Merge pull request #8024 from liamwhite/const-indexing

Add shader support for const buffer indirect addressing

1 files changed, 58 insertions, 1 deletions

diff --git a/src/shader_recompiler/backend/spirv/spirv_emit_context.cpp b/src/shader_recompiler/backend/spirv/spirv_emit_context.cpp
index cd90c084a..aa5b6c9b7 100644
--- a/src/shader_recompiler/backend/spirv/spirv_emit_context.cpp
+++ b/src/shader_recompiler/backend/spirv/spirv_emit_context.cpp
@@ -464,6 +464,7 @@ EmitContext::EmitContext(const Profile& profile_, const RuntimeInfo& runtime_inf
     DefineSharedMemory(program);
     DefineSharedMemoryFunctions(program);
     DefineConstantBuffers(program.info, uniform_binding);
+    DefineConstantBufferIndirectFunctions(program.info);
     DefineStorageBuffers(program.info, storage_binding);
     DefineTextureBuffers(program.info, texture_binding);
     DefineImageBuffers(program.info, image_binding);
@@ -993,7 +994,7 @@ void EmitContext::DefineConstantBuffers(const Info& info, u32& binding) {
         }
         return;
     }
-    IR::Type types{info.used_constant_buffer_types};
+    IR::Type types{info.used_constant_buffer_types | info.used_indirect_cbuf_types};
     if (True(types & IR::Type::U8)) {
         if (profile.support_int8) {
             DefineConstBuffers(*this, info, &UniformDefinitions::U8, binding, U8, 'u', sizeof(u8));
@@ -1027,6 +1028,62 @@ void EmitContext::DefineConstantBuffers(const Info& info, u32& binding) {
     binding += static_cast<u32>(info.constant_buffer_descriptors.size());
 }
 
+void EmitContext::DefineConstantBufferIndirectFunctions(const Info& info) {
+    if (!info.uses_cbuf_indirect) {
+        return;
+    }
+    const auto make_accessor{[&](Id buffer_type, Id UniformDefinitions::*member_ptr) {
+        const Id func_type{TypeFunction(buffer_type, U32[1], U32[1])};
+        const Id func{OpFunction(buffer_type, spv::FunctionControlMask::MaskNone, func_type)};
+        const Id binding{OpFunctionParameter(U32[1])};
+        const Id offset{OpFunctionParameter(U32[1])};
+
+        AddLabel();
+
+        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++) {
+            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++) {
+            AddLabel(buf_labels[i]);
+            const Id cbuf{cbufs[i].*member_ptr};
+            const Id access_chain{OpAccessChain(uniform_type, cbuf, u32_zero_value, offset)};
+            const Id result{OpLoad(buffer_type, access_chain)};
+            OpReturnValue(result);
+        }
+        AddLabel(merge_label);
+        OpUnreachable();
+        OpFunctionEnd();
+        return func;
+    }};
+    IR::Type types{info.used_indirect_cbuf_types};
+    if (True(types & IR::Type::U8)) {
+        load_const_func_u8 = make_accessor(U8, &UniformDefinitions::U8);
+    }
+    if (True(types & IR::Type::U16)) {
+        load_const_func_u16 = make_accessor(U16, &UniformDefinitions::U16);
+    }
+    if (True(types & IR::Type::F32)) {
+        load_const_func_f32 = make_accessor(F32[1], &UniformDefinitions::F32);
+    }
+    if (True(types & IR::Type::U32)) {
+        load_const_func_u32 = make_accessor(U32[1], &UniformDefinitions::U32);
+    }
+    if (True(types & IR::Type::U32x2)) {
+        load_const_func_u32x2 = make_accessor(U32[2], &UniformDefinitions::U32x2);
+    }
+    if (True(types & IR::Type::U32x4)) {
+        load_const_func_u32x4 = make_accessor(U32[4], &UniformDefinitions::U32x4);
+    }
+}
+
 void EmitContext::DefineStorageBuffers(const Info& info, u32& binding) {
     if (info.storage_buffers_descriptors.empty()) {
         return;