diff --git a/OpenCL/inc_common.cl b/OpenCL/inc_common.cl
index 1cd1e33cb..cdce58e90 100644
--- a/OpenCL/inc_common.cl
+++ b/OpenCL/inc_common.cl
@@ -1887,7 +1887,7 @@ DECLSPEC u32 hc_bytealign_S (const u32 a, const u32 b, const int c)
   return r;
 }
 #else
-DECLSPEC u32 hc_bytealign_be (const u32 a, const u32 b, const int c)
+DECLSPEC u32 hc_bytealign_be (const u32x a, const u32x b, const int c)
 {
   const int c_mod_4 = c & 3;
 
diff --git a/OpenCL/inc_hash_scrypt.cl b/OpenCL/inc_hash_scrypt.cl
index 45c054534..91bd37a2a 100644
--- a/OpenCL/inc_hash_scrypt.cl
+++ b/OpenCL/inc_hash_scrypt.cl
@@ -9,6 +9,18 @@
 #include "inc_common.h"
 #include "inc_hash_scrypt.h"
 
+DECLSPEC hc_uint4_t xor_uint4 (const hc_uint4_t a, const hc_uint4_t b)
+{
+  hc_uint4_t r;
+
+  r.x = a.x ^ b.x;
+  r.y = a.y ^ b.y;
+  r.z = a.z ^ b.z;
+  r.w = a.w ^ b.w;
+
+  return r;
+}
+
 #if SCRYPT_R > 1
 DECLSPEC void scrypt_shuffle (PRIVATE_AS u32 *TI)
 {
@@ -144,27 +156,27 @@ DECLSPEC void scrypt_smix_init (GLOBAL_AS u32 *P, PRIVATE_AS u32 *X, GLOBAL_AS v
   const u32 xd4 = bid / 4;
   const u32 xm4 = bid & 3;
 
-  PRIVATE_AS uint4 *X4 = (PRIVATE_AS uint4 *) X;
+  PRIVATE_AS hc_uint4_t *X4 = (PRIVATE_AS hc_uint4_t *) X;
 
-  GLOBAL_AS uint4 *V;
+  GLOBAL_AS hc_uint4_t *V;
 
   switch (xm4)
   {
-    case 0: V = (GLOBAL_AS uint4 *) V0; break;
-    case 1: V = (GLOBAL_AS uint4 *) V1; break;
-    case 2: V = (GLOBAL_AS uint4 *) V2; break;
-    case 3: V = (GLOBAL_AS uint4 *) V3; break;
+    case 0: V = (GLOBAL_AS hc_uint4_t *) ALIGN_PTR_1k (V0); break;
+    case 1: V = (GLOBAL_AS hc_uint4_t *) ALIGN_PTR_1k (V1); break;
+    case 2: V = (GLOBAL_AS hc_uint4_t *) ALIGN_PTR_1k (V2); break;
+    case 3: V = (GLOBAL_AS hc_uint4_t *) ALIGN_PTR_1k (V3); break;
   }
 
-  GLOBAL_AS uint4 *Vx = V + (xd4 * lsz * ySIZE * zSIZE) + (lid * ySIZE * zSIZE);
+  GLOBAL_AS hc_uint4_t *Vx = V + (xd4 * lsz * ySIZE * zSIZE) + (lid * ySIZE * zSIZE);
 
   for (u32 i = 0; i < STATE_CNT4; i++) X[i] = P[i];
 
   for (u32 y = 0; y < ySIZE; y++)
   {
-    GLOBAL_AS uint4 *Vxx = Vx + (y * zSIZE);
+    GLOBAL_AS hc_uint4_t *Vxx = Vx + (y * zSIZE);
 
-    for (u32 z = 0; z < zSIZE; z++) *Vxx++ = X4[z];
+    for (u32 z = 0; z < zSIZE; z++) Vxx[z] = X4[z];
 
     for (u32 i = 0; i < (1 << SCRYPT_TMTO); i++)
     {
@@ -187,20 +199,20 @@ DECLSPEC void scrypt_smix_loop (GLOBAL_AS u32 *P, PRIVATE_AS u32 *X, PRIVATE_AS
   const u32 xd4 = bid / 4;
   const u32 xm4 = bid & 3;
 
-  PRIVATE_AS uint4 *X4 = (PRIVATE_AS uint4 *) X;
-  PRIVATE_AS uint4 *T4 = (PRIVATE_AS uint4 *) T;
+  PRIVATE_AS hc_uint4_t *X4 = (PRIVATE_AS hc_uint4_t *) X;
+  PRIVATE_AS hc_uint4_t *T4 = (PRIVATE_AS hc_uint4_t *) T;
 
-  GLOBAL_AS uint4 *V;
+  GLOBAL_AS hc_uint4_t *V;
 
   switch (xm4)
   {
-    case 0: V = (GLOBAL_AS uint4 *) V0; break;
-    case 1: V = (GLOBAL_AS uint4 *) V1; break;
-    case 2: V = (GLOBAL_AS uint4 *) V2; break;
-    case 3: V = (GLOBAL_AS uint4 *) V3; break;
+    case 0: V = (GLOBAL_AS hc_uint4_t *) ALIGN_PTR_1k (V0); break;
+    case 1: V = (GLOBAL_AS hc_uint4_t *) ALIGN_PTR_1k (V1); break;
+    case 2: V = (GLOBAL_AS hc_uint4_t *) ALIGN_PTR_1k (V2); break;
+    case 3: V = (GLOBAL_AS hc_uint4_t *) ALIGN_PTR_1k (V3); break;
   }
 
-  GLOBAL_AS uint4 *Vx = V + (xd4 * lsz * ySIZE * zSIZE) + (lid * ySIZE * zSIZE);
+  GLOBAL_AS hc_uint4_t *Vx = V + (xd4 * lsz * ySIZE * zSIZE) + (lid * ySIZE * zSIZE);
 
   for (u32 i = 0; i < STATE_CNT4; i++) X[i] = P[i];
 
@@ -216,7 +228,7 @@ DECLSPEC void scrypt_smix_loop (GLOBAL_AS u32 *P, PRIVATE_AS u32 *X, PRIVATE_AS
 
     const u32 km = k - (y << SCRYPT_TMTO);
 
-    GLOBAL_AS uint4 *Vxx = Vx + (y * zSIZE);
+    GLOBAL_AS hc_uint4_t *Vxx = Vx + (y * zSIZE);
 
     for (u32 z = 0; z < zSIZE; z++) T4[z] = *Vxx++;
 
@@ -229,7 +241,7 @@ DECLSPEC void scrypt_smix_loop (GLOBAL_AS u32 *P, PRIVATE_AS u32 *X, PRIVATE_AS
       #endif
     }
 
-    for (u32 z = 0; z < zSIZE; z++) X4[z] = X4[z] ^ T4[z];
+    for (u32 z = 0; z < zSIZE; z++) X4[z] = xor_uint4 (X4[z], T4[z]);
 
     salsa_r (X);
 
diff --git a/OpenCL/inc_hash_scrypt.h b/OpenCL/inc_hash_scrypt.h
index 808661726..d14b2843b 100644
--- a/OpenCL/inc_hash_scrypt.h
+++ b/OpenCL/inc_hash_scrypt.h
@@ -25,24 +25,27 @@
 #define SALSA_CNT4 (SALSA_SZ / 4)
 #define SALSA_CNT44 ((SALSA_SZ / 4) / 4)
 
-//#define VIDX(bid4,lsz,lid,ySIZE,zSIZE,y,z) (((bid4) * (lsz) * (ySIZE) * (zSIZE)) + ((lid) * (ySIZE) * (zSIZE)) + ((y) * (zSIZE)) + (z))
+// should be safe, because in backend.c we use:
+//    u64 size_extra_buffer1 = 4096;
+//  size_extra_buffer1 += base_chunk_size;
+#define ALIGN_PTR_1k(p) ((GLOBAL_AS hc_uint4_t *) (((u64) (p) + 1023) & ~1023UL))
 
-#if defined IS_CUDA
+#if defined IS_INTEL_SDK
 
-DECLSPEC uint4 operator ^ (const uint4 a, const uint4 b)
+typedef struct
 {
-  uint4 r;
+  u32 x, y, z, w;
 
-  r.x = a.x ^ b.x;
-  r.y = a.y ^ b.y;
-  r.z = a.z ^ b.z;
-  r.w = a.w ^ b.w;
+} hc_uint4_t;
 
-  return r;
-}
+#else
+
+typedef uint4 hc_uint4_t;
 
 #endif
 
+DECLSPEC hc_uint4_t xor_uint4 (const hc_uint4_t a, const hc_uint4_t b);
+
 typedef struct
 {
   #ifndef SCRYPT_TMP_ELEM