openkylin
/
qemu
mirror of https://gitee.com/openkylin/qemu.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

target-tricore: fix msub32_suov return wrong results 

If the signed result of the multiplication overflows, we would get a negative
value, which would result in a addition instead of a subtraction.

Now we do the overflow calculation and saturation by hand instead of using
suov32_neg.

Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Reviewed-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Bastian Koppelmann 2015-01-28 12:15:05 +00:00
parent f0cab01b6c
commit 3debbb5af5
1 changed files with 21 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
target-tricore/op_helper.c
View File

@ -443,13 +443,28 @@ target_ulong helper_msub32_ssov(CPUTriCoreState *env, target_ulong r1,
target_ulong helper_msub32_suov(CPUTriCoreState *env, target_ulong r1,
target_ulong r2, target_ulong r3)
{
int64_t t1 = extract64(r1, 0, 32);
int64_t t2 = extract64(r2, 0, 32);
int64_t t3 = extract64(r3, 0, 32);
int64_t result;
uint64_t t1 = extract64(r1, 0, 32);
uint64_t t2 = extract64(r2, 0, 32);
uint64_t t3 = extract64(r3, 0, 32);
uint64_t result;
uint64_t mul;
result = t2 - (t1 * t3);
return suov32_neg(env, result);
mul = (t1 * t3);
result = t2 - mul;
env->PSW_USB_AV = result ^ result * 2u;
env->PSW_USB_SAV |= env->PSW_USB_AV;
/* we calculate ovf by hand here, because the multiplication can overflow on
the host, which would give false results if we compare to less than
zero */
if (mul > t2) {
env->PSW_USB_V = (1 << 31);
env->PSW_USB_SV = (1 << 31);
result = 0;
} else {
env->PSW_USB_V = 0;
}
return result;
}
uint64_t helper_msub64_ssov(CPUTriCoreState *env, target_ulong r1,