Jan 19, 2024 · Jan 17, 2024 · Jan 17, 2024 · Jan 17, 2024 · Jan 17, 2024 · Jan 17, 2024
diff --git a/src/coreclr/jit/helperexpansion.cpp b/src/coreclr/jit/helperexpansion.cpp
    //     ...
    //
    // nullcheckBb (BBJ_COND):                      [weight: 1.0]
    //     tmp = obj;
    //     if (tmp == null)
    //         goto lastBlock;
    //
    // typeCheckBb (BBJ_COND):                      [weight: 0.5]
    //     if (tmp->pMT == likelyClass)
    //     if (obj->pMT == likelyClass)
    //         goto typeCheckSucceedBb;
    //
    // fallbackBb (BBJ_ALWAYS):                     [weight: <profile>]
    //     tmp = helper_call(cls,tmp);
    //     tmp = helper_call(cls,obj);
    //     goto lastBlock;
    //
    // typeCheckSucceedBb (BBJ_ALWAYS):             [weight: <profile>]
    //nop(or tmp = null)
    //tmp = obj;(or tmp = null in case of 'MustNot')
    //
    // lastBlock (BBJ_any):                         [weight: 1.0]
    //     use(tmp);
    // Block 1: nullcheckBb
    // TODO-InlineCast: assertionprop should leave us a mark that objArg is never null, so we can omit this check
    // it's too late to rely on upstream phases to do this for us (unless we do optRepeat).
    GenTree* objTmp      = gtNewLclVarNode(tmpNum);
    GenTree* nullcheckOp = gtNewOperNode(GT_EQ, TYP_INT, objTmp, gtNewNull());
    GenTree* nullcheckOp = gtNewOperNode(GT_EQ, TYP_INT, gtCloneExpr(objArg), gtNewNull());
    nullcheckOp->gtFlags |= GTF_RELOP_JMP_USED;
    BasicBlock* nullcheckBb = fgNewBBFromTreeAfter(BBJ_COND, firstBb, gtNewOperNode(GT_JTRUE, TYP_VOID, nullcheckOp),
                                                   debugInfo, lastBb, true);

    // Set tmp's value to obj by default (before the nullcheck)
    Statement* storeObjStmt = fgNewStmtAtBeg(nullcheckBb, gtNewTempStore(tmpNum, gtCloneExpr(objArg)), debugInfo);
    gtSetStmtInfo(storeObjStmt);
    fgSetStmtSeq(storeObjStmt);

    // if likelyCls == clsArg, we can just use clsArg that we've just spilled to a temp
    // it's a sort of manual CSE.
    GenTree* likelyClsNode = gtNewIconEmbClsHndNode(likelyCls);

    // Block 2: typeCheckBb
    GenTree* mtCheck = gtNewOperNode(GT_EQ, TYP_INT, gtNewMethodTableLookup(gtCloneExpr(objTmp)), likelyClsNode);
    GenTree* mtCheck = gtNewOperNode(GT_EQ, TYP_INT, gtNewMethodTableLookup(gtCloneExpr(objArg)), likelyClsNode);
    mtCheck->gtFlags |= GTF_RELOP_JMP_USED;
    GenTree*    jtrue       = gtNewOperNode(GT_JTRUE, TYP_VOID, mtCheck);
    BasicBlock* typeCheckBb = fgNewBBFromTreeAfter(BBJ_COND, nullcheckBb, jtrue, debugInfo, lastBb, true);
    }
    else
    {
        //Otherwise, no-op (for simplicity, some downstream phase will collect this block)
        typeCheckSucceedTree =gtNewNothingNode();
        //Just return the original obj (assign to tmpNum)
        typeCheckSucceedTree =gtNewTempStore(tmpNum, gtCloneExpr(objArg));
    }
    BasicBlock* typeCheckSucceedBb =
        fgNewBBFromTreeAfter(BBJ_ALWAYS, fallbackBb, typeCheckSucceedTree, debugInfo, lastBb);
Original file line number	Diff line number	Diff line change
Expand Up		@@ -1790,20 +1790,19 @@ bool Compiler::fgLateCastExpansionForCall(BasicBlock** pBlock, Statement* stmt,
		// ...
		//
		// nullcheckBb (BBJ_COND): [weight: 1.0]
		// tmp = obj;
		// if (tmp == null)
		// goto lastBlock;
		//
		// typeCheckBb (BBJ_COND): [weight: 0.5]
		// if (tmp->pMT == likelyClass)
		// if (obj->pMT == likelyClass)
		// goto typeCheckSucceedBb;
		//
		// fallbackBb (BBJ_ALWAYS): [weight: <profile>]
		// tmp = helper_call(cls,tmp);
		// tmp = helper_call(cls,obj);
		// goto lastBlock;
		//
		// typeCheckSucceedBb (BBJ_ALWAYS): [weight: <profile>]
		//nop(or tmp = null)
		//tmp = obj;(or tmp = null in case of 'MustNot')
		//
		// lastBlock (BBJ_any): [weight: 1.0]
		// use(tmp);
Expand All		@@ -1812,23 +1811,17 @@ bool Compiler::fgLateCastExpansionForCall(BasicBlock** pBlock, Statement* stmt,
		// Block 1: nullcheckBb
		// TODO-InlineCast: assertionprop should leave us a mark that objArg is never null, so we can omit this check
		// it's too late to rely on upstream phases to do this for us (unless we do optRepeat).
		GenTree* objTmp = gtNewLclVarNode(tmpNum);
		GenTree* nullcheckOp = gtNewOperNode(GT_EQ, TYP_INT, objTmp, gtNewNull());
		GenTree* nullcheckOp = gtNewOperNode(GT_EQ, TYP_INT, gtCloneExpr(objArg), gtNewNull());
		nullcheckOp->gtFlags \|= GTF_RELOP_JMP_USED;
		BasicBlock* nullcheckBb = fgNewBBFromTreeAfter(BBJ_COND, firstBb, gtNewOperNode(GT_JTRUE, TYP_VOID, nullcheckOp),
		debugInfo, lastBb, true);

		// Set tmp's value to obj by default (before the nullcheck)
		Statement* storeObjStmt = fgNewStmtAtBeg(nullcheckBb, gtNewTempStore(tmpNum, gtCloneExpr(objArg)), debugInfo);
		gtSetStmtInfo(storeObjStmt);
		fgSetStmtSeq(storeObjStmt);

		// if likelyCls == clsArg, we can just use clsArg that we've just spilled to a temp
		// it's a sort of manual CSE.
		GenTree* likelyClsNode = gtNewIconEmbClsHndNode(likelyCls);

		// Block 2: typeCheckBb
		GenTree* mtCheck = gtNewOperNode(GT_EQ, TYP_INT, gtNewMethodTableLookup(gtCloneExpr(objTmp)), likelyClsNode);
		GenTree* mtCheck = gtNewOperNode(GT_EQ, TYP_INT, gtNewMethodTableLookup(gtCloneExpr(objArg)), likelyClsNode);
		mtCheck->gtFlags \|= GTF_RELOP_JMP_USED;
		GenTree* jtrue = gtNewOperNode(GT_JTRUE, TYP_VOID, mtCheck);
		BasicBlock* typeCheckBb = fgNewBBFromTreeAfter(BBJ_COND, nullcheckBb, jtrue, debugInfo, lastBb, true);
Expand All		@@ -1847,8 +1840,8 @@ bool Compiler::fgLateCastExpansionForCall(BasicBlock** pBlock, Statement* stmt,
		}
		else
		{
		//Otherwise, no-op (for simplicity, some downstream phase will collect this block)
		typeCheckSucceedTree =gtNewNothingNode();
		//Just return the original obj (assign to tmpNum)
		typeCheckSucceedTree =gtNewTempStore(tmpNum, gtCloneExpr(objArg));
		}
		BasicBlock* typeCheckSucceedBb =
		fgNewBBFromTreeAfter(BBJ_ALWAYS, fallbackBb, typeCheckSucceedTree, debugInfo, lastBb);
Expand Down