| // |
| // Copyright 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: |
| ANGLE_NO_DISCARD static bool rewrite(TCompiler *compiler, TIntermBlock *root); |
| |
| private: |
| RewriteAssignToSwizzledTraverser(); |
| |
| bool visitBinary(Visit, TIntermBinary *node) override; |
| |
| void nextIteration(); |
| |
| bool didRewrite() { return mDidRewrite; } |
| |
| bool mDidRewrite; |
| }; |
| |
| // static |
| bool RewriteAssignToSwizzledTraverser::rewrite(TCompiler *compiler, TIntermBlock *root) |
| { |
| RewriteAssignToSwizzledTraverser rewrite; |
| do |
| { |
| rewrite.nextIteration(); |
| root->traverse(&rewrite); |
| if (!rewrite.updateTree(compiler, root)) |
| { |
| return false; |
| } |
| } while (rewrite.didRewrite()); |
| |
| return true; |
| } |
| |
| 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 |
| |
| bool RewriteRepeatedAssignToSwizzled(TCompiler *compiler, TIntermBlock *root) |
| { |
| return RewriteAssignToSwizzledTraverser::rewrite(compiler, root); |
| } |
| |
| } // namespace sh |