MIPS: Optimise Math.floor(x/y) to use integer division for MIPS.

src/hydrogen-instructions.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 1515 matching lines @@
 
 HValue* HUnaryMathOperation::Canonicalize() {
   if (op() == kMathFloor) {
     HValue* val = value();
     if (val->IsChange()) val = HChange::cast(val)->value();
 
     // If the input is integer32 then we replace the floor instruction
     // with its input.
     if (val->representation().IsInteger32()) return val;
 
-#if defined(V8_TARGET_ARCH_ARM) || defined(V8_TARGET_ARCH_IA32) || \
-        defined(V8_TARGET_ARCH_X64)
     if (val->IsDiv() && (val->UseCount() == 1)) {
       HDiv* hdiv = HDiv::cast(val);
       HValue* left = hdiv->left();
       HValue* right = hdiv->right();
       // Try to simplify left and right values of the division.
       HValue* new_left = SimplifiedDividendForMathFloorOfDiv(left);
       if (new_left == NULL &&
           hdiv->observed_input_representation(1).IsSmiOrInteger32()) {
         new_left = new(block()->zone())
             HChange(left, Representation::Integer32(), false, false);
         HChange::cast(new_left)->InsertBefore(this);
       }
       HValue* new_right =
           LChunkBuilder::SimplifiedDivisorForMathFloorOfDiv(right);
       if (new_right == NULL &&
+#ifdef V8_TARGET_ARCH_MIPS
+          false &&  // MathFloorOfDiv on MIPS can only operate on HConstant
+#endif
 #ifdef V8_TARGET_ARCH_ARM
           CpuFeatures::IsSupported(SUDIV) &&
 #endif
           hdiv->observed_input_representation(2).IsSmiOrInteger32()) {
         new_right = new(block()->zone())
             HChange(right, Representation::Integer32(), false, false);
         HChange::cast(new_right)->InsertBefore(this);
       }
 
       // Return if left or right are not optimizable.
@@ skipping 15 matching lines @@
       ReplaceAllUsesWith(instr);
       Kill();
       // We know the division had no other uses than this HMathFloor. Delete it.
       // Dead code elimination will deal with |left| and |right| if
       // appropriate.
       hdiv->DeleteAndReplaceWith(NULL);
 
       // Return NULL to remove this instruction from the graph.
       return NULL;
     }
-#endif  // V8_TARGET_ARCH_ARM
   }
   return this;
 }
 
 
 HValue* HCheckInstanceType::Canonicalize() {
   if (check_ == IS_STRING &&
       !value()->type().IsUninitialized() &&
       value()->type().IsString()) {
     return NULL;
@@ skipping 2270 matching lines @@
     case kBackingStore:
       if (!name_.is_null()) stream->Add(*String::cast(*name_)->ToCString());
       stream->Add("[backing-store]");
       break;
   }
 
   stream->Add("@%d", offset());
 }
 
 } }  // namespace v8::internal