simple_idct: simplify some ifdeffery

Signed-off-by: Mans Rullgard <mans@mansr.com>

libavcodec/simple_idct.c

@@ -29,6 +29,8 @@
   based upon some outcommented c code from mpeg2dec (idct_mmx.c
   written by Aaron Holtzman <aholtzma@ess.engr.uvic.ca>)
  */
+
+#include "libavutil/intreadwrite.h"
 #include "avcodec.h"
 #include "dsputil.h"
 #include "mathops.h"
@@ -47,20 +49,11 @@
 static inline void idctRowCondDC (DCTELEM * row)
 {
         int a0, a1, a2, a3, b0, b1, b2, b3;
-#if HAVE_FAST_64BIT
-        uint64_t temp;
-#else
-        uint32_t temp;
-#endif
 
 #if HAVE_FAST_64BIT
-#if HAVE_BIGENDIAN
-#define ROW0_MASK 0xffff000000000000LL
-#else
-#define ROW0_MASK 0xffffLL
-#endif
+#define ROW0_MASK (0xffffLL << 48 * HAVE_BIGENDIAN)
         if (((((uint64_t *)row)[0] & ~ROW0_MASK) | ((uint64_t *)row)[1]) == 0) {
-            temp = (row[0] << 3) & 0xffff;
+            uint64_t temp = (row[0] << 3) & 0xffff;
             temp += temp << 16;
             temp += temp << 32;
             ((uint64_t *)row)[0] = temp;
@@ -72,7 +65,7 @@ static inline void idctRowCondDC (DCTELEM * row)
               ((uint32_t*)row)[2] |
               ((uint32_t*)row)[3] |
               row[1])) {
-            temp = (row[0] << 3) & 0xffff;
+            uint32_t temp = (row[0] << 3) & 0xffff;
             temp += temp << 16;
             ((uint32_t*)row)[0]=((uint32_t*)row)[1] =
                 ((uint32_t*)row)[2]=((uint32_t*)row)[3] = temp;
@@ -100,12 +93,7 @@ static inline void idctRowCondDC (DCTELEM * row)
         b3 = MUL16(W7, row[1]);
         MAC16(b3, -W5, row[3]);
 
-#if HAVE_FAST_64BIT
-        temp = ((uint64_t*)row)[1];
-#else
-        temp = ((uint32_t*)row)[2] | ((uint32_t*)row)[3];
-#endif
-        if (temp != 0) {
+        if (AV_RN64A(row + 4)) {
             a0 += W4*row[4] + W6*row[6];
             a1 += - W4*row[4] - W2*row[6];
             a2 += - W4*row[4] + W2*row[6];