fixed integer overflow warnings

Jenkins warns on left shift of negative numbers and non-aligned read
of int. This commit fixed the two issues.

Change-Id: I389a7fb6a572c643902e40a4c10fefef94500d2c

vp8/common/x86/vp8_asm_stubs.c

@@ -611,16 +611,12 @@ void vp8_sixtap_predict4x4_ssse3
 
           for (r = 0; r < 4; r++)
           {
-  #if !(CONFIG_FAST_UNALIGNED)
             dst_ptr[0]  = src_ptr[0];
             dst_ptr[1]  = src_ptr[1];
             dst_ptr[2]  = src_ptr[2];
             dst_ptr[3]  = src_ptr[3];
-  #else
-              *(uint32_t *)dst_ptr = *(uint32_t *)src_ptr ;
-  #endif
-              dst_ptr     += dst_pitch;
-              src_ptr     += src_pixels_per_line;
+            dst_ptr     += dst_pitch;
+            src_ptr     += src_pixels_per_line;
           }
       }
   }

vp8/encoder/dct.c

@@ -20,10 +20,10 @@ void vp8_short_fdct4x4_c(short *input, short *output, int pitch)
 
     for (i = 0; i < 4; i++)
     {
-        a1 = ((ip[0] + ip[3])<<3);
-        b1 = ((ip[1] + ip[2])<<3);
-        c1 = ((ip[1] - ip[2])<<3);
-        d1 = ((ip[0] - ip[3])<<3);
+        a1 = ((ip[0] + ip[3]) * 8);
+        b1 = ((ip[1] + ip[2]) * 8);
+        c1 = ((ip[1] - ip[2]) * 8);
+        d1 = ((ip[0] - ip[3]) * 8);
 
         op[0] = a1 + b1;
         op[2] = a1 - b1;
@@ -72,10 +72,10 @@ void vp8_short_walsh4x4_c(short *input, short *output, int pitch)
 
     for (i = 0; i < 4; i++)
     {
-        a1 = ((ip[0] + ip[2])<<2);
-        d1 = ((ip[1] + ip[3])<<2);
-        c1 = ((ip[1] - ip[3])<<2);
-        b1 = ((ip[0] - ip[2])<<2);
+        a1 = ((ip[0] + ip[2]) * 4);
+        d1 = ((ip[1] + ip[3]) * 4);
+        c1 = ((ip[1] - ip[3]) * 4);
+        b1 = ((ip[0] - ip[2]) * 4);
 
         op[0] = a1 + d1 + (a1!=0);
         op[1] = b1 + c1;