Improvement on loop unrolling with loops indexing sampler arrays
1) Before this workaround is hardwired on mac, now we move it behind a compil
2) Fix the issue where "break" inside the loop isn't handled while unrolled.
BUG=338474
TEST=webgl conformance test sampler-array-using-loop-index.html
Change-Id: I4996a42c2dea39a8a5af772c256f8e3cb383f59a
Reviewed-on: https://chromium-review.googlesource.com/188079
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Tested-by: Zhenyao Mo <zmo@chromium.org>
Conflicts:
include/GLSLANG/ShaderLang.h
src/compiler/translator/ValidateLimitations.cpp
Change-Id: I546197bd7df1634ebccdd380be14c3250cd56151
Reviewed-on: https://chromium-review.googlesource.com/189061
Reviewed-by: Shannon Woods <shannonwoods@chromium.org>
Tested-by: Zhenyao Mo <zmo@chromium.org>
diff --git a/src/compiler/translator/LoopInfo.cpp b/src/compiler/translator/LoopInfo.cpp
new file mode 100644
index 0000000..226f1b2
--- /dev/null
+++ b/src/compiler/translator/LoopInfo.cpp
@@ -0,0 +1,211 @@
+//
+// Copyright (c) 2002-2014 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/LoopInfo.h"
+
+namespace
+{
+
+int EvaluateIntConstant(TIntermConstantUnion *node)
+{
+ ASSERT(node && node->getUnionArrayPointer());
+ return node->getIConst(0);
+}
+
+int GetLoopIntIncrement(TIntermLoop *node)
+{
+ TIntermNode *expr = node->getExpression();
+ // for expression has one of the following forms:
+ // loop_index++
+ // loop_index--
+ // loop_index += constant_expression
+ // loop_index -= constant_expression
+ // ++loop_index
+ // --loop_index
+ // The last two forms are not specified in the spec, but I am assuming
+ // its an oversight.
+ TIntermUnary *unOp = expr->getAsUnaryNode();
+ TIntermBinary *binOp = unOp ? NULL : expr->getAsBinaryNode();
+
+ TOperator op = EOpNull;
+ TIntermConstantUnion *incrementNode = NULL;
+ if (unOp)
+ {
+ op = unOp->getOp();
+ }
+ else if (binOp)
+ {
+ op = binOp->getOp();
+ ASSERT(binOp->getRight());
+ incrementNode = binOp->getRight()->getAsConstantUnion();
+ ASSERT(incrementNode);
+ }
+
+ int increment = 0;
+ // The operator is one of: ++ -- += -=.
+ switch (op)
+ {
+ case EOpPostIncrement:
+ case EOpPreIncrement:
+ ASSERT(unOp && !binOp);
+ increment = 1;
+ break;
+ case EOpPostDecrement:
+ case EOpPreDecrement:
+ ASSERT(unOp && !binOp);
+ increment = -1;
+ break;
+ case EOpAddAssign:
+ ASSERT(!unOp && binOp);
+ increment = EvaluateIntConstant(incrementNode);
+ break;
+ case EOpSubAssign:
+ ASSERT(!unOp && binOp);
+ increment = - EvaluateIntConstant(incrementNode);
+ break;
+ default:
+ UNREACHABLE();
+ }
+
+ return increment;
+}
+
+} // namespace anonymous
+
+TLoopIndexInfo::TLoopIndexInfo()
+ : mId(-1),
+ mType(EbtVoid),
+ mInitValue(0),
+ mStopValue(0),
+ mIncrementValue(0),
+ mOp(EOpNull),
+ mCurrentValue(0)
+{
+}
+
+void TLoopIndexInfo::fillInfo(TIntermLoop *node)
+{
+ if (node == NULL)
+ return;
+
+ // Here we assume all the operations are valid, because the loop node is
+ // already validated in ValidateLimitations.
+ TIntermSequence &declSeq =
+ node->getInit()->getAsAggregate()->getSequence();
+ TIntermBinary *declInit = declSeq[0]->getAsBinaryNode();
+ TIntermSymbol *symbol = declInit->getLeft()->getAsSymbolNode();
+
+ mId = symbol->getId();
+ mType = symbol->getBasicType();
+
+ if (mType == EbtInt)
+ {
+ TIntermConstantUnion* initNode = declInit->getRight()->getAsConstantUnion();
+ mInitValue = EvaluateIntConstant(initNode);
+ mCurrentValue = mInitValue;
+ mIncrementValue = GetLoopIntIncrement(node);
+
+ TIntermBinary* binOp = node->getCondition()->getAsBinaryNode();
+ mStopValue = EvaluateIntConstant(
+ binOp->getRight()->getAsConstantUnion());
+ mOp = binOp->getOp();
+ }
+}
+
+bool TLoopIndexInfo::satisfiesLoopCondition() const
+{
+ // Relational operator is one of: > >= < <= == or !=.
+ switch (mOp)
+ {
+ case EOpEqual:
+ return (mCurrentValue == mStopValue);
+ case EOpNotEqual:
+ return (mCurrentValue != mStopValue);
+ case EOpLessThan:
+ return (mCurrentValue < mStopValue);
+ case EOpGreaterThan:
+ return (mCurrentValue > mStopValue);
+ case EOpLessThanEqual:
+ return (mCurrentValue <= mStopValue);
+ case EOpGreaterThanEqual:
+ return (mCurrentValue >= mStopValue);
+ default:
+ UNREACHABLE();
+ return false;
+ }
+}
+
+TLoopInfo::TLoopInfo()
+ : loop(NULL)
+{
+}
+
+TLoopInfo::TLoopInfo(TIntermLoop *node)
+ : loop(node)
+{
+ index.fillInfo(node);
+}
+
+TIntermLoop *TLoopStack::findLoop(TIntermSymbol *symbol)
+{
+ if (!symbol)
+ return NULL;
+ for (iterator iter = begin(); iter != end(); ++iter)
+ {
+ if (iter->index.getId() == symbol->getId())
+ return iter->loop;
+ }
+ return NULL;
+}
+
+TLoopIndexInfo *TLoopStack::getIndexInfo(TIntermSymbol *symbol)
+{
+ if (!symbol)
+ return NULL;
+ for (iterator iter = begin(); iter != end(); ++iter)
+ {
+ if (iter->index.getId() == symbol->getId())
+ return &(iter->index);
+ }
+ return NULL;
+}
+
+void TLoopStack::step()
+{
+ ASSERT(!empty());
+ rbegin()->index.step();
+}
+
+bool TLoopStack::satisfiesLoopCondition()
+{
+ ASSERT(!empty());
+ return rbegin()->index.satisfiesLoopCondition();
+}
+
+bool TLoopStack::needsToReplaceSymbolWithValue(TIntermSymbol *symbol)
+{
+ TIntermLoop *loop = findLoop(symbol);
+ return loop && loop->getUnrollFlag();
+}
+
+int TLoopStack::getLoopIndexValue(TIntermSymbol *symbol)
+{
+ TLoopIndexInfo *info = getIndexInfo(symbol);
+ ASSERT(info);
+ return info->getCurrentValue();
+}
+
+void TLoopStack::push(TIntermLoop *loop)
+{
+ TLoopInfo info(loop);
+ push_back(info);
+}
+
+void TLoopStack::pop()
+{
+ pop_back();
+}
+