Add --noopt flag that sets all kind of flags to make unoptimzied code as fast as possible (and not …

runtime/vm/flow_graph_compiler.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_XXX.
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/dart_entry.h"
 #include "vm/debugger.h"
 #include "vm/deopt_instructions.h"
 #include "vm/exceptions.h"
 #include "vm/flow_graph_allocator.h"
 #include "vm/il_printer.h"
 #include "vm/intrinsifier.h"
 #include "vm/locations.h"
 #include "vm/log.h"
 #include "vm/longjump.h"
 #include "vm/object_store.h"
 #include "vm/parser.h"
 #include "vm/raw_object.h"
 #include "vm/stack_frame.h"
 #include "vm/stub_code.h"
 #include "vm/symbols.h"
 
 namespace dart {
 
+DEFINE_FLAG(bool, always_megamorphic_calls, false,
+    "Instance call always as megamorphic.");
 DEFINE_FLAG(bool, trace_inlining_intervals, false,
     "Inlining interval diagnostics");
 DEFINE_FLAG(bool, enable_simd_inline, true,
     "Enable inlining of SIMD related method calls.");
 DEFINE_FLAG(int, min_optimization_counter_threshold, 5000,
     "The minimum invocation count for a function.");
 DEFINE_FLAG(int, optimization_counter_scale, 2000,
     "The scale of invocation count, by size of the function.");
 DEFINE_FLAG(bool, source_lines, false, "Emit source line as assembly comment.");
 
 DECLARE_FLAG(bool, code_comments);
 DECLARE_FLAG(int, deoptimize_every);
 DECLARE_FLAG(charp, deoptimize_filter);
 DECLARE_FLAG(bool, disassemble);
 DECLARE_FLAG(bool, disassemble_optimized);
 DECLARE_FLAG(bool, emit_edge_counters);
 DECLARE_FLAG(bool, enable_type_checks);
 DECLARE_FLAG(bool, intrinsify);
 DECLARE_FLAG(int, optimization_counter_threshold);
 DECLARE_FLAG(bool, propagate_ic_data);
 DECLARE_FLAG(int, regexp_optimization_counter_threshold);
 DECLARE_FLAG(int, reoptimization_counter_threshold);
 DECLARE_FLAG(int, stacktrace_every);
 DECLARE_FLAG(charp, stacktrace_filter);
 DECLARE_FLAG(bool, use_cha);
+DECLARE_FLAG(bool, use_field_guards);
 DECLARE_FLAG(bool, use_osr);
 DECLARE_FLAG(bool, warn_on_javascript_compatibility);
 
+static void NooptModeHandler(bool value) {
+  FLAG_always_megamorphic_calls = value;
+  FLAG_optimization_counter_threshold = -1;

[Florian Schneider, 2015/05/01 20:47:58]

Will this handler called ever with (value == false)?

Maybe do:

if (value) {
  FLAG_always_megamorphic_calls = true;
  FLAG_optimization_counter_threshold = -1;
  FLAG_use_field_guards = false;
}

[srdjan, 2015/05/01 20:55:11]

Done.

+  FLAG_use_field_guards = false;

[Florian Schneider, 2015/05/01 20:47:58]

FLAG_use_osr = false;

to avoid generating OSR checking code?

[srdjan, 2015/05/01 20:55:11]

Done.

+}
+
+
+// --unopt disables optimizer and tunes unoptimized code to run as fast

[Florian Schneider, 2015/05/01 20:47:58]

s/unopt/noopt/

[srdjan, 2015/05/01 20:55:11]

Done.

+// as possible.
+DEFINE_FLAG_HANDLER(NooptModeHandler,
+                    noopt,
+                    "Run fast unoptimized code only.");
+
+
 // Assign locations to incoming arguments, i.e., values pushed above spill slots
 // with PushArgument.  Recursively allocates from outermost to innermost
 // environment.
 void CompilerDeoptInfo::AllocateIncomingParametersRecursive(
     Environment* env,
     intptr_t* stack_height) {
   if (env == NULL) return;
   AllocateIncomingParametersRecursive(env->outer(), stack_height);
   for (Environment::ShallowIterator it(env); !it.Done(); it.Advance()) {
     if (it.CurrentLocation().IsInvalid() &&
@@ skipping 908 matching lines @@
   assembler()->Bind(&intrinsic_slow_path_label_);
 }
 
 
 void FlowGraphCompiler::GenerateInstanceCall(
     intptr_t deopt_id,
     intptr_t token_pos,
     intptr_t argument_count,
     LocationSummary* locs,
     const ICData& ic_data) {
+  if (FLAG_always_megamorphic_calls) {
+    EmitMegamorphicInstanceCall(ic_data, argument_count,
+                                deopt_id, token_pos, locs);
+    return;
+  }
   ASSERT(!ic_data.IsNull());
   uword label_address = 0;
   StubCode* stub_code = isolate()->stub_code();
   if (is_optimizing() && (ic_data.NumberOfUsedChecks() == 0)) {
     // Emit IC call that will count and thus may need reoptimization at
     // function entry.
     ASSERT(!is_optimizing()
            || may_reoptimize()
            || flow_graph().IsCompiledForOsr());
     switch (ic_data.NumArgsTested()) {
@@ skipping 693 matching lines @@
 
 
 void FlowGraphCompiler::FrameStateClear() {
   ASSERT(!is_optimizing());
   frame_state_.TruncateTo(0);
 }
 #endif
 
 
 }  // namespace dart