MIPS: Some assembler-level optimizations on ARM.

src/mips/codegen-mips.cc

-// Copyright 2011 the V8 project authors. All rights reserved.
+// 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
 //       with the distribution.
@@ skipping 86 matching lines @@
   __ lw(t0, FieldMemOperand(a2, JSObject::kElementsOffset));
   __ lw(t1, FieldMemOperand(t0, FixedArray::kLengthOffset));
   // t0: source FixedArray
   // t1: number of elements (smi-tagged)
 
   // Allocate new FixedDoubleArray.
   __ sll(scratch, t1, 2);
   __ Addu(scratch, scratch, FixedDoubleArray::kHeaderSize);
   __ AllocateInNewSpace(scratch, t2, t3, t5, &gc_required, NO_ALLOCATION_FLAGS);
   // t2: destination FixedDoubleArray, not tagged as heap object
+  // Set destination FixedDoubleArray's length and map.
   __ LoadRoot(t5, Heap::kFixedDoubleArrayMapRootIndex);
+  __ sw(t1, MemOperand(t2, FixedDoubleArray::kLengthOffset));
   __ sw(t5, MemOperand(t2, HeapObject::kMapOffset));
-  // Set destination FixedDoubleArray's length.
-  __ sw(t1, MemOperand(t2, FixedDoubleArray::kLengthOffset));
   // Update receiver's map.
 
   __ sw(a3, FieldMemOperand(a2, HeapObject::kMapOffset));
   __ RecordWriteField(a2,
                       HeapObject::kMapOffset,
                       a3,
                       t5,
                       kRAHasBeenSaved,
                       kDontSaveFPRegs,
                       EMIT_REMEMBERED_SET,
@@ skipping 30 matching lines @@
   // Call into runtime if GC is required.
   __ bind(&gc_required);
   __ pop(ra);
   __ Branch(fail);
 
   // Convert and copy elements.
   __ bind(&loop);
   __ lw(t5, MemOperand(a3));
   __ Addu(a3, a3, kIntSize);
   // t5: current element
-  __ JumpIfNotSmi(t5, &convert_hole);
+  __ UntagAndJumpIfNotSmi(t5, t5, &convert_hole);
 
   // Normal smi, convert to double and store.
-  __ SmiUntag(t5);
   if (fpu_supported) {
     CpuFeatures::Scope scope(FPU);
     __ mtc1(t5, f0);
     __ cvt_d_w(f0, f0);
     __ sdc1(f0, MemOperand(t3));
     __ Addu(t3, t3, kDoubleSize);
   } else {
     FloatingPointHelper::ConvertIntToDouble(masm,
                                             t5,
                                             FloatingPointHelper::kCoreRegisters,
                                             f0,
                                             a0,
                                             a1,
                                             t7,
                                             f0);
     __ sw(a0, MemOperand(t3));  // mantissa
     __ sw(a1, MemOperand(t3, kIntSize));  // exponent
     __ Addu(t3, t3, kDoubleSize);
   }
   __ Branch(&entry);
 
   // Hole found, store the-hole NaN.
   __ bind(&convert_hole);
   if (FLAG_debug_code) {
+    // Restore a "smi-untagged" heap object.
+    __ SmiTag(t5);
+    __ Or(t5, t5, Operand(1));
     __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
     __ Assert(eq, "object found in smi-only array", at, Operand(t5));
   }
   __ sw(t0, MemOperand(t3));  // mantissa
   __ sw(t1, MemOperand(t3, kIntSize));  // exponent
   __ Addu(t3, t3, kDoubleSize);
 
   __ bind(&entry);
   __ Branch(&loop, lt, t3, Operand(t2));
 
@@ skipping 18 matching lines @@
   __ lw(t0, FieldMemOperand(a2, JSObject::kElementsOffset));
   __ lw(t1, FieldMemOperand(t0, FixedArray::kLengthOffset));
   // t0: source FixedArray
   // t1: number of elements (smi-tagged)
 
   // Allocate new FixedArray.
   __ sll(a0, t1, 1);
   __ Addu(a0, a0, FixedDoubleArray::kHeaderSize);
   __ AllocateInNewSpace(a0, t2, t3, t5, &gc_required, NO_ALLOCATION_FLAGS);
   // t2: destination FixedArray, not tagged as heap object
+  // Set destination FixedDoubleArray's length and map.
   __ LoadRoot(t5, Heap::kFixedArrayMapRootIndex);
+  __ sw(t1, MemOperand(t2, FixedDoubleArray::kLengthOffset));
   __ sw(t5, MemOperand(t2, HeapObject::kMapOffset));
-  // Set destination FixedDoubleArray's length.
-  __ sw(t1, MemOperand(t2, FixedDoubleArray::kLengthOffset));
 
   // Prepare for conversion loop.
   __ Addu(t0, t0, Operand(FixedDoubleArray::kHeaderSize - kHeapObjectTag + 4));
   __ Addu(a3, t2, Operand(FixedArray::kHeaderSize));
   __ Addu(t2, t2, Operand(kHeapObjectTag));
   __ sll(t1, t1, 1);
   __ Addu(t1, a3, t1);
   __ LoadRoot(t3, Heap::kTheHoleValueRootIndex);
   __ LoadRoot(t5, Heap::kHeapNumberMapRootIndex);
   // Using offsetted addresses.
@@ skipping 84 matching lines @@
   __ Branch(&check_sequential, eq, at, Operand(zero_reg));
 
   // Dispatch on the indirect string shape: slice or cons.
   Label cons_string;
   __ And(at, result, Operand(kSlicedNotConsMask));
   __ Branch(&cons_string, eq, at, Operand(zero_reg));
 
   // Handle slices.
   Label indirect_string_loaded;
   __ lw(result, FieldMemOperand(string, SlicedString::kOffsetOffset));
+  __ lw(string, FieldMemOperand(string, SlicedString::kParentOffset));
   __ sra(at, result, kSmiTagSize);
   __ Addu(index, index, at);
-  __ lw(string, FieldMemOperand(string, SlicedString::kParentOffset));
   __ jmp(&indirect_string_loaded);
 
   // Handle cons strings.
   // Check whether the right hand side is the empty string (i.e. if
   // this is really a flat string in a cons string). If that is not
   // the case we would rather go to the runtime system now to flatten
   // the string.
   __ bind(&cons_string);
   __ lw(result, FieldMemOperand(string, ConsString::kSecondOffset));
   __ LoadRoot(at, Heap::kEmptyStringRootIndex);
@@ skipping 51 matching lines @@
   __ Addu(at, string, index);
   __ lbu(result, MemOperand(at));
   __ bind(&done);
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS