Use immediates when possible for HBoundsCheck and HLoadKeyedFastElement

src/x64/lithium-codegen-x64.cc

 // Copyright 2011 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 2288 matching lines @@
   DeoptimizeIf(below_equal, instr->environment());
 
   // There are two words between the frame pointer and the last argument.
   // Subtracting from length accounts for one of them add one more.
   __ movq(result, Operand(arguments, length, times_pointer_size, kPointerSize));
 }
 
 
 void LCodeGen::DoLoadKeyedFastElement(LLoadKeyedFastElement* instr) {
   Register elements = ToRegister(instr->elements());
-  Register key = ToRegister(instr->key());
   Register result = ToRegister(instr->result());
-  ASSERT(result.is(elements));
 
   // Load the result.
-  __ movq(result, FieldOperand(elements,
-                               key,
-                               times_pointer_size,
-                               FixedArray::kHeaderSize));
+  if (instr->key()->IsConstantOperand()) {
+    int key = ToInteger32(LConstantOperand::cast(instr->key()));

[danno, 2011/08/10 11:03:46]

Move into a "GetOperanXXXX" function. Or can you even use existing
"BuildFastArrayOperand"?

[Jakob Kummerow, 2011/08/10 12:22:48]

Done.

+    __ movq(result, FieldOperand(
+        elements, (key << times_pointer_size) + FixedArray::kHeaderSize));
+  } else {
+    __ movq(result, FieldOperand(elements,
+                                 ToRegister(instr->key()),
+                                 times_pointer_size,
+                                 FixedArray::kHeaderSize));
+  }
 
   // Check for the hole value.
   if (instr->hydrogen()->RequiresHoleCheck()) {
     __ CompareRoot(result, Heap::kTheHoleValueRootIndex);
     DeoptimizeIf(equal, instr->environment());
   }
 }
 
 
 void LCodeGen::DoLoadKeyedFastDoubleElement(
@@ skipping 802 matching lines @@
       case JSObject::DICTIONARY_ELEMENTS:
       case JSObject::NON_STRICT_ARGUMENTS_ELEMENTS:
         UNREACHABLE();
         break;
     }
   }
 }
 
 
 void LCodeGen::DoBoundsCheck(LBoundsCheck* instr) {
-  if (instr->length()->IsRegister()) {
-    __ cmpq(ToRegister(instr->index()), ToRegister(instr->length()));
+  if (instr->index()->IsConstantOperand()) {
+    if (instr->length()->IsRegister()) {
+      __ cmpq(ToRegister(instr->length()),
+              Immediate(ToInteger32(LConstantOperand::cast(instr->index()))));
+    } else {
+      __ cmpq(ToOperand(instr->length()),
+              Immediate(ToInteger32(LConstantOperand::cast(instr->index()))));
+    }
   } else {
-    __ cmpq(ToRegister(instr->index()), ToOperand(instr->length()));
+    if (instr->length()->IsRegister()) {
+      __ cmpq(ToRegister(instr->length()), ToRegister(instr->index()));
+    } else {
+      __ cmpq(ToOperand(instr->length()), ToRegister(instr->index()));
+    }
   }
-  DeoptimizeIf(above_equal, instr->environment());
+  DeoptimizeIf(below_equal, instr->environment());
 }
 
 
 void LCodeGen::DoStoreKeyedFastElement(LStoreKeyedFastElement* instr) {
   Register value = ToRegister(instr->value());
   Register elements = ToRegister(instr->object());
   Register key = instr->key()->IsRegister() ? ToRegister(instr->key()) : no_reg;
 
   // Do the store.
   if (instr->key()->IsConstantOperand()) {
@@ skipping 1028 matching lines @@
   RegisterEnvironmentForDeoptimization(environment);
   ASSERT(osr_pc_offset_ == -1);
   osr_pc_offset_ = masm()->pc_offset();
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64