diff --git a/cuda_helper.h b/cuda_helper.h
index 21f1b1d..0e65368 100644
--- a/cuda_helper.h
+++ b/cuda_helper.h
@@ -343,7 +343,7 @@ uint64_t ROTL64(const uint64_t x, const int offset)
 #endif
 
 __device__ __forceinline__
-uint64_t SWAPDWORDS(const uint64_t value)
+uint64_t SWAPDWORDS(uint64_t value)
 {
 #if __CUDA_ARCH__ >= 320
 	uint2 temp;
diff --git a/groestl_functions_quad.cu b/groestl_functions_quad.cu
index 4085283..7688839 100644
--- a/groestl_functions_quad.cu
+++ b/groestl_functions_quad.cu
@@ -32,8 +32,8 @@ void G256_AddRoundConstantQ_quad(uint32_t &x7, uint32_t &x6, uint32_t &x5, uint3
 
     int andmask = 0xFFFF0000;
 #else
-    /* from sp: weird but faster */
-    int andmask = ((~((threadIdx.x & 0x03) - 3)) & 0xFFFF0000);
+    /* from sp: faster (branching problem with if ?) */
+    uint32_t andmask = -((threadIdx.x & 3) == 3) & 0xFFFF0000U;
 #endif
 
     x0 ^= ((- (rnd & 0x01)    ) & andmask);