shader/memory: Implement ATOM.ADD

ATOM operates atomically on global memory. For now only add ATOM.ADD
since that's what was found in commercial games.

This asserts for ATOM.ADD.S32 (handling the others as unimplemented),
although ATOM.ADD.U32 shouldn't be any different.

This change forces us to change the default type on SPIR-V storage
buffers from float to uint. We could also alias the buffers, but it's
simpler for now to just use uint. While we are at it, abstract the code
to avoid repetition.

1 files changed, 33 insertions, 33 deletions

diff --git a/src/video_core/renderer_vulkan/vk_shader_decompiler.cpp b/src/video_core/renderer_vulkan/vk_shader_decompiler.cpp
index b53078721..1ab22251e 100644
--- a/src/video_core/renderer_vulkan/vk_shader_decompiler.cpp
+++ b/src/video_core/renderer_vulkan/vk_shader_decompiler.cpp
@@ -1123,15 +1123,7 @@ private:
         }
 
         if (const auto gmem = std::get_if<GmemNode>(&*node)) {
-            const Id gmem_buffer = global_buffers.at(gmem->GetDescriptor());
-            const Id real = AsUint(Visit(gmem->GetRealAddress()));
-            const Id base = AsUint(Visit(gmem->GetBaseAddress()));
-
-            Id offset = OpISub(t_uint, real, base);
-            offset = OpUDiv(t_uint, offset, Constant(t_uint, 4U));
-            return {OpLoad(t_float,
-                           OpAccessChain(t_gmem_float, gmem_buffer, Constant(t_uint, 0U), offset)),
-                    Type::Float};
+            return {OpLoad(t_uint, GetGlobalMemoryPointer(*gmem)), Type::Uint};
         }
 
         if (const auto lmem = std::get_if<LmemNode>(&*node)) {
@@ -1142,10 +1134,7 @@ private:
         }
 
         if (const auto smem = std::get_if<SmemNode>(&*node)) {
-            Id address = AsUint(Visit(smem->GetAddress()));
-            address = OpShiftRightLogical(t_uint, address, Constant(t_uint, 2U));
-            const Id pointer = OpAccessChain(t_smem_uint, shared_memory, address);
-            return {OpLoad(t_uint, pointer), Type::Uint};
+            return {OpLoad(t_uint, GetSharedMemoryPointer(*smem)), Type::Uint};
         }
 
         if (const auto internal_flag = std::get_if<InternalFlagNode>(&*node)) {
@@ -1339,20 +1328,10 @@ private:
             target = {OpAccessChain(t_prv_float, local_memory, address), Type::Float};
 
         } else if (const auto smem = std::get_if<SmemNode>(&*dest)) {
-            ASSERT(stage == ShaderType::Compute);
-            Id address = AsUint(Visit(smem->GetAddress()));
-            address = OpShiftRightLogical(t_uint, address, Constant(t_uint, 2U));
-            target = {OpAccessChain(t_smem_uint, shared_memory, address), Type::Uint};
+            target = {GetSharedMemoryPointer(*smem), Type::Uint};
 
         } else if (const auto gmem = std::get_if<GmemNode>(&*dest)) {
-            const Id real = AsUint(Visit(gmem->GetRealAddress()));
-            const Id base = AsUint(Visit(gmem->GetBaseAddress()));
-            const Id diff = OpISub(t_uint, real, base);
-            const Id offset = OpShiftRightLogical(t_uint, diff, Constant(t_uint, 2));
-
-            const Id gmem_buffer = global_buffers.at(gmem->GetDescriptor());
-            target = {OpAccessChain(t_gmem_float, gmem_buffer, Constant(t_uint, 0), offset),
-                      Type::Float};
+            target = {GetGlobalMemoryPointer(*gmem), Type::Uint};
 
         } else {
             UNIMPLEMENTED();
@@ -1804,11 +1783,16 @@ private:
         return {};
     }
 
-    Expression UAtomicAdd(Operation operation) {
-        const auto& smem = std::get<SmemNode>(*operation[0]);
-        Id address = AsUint(Visit(smem.GetAddress()));
-        address = OpShiftRightLogical(t_uint, address, Constant(t_uint, 2U));
-        const Id pointer = OpAccessChain(t_smem_uint, shared_memory, address);
+    Expression AtomicAdd(Operation operation) {
+        Id pointer;
+        if (const auto smem = std::get_if<SmemNode>(&*operation[0])) {
+            pointer = GetSharedMemoryPointer(*smem);
+        } else if (const auto gmem = std::get_if<GmemNode>(&*operation[0])) {
+            pointer = GetGlobalMemoryPointer(*gmem);
+        } else {
+            UNREACHABLE();
+            return {Constant(t_uint, 0), Type::Uint};
+        }
 
         const Id scope = Constant(t_uint, static_cast<u32>(spv::Scope::Device));
         const Id semantics = Constant(t_uint, 0U);
@@ -2243,6 +2227,22 @@ private:
         return {};
     }
 
+    Id GetGlobalMemoryPointer(const GmemNode& gmem) {
+        const Id real = AsUint(Visit(gmem.GetRealAddress()));
+        const Id base = AsUint(Visit(gmem.GetBaseAddress()));
+        const Id diff = OpISub(t_uint, real, base);
+        const Id offset = OpShiftRightLogical(t_uint, diff, Constant(t_uint, 2));
+        const Id buffer = global_buffers.at(gmem.GetDescriptor());
+        return OpAccessChain(t_gmem_uint, buffer, Constant(t_uint, 0), offset);
+    }
+
+    Id GetSharedMemoryPointer(const SmemNode& smem) {
+        ASSERT(stage == ShaderType::Compute);
+        Id address = AsUint(Visit(smem.GetAddress()));
+        address = OpShiftRightLogical(t_uint, address, Constant(t_uint, 2U));
+        return OpAccessChain(t_smem_uint, shared_memory, address);
+    }
+
     static constexpr std::array operation_decompilers = {
         &SPIRVDecompiler::Assign,
 
@@ -2389,7 +2389,7 @@ private:
         &SPIRVDecompiler::AtomicImageXor,
         &SPIRVDecompiler::AtomicImageExchange,
 
-        &SPIRVDecompiler::UAtomicAdd,
+        &SPIRVDecompiler::AtomicAdd,
 
         &SPIRVDecompiler::Branch,
         &SPIRVDecompiler::BranchIndirect,
@@ -2485,9 +2485,9 @@ private:
 
     Id t_smem_uint{};
 
-    const Id t_gmem_float = TypePointer(spv::StorageClass::StorageBuffer, t_float);
+    const Id t_gmem_uint = TypePointer(spv::StorageClass::StorageBuffer, t_uint);
     const Id t_gmem_array =
-        Name(Decorate(TypeRuntimeArray(t_float), spv::Decoration::ArrayStride, 4U), "GmemArray");
+        Name(Decorate(TypeRuntimeArray(t_uint), spv::Decoration::ArrayStride, 4U), "GmemArray");
     const Id t_gmem_struct = MemberDecorate(
         Decorate(TypeStruct(t_gmem_array), spv::Decoration::Block), 0, spv::Decoration::Offset, 0);
     const Id t_gmem_ssbo = TypePointer(spv::StorageClass::StorageBuffer, t_gmem_struct);