commit 1d1227890d26c9092320e0fb6d5c473177ad68c5
author Olli Etuaho <oetuaho@nvidia.com> Fri Nov 06 15:35:17 2015 +0200
committer Olli Etuaho <oetuaho@nvidia.com> Thu Nov 12 09:52:24 2015 +0000
tree 03c26195572da680fb763f4a64e0dcdb6249bc27
parent 7c3848e58bc1dcbd24585f13f98d7c2864a6bfc8

Fix constructor constant folding

The previous solution for constant folding constructors was significantly
overengineered and partially incorrect. Switch to a much simpler
constructor folding function that does not use an AST traverser, but
simply iterates over the constant folded parameters of the constructor
and doesn't do any unnecessary checks. It also reuses some code for
constant folding other built-in functions.

This fixes issues with initializing constant matrices with only a single
parameter. Instead of copying the first component of the constructor
parameter all over the matrix, passing a vec4 or matrix argument now
assigns the values correctly.

BUG=angleproject:1193
TEST=angle_unittests, WebGL conformance tests

Change-Id: I50b10721ea30cb15843fba892c1b1a211f1d72e5
Reviewed-on: https://chromium-review.googlesource.com/311191
Tryjob-Request: Olli Etuaho <oetuaho@nvidia.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Tested-by: Olli Etuaho <oetuaho@nvidia.com>

src/compiler/translator/ParseContext.cpp

diff --git a/src/compiler/translator/ParseContext.cpp b/src/compiler/translator/ParseContext.cpp
index fff2b8e..d537bcb 100644
--- a/src/compiler/translator/ParseContext.cpp
+++ b/src/compiler/translator/ParseContext.cpp
@@ -1369,17 +1369,6 @@
     return false;
 }
 
-bool TParseContext::areAllChildrenConstantFolded(TIntermAggregate *aggrNode)
-{
-    ASSERT(aggrNode != nullptr);
-    for (TIntermNode *&node : *aggrNode->getSequence())
-    {
-        if (node->getAsConstantUnion() == nullptr)
-            return false;
-    }
-    return true;
-}
-
 TPublicType TParseContext::addFullySpecifiedType(TQualifier qualifier,
                                                  bool invariant,
                                                  TLayoutQualifier layoutQualifier,
@@ -2318,7 +2307,7 @@
         type->setPrecision(constructor->getPrecision());
     }
 
-    TIntermTyped *constConstructor = foldConstConstructor(constructor, *type);
+    TIntermTyped *constConstructor = intermediate.foldAggregateBuiltIn(constructor);
     if (constConstructor)
     {
         return constConstructor;
@@ -2327,33 +2316,6 @@
     return constructor;
 }
 
-TIntermTyped *TParseContext::foldConstConstructor(TIntermAggregate *aggrNode, const TType &type)
-{
-    // TODO: Add support for folding array constructors
-    bool canBeFolded = areAllChildrenConstantFolded(aggrNode) && !type.isArray();
-    if (canBeFolded)
-    {
-        bool returnVal             = false;
-        TConstantUnion *unionArray = new TConstantUnion[type.getObjectSize()];
-        if (aggrNode->getSequence()->size() == 1)
-        {
-            returnVal = intermediate.parseConstTree(aggrNode->getLine(), aggrNode, unionArray,
-                                                    aggrNode->getOp(), type, true);
-        }
-        else
-        {
-            returnVal = intermediate.parseConstTree(aggrNode->getLine(), aggrNode, unionArray,
-                                                    aggrNode->getOp(), type);
-        }
-        if (returnVal)
-            return 0;
-
-        return intermediate.addConstantUnion(unionArray, type, aggrNode->getLine());
-    }
-
-    return 0;
-}
-
 //
 // This function returns the tree representation for the vector field(s) being accessed from contant
 // vector.