Final clean up

src/coreclr/jit/assertionprop.cpp

@@ -4764,17 +4764,14 @@ GenTree* Compiler::optAssertionProp_Call(ASSERT_VALARG_TP assertions, GenTreeCal
     {
         return optAssertionProp_Update(call, call, stmt);
     }
-    else if (!optLocalAssertionProp && (call->gtCallType == CT_HELPER))
-    {
-        if (call->gtCallMethHnd == eeFindHelper(CORINFO_HELP_ISINSTANCEOFINTERFACE) ||
-            call->gtCallMethHnd == eeFindHelper(CORINFO_HELP_ISINSTANCEOFARRAY) ||
-            call->gtCallMethHnd == eeFindHelper(CORINFO_HELP_ISINSTANCEOFCLASS) ||
-            call->gtCallMethHnd == eeFindHelper(CORINFO_HELP_ISINSTANCEOFANY) ||
-            call->gtCallMethHnd == eeFindHelper(CORINFO_HELP_CHKCASTINTERFACE) ||
-            call->gtCallMethHnd == eeFindHelper(CORINFO_HELP_CHKCASTARRAY) ||
-            call->gtCallMethHnd == eeFindHelper(CORINFO_HELP_CHKCASTCLASS) ||
-            call->gtCallMethHnd == eeFindHelper(CORINFO_HELP_CHKCASTANY) ||
-            call->gtCallMethHnd == eeFindHelper(CORINFO_HELP_CHKCASTCLASS_SPECIAL))
+    else if (!optLocalAssertionProp && call->IsHelperCall())
+    {
+        const CorInfoHelpFunc helper = eeGetHelperNum(call->gtCallMethHnd);
+        if ((helper == CORINFO_HELP_ISINSTANCEOFINTERFACE) || (helper == CORINFO_HELP_ISINSTANCEOFARRAY) ||
+            (helper == CORINFO_HELP_ISINSTANCEOFCLASS) || (helper == CORINFO_HELP_ISINSTANCEOFANY) ||
+            (helper == CORINFO_HELP_CHKCASTINTERFACE) || (helper == CORINFO_HELP_CHKCASTARRAY) ||
+            (helper == CORINFO_HELP_CHKCASTCLASS) || (helper == CORINFO_HELP_CHKCASTANY) ||
+            (helper == CORINFO_HELP_CHKCASTCLASS_SPECIAL))
         {
             GenTree* arg1 = call->gtArgs.GetArgByIndex(1)->GetNode();
             if (arg1->gtOper != GT_LCL_VAR)
@@ -4804,6 +4801,11 @@ GenTree* Compiler::optAssertionProp_Call(ASSERT_VALARG_TP assertions, GenTreeCal
 
                 return optAssertionProp_Update(arg1, call, stmt);
             }
+
+            // TODO: check optAssertionIsNonNull for the object argument and replace
+            // the helper with its nonnull version, e.g.:
+            // CORINFO_HELP_ISINSTANCEOFANY -> CORINFO_HELP_ISINSTANCEOFANY_NONNULL
+            // so then fgLateCastExpansion can skip the null check.
         }
     }
 

src/coreclr/jit/compiler.cpp

@@ -5056,7 +5056,7 @@ void Compiler::compCompile(void** methodCodePtr, uint32_t* methodCodeSize, JitFl
     DoPhase(this, PHASE_EXPAND_TLS, &Compiler::fgExpandThreadLocalAccess);
 
     // Expand casts
-    DoPhase(this, PHASE_EXPAND_STATIC_INIT, &Compiler::fgLateCastExpansion);
+    DoPhase(this, PHASE_EXPAND_CASTS, &Compiler::fgLateCastExpansion);
 
     // Insert GC Polls
     DoPhase(this, PHASE_INSERT_GC_POLLS, &Compiler::fgInsertGCPolls);

src/coreclr/jit/compphases.h

@@ -98,6 +98,7 @@ CompPhaseNameMacro(PHASE_COMPUTE_EDGE_WEIGHTS2,      "Compute edge weights (2, f
 CompPhaseNameMacro(PHASE_STRESS_SPLIT_TREE,          "Stress gtSplitTree",             false, -1, false)
 CompPhaseNameMacro(PHASE_EXPAND_RTLOOKUPS,           "Expand runtime lookups",         false, -1, true)
 CompPhaseNameMacro(PHASE_EXPAND_STATIC_INIT,         "Expand static init",             false, -1, true)
+CompPhaseNameMacro(PHASE_EXPAND_CASTS,               "Expand casts",                   false, -1, true)
 CompPhaseNameMacro(PHASE_EXPAND_TLS,                 "Expand TLS access",              false, -1, true)
 CompPhaseNameMacro(PHASE_INSERT_GC_POLLS,            "Insert GC Polls",                false, -1, true)
 CompPhaseNameMacro(PHASE_CREATE_THROW_HELPERS,       "Create throw helper blocks",     false, -1, true)

src/coreclr/jit/gentree.h

@@ -4080,6 +4080,7 @@ enum GenTreeCallFlags : unsigned int
     GTF_CALL_M_HAS_LATE_DEVIRT_INFO    = 0x01000000, // this call has late devirtualzation info
     GTF_CALL_M_LDVIRTFTN_INTERFACE     = 0x02000000, // ldvirtftn on an interface type
     GTF_CALL_M_CAST_CAN_BE_EXPANDED    = 0x04000000, // this cast (helper call) can be expanded if it's profitable
+    GTF_CALL_M_CAST_NON_NULL           = 0x08000000, // this cast (helper call) can be expanded if it's profitable
 };
 
 inline constexpr GenTreeCallFlags operator ~(GenTreeCallFlags a)

src/coreclr/jit/helperexpansion.cpp

@@ -1554,6 +1554,25 @@ bool Compiler::fgVNBasedIntrinsicExpansionForCall_ReadUtf8(BasicBlock** pBlock,
     return true;
 }
 
+//------------------------------------------------------------------------------
+// fgLateCastExpansion: Partially inline various cast helpers, e.g.:
+//
+//    tmp = CORINFO_HELP_ISINSTANCEOFINTERFACE(clsHandle, obj);
+//
+// into:
+//
+//    tmp = obj;
+//    if ((obj != null) && (obj->pMT != likelyClassHandle))
+//    {
+//        tmp = CORINFO_HELP_ISINSTANCEOFINTERFACE(clsHandle, obj);
+//    }
+//
+// The goal is to move cast expansion logic from the importer to this phase, for now,
+// this phase only supports "isinst" and for profiled casts only.
+//
+// Returns:
+//    PhaseStatus indicating what, if anything, was changed.
+//
 PhaseStatus Compiler::fgLateCastExpansion()
 {
     if (!doesMethodHaveExpandableCasts())
@@ -1578,6 +1597,18 @@ PhaseStatus Compiler::fgLateCastExpansion()
     return fgExpandHelper<&Compiler::fgLateCastExpansionForCall>(true);
 }
 
+//------------------------------------------------------------------------------
+// fgLateCastExpansionForCall : Expand specific cast helper, see
+//    fgLateCastExpansion's comments.
+//
+// Arguments:
+//    block - Block containing the cast helper to expand
+//    stmt  - Statement containing the cast helper
+//    call  - The cast helper
+//
+// Returns:
+//    True if expanded, false otherwise.
+//
 bool Compiler::fgLateCastExpansionForCall(BasicBlock** pBlock, Statement* stmt, GenTreeCall* call)
 {
     if (!call->IsHelperCall() || !impIsCastHelperMayHaveProfileData(call->GetHelperNum()))
@@ -1774,15 +1805,15 @@ bool Compiler::fgLateCastExpansionForCall(BasicBlock** pBlock, Statement* stmt,
     // Wire up the blocks
     //
     prevBb->SetTarget(nullcheckBb);
-    nullcheckBb->SetTrueTarget(fallbackBb);
+    nullcheckBb->SetTrueTarget(block);
     nullcheckBb->SetFalseTarget(typeCheckBb);
     typeCheckBb->SetTrueTarget(block);
     typeCheckBb->SetFalseTarget(fallbackBb);
     fallbackBb->SetTarget(block);
     fgRemoveRefPred(block, prevBb);
     fgAddRefPred(nullcheckBb, prevBb);
     fgAddRefPred(typeCheckBb, nullcheckBb);
-    fgAddRefPred(fallbackBb, nullcheckBb);
+    fgAddRefPred(block, nullcheckBb);
     fgAddRefPred(fallbackBb, typeCheckBb);
     fgAddRefPred(block, typeCheckBb);
     fgAddRefPred(block, fallbackBb);