Enable inlining of shared generics code within same type (#38229)

This change allows inlining of generic dictionary lookups when the caller and callee are the same exact type and instantiation.

Example:

```
class G<T>
{
    static bool M1() => typeof(T);

    object M2() => new T[1];

    bool M3() => Unsafe.SizeOf<T>();

    static string M()
    {
         // Assume that T is string
         // All M1, M2, M3 are inlined after this change, but were not inlined before this change
         M1(); M2(); M3();

         // Still not inlined - different instantiation, not the same exact type
         G<List<T>>.M1();

         // Still not inlined - different type.
         OtherG<T>.M();
    }
}
```

src/coreclr/src/ToolBox/superpmi/superpmi-shared/icorjitinfoimpl.h

@@ -393,8 +393,7 @@ CorInfoInitClassResult initClass(CORINFO_FIELD_HANDLE field, // Non-NULL - inqui
                                                              // field access NULL - inquire about cctor trigger in
                                                              // method prolog
                                  CORINFO_METHOD_HANDLE  method,             // Method referencing the field or prolog
-                                 CORINFO_CONTEXT_HANDLE context,            // Exact context of method
-                                 BOOL                   speculative = FALSE // TRUE means don't actually run it
+                                 CORINFO_CONTEXT_HANDLE context             // Exact context of method
                                  );
 
 // This used to be called "loadClass".  This records the fact

src/coreclr/src/ToolBox/superpmi/superpmi-shared/methodcontext.cpp

@@ -908,7 +908,6 @@ void MethodContext::repGetBoundaries(CORINFO_METHOD_HANDLE         ftn,
 void MethodContext::recInitClass(CORINFO_FIELD_HANDLE   field,
                                  CORINFO_METHOD_HANDLE  method,
                                  CORINFO_CONTEXT_HANDLE context,
-                                 BOOL                   speculative,
                                  CorInfoInitClassResult result)
 {
     if (InitClass == nullptr)
@@ -920,20 +919,18 @@ void MethodContext::recInitClass(CORINFO_FIELD_HANDLE   field,
     key.field       = (DWORDLONG)field;
     key.method      = (DWORDLONG)method;
     key.context     = (DWORDLONG)context;
-    key.speculative = (DWORD)speculative;
 
     InitClass->Add(key, (DWORD)result);
     DEBUG_REC(dmpInitClass(key, (DWORD)result));
 }
 void MethodContext::dmpInitClass(const Agnostic_InitClass& key, DWORD value)
 {
-    printf("InitClass key fld-%016llX meth-%016llX con-%016llX spec-%u, value res-%u", key.field, key.method,
-           key.context, key.speculative, value);
+    printf("InitClass key fld-%016llX meth-%016llX con-%016llX, value res-%u", key.field, key.method,
+           key.context, value);
 }
 CorInfoInitClassResult MethodContext::repInitClass(CORINFO_FIELD_HANDLE   field,
                                                    CORINFO_METHOD_HANDLE  method,
-                                                   CORINFO_CONTEXT_HANDLE context,
-                                                   BOOL                   speculative)
+                                                   CORINFO_CONTEXT_HANDLE context)
 {
     Agnostic_InitClass key;
     ZeroMemory(&key, sizeof(Agnostic_InitClass)); // We use the input structs as a key and use memcmp to compare.. so we
@@ -942,7 +939,6 @@ CorInfoInitClassResult MethodContext::repInitClass(CORINFO_FIELD_HANDLE   field,
     key.field       = (DWORDLONG)field;
     key.method      = (DWORDLONG)method;
     key.context     = (DWORDLONG)context;
-    key.speculative = (DWORD)speculative;
 
     AssertCodeMsg(InitClass != nullptr, EXCEPTIONCODE_MC, "Didn't find anything for %016llX", (DWORDLONG)key.method);
     AssertCodeMsg(InitClass->GetIndex(key) != -1, EXCEPTIONCODE_MC, "Didn't find %016llX", (DWORDLONG)key.method);

src/coreclr/src/ToolBox/superpmi/superpmi-shared/methodcontext.h

@@ -63,7 +63,6 @@ class MethodContext
         DWORDLONG field;
         DWORDLONG method;
         DWORDLONG context;
-        DWORD     speculative;
     };
     struct DLDL
     {
@@ -631,13 +630,11 @@ class MethodContext
     void recInitClass(CORINFO_FIELD_HANDLE   field,
                       CORINFO_METHOD_HANDLE  method,
                       CORINFO_CONTEXT_HANDLE context,
-                      BOOL                   speculative,
                       CorInfoInitClassResult result);
     void dmpInitClass(const Agnostic_InitClass& key, DWORD value);
     CorInfoInitClassResult repInitClass(CORINFO_FIELD_HANDLE   field,
                                         CORINFO_METHOD_HANDLE  method,
-                                        CORINFO_CONTEXT_HANDLE context,
-                                        BOOL                   speculative);
+                                        CORINFO_CONTEXT_HANDLE context);
 
     void recGetMethodName(CORINFO_METHOD_HANDLE ftn, char* methodname, const char** moduleName);
     void dmpGetMethodName(DLD key, DD value);

src/coreclr/src/ToolBox/superpmi/superpmi-shim-collector/icorjitinfo.cpp

@@ -840,13 +840,12 @@ CorInfoInitClassResult interceptor_ICJI::initClass(
     CORINFO_FIELD_HANDLE field,        // Non-nullptr - inquire about cctor trigger before static field access
                                        // nullptr - inquire about cctor trigger in method prolog
     CORINFO_METHOD_HANDLE  method,     // Method referencing the field or prolog
-    CORINFO_CONTEXT_HANDLE context,    // Exact context of method
-    BOOL                   speculative // TRUE means don't actually run it
+    CORINFO_CONTEXT_HANDLE context     // Exact context of method
     )
 {
     mc->cr->AddCall("initClass");
-    CorInfoInitClassResult temp = original_ICorJitInfo->initClass(field, method, context, speculative);
-    mc->recInitClass(field, method, context, speculative, temp);
+    CorInfoInitClassResult temp = original_ICorJitInfo->initClass(field, method, context);
+    mc->recInitClass(field, method, context, temp);
     return temp;
 }
 

src/coreclr/src/ToolBox/superpmi/superpmi-shim-counter/icorjitinfo.cpp

@@ -653,12 +653,11 @@ CorInfoInitClassResult interceptor_ICJI::initClass(
     CORINFO_FIELD_HANDLE field,        // Non-nullptr - inquire about cctor trigger before static field access
                                        // nullptr - inquire about cctor trigger in method prolog
     CORINFO_METHOD_HANDLE  method,     // Method referencing the field or prolog
-    CORINFO_CONTEXT_HANDLE context,    // Exact context of method
-    BOOL                   speculative // TRUE means don't actually run it
+    CORINFO_CONTEXT_HANDLE context     // Exact context of method
     )
 {
     mcs->AddCall("initClass");
-    return original_ICorJitInfo->initClass(field, method, context, speculative);
+    return original_ICorJitInfo->initClass(field, method, context);
 }
 
 // This used to be called "loadClass".  This records the fact

src/coreclr/src/ToolBox/superpmi/superpmi-shim-simple/icorjitinfo.cpp

@@ -577,11 +577,10 @@ CorInfoInitClassResult interceptor_ICJI::initClass(
     CORINFO_FIELD_HANDLE field,        // Non-nullptr - inquire about cctor trigger before static field access
                                        // nullptr - inquire about cctor trigger in method prolog
     CORINFO_METHOD_HANDLE  method,     // Method referencing the field or prolog
-    CORINFO_CONTEXT_HANDLE context,    // Exact context of method
-    BOOL                   speculative // TRUE means don't actually run it
+    CORINFO_CONTEXT_HANDLE context     // Exact context of method
     )
 {
-    return original_ICorJitInfo->initClass(field, method, context, speculative);
+    return original_ICorJitInfo->initClass(field, method, context);
 }
 
 // This used to be called "loadClass".  This records the fact

src/coreclr/src/ToolBox/superpmi/superpmi/icorjitinfo.cpp

@@ -702,12 +702,11 @@ CorInfoInitClassResult MyICJI::initClass(CORINFO_FIELD_HANDLE field, // Non-null
                                                                      // static field access nullptr - inquire about
                                                                      // cctor trigger in method prolog
                                          CORINFO_METHOD_HANDLE  method,     // Method referencing the field or prolog
-                                         CORINFO_CONTEXT_HANDLE context,    // Exact context of method
-                                         BOOL                   speculative // TRUE means don't actually run it
+                                         CORINFO_CONTEXT_HANDLE context     // Exact context of method
                                          )
 {
     jitInstance->mc->cr->AddCall("initClass");
-    return jitInstance->mc->repInitClass(field, method, context, speculative);
+    return jitInstance->mc->repInitClass(field, method, context);
 }
 
 // This used to be called "loadClass".  This records the fact

src/coreclr/src/inc/corinfo.h

@@ -217,12 +217,12 @@ TODO: Talk about initializing strutures before use
 #endif
 #endif
 
-SELECTANY const GUID JITEEVersionIdentifier = { /* 2ca8d539-5db9-4831-8f1b-ade425f036bd */
-    0x2ca8d539,
-    0x5db9,
-    0x4831,
-    {0x8f, 0x1b, 0xad, 0xe4, 0x25, 0xf0, 0x36, 0xbd}
-  };
+SELECTANY const GUID JITEEVersionIdentifier = { /* 7af97117-55be-4c76-afb2-e26261cb140e */
+    0x7af97117,
+    0x55be,
+    0x4c76,
+    { 0xaf, 0xb2, 0xe2, 0x62, 0x61, 0xcb, 0x14, 0x0e }
+};
 
 //////////////////////////////////////////////////////////////////////////////////////////////////////////
 //
@@ -1038,9 +1038,8 @@ enum CorInfoInitClassResult
     CORINFO_INITCLASS_NOT_REQUIRED  = 0x00, // No class initialization required, but the class is not actually initialized yet
                                             // (e.g. we are guaranteed to run the static constructor in method prolog)
     CORINFO_INITCLASS_INITIALIZED   = 0x01, // Class initialized
-    CORINFO_INITCLASS_SPECULATIVE   = 0x02, // Class may be initialized speculatively
-    CORINFO_INITCLASS_USE_HELPER    = 0x04, // The JIT must insert class initialization helper call.
-    CORINFO_INITCLASS_DONT_INLINE   = 0x08, // The JIT should not inline the method requesting the class initialization. The class
+    CORINFO_INITCLASS_USE_HELPER    = 0x02, // The JIT must insert class initialization helper call.
+    CORINFO_INITCLASS_DONT_INLINE   = 0x04, // The JIT should not inline the method requesting the class initialization. The class
                                             // initialization requires helper class now, but will not require initialization
                                             // if the method is compiled standalone. Or the method cannot be inlined due to some
                                             // requirement around class initialization such as shared generics.
@@ -1105,9 +1104,7 @@ typedef struct CORINFO_VarArgInfo *         CORINFO_VARARGS_HANDLE;
 // Generic tokens are resolved with respect to a context, which is usually the method
 // being compiled. The CORINFO_CONTEXT_HANDLE indicates which exact instantiation
 // (or the open instantiation) is being referred to.
-// CORINFO_CONTEXT_HANDLE is more tightly scoped than CORINFO_MODULE_HANDLE. For cases
-// where the exact instantiation does not matter, CORINFO_MODULE_HANDLE is used.
-typedef CORINFO_METHOD_HANDLE               CORINFO_CONTEXT_HANDLE;
+typedef struct CORINFO_CONTEXT_STRUCT_*     CORINFO_CONTEXT_HANDLE;
 
 typedef struct CORINFO_DEPENDENCY_STRUCT_
 {
@@ -1124,6 +1121,7 @@ enum CorInfoContextFlags
     CORINFO_CONTEXTFLAGS_MASK   = 0x01
 };
 
+#define METHOD_BEING_COMPILED_CONTEXT() ((CORINFO_CONTEXT_HANDLE)1)
 #define MAKE_CLASSCONTEXT(c)  (CORINFO_CONTEXT_HANDLE((size_t) (c) | CORINFO_CONTEXTFLAGS_CLASS))
 #define MAKE_METHODCONTEXT(m) (CORINFO_CONTEXT_HANDLE((size_t) (m) | CORINFO_CONTEXTFLAGS_METHOD))
 
@@ -1254,6 +1252,7 @@ enum CORINFO_RUNTIME_LOOKUP_KIND
     CORINFO_LOOKUP_THISOBJ,
     CORINFO_LOOKUP_METHODPARAM,
     CORINFO_LOOKUP_CLASSPARAM,
+    CORINFO_LOOKUP_NOT_SUPPORTED, // Returned for attempts to inline dictionary lookups
 };
 
 struct CORINFO_LOOKUP_KIND
@@ -2462,8 +2461,8 @@ class ICorStaticInfo
             CORINFO_FIELD_HANDLE    field,          // Non-NULL - inquire about cctor trigger before static field access
                                                     // NULL - inquire about cctor trigger in method prolog
             CORINFO_METHOD_HANDLE   method,         // Method referencing the field or prolog
-            CORINFO_CONTEXT_HANDLE  context,        // Exact context of method
-            BOOL                    speculative = FALSE     // TRUE means don't actually run it
+                                                    // NULL - method being compiled
+            CORINFO_CONTEXT_HANDLE  context         // Exact context of method
             ) = 0;
 
     // This used to be called "loadClass".  This records the fact

src/coreclr/src/jit/ICorJitInfo_API_wrapper.hpp

@@ -655,11 +655,10 @@ CorInfoInitClassResult WrapICorJitInfo::initClass(
             CORINFO_FIELD_HANDLE    field,
 
             CORINFO_METHOD_HANDLE   method,
-            CORINFO_CONTEXT_HANDLE  context,
-            BOOL                    speculative)
+            CORINFO_CONTEXT_HANDLE  context)
 {
     API_ENTER(initClass);
-    CorInfoInitClassResult temp = wrapHnd->initClass(field, method, context, speculative);
+    CorInfoInitClassResult temp = wrapHnd->initClass(field, method, context);
     API_LEAVE(initClass);
     return temp;
 }

src/coreclr/src/jit/compiler.cpp

@@ -4364,7 +4364,7 @@ void Compiler::compCompile(void** methodCodePtr, ULONG* methodCodeSize, JitFlags
 
         // Insert call to class constructor as the first basic block if
         // we were asked to do so.
-        if (info.compCompHnd->initClass(nullptr /* field */, info.compMethodHnd /* method */,
+        if (info.compCompHnd->initClass(nullptr /* field */, nullptr /* method */,
                                         impTokenLookupContextHandle /* context */) &
             CORINFO_INITCLASS_USE_HELPER)
         {
@@ -5390,7 +5390,7 @@ int Compiler::compCompile(CORINFO_MODULE_HANDLE classPtr,
     }
     else
     {
-        impTokenLookupContextHandle = MAKE_METHODCONTEXT(info.compMethodHnd);
+        impTokenLookupContextHandle = METHOD_BEING_COMPILED_CONTEXT();
 
         info.compClassHnd  = info.compCompHnd->getMethodClass(info.compMethodHnd);
         info.compClassAttr = info.compCompHnd->getClassAttribs(info.compClassHnd);

src/coreclr/src/jit/compiler.h

@@ -3649,7 +3649,7 @@ class Compiler
     };
 
     bool impIsPrimitive(CorInfoType type);
-    bool impILConsumesAddr(const BYTE* codeAddr, CORINFO_METHOD_HANDLE fncHandle, CORINFO_MODULE_HANDLE scpHandle);
+    bool impILConsumesAddr(const BYTE* codeAddr);
 
     void impResolveToken(const BYTE* addr, CORINFO_RESOLVED_TOKEN* pResolvedToken, CorInfoTokenKind kind);
 
@@ -7192,6 +7192,7 @@ class Compiler
     var_types eeGetArgType(CORINFO_ARG_LIST_HANDLE list, CORINFO_SIG_INFO* sig);
     var_types eeGetArgType(CORINFO_ARG_LIST_HANDLE list, CORINFO_SIG_INFO* sig, bool* isPinned);
     CORINFO_CLASS_HANDLE eeGetArgClass(CORINFO_SIG_INFO* sig, CORINFO_ARG_LIST_HANDLE list);
+    CORINFO_CLASS_HANDLE eeGetClassFromContext(CORINFO_CONTEXT_HANDLE context);
     unsigned eeGetArgSize(CORINFO_ARG_LIST_HANDLE list, CORINFO_SIG_INFO* sig);
 
     // VOM info, method sigs

src/coreclr/src/jit/ee_il_dll.hpp

@@ -111,6 +111,24 @@ inline CORINFO_CLASS_HANDLE Compiler::eeGetArgClass(CORINFO_SIG_INFO* sig, CORIN
     return argClass;
 }
 
+/*****************************************************************************/
+inline CORINFO_CLASS_HANDLE Compiler::eeGetClassFromContext(CORINFO_CONTEXT_HANDLE context)
+{
+    if (context == METHOD_BEING_COMPILED_CONTEXT())
+    {
+        return impInlineRoot()->info.compClassHnd;
+    }
+
+    if (((SIZE_T)context & CORINFO_CONTEXTFLAGS_MASK) == CORINFO_CONTEXTFLAGS_CLASS)
+    {
+        return CORINFO_CLASS_HANDLE((SIZE_T)context & ~CORINFO_CONTEXTFLAGS_MASK);
+    }
+    else
+    {
+        return info.compCompHnd->getMethodClass(CORINFO_METHOD_HANDLE((SIZE_T)context & ~CORINFO_CONTEXTFLAGS_MASK));
+    }
+}
+
 /*****************************************************************************
  *
  *                  Native Direct Optimizations

src/coreclr/src/jit/flowgraph.cpp

@@ -4886,8 +4886,7 @@ void Compiler::fgFindJumpTargets(const BYTE* codeAddr, IL_OFFSET codeSize, Fixed
                     const bool notLastInstr = (codeAddr < codeEndp - sz);
                     const bool notDebugCode = !opts.compDbgCode;
 
-                    if (notStruct && notLastInstr && notDebugCode &&
-                        impILConsumesAddr(codeAddr + sz, impTokenLookupContextHandle, info.compScopeHnd))
+                    if (notStruct && notLastInstr && notDebugCode && impILConsumesAddr(codeAddr + sz))
                     {
                         // We can skip the addrtaken, as next IL instruction consumes
                         // the address.
@@ -23169,19 +23168,6 @@ void Compiler::fgInvokeInlineeCompiler(GenTreeCall* call, InlineResult* inlineRe
         return;
     }
 
-    if (inlineCandidateInfo->initClassResult & CORINFO_INITCLASS_SPECULATIVE)
-    {
-        // we defer the call to initClass() until inlining is completed in case it fails. If inlining succeeds,
-        // we will call initClass().
-        if (!(info.compCompHnd->initClass(nullptr /* field */, fncHandle /* method */,
-                                          inlineCandidateInfo->exactContextHnd /* context */) &
-              CORINFO_INITCLASS_INITIALIZED))
-        {
-            inlineResult->NoteFatal(InlineObservation::CALLEE_CLASS_INIT_FAILURE);
-            return;
-        }
-    }
-
     // !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
     // The inlining attempt cannot be failed starting from this point.
     // !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
@@ -23513,6 +23499,8 @@ void Compiler::fgInsertInlineeBlocks(InlineInfo* pInlineInfo)
     compGSReorderStackLayout |= InlineeCompiler->compGSReorderStackLayout;
     compHasBackwardJump |= InlineeCompiler->compHasBackwardJump;
 
+    lvaGenericsContextInUse |= InlineeCompiler->lvaGenericsContextInUse;
+
 #ifdef FEATURE_SIMD
     if (InlineeCompiler->usesSIMDTypes())
     {
@@ -23865,18 +23853,7 @@ Statement* Compiler::fgInlinePrependStatements(InlineInfo* inlineInfo)
 
     if (inlineInfo->inlineCandidateInfo->initClassResult & CORINFO_INITCLASS_USE_HELPER)
     {
-        CORINFO_CONTEXT_HANDLE exactContext = inlineInfo->inlineCandidateInfo->exactContextHnd;
-        CORINFO_CLASS_HANDLE   exactClass;
-
-        if (((SIZE_T)exactContext & CORINFO_CONTEXTFLAGS_MASK) == CORINFO_CONTEXTFLAGS_CLASS)
-        {
-            exactClass = CORINFO_CLASS_HANDLE((SIZE_T)exactContext & ~CORINFO_CONTEXTFLAGS_MASK);
-        }
-        else
-        {
-            exactClass = info.compCompHnd->getMethodClass(
-                CORINFO_METHOD_HANDLE((SIZE_T)exactContext & ~CORINFO_CONTEXTFLAGS_MASK));
-        }
+        CORINFO_CLASS_HANDLE exactClass = eeGetClassFromContext(inlineInfo->inlineCandidateInfo->exactContextHnd);
 
         tree    = fgGetSharedCCtor(exactClass);
         newStmt = gtNewStmt(tree, callILOffset);

src/coreclr/src/jit/gentree.cpp

@@ -17462,18 +17462,7 @@ CORINFO_CLASS_HANDLE Compiler::gtGetClassHandle(GenTree* tree, bool* pIsExact, b
 
                     if (context != nullptr)
                     {
-                        CORINFO_CLASS_HANDLE exactClass = nullptr;
-
-                        if (((size_t)context & CORINFO_CONTEXTFLAGS_MASK) == CORINFO_CONTEXTFLAGS_CLASS)
-                        {
-                            exactClass = (CORINFO_CLASS_HANDLE)((size_t)context & ~CORINFO_CONTEXTFLAGS_MASK);
-                        }
-                        else
-                        {
-                            CORINFO_METHOD_HANDLE exactMethod =
-                                (CORINFO_METHOD_HANDLE)((size_t)context & ~CORINFO_CONTEXTFLAGS_MASK);
-                            exactClass = info.compCompHnd->getMethodClass(exactMethod);
-                        }
+                        CORINFO_CLASS_HANDLE exactClass = eeGetClassFromContext(context);
 
                         // Grab the signature in this context.
                         CORINFO_SIG_INFO sig;