Make the array bounds check elimination phase optional (and set the foundation for introducing SSI …

src/ia32/lithium-codegen-ia32.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 477 matching lines @@
 
 
 XMMRegister LCodeGen::ToDoubleRegister(LOperand* op) const {
   ASSERT(op->IsDoubleRegister());
   return ToDoubleRegister(op->index());
 }
 
 
 int LCodeGen::ToInteger32(LConstantOperand* op) const {
   HConstant* constant = chunk_->LookupConstant(op);
-  ASSERT(chunk_->LookupLiteralRepresentation(op).IsInteger32());
-  ASSERT(constant->HasInteger32Value());
   return constant->Integer32Value();
 }
 
 
 Handle<Object> LCodeGen::ToHandle(LConstantOperand* op) const {
   HConstant* constant = chunk_->LookupConstant(op);
   ASSERT(chunk_->LookupLiteralRepresentation(op).IsTagged());
   return constant->handle();
 }
 
@@ skipping 2683 matching lines @@
 
 Operand LCodeGen::BuildFastArrayOperand(
     LOperand* elements_pointer,
     LOperand* key,
     Representation key_representation,
     ElementsKind elements_kind,
     uint32_t offset,
     uint32_t additional_index) {
   Register elements_pointer_reg = ToRegister(elements_pointer);
   int shift_size = ElementsKindToShiftSize(elements_kind);
-  // Even though the HLoad/StoreKeyed instructions force the input
-  // representation for the key to be an integer, the input gets replaced during
-  // bound check elimination with the index argument to the bounds check, which
-  // can be tagged, so that case must be handled here, too.
-  if (key_representation.IsTagged() && (shift_size >= 1)) {
-    shift_size -= kSmiTagSize;
-  }
   if (key->IsConstantOperand()) {
     int constant_value = ToInteger32(LConstantOperand::cast(key));
     if (constant_value & 0xF0000000) {
       Abort("array index constant value too big");
     }
     return Operand(elements_pointer_reg,
                    ((constant_value + additional_index) << shift_size)
                        + offset);
   } else {
+    // Take the tag bit into account while computing the shift size.
+    if (key_representation.IsTagged() && (shift_size >= 1)) {
+      shift_size -= kSmiTagSize;
+    }
     ScaleFactor scale_factor = static_cast<ScaleFactor>(shift_size);
     return Operand(elements_pointer_reg,
                    ToRegister(key),
                    scale_factor,
                    offset + (additional_index << shift_size));
   }
 }
 
 
 void LCodeGen::DoLoadKeyedGeneric(LLoadKeyedGeneric* instr) {
@@ skipping 2726 matching lines @@
                               FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32