Rewrite repeated assignments to swizzled vectors on NVIDIA
This works around the most common instances of a bug that reproduces
on some NVIDIA OpenGL drivers prior to version 397.31.
BUG=chromium:798117
TEST=angle_end2end_tests
Change-Id: Iafc6a9a64e56fa98b42117149fe6867040e932e5
Reviewed-on: https://chromium-review.googlesource.com/1042190
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
diff --git a/src/compiler/translator/Compiler.cpp b/src/compiler/translator/Compiler.cpp
index 0025b5c..74eb7bb 100644
--- a/src/compiler/translator/Compiler.cpp
+++ b/src/compiler/translator/Compiler.cpp
@@ -38,6 +38,7 @@
#include "compiler/translator/tree_ops/RemovePow.h"
#include "compiler/translator/tree_ops/RemoveUnreferencedVariables.h"
#include "compiler/translator/tree_ops/RewriteDoWhile.h"
+#include "compiler/translator/tree_ops/RewriteRepeatedAssignToSwizzled.h"
#include "compiler/translator/tree_ops/ScalarizeVecAndMatConstructorArgs.h"
#include "compiler/translator/tree_ops/SeparateDeclarations.h"
#include "compiler/translator/tree_ops/SimplifyLoopConditions.h"
@@ -737,6 +738,11 @@
ClampFragDepth(root, &getSymbolTable());
}
+ if (compileOptions & SH_REWRITE_REPEATED_ASSIGN_TO_SWIZZLED)
+ {
+ sh::RewriteRepeatedAssignToSwizzled(root);
+ }
+
if (compileOptions & SH_REWRITE_VECTOR_SCALAR_ARITHMETIC)
{
VectorizeVectorScalarArithmetic(root, &getSymbolTable());
diff --git a/src/compiler/translator/tree_ops/RewriteRepeatedAssignToSwizzled.cpp b/src/compiler/translator/tree_ops/RewriteRepeatedAssignToSwizzled.cpp
new file mode 100644
index 0000000..50c5149
--- /dev/null
+++ b/src/compiler/translator/tree_ops/RewriteRepeatedAssignToSwizzled.cpp
@@ -0,0 +1,93 @@
+//
+// Copyright (c) 2018 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.
+//
+// RewriteRepeatedAssignToSwizzled.cpp: Rewrite expressions that assign an assignment to a swizzled
+// vector, like:
+// v.x = z = expression;
+// to:
+// z = expression;
+// v.x = z;
+//
+// Note that this doesn't handle some corner cases: expressions nested inside other expressions,
+// inside loop headers, or inside if conditions.
+
+#include "compiler/translator/tree_ops/RewriteRepeatedAssignToSwizzled.h"
+
+#include "compiler/translator/tree_util/IntermNode_util.h"
+#include "compiler/translator/tree_util/IntermTraverse.h"
+
+namespace sh
+{
+
+namespace
+{
+
+class RewriteAssignToSwizzledTraverser : public TIntermTraverser
+{
+ public:
+ static void rewrite(TIntermBlock *root);
+
+ private:
+ RewriteAssignToSwizzledTraverser();
+
+ bool visitBinary(Visit, TIntermBinary *node) override;
+
+ void nextIteration();
+
+ bool didRewrite() { return mDidRewrite; }
+
+ bool mDidRewrite;
+};
+
+// static
+void RewriteAssignToSwizzledTraverser::rewrite(TIntermBlock *root)
+{
+ RewriteAssignToSwizzledTraverser rewrite;
+ do
+ {
+ rewrite.nextIteration();
+ root->traverse(&rewrite);
+ rewrite.updateTree();
+ } while (rewrite.didRewrite());
+}
+
+RewriteAssignToSwizzledTraverser::RewriteAssignToSwizzledTraverser()
+ : TIntermTraverser(true, false, false), mDidRewrite(false)
+{
+}
+
+void RewriteAssignToSwizzledTraverser::nextIteration()
+{
+ mDidRewrite = false;
+}
+
+bool RewriteAssignToSwizzledTraverser::visitBinary(Visit, TIntermBinary *node)
+{
+ TIntermBinary *rightBinary = node->getRight()->getAsBinaryNode();
+ TIntermBlock *parentBlock = getParentNode()->getAsBlock();
+ if (parentBlock && node->isAssignment() && node->getLeft()->getAsSwizzleNode() && rightBinary &&
+ rightBinary->isAssignment())
+ {
+ TIntermSequence replacements;
+ replacements.push_back(rightBinary);
+ TIntermTyped *rightAssignmentTargetCopy = rightBinary->getLeft()->deepCopy();
+ TIntermBinary *lastAssign =
+ new TIntermBinary(EOpAssign, node->getLeft(), rightAssignmentTargetCopy);
+ replacements.push_back(lastAssign);
+ mMultiReplacements.push_back(NodeReplaceWithMultipleEntry(parentBlock, node, replacements));
+ mDidRewrite = true;
+ return false;
+ }
+ return true;
+}
+
+} // anonymous namespace
+
+void RewriteRepeatedAssignToSwizzled(TIntermBlock *root)
+{
+ RewriteAssignToSwizzledTraverser::rewrite(root);
+}
+
+} // namespace sh
diff --git a/src/compiler/translator/tree_ops/RewriteRepeatedAssignToSwizzled.h b/src/compiler/translator/tree_ops/RewriteRepeatedAssignToSwizzled.h
new file mode 100644
index 0000000..2f2d3b9
--- /dev/null
+++ b/src/compiler/translator/tree_ops/RewriteRepeatedAssignToSwizzled.h
@@ -0,0 +1,28 @@
+//
+// Copyright (c) 2018 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.
+//
+// RewriteRepeatedAssignToSwizzled.h: Rewrite expressions that assign an assignment to a swizzled
+// vector, like:
+// v.x = z = expression;
+// to:
+// z = expression;
+// v.x = z;
+//
+// Note that this doesn't handle some corner cases: expressions nested inside other expressions,
+// inside loop headers, or inside if conditions.
+
+#ifndef COMPILER_TRANSLATOR_TREEOPS_REWRITEREPEATEDASSIGNTOSWIZZLED_H_
+#define COMPILER_TRANSLATOR_TREEOPS_REWRITEREPEATEDASSIGNTOSWIZZLED_H_
+
+namespace sh
+{
+
+class TIntermBlock;
+
+void RewriteRepeatedAssignToSwizzled(TIntermBlock *root);
+
+} // namespace sh
+
+#endif // COMPILER_TRANSLATOR_TREEOPS_REWRITEREPEATEDASSIGNTOSWIZZLED_H_