commit 274f07091e0be543cc00a5b2a6848e714aa5c7f8
author Arun Patole <apatole@nvidia.com> Tue May 05 13:33:30 2015 +0530
committer Olli Etuaho <oetuaho@nvidia.com> Mon May 18 09:04:47 2015 +0000
tree 39bb568419a2ed05bdd7b5a22777f72a1f6cc0ff
parent 8befcff50d9d3c3f8b1295eb420e9cd4beeae2f4

Add constant folding support for min,max and clamp

This change adds necessary mechanism to support constant folding of
built-ins that take more than one parameter and also adds constant
folding support for min, max and clamp built-ins.

BUG=angleproject:913
TESTS=dEQP tests
(126 tests started passing with this change)
dEQP-GLES3.functional.shaders.constant_expressions.builtin_functions.common.min_*
dEQP-GLES3.functional.shaders.constant_expressions.builtin_functions.common.max_*
dEQP-GLES3.functional.shaders.constant_expressions.builtin_functions.common.clamp_*

Change-Id: Iccc9bf503a536f2e3c144627e64572f2f95db9db
Reviewed-on: https://chromium-review.googlesource.com/271251
Reviewed-by: Olli Etuaho <oetuaho@nvidia.com>
Reviewed-by: Jamie Madill <jmadill@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 a9e9516..ef6229a 100644
--- a/src/compiler/translator/ParseContext.cpp
+++ b/src/compiler/translator/ParseContext.cpp
@@ -3323,6 +3323,15 @@
 
                     // Some built-in functions have out parameters too.
                     functionCallLValueErrorCheck(fnCandidate, aggregate);
+
+                    // See if we can constant fold a built-in.
+                    TIntermTyped *foldedNode = intermediate.foldAggregateBuiltIn(op, aggregate);
+                    if (foldedNode)
+                    {
+                        foldedNode->setType(callNode->getType());
+                        foldedNode->getTypePointer()->setQualifier(EvqConst);
+                        callNode = foldedNode;
+                    }
                 }
             }
             else