[turbofan] Initial version of the new LoadElimination.

src/flag-definitions.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file defines all of the flags.  It is separated into different section,
 // for Debug, Release, Logging and Profiling, etc.  To add a new flag, find the
 // correct section, and use one of the DEFINE_ macros, without a trailing ';'.
 //
 // This include does not have a guard, because it is a template-style include,
 // which can be included multiple times in different modes.  It expects to have
@@ skipping 444 matching lines @@
             "use typed feedback for representation inference in Turbofan")
 DEFINE_BOOL(turbo_source_positions, false,
             "track source code positions when building TurboFan IR")
 DEFINE_IMPLICATION(trace_turbo, turbo_source_positions)
 DEFINE_BOOL(function_context_specialization, false,
             "enable function context specialization in TurboFan")
 DEFINE_BOOL(native_context_specialization, true,
             "enable native context specialization in TurboFan")
 DEFINE_BOOL(turbo_inlining, true, "enable inlining in TurboFan")
 DEFINE_BOOL(trace_turbo_inlining, false, "trace TurboFan inlining")
+DEFINE_BOOL(turbo_load_elimination, true, "enable load elimination in TurboFan")
+DEFINE_BOOL(trace_turbo_load_elimination, false,
+            "trace TurboFan load elimination")
 DEFINE_BOOL(loop_assignment_analysis, true, "perform loop assignment analysis")
 DEFINE_BOOL(turbo_profiling, false, "enable profiling in TurboFan")
 DEFINE_BOOL(turbo_verify_allocation, DEBUG_BOOL,
             "verify register allocation in TurboFan")
 DEFINE_BOOL(turbo_move_optimization, true, "optimize gap moves in TurboFan")
 DEFINE_BOOL(turbo_jt, true, "enable jump threading in TurboFan")
 DEFINE_BOOL(turbo_stress_loop_peeling, false,
             "stress loop peeling optimization")
 DEFINE_BOOL(turbo_cf_optimization, true, "optimize control flow in TurboFan")
 DEFINE_BOOL(turbo_frame_elision, true, "elide frames in TurboFan")
@@ skipping 720 matching lines @@
 #undef DEFINE_ALIAS_FLOAT
 #undef DEFINE_ALIAS_ARGS
 
 #undef FLAG_MODE_DECLARE
 #undef FLAG_MODE_DEFINE
 #undef FLAG_MODE_DEFINE_DEFAULTS
 #undef FLAG_MODE_META
 #undef FLAG_MODE_DEFINE_IMPLICATIONS
 
 #undef COMMA