Cycles: Pack kernel textures into buffers for OpenCL

Image textures were being packed into a single buffer for OpenCL, which
limited the amount of memory available for images to the size of one
buffer (usually 4gb on AMD hardware). By packing textures into multiple
buffers that limit is removed, while simultaneously reducing the number
of buffers that need to be passed to each kernel.

Benchmarks were within 2%.

Fixes T51554.

Differential Revision: https://developer.blender.org/D2745

1 files changed, 14 insertions, 11 deletions

diff --git a/intern/cycles/device/opencl/opencl_split.cpp b/intern/cycles/device/opencl/opencl_split.cpp
index 76d9983e9a2..df7c064a24f 100644
--- a/intern/cycles/device/opencl/opencl_split.cpp
+++ b/intern/cycles/device/opencl/opencl_split.cpp
@@ -99,6 +99,8 @@ public:
 
 	void thread_run(DeviceTask *task)
 	{
+		flush_texture_buffers();
+
 		if(task->type == DeviceTask::FILM_CONVERT) {
 			film_convert(*task, task->buffer, task->rgba_byte, task->rgba_half);
 		}
@@ -113,10 +115,19 @@ public:
 			 */
 			typedef struct KernelGlobals {
 				ccl_constant KernelData *data;
+				ccl_global char *buffers[8];
+
+				typedef struct _tex_info_t {
+					uint buffer, padding;
+					ulong offset;
+					uint width, height, depth, options;
+				} _tex_info_t;
+
 #define KERNEL_TEX(type, ttype, name) \
-				ccl_global type *name;
+				_tex_info_t name;
 #include "kernel/kernel_textures.h"
 #undef KERNEL_TEX
+
 				SplitData split_data;
 				SplitParams split_param_data;
 			} KernelGlobals;
@@ -217,11 +228,7 @@ public:
 					            *cached_memory.ray_state,
 					            *cached_memory.rng_state);
 
-/* TODO(sergey): Avoid map lookup here. */
-#define KERNEL_TEX(type, ttype, name) \
-				device->set_kernel_arg_mem(program(), &start_arg_index, #name);
-#include "kernel/kernel_textures.h"
-#undef KERNEL_TEX
+				device->set_kernel_arg_buffers(program(), &start_arg_index);
 
 			start_arg_index +=
 				device->kernel_set_args(program(),
@@ -352,11 +359,7 @@ public:
 			                ray_state,
 			                rtile.rng_state);
 
-/* TODO(sergey): Avoid map lookup here. */
-#define KERNEL_TEX(type, ttype, name) \
-	device->set_kernel_arg_mem(device->program_data_init(), &start_arg_index, #name);
-#include "kernel/kernel_textures.h"
-#undef KERNEL_TEX
+			device->set_kernel_arg_buffers(device->program_data_init(), &start_arg_index);
 
 		start_arg_index +=
 			device->kernel_set_args(device->program_data_init(),