commit 550c600b99d7ee2463e5878d0a9f66ea24c1414a
author Zhenyao Mo <zmo@chromium.org> Wed Feb 26 15:40:48 2014 -0800
committer Zhenyao Mo <zmo@chromium.org> Fri Mar 07 18:59:18 2014 +0000
tree 797b816d4e50f9acf894793efe93eff2e8f02d73
parent 2515c5201ba79f803d6f813de006840728922476

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>

src/compiler/translator/OutputGLSLBase.cpp

diff --git a/src/compiler/translator/OutputGLSLBase.cpp b/src/compiler/translator/OutputGLSLBase.cpp
index e51bd12..816850e 100644
--- a/src/compiler/translator/OutputGLSLBase.cpp
+++ b/src/compiler/translator/OutputGLSLBase.cpp
@@ -161,8 +161,8 @@
 void TOutputGLSLBase::visitSymbol(TIntermSymbol* node)
 {
     TInfoSinkBase& out = objSink();
-    if (mLoopUnroll.NeedsToReplaceSymbolWithValue(node))
-        out << mLoopUnroll.GetLoopIndexValue(node);
+    if (mLoopUnrollStack.needsToReplaceSymbolWithValue(node))
+        out << mLoopUnrollStack.getLoopIndexValue(node);
     else
         out << hashVariableName(node->getSymbol());
 
@@ -645,7 +645,8 @@
     TLoopType loopType = node->getType();
     if (loopType == ELoopFor)  // for loop
     {
-        if (!node->getUnrollFlag()) {
+        if (!node->getUnrollFlag())
+        {
             out << "for (";
             if (node->getInit())
                 node->getInit()->traverse(this);
@@ -659,6 +660,18 @@
                 node->getExpression()->traverse(this);
             out << ")\n";
         }
+        else
+        {
+            // Need to put a one-iteration loop here to handle break.
+            TIntermSequence &declSeq =
+                node->getInit()->getAsAggregate()->getSequence();
+            TIntermSymbol *indexSymbol =
+                declSeq[0]->getAsBinaryNode()->getLeft()->getAsSymbolNode();
+            TString name = hashVariableName(indexSymbol->getSymbol());
+            out << "for (int " << name << " = 0; "
+                << name << " < 1; "
+                << "++" << name << ")\n";
+        }
     }
     else if (loopType == ELoopWhile)  // while loop
     {
@@ -676,15 +689,15 @@
     // Loop body.
     if (node->getUnrollFlag())
     {
-        TLoopIndexInfo indexInfo;
-        mLoopUnroll.FillLoopIndexInfo(node, indexInfo);
-        mLoopUnroll.Push(indexInfo);
-        while (mLoopUnroll.SatisfiesLoopCondition())
+        out << "{\n";
+        mLoopUnrollStack.push(node);
+        while (mLoopUnrollStack.satisfiesLoopCondition())
         {
             visitCodeBlock(node->getBody());
-            mLoopUnroll.Step();
+            mLoopUnrollStack.step();
         }
-        mLoopUnroll.Pop();
+        mLoopUnrollStack.pop();
+        out << "}\n";
     }
     else
     {