MIPS: Simplify stack check instruction in Crankshaft.

src/mips/lithium-codegen-mips.cc

 // Copyright 2011 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 4502 matching lines @@
   class DeferredStackCheck: public LDeferredCode {
    public:
     DeferredStackCheck(LCodeGen* codegen, LStackCheck* instr)
         : LDeferredCode(codegen), instr_(instr) { }
     virtual void Generate() { codegen()->DoDeferredStackCheck(instr_); }
     virtual LInstruction* instr() { return instr_; }
    private:
     LStackCheck* instr_;
   };
 
+  Register scratch = scratch0();
+  DeferredStackCheck* deferred_stack_check =
+      new DeferredStackCheck(this, instr);
+  __ LoadRoot(scratch, Heap::kStackLimitRootIndex);
+  __ Branch(deferred_stack_check->entry(), lo, sp, Operand(scratch));
+  EnsureSpaceForLazyDeopt();
+  __ bind(instr->done_label());
+  deferred_stack_check->SetExit(instr->done_label());
+  // There is no LLazyBailout instruction for stack-checks. We have to
+  // prepare for lazy deoptimization explicitly here.
   ASSERT(instr->HasEnvironment());
   LEnvironment* env = instr->environment();
-  // There is no LLazyBailout instruction for stack-checks. We have to
-  // prepare for lazy deoptimization explicitly here.
-  if (instr->hydrogen()->is_function_entry()) {
-    // Perform stack overflow check.
-    Label done;
-    __ LoadRoot(at, Heap::kStackLimitRootIndex);
-    __ Branch(&done, hs, sp, Operand(at));
-    StackCheckStub stub;
-    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
-    EnsureSpaceForLazyDeopt();
-    __ bind(&done);
-    RegisterEnvironmentForDeoptimization(env, Safepoint::kLazyDeopt);
-    safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
-  } else {
-    ASSERT(instr->hydrogen()->is_backwards_branch());
-    // Perform stack overflow check if this goto needs it before jumping.
-    DeferredStackCheck* deferred_stack_check =
-        new DeferredStackCheck(this, instr);
-    __ LoadRoot(at, Heap::kStackLimitRootIndex);
-    __ Branch(deferred_stack_check->entry(), lo, sp, Operand(at));
-    EnsureSpaceForLazyDeopt();
-    __ bind(instr->done_label());
-    deferred_stack_check->SetExit(instr->done_label());
-    RegisterEnvironmentForDeoptimization(env, Safepoint::kLazyDeopt);
-    // Don't record a deoptimization index for the safepoint here.
-    // This will be done explicitly when emitting call and the safepoint in
-    // the deferred code.
-  }
+  RegisterEnvironmentForDeoptimization(env, Safepoint::kLazyDeopt);
+  // Don't record a deoptimization index for the safepoint here.
+  // This will be done explicitly when emitting call and the safepoint in
+  // the deferred code.
 }
 
 
 void LCodeGen::DoOsrEntry(LOsrEntry* instr) {
   // This is a pseudo-instruction that ensures that the environment here is
   // properly registered for deoptimization and records the assembler's PC
   // offset.
   LEnvironment* environment = instr->environment();
   environment->SetSpilledRegisters(instr->SpilledRegisterArray(),
                                    instr->SpilledDoubleRegisterArray());
 
   // If the environment were already registered, we would have no way of
   // backpatching it with the spill slot operands.
   ASSERT(!environment->HasBeenRegistered());
   RegisterEnvironmentForDeoptimization(environment, Safepoint::kNoLazyDeopt);
   ASSERT(osr_pc_offset_ == -1);
   osr_pc_offset_ = masm()->pc_offset();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal