shader_recompiler: support const buffer indirect addressing on OpenGL SPIR-V

src/shader_recompiler/backend/spirv/spirv_emit_context.cpp

@@ -1043,15 +1043,15 @@ void EmitContext::DefineConstantBufferIndirectFunctions(const Info& info) {
         const Id merge_label{OpLabel()};
         const Id uniform_type{uniform_types.*member_ptr};
 
-        std::array<Id, Info::MAX_CBUFS> buf_labels;
-        std::array<Sirit::Literal, Info::MAX_CBUFS> buf_literals;
-        for (u32 i = 0; i < Info::MAX_CBUFS; i++) {
+        std::array<Id, Info::MAX_INDIRECT_CBUFS> buf_labels;
+        std::array<Sirit::Literal, Info::MAX_INDIRECT_CBUFS> buf_literals;
+        for (u32 i = 0; i < Info::MAX_INDIRECT_CBUFS; i++) {
             buf_labels[i] = OpLabel();
             buf_literals[i] = Sirit::Literal{i};
         }
         OpSelectionMerge(merge_label, spv::SelectionControlMask::MaskNone);
         OpSwitch(binding, buf_labels[0], buf_literals, buf_labels);
-        for (u32 i = 0; i < Info::MAX_CBUFS; i++) {
+        for (u32 i = 0; i < Info::MAX_INDIRECT_CBUFS; i++) {
             AddLabel(buf_labels[i]);
             const Id cbuf{cbufs[i].*member_ptr};
             const Id access_chain{OpAccessChain(uniform_type, cbuf, u32_zero_value, offset)};
@@ -1064,22 +1064,23 @@ void EmitContext::DefineConstantBufferIndirectFunctions(const Info& info) {
         return func;
     }};
     IR::Type types{info.used_indirect_cbuf_types};
-    if (True(types & IR::Type::U8)) {
+    bool supports_aliasing = profile.support_descriptor_aliasing;
+    if (supports_aliasing && True(types & IR::Type::U8)) {
         load_const_func_u8 = make_accessor(U8, &UniformDefinitions::U8);
     }
-    if (True(types & IR::Type::U16)) {
+    if (supports_aliasing && True(types & IR::Type::U16)) {
         load_const_func_u16 = make_accessor(U16, &UniformDefinitions::U16);
     }
-    if (True(types & IR::Type::F32)) {
+    if (supports_aliasing && True(types & IR::Type::F32)) {
         load_const_func_f32 = make_accessor(F32[1], &UniformDefinitions::F32);
     }
-    if (True(types & IR::Type::U32)) {
+    if (supports_aliasing && True(types & IR::Type::U32)) {
         load_const_func_u32 = make_accessor(U32[1], &UniformDefinitions::U32);
     }
-    if (True(types & IR::Type::U32x2)) {
+    if (supports_aliasing && True(types & IR::Type::U32x2)) {
         load_const_func_u32x2 = make_accessor(U32[2], &UniformDefinitions::U32x2);
     }
-    if (True(types & IR::Type::U32x4)) {
+    if (!supports_aliasing || True(types & IR::Type::U32x4)) {
         load_const_func_u32x4 = make_accessor(U32[4], &UniformDefinitions::U32x4);
     }
 }

src/shader_recompiler/ir_opt/collect_shader_info_pass.cpp

@@ -32,13 +32,8 @@ void AddConstantBufferDescriptor(Info& info, u32 index, u32 count) {
 void AddRegisterIndexedLdc(Info& info) {
     info.uses_cbuf_indirect = true;
 
-    // The shader can use any possible constant buffer
-    info.constant_buffer_mask = (1 << Info::MAX_CBUFS) - 1;
-
-    auto& cbufs{info.constant_buffer_descriptors};
-    cbufs.clear();
-    for (u32 i = 0; i < Info::MAX_CBUFS; i++) {
-        cbufs.push_back(ConstantBufferDescriptor{.index = i, .count = 1});
+    for (u32 i = 0; i < Info::MAX_INDIRECT_CBUFS; i++) {
+        AddConstantBufferDescriptor(info, i, 1);
 
         // The shader can use any possible access size
         info.constant_buffer_used_sizes[i] = 0x10'000;

src/shader_recompiler/shader_info.h

@@ -105,6 +105,7 @@ struct ImageDescriptor {
 using ImageDescriptors = boost::container::small_vector<ImageDescriptor, 4>;
 
 struct Info {
+    static constexpr size_t MAX_INDIRECT_CBUFS{16};
     static constexpr size_t MAX_CBUFS{18};
     static constexpr size_t MAX_SSBOS{32};