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[for-10.0,18/25] target/ppc: Set Float3NaNPropRule explicitly

Message ID 20241128104310.3452934-19-peter.maydell@linaro.org (mailing list archive)
State New
Headers show
Series fpu: Make pickNaNMulAdd behaviour runtime selected | expand

Commit Message

Peter Maydell Nov. 28, 2024, 10:43 a.m. UTC 
Set the Float3NaNPropRule explicitly for PPC, and remove the
ifdef from pickNaNMulAdd().

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

Comments

Richard Henderson Nov. 28, 2024, 5:53 p.m. UTC | #1 
On 11/28/24 04:43, Peter Maydell wrote:
> Set the Float3NaNPropRule explicitly for PPC, and remove the
> ifdef from pickNaNMulAdd().
> 
> Signed-off-by: Peter Maydell<peter.maydell@linaro.org>
> ---
>   target/ppc/cpu_init.c          | 8 ++++++++
>   fpu/softfloat-specialize.c.inc | 6 ------
>   2 files changed, 8 insertions(+), 6 deletions(-)

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

r~
diff mbox series

Patch

diff --git a/target/ppc/cpu_init.c b/target/ppc/cpu_init.c
index f18908a643a..eb9d7b13701 100644
--- a/target/ppc/cpu_init.c
+++ b/target/ppc/cpu_init.c
@@ -7270,6 +7270,14 @@  static void ppc_cpu_reset_hold(Object *obj, ResetType type)
      */
     set_float_2nan_prop_rule(float_2nan_prop_ab, &env->fp_status);
     set_float_2nan_prop_rule(float_2nan_prop_ab, &env->vec_status);
+    /*
+     * NaN propagation for fused multiply-add:
+     * if fRA is a NaN return it; otherwise if fRB is a NaN return it;
+     * otherwise return fRC. Note that muladd on PPC is (fRA * fRC) + frB
+     * whereas QEMU labels the operands as (a * b) + c.
+     */
+    set_float_3nan_prop_rule(float_3nan_prop_acb, &env->fp_status);
+    set_float_3nan_prop_rule(float_3nan_prop_acb, &env->vec_status);
     /*
      * For PPC, the (inf,zero,qnan) case sets InvalidOp, but we prefer
      * to return an input NaN if we have one (ie c) rather than generating
diff --git a/fpu/softfloat-specialize.c.inc b/fpu/softfloat-specialize.c.inc
index 32edb493776..d89ef62b38a 100644
--- a/fpu/softfloat-specialize.c.inc
+++ b/fpu/softfloat-specialize.c.inc
@@ -508,12 +508,6 @@  static int pickNaNMulAdd(FloatClass a_cls, FloatClass b_cls, FloatClass c_cls,
         } else {
             rule = float_3nan_prop_s_cab;
         }
-#elif defined(TARGET_PPC)
-        /*
-         * If fRA is a NaN return it; otherwise if fRB is a NaN return it;
-         * otherwise return fRC. Note that muladd on PPC is (fRA * fRC) + frB
-         */
-        rule = float_3nan_prop_acb;
 #elif defined(TARGET_S390X)
         rule = float_3nan_prop_s_abc;
 #elif defined(TARGET_SPARC)