private static bool Object_getClass(EmitIntrinsicContext eic)
{
// this is the null-check idiom that javac uses (both in its own source and in the code it generates)
if (eic.MatchRange(0, 2) &&
eic.Match(1, NormalizedByteCode.__pop))
{
eic.Emitter.Emit(OpCodes.Dup);
eic.Emitter.EmitNullCheck();
return(true);
}
// this optimizes obj1.getClass() ==/!= obj2.getClass()
else if (eic.MatchRange(0, 4) &&
eic.Match(1, NormalizedByteCode.__aload) &&
eic.Match(2, NormalizedByteCode.__invokevirtual) &&
(eic.Match(3, NormalizedByteCode.__if_acmpeq) || eic.Match(3, NormalizedByteCode.__if_acmpne)) &&
(IsSafeForGetClassOptimization(eic.GetStackTypeWrapper(0, 0)) || IsSafeForGetClassOptimization(eic.GetStackTypeWrapper(2, 0))))
{
ClassFile.ConstantPoolItemMI cpi = eic.GetMethodref(2);
if (cpi.Class == "java.lang.Object" && cpi.Name == "getClass" && cpi.Signature == "()Ljava.lang.Class;")
{
// we can't patch the current opcode, so we have to emit the first call to GetTypeHandle here
eic.Emitter.Emit(OpCodes.Callvirt, Compiler.getTypeMethod);
eic.PatchOpCode(2, NormalizedByteCode.__intrinsic_gettype);
return(true);
}
}
// this optimizes obj.getClass() == Xxx.class
else if (eic.MatchRange(0, 3) &&
eic.Match(1, NormalizedByteCode.__ldc) && eic.GetConstantType(1) == ClassFile.ConstantType.Class &&
(eic.Match(2, NormalizedByteCode.__if_acmpeq) || eic.Match(2, NormalizedByteCode.__if_acmpne)))
{
TypeWrapper tw = eic.GetClassLiteral(1);
if (tw.IsGhost || tw.IsGhostArray || tw.IsUnloadable || (tw.IsRemapped && tw.IsFinal && tw is DotNetTypeWrapper))
{
return(false);
}
eic.Emitter.Emit(OpCodes.Callvirt, Compiler.getTypeMethod);
eic.Emitter.Emit(OpCodes.Ldtoken, (tw.IsRemapped && tw.IsFinal) ? tw.TypeAsTBD : tw.TypeAsBaseType);
eic.Emitter.Emit(OpCodes.Call, Compiler.getTypeFromHandleMethod);
eic.PatchOpCode(1, NormalizedByteCode.__nop);
return(true);
}
return(false);
}
