Native construction of RegExp result objects, with in-object index and input.

src/ia32/codegen-ia32.cc

Index: src/ia32/codegen-ia32.cc
diff --git a/src/ia32/codegen-ia32.cc b/src/ia32/codegen-ia32.cc
index bbbcd3a09a9002d2d067cff4ea1f866606ec91ce..9a4f472abdb8f0010cd0fafaf1b26bf3152e2726 100644
--- a/src/ia32/codegen-ia32.cc
+++ b/src/ia32/codegen-ia32.cc
@@ -6523,7 +6523,7 @@ void CodeGenerator::GenerateStringCompare(ZoneList<Expression*>* args) {
 
 
 void CodeGenerator::GenerateRegExpExec(ZoneList<Expression*>* args) {
-  ASSERT_EQ(args->length(), 4);
+  ASSERT_EQ(4, args->length());
 
   // Load the arguments on the stack and call the stub.
   Load(args->at(0));
@@ -6536,6 +6536,95 @@ void CodeGenerator::GenerateRegExpExec(ZoneList<Expression*>* args) {
 }
 
 
+void CodeGenerator::GenerateRegExpConstructResult(ZoneList<Expression*>* args) {
+  // No stub. This code only occurs a few times in regexp.js.
+  const int kMaxInlineLength = 100;
+  ASSERT_EQ(3, args->length());
+  Load(args->at(0));  // Size of array, smi.
+  Load(args->at(1));  // "index" property value.
+  Load(args->at(2));  // "input" property value.
+  {
+    VirtualFrame::SpilledScope spilled_scope;
+
+    Label slowcase;
+    Label done;
+    __ mov(ebx, Operand(esp, kPointerSize * 2));
+    __ test(ebx, Immediate(0x01));

[Søren Thygesen Gjesse, 2010/04/13 07:22:29]

kHeapObjectTag?

[Lasse Reichstein, 2010/04/13 09:50:56]

Changed to kSmiTagMask.

+    __ j(not_zero, &slowcase);
+    __ cmp(Operand(ebx), Immediate(Smi::FromInt(kMaxInlineLength)));
+    __ j(above, &slowcase);
+    // Smi-tagging is equivalent to multiplying by 2.
+    STATIC_ASSERT(kSmiTag == 0);
+    STATIC_ASSERT(kSmiTagSize == 1);
+    // Allocate RegExpResult followed by FixedArray with size in ebx.
+    // JSArray:   [Map][empty properties][Elements][Length-smi][index][input]
+    // Elements:  [Map][Length][..elements..]
+    __ AllocateInNewSpace(JSArray::kRegExpResultSize + FixedArray::kHeaderSize,

[Søren Thygesen Gjesse, 2010/04/13 07:22:29]

JSArray::kRegExpResultSize -> JSRegExpResult::kSize

+                          times_half_pointer_size,

[Lasse Reichstein, 2010/04/13 09:50:56]

Done.

+                          ebx,  // In: Number of elements (times 2, being a smi)
+                          eax,  // Out: Start of allocation (tagged).
+                          ecx,  // Out: End of allocation.
+                          edx,  // Scratch register
+                          &slowcase,
+                          TAG_OBJECT);
+    // eax: Start of allocated area, object-tagged.
+
+    // Set JSArray map to global.regexp_result_map().
+    // Set empty properties FixedArray.
+    // Set elements to point to FixedArray allocated right after the JSArray.
+    // Interleave operations for better latency.
+    __ mov(edx, ContextOperand(esi, Context::GLOBAL_INDEX));
+    __ mov(ecx, Immediate(Factory::empty_fixed_array()));
+    __ lea(ebx, Operand(eax, JSArray::kRegExpResultSize));
+    __ mov(edx, FieldOperand(edx, GlobalObject::kGlobalContextOffset));
+    __ mov(FieldOperand(eax, JSObject::kElementsOffset), ebx);
+    __ mov(FieldOperand(eax, JSObject::kPropertiesOffset), ecx);
+    __ mov(edx, ContextOperand(edx, Context::REGEXP_RESULT_MAP_INDEX));
+    __ mov(FieldOperand(eax, HeapObject::kMapOffset), edx);
+
+    // Set input, index and length fields from arguments.
+    __ pop(FieldOperand(eax, JSArray::kSize + kPointerSize));

[Søren Thygesen Gjesse, 2010/04/13 07:22:29]

Please add constants JSRegExpResult::kIndexOffset and
JSRegExpResult::kInputOffset.

[Lasse Reichstein, 2010/04/13 09:50:56]

Done.

+    __ pop(FieldOperand(eax, JSArray::kSize));
+    __ pop(ecx);
+    __ mov(FieldOperand(eax, JSArray::kLengthOffset), ecx);
+
+    // Fill out the elements FixedArray.
+    // eax: JSArray.
+    // ebx: FixedArray.
+    // ecx: Number of elements in array, as smi.
+
+    // Set map.
+    __ mov(FieldOperand(ebx, HeapObject::kMapOffset),
+           Immediate(Factory::fixed_array_map()));
+    // Set length.
+    __ SmiUntag(ecx);
+    __ mov(FieldOperand(ebx, FixedArray::kLengthOffset), ecx);
+    // Fill contents of fixed-array with the-hole.
+    __ mov(edx, Immediate(Factory::the_hole_value()));
+    __ lea(ebx, FieldOperand(ebx, FixedArray::kHeaderSize));
+    // Fill fixed array elements with hole.
+    // eax: JSArray.
+    // ecx: Number of elements to fill.
+    // ebx: Start of elements in FixedArray.
+    // edx: the hole.
+    Label loop;
+    __ test(ecx, Operand(ecx));
+    __ bind(&loop);
+    __ j(less_equal, &done);  // Jump if ecx is negative or zero.
+    __ sub(Operand(ecx), Immediate(1));
+    __ mov(Operand(ebx, ecx, times_pointer_size, 0), edx);
+    __ jmp(&loop);
+
+    __ bind(&slowcase);
+    __ CallRuntime(Runtime::kRegExpConstructResult, 3);
+
+    __ bind(&done);
+  }
+  frame_->Forget(3);
+  frame_->Push(eax);
+}
+
+
 void CodeGenerator::GenerateNumberToString(ZoneList<Expression*>* args) {
   ASSERT_EQ(args->length(), 1);