From c0ba800f64b6ec2054efc3bb521a384b1df0830a Mon Sep 17 00:00:00 2001
From: Brecht Van Lommel <brecht@blender.org>
Date: Fri, 17 Jan 2025 09:34:35 +0100
Subject: [PATCH] Refactor: Cycles: Avoid double host alloc in HIP-RT

This code should be changed to not modify host pointers directly. But as
long as we are going to do it, avoid unnecessary alloc and immediate free.

Pull Request: https://projects.blender.org/blender/blender/pulls/132912
---
 intern/cycles/device/hiprt/device_impl.cpp | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/intern/cycles/device/hiprt/device_impl.cpp b/intern/cycles/device/hiprt/device_impl.cpp
index eba24e06f7c..6001027f0da 100644
--- a/intern/cycles/device/hiprt/device_impl.cpp
+++ b/intern/cycles/device/hiprt/device_impl.cpp
@@ -1015,12 +1015,13 @@ hiprtScene HIPRTDevice::build_tlas(BVHHIPRT *bvh,
   blas_ptr.copy_to_device();
   transform_headers.copy_to_device();
   {
-    instance_transform_matrix.alloc(frame_count);
-    instance_transform_matrix.host_free();
     instance_transform_matrix.host_pointer = transform_matrix.data();
     instance_transform_matrix.data_elements = sizeof(hiprtFrameMatrix);
     instance_transform_matrix.data_type = TYPE_UCHAR;
     instance_transform_matrix.data_size = frame_count;
+    instance_transform_matrix.data_width = frame_count;
+    instance_transform_matrix.data_height = 0;
+    instance_transform_matrix.data_depth = 0;
     instance_transform_matrix.copy_to_device();
     instance_transform_matrix.host_pointer = nullptr;
   }
@@ -1068,12 +1069,13 @@ hiprtScene HIPRTDevice::build_tlas(BVHHIPRT *bvh,
 
   if (bvh->custom_prim_info.size()) {
     size_t data_size = bvh->custom_prim_info.size();
-    custom_prim_info.alloc(data_size);
-    custom_prim_info.host_free();
     custom_prim_info.host_pointer = bvh->custom_prim_info.data();
     custom_prim_info.data_elements = 2;
     custom_prim_info.data_type = TYPE_INT;
     custom_prim_info.data_size = data_size;
+    custom_prim_info.data_width = data_size;
+    custom_prim_info.data_height = 0;
+    custom_prim_info.data_depth = 0;
     custom_prim_info.copy_to_device();
     custom_prim_info.host_pointer = nullptr;
 
@@ -1082,12 +1084,13 @@ hiprtScene HIPRTDevice::build_tlas(BVHHIPRT *bvh,
 
   if (bvh->prims_time.size()) {
     size_t data_size = bvh->prims_time.size();
-    prims_time.alloc(data_size);
-    prims_time.host_free();
     prims_time.host_pointer = bvh->prims_time.data();
     prims_time.data_elements = 2;
     prims_time.data_type = TYPE_FLOAT;
     prims_time.data_size = data_size;
+    prims_time.data_width = data_size;
+    prims_time.data_height = 0;
+    prims_time.data_depth = 0;
     prims_time.copy_to_device();
     prims_time.host_pointer = nullptr;