/translate.c
@@ -2420,7 +2420,7 @@ static void gen_pusha(DisasContext *s)
{
int i;
gen_op_movl_A0_reg(R_ESP);
- gen_op_addl_A0_im(-8 << s->dflag);
+ gen_op_addl_A0_im(-(8 << s->dflag));
Better as -8U << s->d_flag?
That's even more confusing to me. I wouldn't want to require other
people to read the C specification to find out how many type conversions
are happening in that statement. (Because I will have to do that, to
find out what's the type of "-8U").
I would prefer an expression that doesn't involve any type conversion.
But you are more familiar with that code, so it's up to you.
Ping? I would really like to fix this warning to be able to enable
check-mode by default in QEMU 2.5. Are there objections to get this
patch included?
None.
r~