Add --trace-hydrogen-filter flag.

The flag restricts hydrogen.cfg output to functions passing the filter,
similar to what --hydrogen-filter does for optimization in general.

This is useful for investigating large repro cases where tracing all
functions would lead to an impractically large hydrogen.cfg file, but
restricting optimization using --hydrogen-filter is undesirable
(e.g. because it might cause the issue to no longer reproduce).

R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/22926025

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16302 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/compiler.cc

@@ -362,7 +362,7 @@ OptimizingCompiler::Status OptimizingCompiler::CreateGraph() {
   }
 
   // Take --hydrogen-filter into account.
-  if (!info()->closure()->PassesHydrogenFilter()) {
+  if (!info()->closure()->PassesFilter(FLAG_hydrogen_filter)) {
     info()->AbortOptimization();
     return SetLastStatus(BAILED_OUT);
   }
@@ -1258,9 +1258,10 @@ CompilationPhase::~CompilationPhase() {
 bool CompilationPhase::ShouldProduceTraceOutput() const {
   // Trace if the appropriate trace flag is set and the phase name's first
   // character is in the FLAG_trace_phase command line parameter.
-  bool tracing_on = info()->IsStub() ?
-      FLAG_trace_hydrogen_stubs :
-      FLAG_trace_hydrogen;
+  bool tracing_on = info()->IsStub()
+      ? FLAG_trace_hydrogen_stubs
+      : (FLAG_trace_hydrogen &&
+         info()->closure()->PassesFilter(FLAG_trace_hydrogen_filter));
   return (tracing_on &&
       OS::StrChr(const_cast<char*>(FLAG_trace_phase), name_[0]) != NULL);
 }

src/flag-definitions.h

@@ -256,6 +256,7 @@ DEFINE_bool(collect_megamorphic_maps_from_stub_cache,
             "crankshaft harvests type feedback from stub cache")
 DEFINE_bool(hydrogen_stats, false, "print statistics for hydrogen")
 DEFINE_bool(trace_hydrogen, false, "trace generated hydrogen to file")
+DEFINE_string(trace_hydrogen_filter, "*", "hydrogen tracing filter")
 DEFINE_bool(trace_hydrogen_stubs, false, "trace generated hydrogen for stubs")
 DEFINE_string(trace_hydrogen_file, NULL, "trace hydrogen to given file name")
 DEFINE_string(trace_phase, "HLZ", "trace generated IR for specified phases")

src/objects.cc

@@ -9620,17 +9620,17 @@ Context* JSFunction::NativeContextFromLiterals(FixedArray* literals) {
 }
 
 
-bool JSFunction::PassesHydrogenFilter() {
+// The filter is a pattern that matches function names in this way:
+//   "*"      all; the default
+//   "-"      all but the top-level function
+//   "-name"  all but the function "name"
+//   ""       only the top-level function
+//   "name"   only the function "name"
+//   "name*"  only functions starting with "name"
+bool JSFunction::PassesFilter(const char* raw_filter) {
+  if (*raw_filter == '*') return true;
   String* name = shared()->DebugName();
-  // The filter string is a pattern that matches functions in this way:
-  //   "*"      all; the default
-  //   "-"      all but the top-level function
-  //   "-name"  all but the function "name"
-  //   ""       only the top-level function
-  //   "name"   only the function "name"
-  //   "name*"  only functions starting with "name"
-  if (*FLAG_hydrogen_filter != '*') {
-    Vector<const char> filter = CStrVector(FLAG_hydrogen_filter);
+  Vector<const char> filter = CStrVector(raw_filter);
   if (filter.length() == 0) return name->length() == 0;
   if (filter[0] != '-' && name->IsUtf8EqualTo(filter)) return true;
   if (filter[0] == '-' &&
@@ -9642,9 +9642,6 @@ bool JSFunction::PassesHydrogenFilter() {
     return true;
   }
   return false;
-  }
-
-  return true;
 }
 
 

src/objects.h

@@ -7081,7 +7081,8 @@ class JSFunction: public JSObject {
   // Retrieve the native context from a function's literal array.
   static Context* NativeContextFromLiterals(FixedArray* literals);
 
-  bool PassesHydrogenFilter();
+  // Used for flags such as --hydrogen-filter.
+  bool PassesFilter(const char* raw_filter);
 
   // Layout descriptors. The last property (from kNonWeakFieldsEndOffset to
   // kSize) is weak and has special handling during garbage collection.

src/runtime-profiler.cc

@@ -127,7 +127,7 @@ static void GetICCounts(Code* shared_code,
 void RuntimeProfiler::Optimize(JSFunction* function, const char* reason) {
   ASSERT(function->IsOptimizable());
 
-  if (FLAG_trace_opt && function->PassesHydrogenFilter()) {
+  if (FLAG_trace_opt && function->PassesFilter(FLAG_hydrogen_filter)) {
     PrintF("[marking ");
     function->ShortPrint();
     PrintF(" for recompilation, reason: %s", reason);