shader/memory: Implement RED.E.ADD

Implements a reduction operation. It's an atomic operation that doesn't
return a value.

This commit introduces another primitive because some shading languages
might have a primitive for reduction operations.

src/video_core/engines/shader_bytecode.h

@@ -988,6 +988,12 @@ union Instruction {
         BitField<46, 2, u64> cache_mode;
     } stg;
 
+    union {
+        BitField<23, 3, AtomicOp> operation;
+        BitField<48, 1, u64> extended;
+        BitField<20, 3, GlobalAtomicType> type;
+    } red;
+
     union {
         BitField<52, 4, AtomicOp> operation;
         BitField<49, 3, GlobalAtomicType> type;
@@ -1733,6 +1739,7 @@ public:
         ST_S,
         ST,    // Store in generic memory
         STG,   // Store in global memory
+        RED,   // Reduction operation
         ATOM,  // Atomic operation on global memory
         ATOMS, // Atomic operation on shared memory
         AL2P,  // Transforms attribute memory into physical memory
@@ -2039,6 +2046,7 @@ private:
             INST("1110111101010---", Id::ST_L, Type::Memory, "ST_L"),
             INST("101-------------", Id::ST, Type::Memory, "ST"),
             INST("1110111011011---", Id::STG, Type::Memory, "STG"),
+            INST("1110101111111---", Id::RED, Type::Memory, "RED"),
             INST("11101101--------", Id::ATOM, Type::Memory, "ATOM"),
             INST("11101100--------", Id::ATOMS, Type::Memory, "ATOMS"),
             INST("1110111110100---", Id::AL2P, Type::Memory, "AL2P"),

src/video_core/renderer_opengl/gl_shader_decompiler.cpp

@@ -2119,8 +2119,14 @@ private:
             return {};
         }
         return {fmt::format("atomic{}({}, {})", opname, Visit(operation[0]).GetCode(),
-                            Visit(operation[1]).As(type)),
+                            Visit(operation[1]).AsUint()),
-                type};
+                Type::Uint};
+    }
+
+    template <const std::string_view& opname, Type type>
+    Expression Reduce(Operation operation) {
+        code.AddLine("{};", Atomic<opname, type>(operation).GetCode());
+        return {};
     }
 
     Expression Branch(Operation operation) {
@@ -2479,6 +2485,20 @@ private:
         &GLSLDecompiler::Atomic<Func::Or, Type::Int>,
         &GLSLDecompiler::Atomic<Func::Xor, Type::Int>,
 
+        &GLSLDecompiler::Reduce<Func::Add, Type::Uint>,
+        &GLSLDecompiler::Reduce<Func::Min, Type::Uint>,
+        &GLSLDecompiler::Reduce<Func::Max, Type::Uint>,
+        &GLSLDecompiler::Reduce<Func::And, Type::Uint>,
+        &GLSLDecompiler::Reduce<Func::Or, Type::Uint>,
+        &GLSLDecompiler::Reduce<Func::Xor, Type::Uint>,
+
+        &GLSLDecompiler::Reduce<Func::Add, Type::Int>,
+        &GLSLDecompiler::Reduce<Func::Min, Type::Int>,
+        &GLSLDecompiler::Reduce<Func::Max, Type::Int>,
+        &GLSLDecompiler::Reduce<Func::And, Type::Int>,
+        &GLSLDecompiler::Reduce<Func::Or, Type::Int>,
+        &GLSLDecompiler::Reduce<Func::Xor, Type::Int>,
+
         &GLSLDecompiler::Branch,
         &GLSLDecompiler::BranchIndirect,
         &GLSLDecompiler::PushFlowStack,

src/video_core/renderer_vulkan/vk_shader_decompiler.cpp

@@ -1941,11 +1941,8 @@ private:
         return {};
     }
 
-    template <Id (Module::*func)(Id, Id, Id, Id, Id), Type result_type,
+    template <Id (Module::*func)(Id, Id, Id, Id, Id)>
-              Type value_type = result_type>
     Expression Atomic(Operation operation) {
-        const Id type_def = GetTypeDefinition(result_type);
-
         Id pointer;
         if (const auto smem = std::get_if<SmemNode>(&*operation[0])) {
             pointer = GetSharedMemoryPointer(*smem);
@@ -1953,15 +1950,19 @@ private:
             pointer = GetGlobalMemoryPointer(*gmem);
         } else {
             UNREACHABLE();
-            return {Constant(type_def, 0), result_type};
+            return {v_float_zero, Type::Float};
         }
-
-        const Id value = As(Visit(operation[1]), value_type);
-
         const Id scope = Constant(t_uint, static_cast<u32>(spv::Scope::Device));
-        const Id semantics = Constant(type_def, 0);
+        const Id semantics = Constant(t_uint, 0);
+        const Id value = AsUint(Visit(operation[1]));
 
-        return {(this->*func)(type_def, pointer, scope, semantics, value), result_type};
+        return {(this->*func)(t_uint, pointer, scope, semantics, value), Type::Uint};
+    }
+
+    template <Id (Module::*func)(Id, Id, Id, Id, Id)>
+    Expression Reduce(Operation operation) {
+        Atomic<func>(operation);
+        return {};
     }
 
     Expression Branch(Operation operation) {
@@ -2550,21 +2551,35 @@ private:
         &SPIRVDecompiler::AtomicImageXor,
         &SPIRVDecompiler::AtomicImageExchange,
 
-        &SPIRVDecompiler::Atomic<&Module::OpAtomicExchange, Type::Uint>,
+        &SPIRVDecompiler::Atomic<&Module::OpAtomicExchange>,
-        &SPIRVDecompiler::Atomic<&Module::OpAtomicIAdd, Type::Uint>,
+        &SPIRVDecompiler::Atomic<&Module::OpAtomicIAdd>,
-        &SPIRVDecompiler::Atomic<&Module::OpAtomicUMin, Type::Uint>,
+        &SPIRVDecompiler::Atomic<&Module::OpAtomicUMin>,
-        &SPIRVDecompiler::Atomic<&Module::OpAtomicUMax, Type::Uint>,
+        &SPIRVDecompiler::Atomic<&Module::OpAtomicUMax>,
-        &SPIRVDecompiler::Atomic<&Module::OpAtomicAnd, Type::Uint>,
+        &SPIRVDecompiler::Atomic<&Module::OpAtomicAnd>,
-        &SPIRVDecompiler::Atomic<&Module::OpAtomicOr, Type::Uint>,
+        &SPIRVDecompiler::Atomic<&Module::OpAtomicOr>,
-        &SPIRVDecompiler::Atomic<&Module::OpAtomicXor, Type::Uint>,
+        &SPIRVDecompiler::Atomic<&Module::OpAtomicXor>,
 
-        &SPIRVDecompiler::Atomic<&Module::OpAtomicExchange, Type::Int>,
+        &SPIRVDecompiler::Atomic<&Module::OpAtomicExchange>,
-        &SPIRVDecompiler::Atomic<&Module::OpAtomicIAdd, Type::Int>,
+        &SPIRVDecompiler::Atomic<&Module::OpAtomicIAdd>,
-        &SPIRVDecompiler::Atomic<&Module::OpAtomicSMin, Type::Int>,
+        &SPIRVDecompiler::Atomic<&Module::OpAtomicSMin>,
-        &SPIRVDecompiler::Atomic<&Module::OpAtomicSMax, Type::Int>,
+        &SPIRVDecompiler::Atomic<&Module::OpAtomicSMax>,
-        &SPIRVDecompiler::Atomic<&Module::OpAtomicAnd, Type::Int>,
+        &SPIRVDecompiler::Atomic<&Module::OpAtomicAnd>,
-        &SPIRVDecompiler::Atomic<&Module::OpAtomicOr, Type::Int>,
+        &SPIRVDecompiler::Atomic<&Module::OpAtomicOr>,
-        &SPIRVDecompiler::Atomic<&Module::OpAtomicXor, Type::Int>,
+        &SPIRVDecompiler::Atomic<&Module::OpAtomicXor>,
+
+        &SPIRVDecompiler::Reduce<&Module::OpAtomicIAdd>,
+        &SPIRVDecompiler::Reduce<&Module::OpAtomicUMin>,
+        &SPIRVDecompiler::Reduce<&Module::OpAtomicUMax>,
+        &SPIRVDecompiler::Reduce<&Module::OpAtomicAnd>,
+        &SPIRVDecompiler::Reduce<&Module::OpAtomicOr>,
+        &SPIRVDecompiler::Reduce<&Module::OpAtomicXor>,
+
+        &SPIRVDecompiler::Reduce<&Module::OpAtomicIAdd>,
+        &SPIRVDecompiler::Reduce<&Module::OpAtomicSMin>,
+        &SPIRVDecompiler::Reduce<&Module::OpAtomicSMax>,
+        &SPIRVDecompiler::Reduce<&Module::OpAtomicAnd>,
+        &SPIRVDecompiler::Reduce<&Module::OpAtomicOr>,
+        &SPIRVDecompiler::Reduce<&Module::OpAtomicXor>,
 
         &SPIRVDecompiler::Branch,
         &SPIRVDecompiler::BranchIndirect,

src/video_core/shader/decode/memory.cpp

@@ -378,13 +378,27 @@ u32 ShaderIR::DecodeMemory(NodeBlock& bb, u32 pc) {
 
             if (IsUnaligned(type)) {
                 const u32 mask = GetUnalignedMask(type);
-                value = InsertUnaligned(gmem, std::move(value), real_address, mask, size);
+                value = InsertUnaligned(gmem, move(value), real_address, mask, size);
             }
 
             bb.push_back(Operation(OperationCode::Assign, gmem, value));
         }
         break;
     }
+    case OpCode::Id::RED: {
+        UNIMPLEMENTED_IF_MSG(instr.red.type != GlobalAtomicType::U32);
+        UNIMPLEMENTED_IF_MSG(instr.red.operation != AtomicOp::Add);
+        const auto [real_address, base_address, descriptor] =
+            TrackGlobalMemory(bb, instr, true, true);
+        if (!real_address || !base_address) {
+            // Tracking failed, skip atomic.
+            break;
+        }
+        Node gmem = MakeNode<GmemNode>(real_address, base_address, descriptor);
+        Node value = GetRegister(instr.gpr0);
+        bb.push_back(Operation(OperationCode::ReduceIAdd, move(gmem), move(value)));
+        break;
+    }
     case OpCode::Id::ATOM: {
         UNIMPLEMENTED_IF_MSG(instr.atom.operation == AtomicOp::Inc ||
                                  instr.atom.operation == AtomicOp::Dec ||

src/video_core/shader/node.h

@@ -178,6 +178,20 @@ enum class OperationCode {
     AtomicIOr,       /// (memory, int) -> int
     AtomicIXor,      /// (memory, int) -> int
 
+    ReduceUAdd, /// (memory, uint) -> void
+    ReduceUMin, /// (memory, uint) -> void
+    ReduceUMax, /// (memory, uint) -> void
+    ReduceUAnd, /// (memory, uint) -> void
+    ReduceUOr,  /// (memory, uint) -> void
+    ReduceUXor, /// (memory, uint) -> void
+
+    ReduceIAdd, /// (memory, int) -> void
+    ReduceIMin, /// (memory, int) -> void
+    ReduceIMax, /// (memory, int) -> void
+    ReduceIAnd, /// (memory, int) -> void
+    ReduceIOr,  /// (memory, int) -> void
+    ReduceIXor, /// (memory, int) -> void
+
     Branch,         /// (uint branch_target) -> void
     BranchIndirect, /// (uint branch_target) -> void
     PushFlowStack,  /// (uint branch_target) -> void