On 21/03/14 01:25, Olivier Danet wrote:
The signed integer division -0x8000_0000_0000_0000 / -1 must be handled
separately to avoid an overflow on the QEMU host.
Negative overflow must be a negative number for correct sign
extension in Sparc64 mode. Use<stdint.h> constants.
Signed-off-by: Olivier Danet<oda...@caramail.com>
---
target-sparc/helper.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)
diff --git a/target-sparc/helper.c b/target-sparc/helper.c
index f3c7fbf..ae7740b 100644
--- a/target-sparc/helper.c
+++ b/target-sparc/helper.c
@@ -85,8 +85,8 @@ static target_ulong helper_udiv_common(CPUSPARCState *env,
target_ulong a,
}
x0 = x0 / x1;
- if (x0> 0xffffffff) {
- x0 = 0xffffffff;
+ if (x0> UINT32_MAX) {
+ x0 = UINT32_MAX;
overflow = 1;
}
@@ -122,12 +122,15 @@ static target_ulong helper_sdiv_common(CPUSPARCState
*env, target_ulong a,
if (x1 == 0) {
cpu_restore_state(CPU(cpu), GETPC());
helper_raise_exception(env, TT_DIV_ZERO);
- }
-
- x0 = x0 / x1;
- if ((int32_t) x0 != x0) {
- x0 = x0< 0 ? 0x80000000 : 0x7fffffff;
+ } else if (x1 == -1&& x0 == INT64_MIN) {
+ x0 = INT32_MAX;
overflow = 1;
+ } else {
+ x0 = x0 / x1;
+ if ((int32_t) x0 != x0) {
+ x0 = x0< 0 ? INT32_MIN : INT32_MAX;
+ overflow = 1;
+ }
}
if (cc) {
Hi Olivier,
This basic patch looks good to me. My only comment is that I suspect for
bisection purposes it may be better to split this into 2 patches - one
to perform the conversion of all existing constants to INT*_MAX and
INT*_MIN, and then a second to add your change to prevent the crash.
I'll let Richard have the final say though.
Having said that, I will definitely give it a test over the next couple
of days when I get a moment.
ATB,
Mark.
