Set the 2-NaN propagation rule explicitly in env->fp_status.

Really we only need to do this at CPU reset (after reset has zeroed
out most of the CPU state struct, which typically includes fp_status
fields).  However target/hppa does not currently implement CPU reset
at all, so leave a TODO comment to note that this could be moved if
we ever do implement reset.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/hppa/fpu_helper.c       | 6 ++++++
 fpu/softfloat-specialize.c.inc | 4 ++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/target/hppa/fpu_helper.c b/target/hppa/fpu_helper.c
index deaed2b65d1..0e44074ba82 100644
--- a/target/hppa/fpu_helper.c
+++ b/target/hppa/fpu_helper.c
@@ -49,6 +49,12 @@ void HELPER(loaded_fr0)(CPUHPPAState *env)
     d = FIELD_EX32(shadow, FPSR, D);
     set_flush_to_zero(d, &env->fp_status);
     set_flush_inputs_to_zero(d, &env->fp_status);
+
+    /*
+     * TODO: we only need to do this at CPU reset, but currently
+     * HPPA does note implement a CPU reset method at all...
+     */
+    set_float_2nan_prop_rule(float_2nan_prop_s_ab, &env->fp_status);
 }
 
 void cpu_hppa_loaded_fr0(CPUHPPAState *env)
diff --git a/fpu/softfloat-specialize.c.inc b/fpu/softfloat-specialize.c.inc
index bbc3b70fa9d..4e51cf8d083 100644
--- a/fpu/softfloat-specialize.c.inc
+++ b/fpu/softfloat-specialize.c.inc
@@ -403,9 +403,9 @@ static int pickNaN(FloatClass a_cls, FloatClass b_cls,
 #if defined(TARGET_AVR) || defined(TARGET_HEXAGON) \
     || defined(TARGET_RISCV) || defined(TARGET_SH4) \
     || defined(TARGET_TRICORE) || defined(TARGET_ARM) || defined(TARGET_MIPS) \
-    || defined(TARGET_LOONGARCH64)
+    || defined(TARGET_LOONGARCH64) || defined(TARGET_HPPA)
         g_assert_not_reached();
-#elif defined(TARGET_HPPA) || defined(TARGET_S390X)
+#elif defined(TARGET_S390X)
         rule = float_2nan_prop_s_ab;
 #elif defined(TARGET_PPC) || defined(TARGET_M68K)
         /*
-- 
2.34.1

On 10/25/24 15:12, Peter Maydell wrote:
> Set the 2-NaN propagation rule explicitly in env->fp_status.
> 
> Really we only need to do this at CPU reset (after reset has zeroed
> out most of the CPU state struct, which typically includes fp_status
> fields).  However target/hppa does not currently implement CPU reset
> at all, so leave a TODO comment to note that this could be moved if
> we ever do implement reset.
> 
> Signed-off-by: Peter Maydell<peter.maydell@linaro.org>
> ---
>   target/hppa/fpu_helper.c       | 6 ++++++
>   fpu/softfloat-specialize.c.inc | 4 ++--
>   2 files changed, 8 insertions(+), 2 deletions(-)

We could do this in hppa_cpu_init().  Anyway,

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~