tcg: declare internal helpers as const and pure

TCG internal helpers only access to the values passed in arguments, and
do not modify the CPU internal state. Thus they can be declared as
const and pure.
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

tcg/tcg-op.h

@@ -364,7 +364,11 @@ static inline void tcg_gen_helperN(void *func, int flags, int sizemask,
     tcg_temp_free_ptr(fn);
 }
 
-/* FIXME: Should this be pure?  */
+/* Note: Both tcg_gen_helper32() and tcg_gen_helper64() are currently
+   reserved for helpers in tcg-runtime.c. These helpers are all const
+   and pure, hence the call to tcg_gen_callN() with TCG_CALL_CONST |
+   TCG_CALL_PURE. This may need to be adjusted if these functions
+   start to be used with other helpers. */
 static inline void tcg_gen_helper32(void *func, TCGv_i32 ret,
                                     TCGv_i32 a, TCGv_i32 b)
 {
@@ -373,11 +377,11 @@ static inline void tcg_gen_helper32(void *func, TCGv_i32 ret,
     fn = tcg_const_ptr((tcg_target_long)func);
     args[0] = GET_TCGV_I32(a);
     args[1] = GET_TCGV_I32(b);
-    tcg_gen_callN(&tcg_ctx, fn, 0, 0, GET_TCGV_I32(ret), 2, args);
+    tcg_gen_callN(&tcg_ctx, fn, TCG_CALL_CONST | TCG_CALL_PURE,
+                  0, GET_TCGV_I32(ret), 2, args);
     tcg_temp_free_ptr(fn);
 }
 
-/* FIXME: Should this be pure?  */
 static inline void tcg_gen_helper64(void *func, TCGv_i64 ret,
                                     TCGv_i64 a, TCGv_i64 b)
 {
@@ -386,7 +390,8 @@ static inline void tcg_gen_helper64(void *func, TCGv_i64 ret,
     fn = tcg_const_ptr((tcg_target_long)func);
     args[0] = GET_TCGV_I64(a);
     args[1] = GET_TCGV_I64(b);
-    tcg_gen_callN(&tcg_ctx, fn, 0, 7, GET_TCGV_I64(ret), 2, args);
+    tcg_gen_callN(&tcg_ctx, fn, TCG_CALL_CONST | TCG_CALL_PURE,
+                  7, GET_TCGV_I64(ret), 2, args);
     tcg_temp_free_ptr(fn);
 }