Intrinsify typeof(T).GetGenericTypeDefinition() (#103528)

 Co-authored-by: Jan Kotas <jkotas@microsoft.com>

Author: Sergio0694

src/coreclr/inc/corinfo.h

@@ -2082,6 +2082,22 @@ class ICorStaticInfo
  CORINFO_METHOD_HANDLE meth1Hnd,
  CORINFO_METHOD_HANDLE meth2Hnd) = 0;
 
+ //------------------------------------------------------------------------------
+ // getTypeDefinition: Get the (unconstructed) type definition from a given type handle.
+ //
+ // Arguments:
+ // type - The input type handle
+ //
+ // Return Value:
+ // The type handle for the (unconstructed) type definition from type.
+ //
+ // Remarks:
+ // This is equivalent of Type.GetGenericTypeDefinition(). Given a generic type handle, it will
+ // return the original type definition (eg. for Foo<int> it will return Foo<>). If called with
+ // an unconstructed generic type, the method returns the same type as the input. This method
+ // should only be called when the input type is in fact a generic type.
+ virtual CORINFO_CLASS_HANDLE getTypeDefinition(CORINFO_CLASS_HANDLE type) = 0;
+
  // Decides if you have any limitations for inlining. If everything's OK, it will return
  // INLINE_PASS.
  //

src/coreclr/inc/icorjitinfoimpl_generated.h

@@ -48,6 +48,9 @@ bool haveSameMethodDefinition(
  CORINFO_METHOD_HANDLE meth1Hnd,
  CORINFO_METHOD_HANDLE meth2Hnd) override;
 
+CORINFO_CLASS_HANDLE getTypeDefinition(
+ CORINFO_CLASS_HANDLE type) override;
+
 CorInfoInline canInline(
  CORINFO_METHOD_HANDLE callerHnd,
  CORINFO_METHOD_HANDLE calleeHnd) override;

src/coreclr/inc/jiteeversionguid.h

@@ -43,11 +43,11 @@ typedef const GUID *LPCGUID;
 #define GUID_DEFINED
 #endif // !GUID_DEFINED
 
-constexpr GUID JITEEVersionIdentifier = { /* 64fe30fb-0a27-4b1d-b89e-306e552ac848 */
- 0x64fe30fb,
- 0x0a27,
- 0x4b1d,
- {0xb8, 0x9e, 0x30, 0x6e, 0x55, 0x2a, 0xc8, 0x48}
+constexpr GUID JITEEVersionIdentifier = { /* 273ba350-32bf-4714-beb0-7fa46c11364d */
+ 0x273ba350,
+ 0x32bf,
+ 0x4714,
+ {0xbe, 0xb0, 0x7f, 0xa4, 0x6c, 0x11, 0x36, 0x4d}
  };
 
 //////////////////////////////////////////////////////////////////////////////////////////////////////////

src/coreclr/jit/ICorJitInfo_names_generated.h

@@ -11,6 +11,7 @@ DEF_CLR_API(setMethodAttribs)
 DEF_CLR_API(getMethodSig)
 DEF_CLR_API(getMethodInfo)
 DEF_CLR_API(haveSameMethodDefinition)
+DEF_CLR_API(getTypeDefinition)
 DEF_CLR_API(canInline)
 DEF_CLR_API(beginInlining)
 DEF_CLR_API(reportInliningDecision)

src/coreclr/jit/ICorJitInfo_wrapper_generated.hpp

@@ -79,6 +79,15 @@ bool WrapICorJitInfo::haveSameMethodDefinition(
  return temp;
 }
 
+CORINFO_CLASS_HANDLE WrapICorJitInfo::getTypeDefinition(
+ CORINFO_CLASS_HANDLE type)
+{
+ API_ENTER(getTypeDefinition);
+ CORINFO_CLASS_HANDLE temp = wrapHnd->getTypeDefinition(type);
+ API_LEAVE(getTypeDefinition);
+ return temp;
+}
+
 CorInfoInline WrapICorJitInfo::canInline(
  CORINFO_METHOD_HANDLE callerHnd,
  CORINFO_METHOD_HANDLE calleeHnd)

src/coreclr/jit/compiler.h

@@ -4589,6 +4589,7 @@ class Compiler
 #endif
  void impResetLeaveBlock(BasicBlock* block, unsigned jmpAddr);
  GenTree* impTypeIsAssignable(GenTree* typeTo, GenTree* typeFrom);
+ GenTree* impGetGenericTypeDefinition(GenTree* type);
 
  // Mirrors StringComparison.cs
  enum StringComparison

src/coreclr/jit/fgbasic.cpp

@@ -1387,6 +1387,7 @@ void Compiler::fgFindJumpTargets(const BYTE* codeAddr, IL_OFFSET codeSize, Fixed
  case NI_System_Type_get_IsByRefLike:
  case NI_System_Type_get_IsGenericType:
  case NI_System_Type_GetTypeFromHandle:
+ case NI_System_Type_GetGenericTypeDefinition:
  case NI_System_String_get_Length:
  case NI_System_Buffers_Binary_BinaryPrimitives_ReverseEndianness:
 #if defined(FEATURE_HW_INTRINSICS)

src/coreclr/jit/importer.cpp

@@ -2490,6 +2490,42 @@ GenTree* Compiler::impTypeIsAssignable(GenTree* typeTo, GenTree* typeFrom)
  return nullptr;
 }
 
+//------------------------------------------------------------------------
+// impGetGenericTypeDefinition: gets the generic type definition from a 'typeof' expression.
+//
+// Arguments:
+// type - The 'GenTree' node to inspect.
+//
+// Notes:
+// If successful, this method will call 'impPopStack()' before returning.
+//
+GenTree* Compiler::impGetGenericTypeDefinition(GenTree* type)
+{
+ // This intrinsic requires the first arg to be some `typeof()` expression,
+ // ie. it applies to cases such as `typeof(...).GetGenericTypeDefinition()`.
+ CORINFO_CLASS_HANDLE hClassType = NO_CLASS_HANDLE;
+ if (gtIsTypeof(type, &hClassType))
+ {
+ // Check that the 'typeof()' expression is being used on a type that is in fact generic.
+ // If that is not the case, we don't expand the intrinsic. This will end up using
+ // the usual Type.GetGenericTypeDefinition() at runtime, which will throw in this case.
+ if (info.compCompHnd->getTypeInstantiationArgument(hClassType, 0) != NO_CLASS_HANDLE)
+ {
+ CORINFO_CLASS_HANDLE hClassResult = info.compCompHnd->getTypeDefinition(hClassType);
+
+ GenTree* handle = gtNewIconEmbClsHndNode(hClassResult);
+ GenTree* retNode = gtNewHelperCallNode(CORINFO_HELP_TYPEHANDLE_TO_RUNTIMETYPE, TYP_REF, handle);
+
+ // Drop the typeof(T) node
+ impPopStack();
+
+ return retNode;
+ }
+ }
+
+ return nullptr;
+}
+
 /*****************************************************************************
  * 'logMsg' is true if a log message needs to be logged. false if the caller has
  * already logged it (presumably in a more detailed fashion than done here)

src/coreclr/jit/importercalls.cpp

@@ -3321,6 +3321,9 @@ GenTree* Compiler::impIntrinsic(CORINFO_CLASS_HANDLE clsHnd,
  case NI_System_Type_op_Equality:
  case NI_System_Type_op_Inequality:
 
+ // This allows folding "typeof(...).GetGenericTypeDefinition() == typeof(...)"
+ case NI_System_Type_GetGenericTypeDefinition:
+
  // These may lead to early dead code elimination
  case NI_System_Type_get_IsValueType:
  case NI_System_Type_get_IsPrimitive:
@@ -3856,6 +3859,14 @@ GenTree* Compiler::impIntrinsic(CORINFO_CLASS_HANDLE clsHnd,
  break;
  }
 
+ case NI_System_Type_GetGenericTypeDefinition:
+ {
+ GenTree* type = impStackTop(0).val;
+
+ retNode = impGetGenericTypeDefinition(type);
+ break;
+ }
+
  case NI_System_Type_op_Equality:
  case NI_System_Type_op_Inequality:
  {
@@ -10220,6 +10231,10 @@ NamedIntrinsic Compiler::lookupNamedIntrinsic(CORINFO_METHOD_HANDLE method)
  {
  result = NI_System_Type_GetTypeFromHandle;
  }
+ else if (strcmp(methodName, "GetGenericTypeDefinition") == 0)
+ {
+ result = NI_System_Type_GetGenericTypeDefinition;
+ }
  else if (strcmp(methodName, "IsAssignableFrom") == 0)
  {
  result = NI_System_Type_IsAssignableFrom;

src/coreclr/jit/namedintrinsiclist.h

@@ -89,6 +89,7 @@ enum NamedIntrinsic : unsigned short
  NI_System_Type_op_Equality,
  NI_System_Type_op_Inequality,
  NI_System_Type_GetTypeFromHandle,
+ NI_System_Type_GetGenericTypeDefinition,
  NI_System_Array_Clone,
  NI_System_Array_GetLength,
  NI_System_Array_GetLowerBound,