Change --hydrogen-filter to allow specifying a negative filter for optimized functions.

src/compiler.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 226 matching lines @@
       (info->osr_ast_id() != AstNode::kNoNumber &&
        scope->num_parameters() + 1 + scope->num_stack_slots() > locals_limit)) {
     info->AbortOptimization();
     info->shared_info()->DisableOptimization();
     // True indicates the compilation pipeline is still going, not
     // necessarily that we optimized the code.
     return true;
   }
 
   // Take --hydrogen-filter into account.
-  Vector<const char> filter = CStrVector(FLAG_hydrogen_filter);
   Handle<String> name = info->function()->debug_name();
-  bool match = filter.is_empty() || name->IsEqualTo(filter);
-  if (!match) {
-    info->SetCode(code);
-    return true;
+  if (*FLAG_hydrogen_filter != '\0') {
+    Vector<const char> filter = CStrVector(FLAG_hydrogen_filter);
+    if ((filter[0] == '-'
+         && name->IsEqualTo(filter.SubVector(1, filter.length())))
+        || (filter[0] != '-' && !name->IsEqualTo(filter))) {
+      info->SetCode(code);
+      return true;
+    }
   }
 
   // Recompile the unoptimized version of the code if the current version
   // doesn't have deoptimization support. Alternatively, we may decide to
   // run the full code generator to get a baseline for the compile-time
   // performance of the hydrogen-based compiler.
   int64_t start = OS::Ticks();
   bool should_recompile = !info->shared_info()->has_deoptimization_support();
   if (should_recompile || FLAG_hydrogen_stats) {
     HPhase phase(HPhase::kFullCodeGen);
@@ skipping 539 matching lines @@
     }
   }
 
   GDBJIT(AddCode(Handle<String>(shared->DebugName()),
                  Handle<Script>(info->script()),
                  Handle<Code>(info->code()),
                  info));
 }
 
 } }  // namespace v8::internal