Workaround for AMD GPU OpenCL compiler.

intern/cycles/kernel/kernel_subsurface.h

@@ -399,6 +399,12 @@ ccl_device_noinline void subsurface_scatter_multi_setup(
 #else
 	Ray *ray = &ss_isect->ray;
 #endif
+
+	/* Workaround for AMD GPU OpenCL compiler. Most probably cache bypass issue. */
+#if defined(__SPLIT_KERNEL__) && defined(__KERNEL_OPENCL_AMD__) && defined(__KERNEL_GPU__)
+	kernel_split_params.dummy_sd_flag = sd->flag;
+#endif
+
 	/* Setup new shading point. */
 	shader_setup_from_subsurface(kg, sd, &ss_isect->hits[hit], ray);
 

intern/cycles/kernel/split/kernel_split_data_types.h

@@ -43,6 +43,9 @@ typedef struct SplitParams {
 	ccl_global char *use_queues_flag;
 
 	ccl_global float *buffer;
+
+	/* Place for storing sd->flag. AMD GPU OpenCL compiler workaround */
+	int dummy_sd_flag;
 } SplitParams;
 
 /* Global memory variables [porting]; These memory is used for