From: Peter Maydell Date: Wed, 11 Dec 2024 15:30:59 +0000 (+0000) Subject: target/hppa: Set Float3NaNPropRule explicitly X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=f8023791f21bf46229ce403566ca476b86e06505;p=qemu.git target/hppa: Set Float3NaNPropRule explicitly Set the Float3NaNPropRule explicitly for HPPA, and remove the ifdef from pickNaNMulAdd(). HPPA is the only target that was using the default branch of the ifdef ladder (other targets either do not use muladd or set default_nan_mode), so we can remove the ifdef fallback entirely now (allowing the "rule not set" case to fall into the default of the switch statement and assert). We add a TODO note that the HPPA rule is probably wrong; this is not a behavioural change for this refactoring. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20241202131347.498124-26-peter.maydell@linaro.org --- diff --git a/fpu/softfloat-specialize.c.inc b/fpu/softfloat-specialize.c.inc index 67428dab98..5fbc953e71 100644 --- a/fpu/softfloat-specialize.c.inc +++ b/fpu/softfloat-specialize.c.inc @@ -504,10 +504,6 @@ static int pickNaNMulAdd(FloatClass a_cls, FloatClass b_cls, FloatClass c_cls, } } - if (rule == float_3nan_prop_none) { - rule = float_3nan_prop_abc; - } - assert(rule != float_3nan_prop_none); if (have_snan && (rule & R_3NAN_SNAN_MASK)) { /* We have at least one SNaN input and should prefer it */ diff --git a/target/hppa/fpu_helper.c b/target/hppa/fpu_helper.c index 393cae33bf..69c4ce3783 100644 --- a/target/hppa/fpu_helper.c +++ b/target/hppa/fpu_helper.c @@ -55,6 +55,14 @@ void HELPER(loaded_fr0)(CPUHPPAState *env) * HPPA does note implement a CPU reset method at all... */ set_float_2nan_prop_rule(float_2nan_prop_s_ab, &env->fp_status); + /* + * TODO: The HPPA architecture reference only documents its NaN + * propagation rule for 2-operand operations. Testing on real hardware + * might be necessary to confirm whether this order for muladd is correct. + * Not preferring the SNaN is almost certainly incorrect as it diverges + * from the documented rules for 2-operand operations. + */ + set_float_3nan_prop_rule(float_3nan_prop_abc, &env->fp_status); /* For inf * 0 + NaN, return the input NaN */ set_float_infzeronan_rule(float_infzeronan_dnan_never, &env->fp_status); }