[GPU] Eliminate unused shader I/O, UCP culling, centroid on Vulkan

For more optimal usage of exports and the parameter cache on the host regardless of how effective the optimizations in the host GPU driver are. Also reserve space for Vulkan/Metal/D3D11-specific HostVertexShaderTypes to use one more bit for the host vertex shader type in the shader modification bits, so that won't have to be done in the future as that would require invalidating shader storages (which are invalidated by this commit) again.

src/xenia/gpu/shader.h

@@ -22,6 +22,7 @@
 #include "xenia/base/byte_order.h"
 #include "xenia/base/math.h"
 #include "xenia/base/string_buffer.h"
+#include "xenia/gpu/registers.h"
 #include "xenia/gpu/ucode.h"
 #include "xenia/gpu/xenos.h"
 
@@ -652,11 +653,11 @@ void ParseAluInstruction(const ucode::AluInstruction& op,
 
 class Shader {
  public:
-  // Type of the vertex shader in a D3D11-like rendering pipeline - shader
-  // interface depends on in, so it must be known at translation time.
-  // If values are changed, INVALIDATE SHADER STORAGES (increase their version
-  // constexpr) where those are stored! And check bit count where this is
-  // packed. This is : uint32_t for simplicity of packing in bit fields.
+  // Type of the vertex shader on the host - shader interface depends on in, so
+  // it must be known at translation time. If values are changed, INVALIDATE
+  // SHADER STORAGES (increase their version constexpr) where those are stored!
+  // And check bit count where this is packed. This is : uint32_t for simplicity
+  // of packing in bit fields.
   enum class HostVertexShaderType : uint32_t {
     kVertex,
 
@@ -668,9 +669,22 @@ class Shader {
     kQuadDomainCPIndexed,
     kQuadDomainPatchIndexed,
     kDomainEnd,
+
+    // For implementation without unconditional support for memory writes from
+    // vertex shaders, vertex shader converted to a compute shader doing only
+    // memory export.
+    kMemexportCompute,
+
+    // 4 host vertices for 1 guest vertex, for implementations without
+    // unconditional geometry shader support.
+    kPointListAsTriangleStrip,
+    // 3 guest vertices processed by the host shader invocation to choose the
+    // strip orientation, for implementations without unconditional geometry
+    // shader support.
+    kRectangleListAsTriangleStrip,
   };
   // For packing HostVertexShaderType in bit fields.
-  static constexpr uint32_t kHostVertexShaderTypeBitCount = 3;
+  static constexpr uint32_t kHostVertexShaderTypeBitCount = 4;
 
   static constexpr bool IsHostVertexShaderTypeDomain(
       HostVertexShaderType host_vertex_shader_type) {
@@ -932,6 +946,21 @@ class Shader {
     return uses_texture_fetch_instruction_results_;
   }
 
+  // Whether each interpolator is written on any execution path.
+  uint32_t writes_interpolators() const { return writes_interpolators_; }
+
+  // Whether the system vertex shader exports are written on any execution path.
+  uint32_t writes_point_size_edge_flag_kill_vertex() const {
+    return writes_point_size_edge_flag_kill_vertex_;
+  }
+
+  // Returns the mask of the interpolators the pixel shader potentially requires
+  // from the vertex shader, and also the PsParamGen destination register, or
+  // UINT32_MAX if it's not needed.
+  uint32_t GetInterpolatorInputMask(reg::SQ_PROGRAM_CNTL sq_program_cntl,
+                                    reg::SQ_CONTEXT_MISC sq_context_misc,
+                                    uint32_t& param_gen_pos_out) const;
+
   // True if the shader overrides the pixel depth.
   bool writes_depth() const { return writes_depth_; }
 
@@ -1018,11 +1047,13 @@ class Shader {
   std::set<uint32_t> label_addresses_;
   uint32_t cf_pair_index_bound_ = 0;
   uint32_t register_static_address_bound_ = 0;
+  uint32_t writes_interpolators_ = 0;
+  uint32_t writes_point_size_edge_flag_kill_vertex_ = 0;
+  uint32_t writes_color_targets_ = 0b0000;
   bool uses_register_dynamic_addressing_ = false;
   bool kills_pixels_ = false;
   bool uses_texture_fetch_instruction_results_ = false;
   bool writes_depth_ = false;
-  uint32_t writes_color_targets_ = 0b0000;
 
   // Modification bits -> translation.
   std::unordered_map<uint64_t, Translation*> translations_;