MIPS: Branch delay slot and other optimizations.

src/mips/stub-cache-mips.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 559 matching lines @@
     MacroAssembler* masm,
     Register receiver,
     Register holder,
     Register name,
     Handle<JSObject> holder_obj) {
   PushInterceptorArguments(masm, receiver, holder, name, holder_obj);
 
   ExternalReference ref =
       ExternalReference(IC_Utility(IC::kLoadPropertyWithInterceptorOnly),
           masm->isolate());
-  __ li(a0, Operand(5));
-  __ li(a1, Operand(ref));
+  __ PrepareCEntryArgs(5);
+  __ PrepareCEntryFunction(ref);
 
   CEntryStub stub(1);
   __ CallStub(&stub);
 }
 
 
 static const int kFastApiCallArguments = 3;
 
 
 // Reserves space for the extra arguments to FastHandleApiCall in the
@@ skipping 3508 matching lines @@
   //  -- ra    : return address
   //  -- a0    : key
   //  -- a1    : receiver
   // -----------------------------------
   Label miss_force_generic;
 
   // This stub is meant to be tail-jumped to, the receiver must already
   // have been verified by the caller to not be a smi.
 
   // Check that the key is a smi.
-  __ JumpIfNotSmi(a0, &miss_force_generic);
+  __ JumpIfNotSmi(a0, &miss_force_generic, at, USE_DELAY_SLOT);
+  // The delay slot can be safely used here, a1 is an object pointer.
 
   // Get the elements array.
   __ lw(a2, FieldMemOperand(a1, JSObject::kElementsOffset));
   __ AssertFastElements(a2);
 
   // Check that the key is within bounds.
   __ lw(a3, FieldMemOperand(a2, FixedArray::kLengthOffset));
-  __ Branch(&miss_force_generic, hs, a0, Operand(a3));
+  __ Branch(USE_DELAY_SLOT, &miss_force_generic, hs, a0, Operand(a3));
 
   // Load the result and make sure it's not the hole.
   __ Addu(a3, a2, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
   STATIC_ASSERT(kSmiTag == 0 && kSmiTagSize < kPointerSizeLog2);
   __ sll(t0, a0, kPointerSizeLog2 - kSmiTagSize);
   __ Addu(t0, t0, a3);
   __ lw(t0, MemOperand(t0));
   __ LoadRoot(t1, Heap::kTheHoleValueRootIndex);
   __ Branch(&miss_force_generic, eq, t0, Operand(t1));
+  __ Ret(USE_DELAY_SLOT);
   __ mov(v0, t0);
-  __ Ret();
 
   __ bind(&miss_force_generic);
   Handle<Code> stub =
       masm->isolate()->builtins()->KeyedLoadIC_MissForceGeneric();
   __ Jump(stub, RelocInfo::CODE_TARGET);
 }
 
 
 void KeyedLoadStubCompiler::GenerateLoadFastDoubleElement(
     MacroAssembler* masm) {
@@ skipping 369 matching lines @@
     __ Jump(ic_slow, RelocInfo::CODE_TARGET);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS