Port and integrate the irregexp engine from V8

runtime/vm/intrinsifier_arm64.cc

Index: runtime/vm/intrinsifier_arm64.cc
diff --git a/runtime/vm/intrinsifier_arm64.cc b/runtime/vm/intrinsifier_arm64.cc
index 65229be8c865f594a0649ca088ca6f62d560b1cb..03d3875eebc681a47d80af0935017ec9825b3a65 100644
--- a/runtime/vm/intrinsifier_arm64.cc
+++ b/runtime/vm/intrinsifier_arm64.cc
@@ -8,9 +8,11 @@
 #include "vm/intrinsifier.h"
 
 #include "vm/assembler.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 {
@@ -1517,6 +1519,44 @@ void Intrinsifier::TwoByteString_equality(Assembler* assembler) {
 }
 
 
+void Intrinsifier::JSRegExp_ExecuteMatch(Assembler* assembler) {
+  static const intptr_t kRegExpParamOffset = + 2 * kWordSize;
+  static const intptr_t kStringParamOffset = + 1 * kWordSize;
+  // const Smi& start_index is located at   (+ 0 * kWordSize).
+
+  // Register assignments are as follows:
+  // R0: The appropriate specialized matcher function.
+  // R2: The regexp object.
+  // R4: Temp.
+  // 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, PP);

[Florian Schneider, 2014/10/07 12:49:37]

I don't think you can use PP here, since the pool register is not set up like it
is in normal function here in intrinsic code. The FlowGraphCompiler disables the
constant pool for instrinsics, but better use kNoPP instead to be safe.

[jgruber1, 2014/10/07 15:00:25]

Done.

+  __ AddImmediate(R1, R1, -kOneByteStringCid, PP);

[Florian Schneider, 2014/10/07 12:49:37]

kNoPP here and below as well.

[jgruber1, 2014/10/07 15:00:25]

Done.

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