Cycles: add unit tests for supported constant folding rules.

Code coverage of different combinations of secondary conditions
is obviously not complete because there are so many of them, but
all main rules should be there.

The reason for CORRECT vs INVALID is that both words have the same
number of characters so calls line up, but look quite different.

Reviewers: #cycles, sergey

Reviewed By: #cycles, sergey

Subscribers: dingto, sergey, brecht

Differential Revision: https://developer.blender.org/D2130

intern/cycles/render/constant_fold.cpp

@@ -40,7 +40,8 @@ bool ConstantFolder::all_inputs_constant() const
 
 void ConstantFolder::make_constant(float value) const
 {
-	VLOG(1) << "Replacing " << node->name << " with constant " << value << ".";
+	VLOG(1) << "Folding " << node->name << "::" << output->name() << " to constant (" << value << ").";
+
 	foreach(ShaderInput *sock, output->links) {
 		sock->set(value);
 	}
@@ -50,6 +51,8 @@ void ConstantFolder::make_constant(float value) const
 
 void ConstantFolder::make_constant(float3 value) const
 {
+	VLOG(1) << "Folding " << node->name << "::" << output->name() << " to constant " << value << ".";
+
 	foreach(ShaderInput *sock, output->links) {
 		sock->set(value);
 	}
@@ -90,6 +93,8 @@ void ConstantFolder::bypass(ShaderOutput *new_output) const
 {
 	assert(new_output);
 
+	VLOG(1) << "Folding " << node->name << "::" << output->name() << " to socket " << new_output->parent->name << "::" << new_output->name() << ".";
+
 	/* Remove all outgoing links from socket and connect them to new_output instead.
 	 * The graph->relink method affects node inputs, so it's not safe to use in constant
 	 * folding if the node has multiple outputs and will thus be folded multiple times. */
@@ -105,6 +110,9 @@ void ConstantFolder::bypass(ShaderOutput *new_output) const
 void ConstantFolder::discard() const
 {
 	assert(output->type() == SocketType::CLOSURE);
+
+	VLOG(1) << "Discarding closure " << node->name << ".";
+
 	graph->disconnect(output);
 }
 

intern/cycles/test/CMakeLists.txt

@@ -26,12 +26,12 @@ set(ALL_CYCLES_LIBRARIES
 	cycles_device
 	cycles_bvh
 	cycles_graph
-	cycles_kernel_osl
 	cycles_util
 	${OPENIMAGEIO_LIBRARIES}
 )
 if(WITH_CYCLES_OSL)
 	list(APPEND ALL_CYCLES_LIBRARIES
+		cycles_kernel_osl
 		${OSL_LIBRARIES}
 		${LLVM_LIBRARIES}
 	)