Cycles: merge of cycles-x branch, a major update to the renderer

This includes much improved GPU rendering performance, viewport interactivity,
new shadow catcher, revamped sampling settings, subsurface scattering anisotropy,
new GPU volume sampling, improved PMJ sampling pattern, and more.

Some features have also been removed or changed, breaking backwards compatibility.
Including the removal of the OpenCL backend, for which alternatives are under
development.

Release notes and code docs:
https://wiki.blender.org/wiki/Reference/Release_Notes/3.0/Cycles
https://wiki.blender.org/wiki/Source/Render/Cycles

Credits:
* Sergey Sharybin
* Brecht Van Lommel
* Patrick Mours (OptiX backend)
* Christophe Hery (subsurface scattering anisotropy)
* William Leeson (PMJ sampling pattern)
* Alaska (various fixes and tweaks)
* Thomas Dinges (various fixes)

For the full commit history, see the cycles-x branch. This squashes together
all the changes since intermediate changes would often fail building or tests.

Ref T87839, T87837, T87836
Fixes T90734, T89353, T80267, T80267, T77185, T69800

1 files changed, 114 insertions, 0 deletions

diff --git a/intern/cycles/kernel/device/cuda/config.h b/intern/cycles/kernel/device/cuda/config.h
new file mode 100644
index 00000000000..46196dcdb51
--- /dev/null
+++ b/intern/cycles/kernel/device/cuda/config.h
@@ -0,0 +1,114 @@
+/*
+ * Copyright 2011-2013 Blender Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* Device data taken from CUDA occupancy calculator.
+ *
+ * Terminology
+ * - CUDA GPUs have multiple streaming multiprocessors
+ * - Each multiprocessor executes multiple thread blocks
+ * - Each thread block contains a number of threads, also known as the block size
+ * - Multiprocessors have a fixed number of registers, and the amount of registers
+ *   used by each threads limits the number of threads per block.
+ */
+
+/* 3.0 and 3.5 */
+#if __CUDA_ARCH__ == 300 || __CUDA_ARCH__ == 350
+#  define GPU_MULTIPRESSOR_MAX_REGISTERS 65536
+#  define GPU_MULTIPROCESSOR_MAX_BLOCKS 16
+#  define GPU_BLOCK_MAX_THREADS 1024
+#  define GPU_THREAD_MAX_REGISTERS 63
+
+/* tunable parameters */
+#  define GPU_KERNEL_BLOCK_NUM_THREADS 256
+#  define GPU_KERNEL_MAX_REGISTERS 63
+
+/* 3.2 */
+#elif __CUDA_ARCH__ == 320
+#  define GPU_MULTIPRESSOR_MAX_REGISTERS 32768
+#  define GPU_MULTIPROCESSOR_MAX_BLOCKS 16
+#  define GPU_BLOCK_MAX_THREADS 1024
+#  define GPU_THREAD_MAX_REGISTERS 63
+
+/* tunable parameters */
+#  define GPU_KERNEL_BLOCK_NUM_THREADS 256
+#  define GPU_KERNEL_MAX_REGISTERS 63
+
+/* 3.7 */
+#elif __CUDA_ARCH__ == 370
+#  define GPU_MULTIPRESSOR_MAX_REGISTERS 65536
+#  define GPU_MULTIPROCESSOR_MAX_BLOCKS 16
+#  define GPU_BLOCK_MAX_THREADS 1024
+#  define GPU_THREAD_MAX_REGISTERS 255
+
+/* tunable parameters */
+#  define GPU_KERNEL_BLOCK_NUM_THREADS 256
+#  define GPU_KERNEL_MAX_REGISTERS 63
+
+/* 5.x, 6.x */
+#elif __CUDA_ARCH__ <= 699
+#  define GPU_MULTIPRESSOR_MAX_REGISTERS 65536
+#  define GPU_MULTIPROCESSOR_MAX_BLOCKS 32
+#  define GPU_BLOCK_MAX_THREADS 1024
+#  define GPU_THREAD_MAX_REGISTERS 255
+
+/* tunable parameters */
+#  define GPU_KERNEL_BLOCK_NUM_THREADS 256
+/* CUDA 9.0 seems to cause slowdowns on high-end Pascal cards unless we increase the number of
+ * registers */
+#  if __CUDACC_VER_MAJOR__ >= 9 && __CUDA_ARCH__ >= 600
+#    define GPU_KERNEL_MAX_REGISTERS 64
+#  else
+#    define GPU_KERNEL_MAX_REGISTERS 48
+#  endif
+
+/* 7.x, 8.x */
+#elif __CUDA_ARCH__ <= 899
+#  define GPU_MULTIPRESSOR_MAX_REGISTERS 65536
+#  define GPU_MULTIPROCESSOR_MAX_BLOCKS 32
+#  define GPU_BLOCK_MAX_THREADS 1024
+#  define GPU_THREAD_MAX_REGISTERS 255
+
+/* tunable parameters */
+#  define GPU_KERNEL_BLOCK_NUM_THREADS 512
+#  define GPU_KERNEL_MAX_REGISTERS 96
+
+/* unknown architecture */
+#else
+#  error "Unknown or unsupported CUDA architecture, can't determine launch bounds"
+#endif
+
+/* Compute number of threads per block and minimum blocks per multiprocessor
+ * given the maximum number of registers per thread. */
+
+#define ccl_gpu_kernel(block_num_threads, thread_num_registers) \
+  extern "C" __global__ void __launch_bounds__(block_num_threads, \
+                                               GPU_MULTIPRESSOR_MAX_REGISTERS / \
+                                                   (block_num_threads * thread_num_registers))
+
+/* sanity checks */
+
+#if GPU_KERNEL_BLOCK_NUM_THREADS > GPU_BLOCK_MAX_THREADS
+#  error "Maximum number of threads per block exceeded"
+#endif
+
+#if GPU_MULTIPRESSOR_MAX_REGISTERS / (GPU_KERNEL_BLOCK_NUM_THREADS * GPU_KERNEL_MAX_REGISTERS) > \
+    GPU_MULTIPROCESSOR_MAX_BLOCKS
+#  error "Maximum number of blocks per multiprocessor exceeded"
+#endif
+
+#if GPU_KERNEL_MAX_REGISTERS > GPU_THREAD_MAX_REGISTERS
+#  error "Maximum number of registers per thread exceeded"
+#endif