MIPS: Minor optimizations in Builtins::Generate_ArgumentsAdaptorTrampoline.

src/mips/builtins-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 1717 matching lines @@
     __ Branch(USE_DELAY_SLOT, &copy, ne, a0, Operand(a2));
     __ addiu(a0, a0, -kPointerSize);  // In delay slot.
 
     __ jmp(&invoke);
   }
 
   {  // Too few parameters: Actual < expected.
     __ bind(&too_few);
     EnterArgumentsAdaptorFrame(masm);
 
-    // TODO(MIPS): Optimize these loops.
-
     // Calculate copy start address into a0 and copy end address is fp.
     // a0: actual number of arguments as a smi
     // a1: function
     // a2: expected number of arguments
     // a3: code entry to call
     __ sll(a0, a0, kPointerSizeLog2 - kSmiTagSize);
     __ Addu(a0, fp, a0);
     // Adjust for return address and receiver.
     __ Addu(a0, a0, Operand(2 * kPointerSize));
     // Compute copy end address. Also adjust for return address.
     __ Addu(t3, fp, kPointerSize);
 
     // Copy the arguments (including the receiver) to the new stack frame.
     // a0: copy start address
     // a1: function
     // a2: expected number of arguments
     // a3: code entry to call
     // t3: copy end address
     Label copy;
     __ bind(&copy);
     __ lw(t0, MemOperand(a0));  // Adjusted above for return addr and receiver.
-    __ push(t0);
+    __ Subu(sp, sp, kPointerSize);
     __ Subu(a0, a0, kPointerSize);
-    __ Branch(&copy, ne, a0, Operand(t3));
+    __ Branch(USE_DELAY_SLOT, &copy, ne, a0, Operand(t3));
+    __ sw(t0, MemOperand(sp));  // In the delay slot.
 
     // Fill the remaining expected arguments with undefined.
     // a1: function
     // a2: expected number of arguments
     // a3: code entry to call
     __ LoadRoot(t0, Heap::kUndefinedValueRootIndex);
     __ sll(t2, a2, kPointerSizeLog2);
     __ Subu(a2, fp, Operand(t2));
     __ Addu(a2, a2, Operand(-4 * kPointerSize));  // Adjust for frame.
 
     Label fill;
     __ bind(&fill);
-    __ push(t0);
-    __ Branch(&fill, ne, sp, Operand(a2));
+    __ Subu(sp, sp, kPointerSize);
+    __ Branch(USE_DELAY_SLOT, &fill, ne, sp, Operand(a2));
+    __ sw(t0, MemOperand(sp));
   }
 
   // Call the entry point.
   __ bind(&invoke);
 
   __ Call(a3);
 
   // Store offset of return address for deoptimizer.
   masm->isolate()->heap()->SetArgumentsAdaptorDeoptPCOffset(masm->pc_offset());
 
   // Exit frame and return.
   LeaveArgumentsAdaptorFrame(masm);
   __ Ret();
 
 
   // -------------------------------------------
   // Don't adapt arguments.
   // -------------------------------------------
   __ bind(&dont_adapt_arguments);
   __ Jump(a3);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS