Add various NaN-handling macros

These simplify the implementation of the floating-point Altivec
instructions and reduce clutter.

Signed-off-by: Nathan Froyd <froydnj@codesourcery.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6511 c046a42c-6fe2-441c-8c8c-71466251a162

target-ppc/op_helper.c

@@ -1965,6 +1965,23 @@ target_ulong helper_dlmzb (target_ulong high, target_ulong low, uint32_t update_
   for (index = ARRAY_SIZE(r->element)-1; index >= 0; index--)
 #endif
 
+/* If X is a NaN, store the corresponding QNaN into RESULT.  Otherwise,
+ * execute the following block.  */
+#define DO_HANDLE_NAN(result, x)                \
+    if (float32_is_nan(x) || float32_is_signaling_nan(x)) {     \
+        CPU_FloatU __f;                                         \
+        __f.f = x;                                              \
+        __f.l = __f.l | (1 << 22);  /* Set QNaN bit. */         \
+        result = __f.f;                                         \
+    } else
+
+#define HANDLE_NAN1(result, x)                  \
+    DO_HANDLE_NAN(result, x)
+#define HANDLE_NAN2(result, x, y)               \
+    DO_HANDLE_NAN(result, x) DO_HANDLE_NAN(result, y)
+#define HANDLE_NAN3(result, x, y, z)            \
+    DO_HANDLE_NAN(result, x) DO_HANDLE_NAN(result, y) DO_HANDLE_NAN(result, z)
+
 /* Saturating arithmetic helpers.  */
 #define SATCVT(from, to, from_type, to_type, min, max, use_min, use_max) \
     static always_inline to_type cvt##from##to (from_type x, int *sat)  \
@@ -2818,6 +2835,10 @@ VUPK(lsh, s32, s16, UPKLO)
 #undef UPKHI
 #undef UPKLO
 
+#undef DO_HANDLE_NAN
+#undef HANDLE_NAN1
+#undef HANDLE_NAN2
+#undef HANDLE_NAN3
 #undef VECTOR_FOR_INORDER_I
 #undef HI_IDX
 #undef LO_IDX