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author | Bastian Koppelmann <kbastian@mail.uni-paderborn.de> | 2015-01-28 12:15:05 +0000 |
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committer | Bastian Koppelmann <kbastian@mail.uni-paderborn.de> | 2015-03-03 01:04:53 +0000 |
commit | 3debbb5af5f63440b170b71bf3aecc0e778f5691 (patch) | |
tree | bf7c6c553a6550f9e4f8f06b182cff0509d56b7b /target-tricore | |
parent | f0cab01b6c9bb9c2f5085837ca86d70d144cca9d (diff) | |
download | qemu-3debbb5af5f63440b170b71bf3aecc0e778f5691.zip qemu-3debbb5af5f63440b170b71bf3aecc0e778f5691.tar.gz qemu-3debbb5af5f63440b170b71bf3aecc0e778f5691.tar.bz2 |
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>
Diffstat (limited to 'target-tricore')
-rw-r--r-- | target-tricore/op_helper.c | 27 |
1 files changed, 21 insertions, 6 deletions
diff --git a/target-tricore/op_helper.c b/target-tricore/op_helper.c index ed26b30..08bf4ae 100644 --- a/target-tricore/op_helper.c +++ b/target-tricore/op_helper.c @@ -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, |