Integrate the Irregexp Regular Expression Engine.

runtime/vm/intrinsifier_arm.cc

Index: runtime/vm/intrinsifier_arm.cc
diff --git a/runtime/vm/intrinsifier_arm.cc b/runtime/vm/intrinsifier_arm.cc
index 367ffa712e8adbd516f8e2642239f242af5aa0d2..9e246a71fe66b6621c480ece3ecfca1a6e16f27a 100644
--- a/runtime/vm/intrinsifier_arm.cc
+++ b/runtime/vm/intrinsifier_arm.cc
@@ -9,9 +9,11 @@
 
 #include "vm/assembler.h"
 #include "vm/cpu.h"
+#include "vm/dart_entry.h"
 #include "vm/flow_graph_compiler.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
+#include "vm/regexp_assembler.h"
 #include "vm/symbols.h"
 
 namespace dart {
@@ -1970,6 +1972,43 @@ void Intrinsifier::TwoByteString_equality(Assembler* assembler) {
 }
 
 
+void Intrinsifier::JSRegExp_ExecuteMatch(Assembler* assembler) {
+  static const intptr_t kRegExpParamOffset = + 2 * kWordSize;

[Ivan Posva, 2014/11/14 08:42:50]

+ 2 is is unusual style.

[zerny-google, 2014/11/14 12:18:57]

Done.

+  static const intptr_t kStringParamOffset = + 1 * kWordSize;
+  // const Smi& start_index is located at   (+ 0 * kWordSize).

[Ivan Posva, 2014/11/14 08:42:50]

Code in comments?

[zerny-google, 2014/11/14 12:18:57]

Done.

+
+  // Register assignments are as follows:
+  // R0: The appropriate specialized matcher function.

[Ivan Posva, 2014/11/14 08:42:50]

These register assignments are not valid at this point. See line 1767 above for
an example.
In general a comment documenting registers coming in briefly describes the
operation being done in the block followed by a list of current register values.

Incoming we have this following setup:
// R0: Function. (Will be reloaded with the correct target function).
// R4: Arguments descriptor. (Needs to be preserved).
// R5: IC-Data (for methods).

[zerny-google, 2014/11/14 12:18:57]

Done.

+  // R2: The regexp object.
+  // R5: Temp.
+  // R1: Temp, Pointer to the function's code which we then tail-call.
+
+  __ ldr(R2, Address(SP, kRegExpParamOffset));
+  __ ldr(R1, Address(SP, kStringParamOffset));
+
+  // Load the specialized function pointer into R0. Leverage the fact the
+  // string CIDs as well as stored function pointers are in sequence.
+
+  __ LoadClassId(R1, R1);
+  __ AddImmediate(R1, R1, -kOneByteStringCid);
+  __ add(R1, R2, Operand(R1, LSL, kWordSizeLog2));
+  __ ldr(R0, FieldAddress(R1, JSRegExp::function_offset(kOneByteStringCid)));
+
+  // Registers have been set up for the lazy compile stub at this point.
+  // It expects the function in R0, the argument descriptor in R4, and
+  // IC-Data in R5. Explicitly null out IC-Data to ensure its validity.

[Ivan Posva, 2014/11/14 08:42:50]

It is not clear to me from this comment why the IC-data needs to be set to 0.

[zerny-google, 2014/11/14 12:18:57]

I think maybe some previous version of the stub used the ic-data register as a
temp and so it was cleared here. Removed the unneeded clearing from all
platforms.

+
+  static const intptr_t arg_count = RegExpMacroAssembler::kParamCount;
+  __ LoadObject(R4, Array::Handle(ArgumentsDescriptor::New(arg_count)));
+  __ eor(R5, R5, Operand(R5));
+
+  // Tail-call the function.
+  __ ldr(R1, FieldAddress(R0, Function::instructions_offset()));
+  __ AddImmediate(R1, Instructions::HeaderSize() - kHeapObjectTag);
+  __ bx(R1);
+}
+
+
 // On stack: user tag (+0).
 void Intrinsifier::UserTag_makeCurrent(Assembler* assembler) {
   // R1: Isolate.