anv: add INTEL_DEBUG=rt_notrace

Reviewed-by: Kevin Chuang <kaiwenjon23@gmail.com>
Reviewed-by: Sagar Ghuge <sagar.ghuge@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34169>

docs/envvars.rst

@@ -582,6 +582,8 @@ Intel driver environment variables
       mark all state dirty on each draw call
    ``rt``
       dump shader assembly for ray tracing shaders
+   ``rt_notrace``
+      skip trace rays operation (does not disable AS generation; see bvh_no_build)
    ``sf``
       emit messages about the strips & fans unit (for old gens, includes
       the SF program)

src/intel/dev/intel_debug.c

@@ -94,6 +94,7 @@ static const struct debug_control debug_control[] = {
                     DEBUG_TES | DEBUG_GS | DEBUG_CS |
                     DEBUG_RT | DEBUG_TASK | DEBUG_MESH },
    { "rt",          DEBUG_RT },
+   { "rt_notrace",  DEBUG_RT_NO_TRACE},
    { "bvh_blas",    DEBUG_BVH_BLAS},
    { "bvh_tlas",    DEBUG_BVH_TLAS},
    { "bvh_blas_ir_hdr", DEBUG_BVH_BLAS_IR_HDR},

src/intel/dev/intel_debug.h

@@ -107,6 +107,7 @@ extern uint64_t intel_debug;
 #define DEBUG_BVH_TLAS_IR_AS      (1ull << 59)
 #define DEBUG_BVH_NO_BUILD        (1ull << 60)
 #define DEBUG_NO_SEND_GATHER      (1ull << 61)
+#define DEBUG_RT_NO_TRACE         (1ull << 62)
 
 #define DEBUG_ANY                 (~0ull)
 

src/intel/vulkan/genX_cmd_compute.c

@@ -1165,6 +1165,9 @@ cmd_buffer_trace_rays(struct anv_cmd_buffer *cmd_buffer,
    struct anv_ray_tracing_pipeline *pipeline =
       anv_pipeline_to_ray_tracing(rt->base.pipeline);
 
+   if (INTEL_DEBUG(DEBUG_RT_NO_TRACE))
+      return;
+
    if (anv_batch_has_error(&cmd_buffer->batch))
       return;