Array index computation dehoisting.

src/x64/lithium-codegen-x64.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 2359 matching lines @@
   // 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 result = ToRegister(instr->result());
 
   // Load the result.
   __ movq(result,
-          BuildFastArrayOperand(instr->elements(), instr->key(),
+          BuildFastArrayOperand(instr->elements(),
+                                instr->key(),
                                 FAST_ELEMENTS,
-                                FixedArray::kHeaderSize - kHeapObjectTag));
+                                FixedArray::kHeaderSize - kHeapObjectTag,
+                                instr->additional_index()));
 
   // Check for the hole value.
   if (instr->hydrogen()->RequiresHoleCheck()) {
     __ CompareRoot(result, Heap::kTheHoleValueRootIndex);
     DeoptimizeIf(equal, instr->environment());
   }
 }
 
 
 void LCodeGen::DoLoadKeyedFastDoubleElement(
     LLoadKeyedFastDoubleElement* instr) {
   XMMRegister result(ToDoubleRegister(instr->result()));
 
   int offset = FixedDoubleArray::kHeaderSize - kHeapObjectTag +
       sizeof(kHoleNanLower32);
   Operand hole_check_operand = BuildFastArrayOperand(
       instr->elements(),
       instr->key(),
       FAST_DOUBLE_ELEMENTS,
-      offset);
+      offset,
+      instr->additional_index());
   __ cmpl(hole_check_operand, Immediate(kHoleNanUpper32));
   DeoptimizeIf(equal, instr->environment());
 
   Operand double_load_operand = BuildFastArrayOperand(
-      instr->elements(), instr->key(), FAST_DOUBLE_ELEMENTS,
-      FixedDoubleArray::kHeaderSize - kHeapObjectTag);
+      instr->elements(),
+      instr->key(),
+      FAST_DOUBLE_ELEMENTS,
+      FixedDoubleArray::kHeaderSize - kHeapObjectTag,
+      instr->additional_index());
   __ movsd(result, double_load_operand);
 }
 
 
 Operand LCodeGen::BuildFastArrayOperand(
     LOperand* elements_pointer,
     LOperand* key,
     ElementsKind elements_kind,
-    uint32_t offset) {
+    uint32_t offset,
+    uint32_t additional_index) {
   Register elements_pointer_reg = ToRegister(elements_pointer);
   int shift_size = ElementsKindToShiftSize(elements_kind);
   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 * (1 << shift_size) + offset);
+                   (constant_value + additional_index) * (1 << shift_size)
+                       + offset);
   } else {
     ScaleFactor scale_factor = static_cast<ScaleFactor>(shift_size);
-    return Operand(elements_pointer_reg, ToRegister(key),
-                   scale_factor, offset);
+    return Operand(elements_pointer_reg,
+                   ToRegister(key),
+                   scale_factor,
+                   offset + (additional_index << shift_size));
   }
 }
 
 
 void LCodeGen::DoLoadKeyedSpecializedArrayElement(
     LLoadKeyedSpecializedArrayElement* instr) {
   ElementsKind elements_kind = instr->elements_kind();
   Operand operand(BuildFastArrayOperand(instr->external_pointer(),
-                                        instr->key(), elements_kind, 0));
+                                        instr->key(),
+                                        elements_kind,
+                                        0,
+                                        instr->additional_index()));
   if (elements_kind == EXTERNAL_FLOAT_ELEMENTS) {
     XMMRegister result(ToDoubleRegister(instr->result()));
     __ movss(result, operand);
     __ cvtss2sd(result, result);
   } else if (elements_kind == EXTERNAL_DOUBLE_ELEMENTS) {
     __ movsd(ToDoubleRegister(instr->result()), operand);
   } else {
     Register result(ToRegister(instr->result()));
     switch (elements_kind) {
       case EXTERNAL_BYTE_ELEMENTS:
@@ skipping 881 matching lines @@
       ? isolate()->builtins()->StoreIC_Initialize_Strict()
       : isolate()->builtins()->StoreIC_Initialize();
   CallCode(ic, RelocInfo::CODE_TARGET, instr);
 }
 
 
 void LCodeGen::DoStoreKeyedSpecializedArrayElement(
     LStoreKeyedSpecializedArrayElement* instr) {
   ElementsKind elements_kind = instr->elements_kind();
   Operand operand(BuildFastArrayOperand(instr->external_pointer(),
-                                        instr->key(), elements_kind, 0));
+                                        instr->key(),
+                                        elements_kind,
+                                        0,
+                                        instr->additional_index()));
   if (elements_kind == EXTERNAL_FLOAT_ELEMENTS) {
     XMMRegister value(ToDoubleRegister(instr->value()));
     __ cvtsd2ss(value, value);
     __ movss(operand, value);
   } else if (elements_kind == EXTERNAL_DOUBLE_ELEMENTS) {
     __ movsd(operand, ToDoubleRegister(instr->value()));
   } else {
     Register value(ToRegister(instr->value()));
     switch (elements_kind) {
       case EXTERNAL_PIXEL_ELEMENTS:
@@ skipping 49 matching lines @@
   }
   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()) {
-    ASSERT(!instr->hydrogen()->NeedsWriteBarrier());
-    LConstantOperand* const_operand = LConstantOperand::cast(instr->key());
-    int offset =
-        ToInteger32(const_operand) * kPointerSize + FixedArray::kHeaderSize;
-    __ movq(FieldOperand(elements, offset), value);
-  } else {
-    __ movq(FieldOperand(elements,
-                         key,
-                         times_pointer_size,
-                         FixedArray::kHeaderSize),
-            value);
-  }
+  Operand operand = BuildFastArrayOperand(instr->object(),
+                                          instr->key(),
+                                          FAST_ELEMENTS,
+                                          FixedArray::kHeaderSize
+                                              - kHeapObjectTag,
+                                          instr->additional_index());
+  __ movq(operand, value);
 
   if (instr->hydrogen()->NeedsWriteBarrier()) {
+    ASSERT(!instr->key()->IsConstantOperand());
     HType type = instr->hydrogen()->value()->type();
     SmiCheck check_needed =
         type.IsHeapObject() ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
     // Compute address of modified element and store it into key register.
-    __ lea(key, FieldOperand(elements,
-                             key,
-                             times_pointer_size,
-                             FixedArray::kHeaderSize));
+    __ lea(key, operand);
     __ RecordWrite(elements,
                    key,
                    value,
                    kSaveFPRegs,
                    EMIT_REMEMBERED_SET,
                    check_needed);
   }
 }
 
 
 void LCodeGen::DoStoreKeyedFastDoubleElement(
     LStoreKeyedFastDoubleElement* instr) {
   XMMRegister value = ToDoubleRegister(instr->value());
 
   if (instr->NeedsCanonicalization()) {
     Label have_value;
 
     __ ucomisd(value, value);
     __ j(parity_odd, &have_value);  // NaN.
 
     __ Set(kScratchRegister, BitCast<uint64_t>(
         FixedDoubleArray::canonical_not_the_hole_nan_as_double()));
     __ movq(value, kScratchRegister);
 
     __ bind(&have_value);
   }
 
   Operand double_store_operand = BuildFastArrayOperand(
-      instr->elements(), instr->key(), FAST_DOUBLE_ELEMENTS,
-      FixedDoubleArray::kHeaderSize - kHeapObjectTag);
+      instr->elements(),
+      instr->key(),
+      FAST_DOUBLE_ELEMENTS,
+      FixedDoubleArray::kHeaderSize - kHeapObjectTag,
+      instr->additional_index());
   __ movsd(double_store_operand, value);
 }
 
 void LCodeGen::DoStoreKeyedGeneric(LStoreKeyedGeneric* instr) {
   ASSERT(ToRegister(instr->object()).is(rdx));
   ASSERT(ToRegister(instr->key()).is(rcx));
   ASSERT(ToRegister(instr->value()).is(rax));
 
   Handle<Code> ic = (instr->strict_mode_flag() == kStrictMode)
       ? isolate()->builtins()->KeyedStoreIC_Initialize_Strict()
@@ skipping 1342 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64