softfloat: add xtensa specialization for pickNaNMulAdd
pickNaNMulAdd logic on Xtensa is to apply pickNaN to the inputs of the
expression (a * b) + c. However if default NaN is produces as a result
of (a * b) calculation it is not considered when c is NaN.
So with two pickNaN variants there must be two pickNaNMulAdd variants.
In addition the invalid flag is always set when (a * b) produces NaN.
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: "Alex Bennée" <alex.bennee@linaro.org>
Cc: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
diff --git a/fpu/softfloat-specialize.c.inc b/fpu/softfloat-specialize.c.inc
index efbd163..dc4ea33 100644
--- a/fpu/softfloat-specialize.c.inc
+++ b/fpu/softfloat-specialize.c.inc
@@ -586,6 +586,32 @@
} else {
return 1;
}
+#elif defined(TARGET_XTENSA)
+ /*
+ * For Xtensa, the (inf,zero,nan) case sets InvalidOp and returns
+ * an input NaN if we have one (ie c).
+ */
+ if (infzero) {
+ float_raise(float_flag_invalid, status);
+ return 2;
+ }
+ if (status->use_first_nan) {
+ if (is_nan(a_cls)) {
+ return 0;
+ } else if (is_nan(b_cls)) {
+ return 1;
+ } else {
+ return 2;
+ }
+ } else {
+ if (is_nan(c_cls)) {
+ return 2;
+ } else if (is_nan(b_cls)) {
+ return 1;
+ } else {
+ return 0;
+ }
+ }
#else
/* A default implementation: prefer a to b to c.
* This is unlikely to actually match any real implementation.
