DFG should have richer debug output for CFA and phi processing
https://bugs.webkit.org/show_bug.cgi?id=72922
Reviewed by Gavin Barraclough.
In the default verbose mode, we now print information about variable
state at the bottom of basic blocks in addition to the top, and we
also print local variable linking. In the verbose propagation mode,
the state of phi processing is dumped more richly and CFA merging (the
most subtle part of CFA) is traced as well.
* dfg/DFGAbstractState.cpp:
(JSC::DFG::AbstractState::endBasicBlock):
(JSC::DFG::AbstractState::mergeStateAtTail):
* dfg/DFGAbstractValue.h:
(JSC::DFG::StructureAbstractValue::dump):
(JSC::DFG::AbstractValue::dump):
* dfg/DFGByteCodeParser.cpp:
(JSC::DFG::ByteCodeParser::processPhiStack):
(JSC::DFG::ByteCodeParser::parse):
* dfg/DFGCommon.h:
(JSC::DFG::NodeIndexTraits::dump):
* dfg/DFGDriver.cpp:
(JSC::DFG::compile):
* dfg/DFGGraph.cpp:
(JSC::DFG::Graph::dump):
* dfg/DFGNode.h:
(JSC::DFG::Node::dumpChildren):
* dfg/DFGOSRExitCompiler.cpp:
* dfg/DFGOperands.h:
(JSC::DFG::OperandValueTraits::dump):
(JSC::DFG::dumpOperands):
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@100975 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/Source/JavaScriptCore/dfg/DFGAbstractState.cpp b/Source/JavaScriptCore/dfg/DFGAbstractState.cpp
index 6008e4c..10e645d 100644
--- a/Source/JavaScriptCore/dfg/DFGAbstractState.cpp
+++ b/Source/JavaScriptCore/dfg/DFGAbstractState.cpp
@@ -133,11 +133,19 @@
bool changed = false;
if (mergeMode != DontMerge || !ASSERT_DISABLED) {
- for (size_t argument = 0; argument < block->variablesAtTail.numberOfArguments(); ++argument)
+ for (size_t argument = 0; argument < block->variablesAtTail.numberOfArguments(); ++argument) {
+#if DFG_ENABLE(DEBUG_PROPAGATION_VERBOSE)
+ printf(" Merging state for argument %lu.\n", argument);
+#endif
changed |= mergeStateAtTail(block->valuesAtTail.argument(argument), m_variables.argument(argument), block->variablesAtTail.argument(argument));
+ }
- for (size_t local = 0; local < block->variablesAtTail.numberOfLocals(); ++local)
+ for (size_t local = 0; local < block->variablesAtTail.numberOfLocals(); ++local) {
+#if DFG_ENABLE(DEBUG_PROPAGATION_VERBOSE)
+ printf(" Merging state for local %lu.\n", local);
+#endif
changed |= mergeStateAtTail(block->valuesAtTail.local(local), m_variables.local(local), block->variablesAtTail.local(local));
+ }
}
ASSERT(mergeMode != DontMerge || !changed);
@@ -687,23 +695,36 @@
if (!node.refCount())
return false;
+#if DFG_ENABLE(DEBUG_PROPAGATION_VERBOSE)
+ printf(" It's live, node @%u.\n", nodeIndex);
+#endif
+
switch (node.op) {
case Phi:
case SetArgument:
case Flush:
// The block transfers the value from head to tail.
source = &inVariable;
+#if DFG_ENABLE(DEBUG_PROPAGATION_VERBOSE)
+ printf(" Transfering from head to tail.\n");
+#endif
break;
case GetLocal:
// The block refines the value with additional speculations.
source = &forNode(nodeIndex);
+#if DFG_ENABLE(DEBUG_PROPAGATION_VERBOSE)
+ printf(" Refining.\n");
+#endif
break;
case SetLocal:
// The block sets the variable, and potentially refines it, both
// before and after setting it.
source = &forNode(node.child1());
+#if DFG_ENABLE(DEBUG_PROPAGATION_VERBOSE)
+ printf(" Setting.\n");
+#endif
break;
default:
@@ -715,6 +736,9 @@
if (destination == *source) {
// Abstract execution did not change the output value of the variable, for this
// basic block, on this iteration.
+#if DFG_ENABLE(DEBUG_PROPAGATION_VERBOSE)
+ printf(" Not changed!\n");
+#endif
return false;
}
@@ -722,6 +746,9 @@
// this variable after execution of this basic block. Update the state, and return
// true to indicate that the fixpoint must go on!
destination = *source;
+#if DFG_ENABLE(DEBUG_PROPAGATION_VERBOSE)
+ printf(" Changed!\n");
+#endif
return true;
}
