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, 6 deletions

diff --git a/intern/cycles/kernel/closure/alloc.h b/intern/cycles/kernel/closure/alloc.h
index 72a8c2ba090..211eedbddbd 100644
--- a/intern/cycles/kernel/closure/alloc.h
+++ b/intern/cycles/kernel/closure/alloc.h
@@ -18,14 +18,17 @@
 
 CCL_NAMESPACE_BEGIN
 
-ccl_device ShaderClosure *closure_alloc(ShaderData *sd, int size, ClosureType type, float3 weight)
+ccl_device ccl_private ShaderClosure *closure_alloc(ccl_private ShaderData *sd,
+                                                    int size,
+                                                    ClosureType type,
+                                                    float3 weight)
 {
   kernel_assert(size <= sizeof(ShaderClosure));
 
   if (sd->num_closure_left == 0)
     return NULL;
 
-  ShaderClosure *sc = &sd->closure[sd->num_closure];
+  ccl_private ShaderClosure *sc = &sd->closure[sd->num_closure];
 
   sc->type = type;
   sc->weight = weight;
@@ -36,7 +39,7 @@ ccl_device ShaderClosure *closure_alloc(ShaderData *sd, int size, ClosureType ty
   return sc;
 }
 
-ccl_device ccl_addr_space void *closure_alloc_extra(ShaderData *sd, int size)
+ccl_device ccl_private void *closure_alloc_extra(ccl_private ShaderData *sd, int size)
 {
   /* Allocate extra space for closure that need more parameters. We allocate
    * in chunks of sizeof(ShaderClosure) starting from the end of the closure
@@ -54,10 +57,12 @@ ccl_device ccl_addr_space void *closure_alloc_extra(ShaderData *sd, int size)
   }
 
   sd->num_closure_left -= num_extra;
-  return (ccl_addr_space void *)(sd->closure + sd->num_closure + sd->num_closure_left);
+  return (ccl_private void *)(sd->closure + sd->num_closure + sd->num_closure_left);
 }
 
-ccl_device_inline ShaderClosure *bsdf_alloc(ShaderData *sd, int size, float3 weight)
+ccl_device_inline ccl_private ShaderClosure *bsdf_alloc(ccl_private ShaderData *sd,
+                                                        int size,
+                                                        float3 weight)
 {
   kernel_assert(isfinite3_safe(weight));
 
@@ -66,7 +71,7 @@ ccl_device_inline ShaderClosure *bsdf_alloc(ShaderData *sd, int size, float3 wei
   /* Use comparison this way to help dealing with non-finite weight: if the average is not finite
    * we will not allocate new closure. */
   if (sample_weight >= CLOSURE_WEIGHT_CUTOFF) {
-    ShaderClosure *sc = closure_alloc(sd, size, CLOSURE_NONE_ID, weight);
+    ccl_private ShaderClosure *sc = closure_alloc(sd, size, CLOSURE_NONE_ID, weight);
     if (sc == NULL) {
       return NULL;
     }