1 files changed, 82 insertions, 0 deletions
diff --git a/gfx/angle/checkout/src/compiler/translator/tree_ops/d3d/AggregateAssignArraysInSSBOs.cpp b/gfx/angle/checkout/src/compiler/translator/tree_ops/d3d/AggregateAssignArraysInSSBOs.cpp
new file mode 100644
index 0000000000..d9a0c9bebc
--- /dev/null
+++ b/gfx/angle/checkout/src/compiler/translator/tree_ops/d3d/AggregateAssignArraysInSSBOs.cpp
@@ -0,0 +1,82 @@
+//
+// Copyright 2022 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+
+#include "compiler/translator/tree_ops/d3d/AggregateAssignArraysInSSBOs.h"
+
+#include "compiler/translator/StaticType.h"
+#include "compiler/translator/Symbol.h"
+#include "compiler/translator/tree_util/IntermNode_util.h"
+#include "compiler/translator/tree_util/IntermTraverse.h"
+#include "compiler/translator/util.h"
+
+namespace sh
+{
+
+namespace
+{
+
+class AggregateAssignArraysInSSBOsTraverser : public TIntermTraverser
+{
+  public:
+    AggregateAssignArraysInSSBOsTraverser(TSymbolTable *symbolTable)
+        : TIntermTraverser(true, false, false, symbolTable)
+    {}
+
+  protected:
+    bool visitBinary(Visit visit, TIntermBinary *node) override
+    {
+        // Replace all aggregate assignments to arrays in SSBOs with element-by-element assignments.
+        // TODO(anglebug.com/7363): this implementation only works for the simple case (assignment
+        // statement), not more complex cases such as assignment-as-expression or functions with
+        // side effects in the RHS.
+
+        if (node->getOp() != EOpAssign)
+        {
+            return true;
+        }
+        else if (!node->getLeft()->getType().isArray())
+        {
+            return true;
+        }
+        else if (!IsInShaderStorageBlock(node->getLeft()))
+        {
+            return true;
+        }
+        const TType *mediumpIndexType = StaticType::Get<EbtInt, EbpMedium, EvqTemporary, 1, 1>();
+        auto *indexVariable           = CreateTempVariable(mSymbolTable, mediumpIndexType);
+        auto *indexInit =
+            CreateTempInitDeclarationNode(indexVariable, CreateZeroNode(indexVariable->getType()));
+        auto *arraySizeNode   = CreateIndexNode(node->getOutermostArraySize());
+        auto *indexSymbolNode = CreateTempSymbolNode(indexVariable);
+        auto *cond = new TIntermBinary(EOpLessThan, indexSymbolNode->deepCopy(), arraySizeNode);
+        auto *indexIncrement =
+            new TIntermUnary(EOpPreIncrement, indexSymbolNode->deepCopy(), nullptr);
+        auto *forLoopBody = new TIntermBlock();
+        auto *indexedLeft =
+            new TIntermBinary(EOpIndexDirect, node->getLeft(), indexSymbolNode->deepCopy());
+        auto *indexedRight =
+            new TIntermBinary(EOpIndexDirect, node->getRight(), indexSymbolNode->deepCopy());
+        auto *assign = new TIntermBinary(TOperator::EOpAssign, indexedLeft, indexedRight);
+        forLoopBody->appendStatement(assign);
+        auto *forLoop =
+            new TIntermLoop(ELoopFor, indexInit, cond, indexIncrement, EnsureBlock(forLoopBody));
+        queueReplacement(forLoop, OriginalNode::IS_DROPPED);
+        return false;
+    }
+};
+
+}  // namespace
+
+bool AggregateAssignArraysInSSBOs(TCompiler *compiler,
+                                  TIntermBlock *root,
+                                  TSymbolTable *symbolTable)
+{
+    AggregateAssignArraysInSSBOsTraverser traverser(symbolTable);
+    root->traverse(&traverser);
+    return traverser.updateTree(compiler, root);
+}
+
+}  // namespace sh