Begin using a list of bailouts instead of a singleton in the fast code generator.

src/x64/fast-codegen-x64.cc

 // Copyright 2010 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 138 matching lines @@
   if (is_smi(accumulator0()) && is_smi(accumulator1())) {
     // If both operands are known to be a smi then there is no need to check
     // the operands or result.
     if (destination().is(no_reg)) {
       __ or_(accumulator1(), accumulator0());
     } else {
       // Leave the result in the destination register.  Bitwise or is
       // commutative.
       __ or_(destination(), other_accumulator(destination()));
     }
-  } else if (destination().is(no_reg)) {
-    // Result is not needed but do not clobber the operands in case of
-    // bailout.
-    __ movq(scratch0(), accumulator1());
-    __ or_(scratch0(), accumulator0());
-    __ JumpIfNotSmi(scratch0(), bailout());
   } else {
-    // Preserve the destination operand in a scratch register in case of
-    // bailout.
-    __ movq(scratch0(), destination());
-    __ or_(destination(), other_accumulator(destination()));
-    __ JumpIfNotSmi(destination(), bailout());
+    // Left is in accumulator1, right in accumulator0.
+    if (destination().is(accumulator0())) {
+      __ movq(scratch0(), accumulator0());
+      __ or_(destination(), accumulator1());  // Or is commutative.
+      Label* bailout =
+          info()->AddBailout(accumulator1(), scratch0());  // Left, right.
+      __ JumpIfNotSmi(destination(), bailout);
+    } else if (destination().is(accumulator1())) {
+      __ movq(scratch0(), accumulator1());
+      __ or_(destination(), accumulator0());
+      Label* bailout = info()->AddBailout(scratch0(), accumulator0());
+      __ JumpIfNotSmi(destination(), bailout);
+    } else {
+      ASSERT(destination().is(no_reg));
+      __ movq(scratch0(), accumulator1());
+      __ or_(scratch0(), accumulator0());
+      Label* bailout = info()->AddBailout(accumulator1(), accumulator0());
+      __ JumpIfNotSmi(scratch0(), bailout);
+    }
   }
 
-
   // If we didn't bailout, the result (in fact, both inputs too) is known to
   // be a smi.
   set_as_smi(accumulator0());
   set_as_smi(accumulator1());
 }
 
 
 void FastCodeGenerator::Generate(CompilationInfo* compilation_info) {
   ASSERT(info_ == NULL);
   info_ = compilation_info;
 
   // Save the caller's frame pointer and set up our own.
   Comment prologue_cmnt(masm(), ";; Prologue");
   __ push(rbp);
   __ movq(rbp, rsp);
   __ push(rsi);  // Context.
   __ push(rdi);  // Closure.
   // Note that we keep a live register reference to esi (context) at this
   // point.
 
+  Label* bailout_to_beginning = info()->AddBailout();
   // Receiver (this) is allocated to a fixed register.
   if (info()->has_this_properties()) {
     Comment cmnt(masm(), ";; MapCheck(this)");
     if (FLAG_print_ir) {
       PrintF("MapCheck(this)\n");
     }
     ASSERT(info()->has_receiver() && info()->receiver()->IsHeapObject());
     Handle<HeapObject> object = Handle<HeapObject>::cast(info()->receiver());
     Handle<Map> map(object->map());
     EmitLoadReceiver();
-    __ CheckMap(receiver_reg(), map, bailout(), false);
+    __ CheckMap(receiver_reg(), map, bailout_to_beginning, false);
   }
 
   // If there is a global variable access check if the global object is the
   // same as at lazy-compilation time.
   if (info()->has_globals()) {
     Comment cmnt(masm(), ";; MapCheck(GLOBAL)");
     if (FLAG_print_ir) {
       PrintF("MapCheck(GLOBAL)\n");
     }
     ASSERT(info()->has_global_object());
     Handle<Map> map(info()->global_object()->map());
     __ movq(scratch0(), CodeGenerator::GlobalObject());
-    __ CheckMap(scratch0(), map, bailout(), true);
+    __ CheckMap(scratch0(), map, bailout_to_beginning, true);
   }
 
   VisitStatements(info()->function()->body());
 
   Comment return_cmnt(masm(), ";; Return(<undefined>)");
   if (FLAG_print_ir) {
     PrintF("Return(<undefined>)\n");
   }
   __ LoadRoot(rax, Heap::kUndefinedValueRootIndex);
   __ movq(rsp, rbp);
   __ pop(rbp);
   __ ret((scope()->num_parameters() + 1) * kPointerSize);
-
-  __ bind(&bailout_);
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal