diff options
| -rw-r--r-- | target/s390x/fpu_helper.c | 38 |
1 files changed, 32 insertions, 6 deletions
diff --git a/target/s390x/fpu_helper.c b/target/s390x/fpu_helper.c index de02cf792d..dcad9c367a 100644 --- a/target/s390x/fpu_helper.c +++ b/target/s390x/fpu_helper.c @@ -63,13 +63,39 @@ static void handle_exceptions(CPUS390XState *env, uintptr_t retaddr) env->fpu_status.float_exception_flags = 0; s390_exc = s390_softfloat_exc_to_ieee(qemu_exc); - /* Install the exceptions that we raised. */ - env->fpc |= s390_exc << 16; + /* + * FIXME: + * 1. Right now, all inexact conditions are inidicated as + * "truncated" (0) and never as "incremented" (1) in the DXC. + * 2. Only traps due to invalid/divbyzero are suppressing. Other traps + * are completing, meaning the target register has to be written! + * This, however will mean that we have to write the register before + * triggering the trap - impossible right now. + */ + + /* + * invalid/divbyzero cannot coexist with other conditions. + * overflow/underflow however can coexist with inexact, we have to + * handle it separatly. + */ + if (s390_exc & ~S390_IEEE_MASK_INEXACT) { + if (s390_exc & ~S390_IEEE_MASK_INEXACT & env->fpc >> 24) { + /* trap condition - inexact reported along */ + tcg_s390_data_exception(env, s390_exc, retaddr); + } + /* nontrap condition - inexact handled differently */ + env->fpc |= (s390_exc & ~S390_IEEE_MASK_INEXACT) << 16; + } - /* Send signals for enabled exceptions. */ - s390_exc &= env->fpc >> 24; - if (s390_exc) { - tcg_s390_data_exception(env, s390_exc, retaddr); + /* inexact handling */ + if (s390_exc & S390_IEEE_MASK_INEXACT) { + /* trap condition - overflow/underflow _not_ reported along */ + if (s390_exc & S390_IEEE_MASK_INEXACT & env->fpc >> 24) { + tcg_s390_data_exception(env, s390_exc & S390_IEEE_MASK_INEXACT, + retaddr); + } + /* nontrap condition */ + env->fpc |= (s390_exc & S390_IEEE_MASK_INEXACT) << 16; } } |