Improve code generation for bounds checks.

src/arm64/lithium-codegen-arm64.cc

 // Copyright 2013 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 1757 matching lines @@
     case Token::BIT_AND: __ And(result, left, right); break;
     case Token::BIT_OR:  __ Orr(result, left, right); break;
     case Token::BIT_XOR: __ Eor(result, left, right); break;
     default:
       UNREACHABLE();
       break;
   }
 }
 
 
-void LCodeGen::ApplyCheckIf(Condition cc, LBoundsCheck* check) {
-  if (FLAG_debug_code && check->hydrogen()->skip_check()) {
+void LCodeGen::DoBoundsCheck(LBoundsCheck *instr) {
+  Condition cc = instr->hydrogen()->allow_equality() ? hi : hs;
+  ASSERT(instr->hydrogen()->index()->representation().IsInteger32());
+  ASSERT(instr->hydrogen()->length()->representation().IsInteger32());
+  if (instr->index()->IsConstantOperand()) {
+    Operand index = ToOperand32I(instr->index());
+    Register length = ToRegister32(instr->length());
+    __ Cmp(length, index);
+    cc = ReverseConditionForCmp(cc);
+  } else {
+    Register index = ToRegister32(instr->index());
+    Operand length = ToOperand32I(instr->length());
+    __ Cmp(index, length);
+  }
+  if (FLAG_debug_code && instr->hydrogen()->skip_check()) {
     __ Assert(InvertCondition(cc), kEliminatedBoundsCheckFailed);
   } else {
-    DeoptimizeIf(cc, check->environment());
+    DeoptimizeIf(cc, instr->environment());
   }
 }
 
 
-void LCodeGen::DoBoundsCheck(LBoundsCheck *instr) {
-  if (instr->hydrogen()->skip_check()) return;
-
-  ASSERT(instr->hydrogen()->length()->representation().IsInteger32());
-  Register length = ToRegister32(instr->length());
-
-  if (instr->index()->IsConstantOperand()) {
-    int constant_index =
-        ToInteger32(LConstantOperand::cast(instr->index()));
-
-    if (instr->hydrogen()->length()->representation().IsSmi()) {
-      __ Cmp(length, Smi::FromInt(constant_index));
-    } else {
-      __ Cmp(length, constant_index);
-    }
-  } else {
-  ASSERT(instr->hydrogen()->index()->representation().IsInteger32());
-    __ Cmp(length, ToRegister32(instr->index()));
-  }
-  Condition condition = instr->hydrogen()->allow_equality() ? lo : ls;
-  ApplyCheckIf(condition, instr);
-}
-
-
 void LCodeGen::DoBranch(LBranch* instr) {
   Representation r = instr->hydrogen()->value()->representation();
   Label* true_label = instr->TrueLabel(chunk_);
   Label* false_label = instr->FalseLabel(chunk_);
 
   if (r.IsInteger32()) {
     ASSERT(!info()->IsStub());
     EmitCompareAndBranch(instr, ne, ToRegister32(instr->value()), 0);
   } else if (r.IsSmi()) {
     ASSERT(!info()->IsStub());
@@ skipping 4108 matching lines @@
   __ Ldr(result, FieldMemOperand(object, JSObject::kPropertiesOffset));
   // Index is equal to negated out of object property index plus 1.
   __ Sub(result, result, Operand::UntagSmiAndScale(index, kPointerSizeLog2));
   __ Ldr(result, FieldMemOperand(result,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ Bind(deferred->exit());
   __ Bind(&done);
 }
 
 } }  // namespace v8::internal