Cycles: Kernel address space changes for MSL

This is the first of a sequence of changes to support compiling Cycles kernels as MSL (Metal Shading Language) in preparation for a Metal GPU device implementation.

MSL requires that all pointer types be declared with explicit address space attributes (device, thread, etc...). There is already precedent for this with Cycles' address space macros (ccl_global, ccl_private, etc...), therefore the first step of MSL-enablement is to apply these consistently. Line-for-line this represents the largest change required to enable MSL. Applying this change first will simplify future patches as well as offering the emergent benefit of enhanced descriptiveness.

The vast majority of deltas in this patch fall into one of two cases:

- Ensuring ccl_private is specified for thread-local pointer types
- Ensuring ccl_global is specified for device-wide pointer types

Additionally, the ccl_addr_space qualifier can be removed. Prior to Cycles X, ccl_addr_space was used as a context-dependent address space qualifier, but now it is either redundant (e.g. in struct typedefs), or can be replaced by ccl_global in the case of pointer types. Associated function variants (e.g. lcg_step_float_addrspace) are also redundant.

In cases where address space qualifiers are chained with "const", this patch places the address space qualifier first. The rationale for this is that the choice of address space is likely to have the greater impact on runtime performance and overall architecture.

The final part of this patch is the addition of a metal/compat.h header. This is partially complete and will be extended in future patches, paving the way for the full Metal implementation.

Ref T92212

Reviewed By: brecht

Maniphest Tasks: T92212

Differential Revision: https://developer.blender.org/D12864

1 files changed, 11 insertions, 7 deletions

diff --git a/intern/cycles/kernel/kernel_passes.h b/intern/cycles/kernel/kernel_passes.h
index 67466b28170..b981e750dda 100644
--- a/intern/cycles/kernel/kernel_passes.h
+++ b/intern/cycles/kernel/kernel_passes.h
@@ -36,7 +36,9 @@ ccl_device_forceinline ccl_global float *kernel_pass_pixel_render_buffer(
 #ifdef __DENOISING_FEATURES__
 
 ccl_device_forceinline void kernel_write_denoising_features_surface(
-    INTEGRATOR_STATE_ARGS, const ShaderData *sd, ccl_global float *ccl_restrict render_buffer)
+    INTEGRATOR_STATE_ARGS,
+    ccl_private const ShaderData *sd,
+    ccl_global float *ccl_restrict render_buffer)
 {
   if (!(INTEGRATOR_STATE(path, flag) & PATH_RAY_DENOISING_FEATURES)) {
     return;
@@ -55,7 +57,7 @@ ccl_device_forceinline void kernel_write_denoising_features_surface(
   float sum_weight = 0.0f, sum_nonspecular_weight = 0.0f;
 
   for (int i = 0; i < sd->num_closure; i++) {
-    const ShaderClosure *sc = &sd->closure[i];
+    ccl_private const ShaderClosure *sc = &sd->closure[i];
 
     if (!CLOSURE_IS_BSDF_OR_BSSRDF(sc->type)) {
       continue;
@@ -71,11 +73,11 @@ ccl_device_forceinline void kernel_write_denoising_features_surface(
      * To account for this, we scale their weight by the average fresnel factor (the same is also
      * done for the sample weight in the BSDF setup, so we don't need to scale that here). */
     if (CLOSURE_IS_BSDF_MICROFACET_FRESNEL(sc->type)) {
-      MicrofacetBsdf *bsdf = (MicrofacetBsdf *)sc;
+      ccl_private MicrofacetBsdf *bsdf = (ccl_private MicrofacetBsdf *)sc;
       closure_albedo *= bsdf->extra->fresnel_color;
     }
     else if (sc->type == CLOSURE_BSDF_PRINCIPLED_SHEEN_ID) {
-      PrincipledSheenBsdf *bsdf = (PrincipledSheenBsdf *)sc;
+      ccl_private PrincipledSheenBsdf *bsdf = (ccl_private PrincipledSheenBsdf *)sc;
       closure_albedo *= bsdf->avg_value;
     }
     else if (sc->type == CLOSURE_BSDF_HAIR_PRINCIPLED_ID) {
@@ -151,7 +153,9 @@ ccl_device_forceinline void kernel_write_denoising_features_volume(INTEGRATOR_ST
 
 /* Write shadow catcher passes on a bounce from the shadow catcher object. */
 ccl_device_forceinline void kernel_write_shadow_catcher_bounce_data(
-    INTEGRATOR_STATE_ARGS, const ShaderData *sd, ccl_global float *ccl_restrict render_buffer)
+    INTEGRATOR_STATE_ARGS,
+    ccl_private const ShaderData *sd,
+    ccl_global float *ccl_restrict render_buffer)
 {
   if (!kernel_data.integrator.has_shadow_catcher) {
     return;
@@ -178,7 +182,7 @@ ccl_device_forceinline void kernel_write_shadow_catcher_bounce_data(
 
 #endif /* __SHADOW_CATCHER__ */
 
-ccl_device_inline size_t kernel_write_id_pass(float *ccl_restrict buffer,
+ccl_device_inline size_t kernel_write_id_pass(ccl_global float *ccl_restrict buffer,
                                               size_t depth,
                                               float id,
                                               float matte_weight)
@@ -188,7 +192,7 @@ ccl_device_inline size_t kernel_write_id_pass(float *ccl_restrict buffer,
 }
 
 ccl_device_inline void kernel_write_data_passes(INTEGRATOR_STATE_ARGS,
-                                                const ShaderData *sd,
+                                                ccl_private const ShaderData *sd,
                                                 ccl_global float *ccl_restrict render_buffer)
 {
 #ifdef __PASSES__