Array index computation dehoisting.

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 2408 matching lines @@
   // Subtracting from length accounts for one of them add one more.
   __ mov(result, Operand(arguments, length, times_4, kPointerSize));
 }
 
 
 void LCodeGen::DoLoadKeyedFastElement(LLoadKeyedFastElement* instr) {
   Register result = ToRegister(instr->result());
 
   // Load the result.
   __ mov(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()) {
     __ cmp(result, factory()->the_hole_value());
     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());
   __ cmp(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());
   __ movdbl(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) << 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) {
     __ movdbl(ToDoubleRegister(instr->result()), operand);
   } else {
     Register result(ToRegister(instr->result()));
     switch (elements_kind) {
       case EXTERNAL_BYTE_ELEMENTS:
@@ skipping 916 matching lines @@
     __ cmp(ToRegister(instr->index()), ToOperand(instr->length()));
     DeoptimizeIf(above_equal, instr->environment());
   }
 }
 
 
 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) {
     __ cvtsd2ss(xmm0, ToDoubleRegister(instr->value()));
     __ movss(operand, xmm0);
   } else if (elements_kind == EXTERNAL_DOUBLE_ELEMENTS) {
     __ movdbl(operand, ToDoubleRegister(instr->value()));
   } else {
     Register value = ToRegister(instr->value());
     switch (elements_kind) {
       case EXTERNAL_PIXEL_ELEMENTS:
       case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
@@ skipping 20 matching lines @@
     }
   }
 }
 
 
 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;
-    __ mov(FieldOperand(elements, offset), value);
-  } else {
-    __ mov(FieldOperand(elements,
-                        key,
-                        times_pointer_size,
-                        FixedArray::kHeaderSize),
-           value);
-  }
+  Operand operand = BuildFastArrayOperand(
+      instr->object(),
+      instr->key(),
+      FAST_ELEMENTS,
+      FixedArray::kHeaderSize - kHeapObjectTag,
+      instr->additional_index());
+  __ mov(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.
 
     ExternalReference canonical_nan_reference =
         ExternalReference::address_of_canonical_non_hole_nan();
     __ movdbl(value, Operand::StaticVariable(canonical_nan_reference));
     __ 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());
   __ movdbl(double_store_operand, value);
 }
 
 
 void LCodeGen::DoStoreKeyedGeneric(LStoreKeyedGeneric* instr) {
   ASSERT(ToRegister(instr->context()).is(esi));
   ASSERT(ToRegister(instr->object()).is(edx));
   ASSERT(ToRegister(instr->key()).is(ecx));
   ASSERT(ToRegister(instr->value()).is(eax));
 
@@ skipping 1534 matching lines @@
                               FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32