JIT: remove early prop's type propagation (#45655)

This doesn't do any actual propagation, so remove it and the associated
tracking flags.

src/coreclr/jit/block.h

@@ -412,14 +412,13 @@ struct BasicBlock : private LIR::Range
                                                 // cases, because the BB occurs in a loop, and we've determined that all
                                                 // paths in the loop body leading to BB include a call.
 
-#define BBF_HAS_VTABREF         MAKE_BBFLAG(20) // BB contains reference of vtable
-#define BBF_HAS_IDX_LEN         MAKE_BBFLAG(21) // BB contains simple index or length expressions on an array local var.
-#define BBF_HAS_NEWARRAY        MAKE_BBFLAG(22) // BB contains 'new' of an array
-#define BBF_HAS_NEWOBJ          MAKE_BBFLAG(23) // BB contains 'new' of an object type.
+#define BBF_HAS_IDX_LEN         MAKE_BBFLAG(20) // BB contains simple index or length expressions on an array local var.
+#define BBF_HAS_NEWARRAY        MAKE_BBFLAG(21) // BB contains 'new' of an array
+#define BBF_HAS_NEWOBJ          MAKE_BBFLAG(22) // BB contains 'new' of an object type.
 
 #if defined(FEATURE_EH_FUNCLETS) && defined(TARGET_ARM)
 
-#define BBF_FINALLY_TARGET      MAKE_BBFLAG(24) // BB is the target of a finally return: where a finally will return during
+#define BBF_FINALLY_TARGET      MAKE_BBFLAG(23) // BB is the target of a finally return: where a finally will return during
                                                 // non-exceptional flow. Because the ARM calling sequence for calling a
                                                 // finally explicitly sets the return address to the finally target and jumps
                                                 // to the finally, instead of using a call instruction, ARM needs this to
@@ -428,27 +427,27 @@ struct BasicBlock : private LIR::Range
 
 #endif // defined(FEATURE_EH_FUNCLETS) && defined(TARGET_ARM)
 
-#define BBF_BACKWARD_JUMP       MAKE_BBFLAG(25) // BB is surrounded by a backward jump/switch arc
-#define BBF_RETLESS_CALL        MAKE_BBFLAG(26) // BBJ_CALLFINALLY that will never return (and therefore, won't need a paired
+#define BBF_BACKWARD_JUMP       MAKE_BBFLAG(24) // BB is surrounded by a backward jump/switch arc
+#define BBF_RETLESS_CALL        MAKE_BBFLAG(25) // BBJ_CALLFINALLY that will never return (and therefore, won't need a paired
                                                 // BBJ_ALWAYS); see isBBCallAlwaysPair().
-#define BBF_LOOP_PREHEADER      MAKE_BBFLAG(27) // BB is a loop preheader block
+#define BBF_LOOP_PREHEADER      MAKE_BBFLAG(26) // BB is a loop preheader block
+#define BBF_COLD                MAKE_BBFLAG(27) // BB is cold
 
-#define BBF_COLD                MAKE_BBFLAG(28) // BB is cold
-#define BBF_PROF_WEIGHT         MAKE_BBFLAG(29) // BB weight is computed from profile data
-#define BBF_IS_LIR              MAKE_BBFLAG(30) // Set if the basic block contains LIR (as opposed to HIR)
-#define BBF_KEEP_BBJ_ALWAYS     MAKE_BBFLAG(31) // A special BBJ_ALWAYS block, used by EH code generation. Keep the jump kind
+#define BBF_PROF_WEIGHT         MAKE_BBFLAG(28) // BB weight is computed from profile data
+#define BBF_IS_LIR              MAKE_BBFLAG(29) // Set if the basic block contains LIR (as opposed to HIR)
+#define BBF_KEEP_BBJ_ALWAYS     MAKE_BBFLAG(30) // A special BBJ_ALWAYS block, used by EH code generation. Keep the jump kind
                                                 // as BBJ_ALWAYS. Used for the paired BBJ_ALWAYS block following the
                                                 // BBJ_CALLFINALLY block, as well as, on x86, the final step block out of a
                                                 // finally.
+#define BBF_CLONED_FINALLY_BEGIN           MAKE_BBFLAG(31) // First block of a cloned finally region
 
-#define BBF_CLONED_FINALLY_BEGIN           MAKE_BBFLAG(32) // First block of a cloned finally region
-#define BBF_CLONED_FINALLY_END             MAKE_BBFLAG(33) // Last block of a cloned finally region
-#define BBF_HAS_CALL                       MAKE_BBFLAG(34) // BB contains a call
-#define BBF_DOMINATED_BY_EXCEPTIONAL_ENTRY MAKE_BBFLAG(35) // Block is dominated by exceptional entry.
+#define BBF_CLONED_FINALLY_END             MAKE_BBFLAG(32) // Last block of a cloned finally region
+#define BBF_HAS_CALL                       MAKE_BBFLAG(33) // BB contains a call
+#define BBF_DOMINATED_BY_EXCEPTIONAL_ENTRY MAKE_BBFLAG(34) // Block is dominated by exceptional entry.
+#define BBF_BACKWARD_JUMP_TARGET           MAKE_BBFLAG(35) // Block is a target of a backward jump
 
-#define BBF_BACKWARD_JUMP_TARGET           MAKE_BBFLAG(36) // Block is a target of a backward jump
-#define BBF_PATCHPOINT                     MAKE_BBFLAG(37) // Block is a patchpoint
-#define BBF_HAS_CLASS_PROFILE              MAKE_BBFLAG(38) // BB contains a call needing a class profile
+#define BBF_PATCHPOINT                     MAKE_BBFLAG(36) // Block is a patchpoint
+#define BBF_HAS_CLASS_PROFILE              MAKE_BBFLAG(37) // BB contains a call needing a class profile
 
 // clang-format on
 
@@ -469,7 +468,7 @@ struct BasicBlock : private LIR::Range
 
 #define BBF_COMPACT_UPD                                                                                                \
     (BBF_CHANGED | BBF_GC_SAFE_POINT | BBF_HAS_JMP | BBF_HAS_IDX_LEN | BBF_BACKWARD_JUMP | BBF_HAS_NEWARRAY |          \
-     BBF_HAS_NEWOBJ | BBF_HAS_NULLCHECK | BBF_HAS_VTABREF)
+     BBF_HAS_NEWOBJ | BBF_HAS_NULLCHECK)
 
 // Flags a block should not have had before it is split.
 
@@ -493,7 +492,7 @@ struct BasicBlock : private LIR::Range
 #define BBF_SPLIT_GAINED                                                                                               \
     (BBF_DONT_REMOVE | BBF_HAS_LABEL | BBF_HAS_JMP | BBF_BACKWARD_JUMP | BBF_HAS_IDX_LEN | BBF_HAS_NEWARRAY |          \
      BBF_PROF_WEIGHT | BBF_HAS_NEWOBJ | BBF_KEEP_BBJ_ALWAYS | BBF_CLONED_FINALLY_END | BBF_HAS_NULLCHECK |             \
-     BBF_HAS_VTABREF | BBF_HAS_CLASS_PROFILE)
+     BBF_HAS_CLASS_PROFILE)
 
 #ifndef __GNUC__ // GCC doesn't like C_ASSERT at global scope
     static_assert_no_msg((BBF_SPLIT_NONEXIST & BBF_SPLIT_LOST) == 0);

src/coreclr/jit/compiler.h

@@ -6705,15 +6705,14 @@ class Compiler
 #define OMF_HAS_NEWARRAY 0x00000001         // Method contains 'new' of an array
 #define OMF_HAS_NEWOBJ 0x00000002           // Method contains 'new' of an object type.
 #define OMF_HAS_ARRAYREF 0x00000004         // Method contains array element loads or stores.
-#define OMF_HAS_VTABLEREF 0x00000008        // Method contains method table reference.
-#define OMF_HAS_NULLCHECK 0x00000010        // Method contains null check.
-#define OMF_HAS_FATPOINTER 0x00000020       // Method contains call, that needs fat pointer transformation.
-#define OMF_HAS_OBJSTACKALLOC 0x00000040    // Method contains an object allocated on the stack.
-#define OMF_HAS_GUARDEDDEVIRT 0x00000080    // Method contains guarded devirtualization candidate
-#define OMF_HAS_EXPRUNTIMELOOKUP 0x00000100 // Method contains a runtime lookup to an expandable dictionary.
-#define OMF_HAS_PATCHPOINT 0x00000200       // Method contains patchpoints
-#define OMF_NEEDS_GCPOLLS 0x00000400        // Method needs GC polls
-#define OMF_HAS_FROZEN_STRING 0x00000800    // Method has a frozen string (REF constant int), currently only on CoreRT.
+#define OMF_HAS_NULLCHECK 0x00000008        // Method contains null check.
+#define OMF_HAS_FATPOINTER 0x00000010       // Method contains call, that needs fat pointer transformation.
+#define OMF_HAS_OBJSTACKALLOC 0x00000020    // Method contains an object allocated on the stack.
+#define OMF_HAS_GUARDEDDEVIRT 0x00000040    // Method contains guarded devirtualization candidate
+#define OMF_HAS_EXPRUNTIMELOOKUP 0x00000080 // Method contains a runtime lookup to an expandable dictionary.
+#define OMF_HAS_PATCHPOINT 0x00000100       // Method contains patchpoints
+#define OMF_NEEDS_GCPOLLS 0x00000200        // Method needs GC polls
+#define OMF_HAS_FROZEN_STRING 0x00000400    // Method has a frozen string (REF constant int), currently only on CoreRT.
 
     bool doesMethodHaveFatPointer()
     {
@@ -6813,7 +6812,6 @@ class Compiler
     {
         OPK_INVALID,
         OPK_ARRAYLEN,
-        OPK_OBJ_GETTYPE,
         OPK_NULLCHECK
     };
 

src/coreclr/jit/earlyprop.cpp

@@ -4,7 +4,7 @@
 //                                    Early Value Propagation
 //
 // This phase performs an SSA-based value propagation optimization that currently only applies to array
-// lengths, runtime type handles, and explicit null checks. An SSA-based backwards tracking of local variables
+// lengths and explicit null checks. An SSA-based backwards tracking of local variables
 // is performed at each point of interest, e.g., an array length reference site, a method table reference site, or
 // an indirection.
 // The tracking continues until an interesting value is encountered. The value is then used to rewrite
@@ -18,17 +18,15 @@
 bool Compiler::optDoEarlyPropForFunc()
 {
     bool propArrayLen  = (optMethodFlags & OMF_HAS_NEWARRAY) && (optMethodFlags & OMF_HAS_ARRAYREF);
-    bool propGetType   = (optMethodFlags & (OMF_HAS_NEWOBJ | OMF_HAS_NEWARRAY)) && (optMethodFlags & OMF_HAS_VTABLEREF);
     bool propNullCheck = (optMethodFlags & OMF_HAS_NULLCHECK) != 0;
-    return propArrayLen || propGetType || propNullCheck;
+    return propArrayLen || propNullCheck;
 }
 
 bool Compiler::optDoEarlyPropForBlock(BasicBlock* block)
 {
     bool bbHasArrayRef  = (block->bbFlags & BBF_HAS_IDX_LEN) != 0;
-    bool bbHasVtableRef = (block->bbFlags & BBF_HAS_VTABREF) != 0;
     bool bbHasNullCheck = (block->bbFlags & BBF_HAS_NULLCHECK) != 0;
-    return bbHasArrayRef || bbHasVtableRef || bbHasNullCheck;
+    return bbHasArrayRef || bbHasNullCheck;
 }
 
 //--------------------------------------------------------------------
@@ -321,26 +319,7 @@ GenTree* Compiler::optEarlyPropRewriteTree(GenTree* tree, LocalNumberToNullCheck
     }
     else
     {
-        assert(tree->OperIsIndir());
-        if (gtIsVtableRef(tree))
-        {
-            // Don't propagate type handles that are used as null checks, which are usually in
-            // form of
-            //      *  stmtExpr  void  (top level)
-            //      \--*  indir     int
-            //          \--*  lclVar    ref    V02 loc0
-            if (compCurStmt->GetRootNode() == tree)
-            {
-                return nullptr;
-            }
-
-            objectRefPtr = tree->AsIndir()->Addr();
-            propKind     = optPropKind::OPK_OBJ_GETTYPE;
-        }
-        else
-        {
-            return nullptr;
-        }
+        return nullptr;
     }
 
     if (!objectRefPtr->OperIsScalarLocal() || !lvaInSsa(objectRefPtr->AsLclVarCommon()->GetLclNum()))
@@ -355,11 +334,6 @@ GenTree* Compiler::optEarlyPropRewriteTree(GenTree* tree, LocalNumberToNullCheck
             optCheckFlagsAreSet(OMF_HAS_ARRAYREF, "OMF_HAS_ARRAYREF", BBF_HAS_IDX_LEN, "BBF_HAS_IDX_LEN", tree,
                                 compCurBB);
         }
-        else
-        {
-            optCheckFlagsAreSet(OMF_HAS_VTABLEREF, "OMF_HAS_VTABLEREF", BBF_HAS_VTABREF, "BBF_HAS_VTABREF", tree,
-                                compCurBB);
-        }
     }
 #endif
 
@@ -369,7 +343,7 @@ GenTree* Compiler::optEarlyPropRewriteTree(GenTree* tree, LocalNumberToNullCheck
 
     if (actualVal != nullptr)
     {
-        assert((propKind == optPropKind::OPK_ARRAYLEN) || (propKind == optPropKind::OPK_OBJ_GETTYPE));
+        assert(propKind == optPropKind::OPK_ARRAYLEN);
         assert(actualVal->IsCnsIntOrI());
         assert(actualVal->GetNodeSize() == TREE_NODE_SZ_SMALL);
 
@@ -550,14 +524,6 @@ GenTree* Compiler::optPropGetValueRec(unsigned lclNum, unsigned ssaNum, optPropK
                     }
                 }
             }
-            else if (valueKind == optPropKind::OPK_OBJ_GETTYPE)
-            {
-                value = getObjectHandleNodeFromAllocation(treeRhs DEBUGARG(ssaVarDsc->GetBlock()));
-                if (value != nullptr)
-                {
-                    assert(value->IsCnsIntOrI());
-                }
-            }
         }
     }
 

src/coreclr/jit/flowgraph.cpp

@@ -15442,8 +15442,7 @@ bool Compiler::fgOptimizeBranch(BasicBlock* bJump)
     gtReverseCond(condTree);
 
     // We need to update the following flags of the bJump block if they were set in the bDest block
-    bJump->bbFlags |=
-        (bDest->bbFlags & (BBF_HAS_NEWOBJ | BBF_HAS_NEWARRAY | BBF_HAS_NULLCHECK | BBF_HAS_IDX_LEN | BBF_HAS_VTABREF));
+    bJump->bbFlags |= (bDest->bbFlags & (BBF_HAS_NEWOBJ | BBF_HAS_NEWARRAY | BBF_HAS_NULLCHECK | BBF_HAS_IDX_LEN));
 
     bJump->bbJumpKind = BBJ_COND;
     bJump->bbJumpDest = bDest->bbNext;

src/coreclr/jit/gentree.cpp

@@ -12995,8 +12995,6 @@ GenTree* Compiler::gtFoldTypeCompare(GenTree* tree)
 
     // Update various flags
     objMT->gtFlags |= GTF_EXCEPT;
-    compCurBB->bbFlags |= BBF_HAS_VTABREF;
-    optMethodFlags |= OMF_HAS_VTABLEREF;
 
     // Compare the two method tables
     GenTree* const compare = gtCreateHandleCompare(oper, objMT, knownMT, typeCheckInliningResult);

src/coreclr/jit/optimizer.cpp

@@ -4281,8 +4281,7 @@ void Compiler::fgOptWhileLoop(BasicBlock* block)
     // Flag the block that received the copy as potentially having an array/vtable
     // reference, nullcheck, object/array allocation if the block copied from did;
     // this is a conservative guess.
-    if (auto copyFlags = bTest->bbFlags &
-                         (BBF_HAS_VTABREF | BBF_HAS_IDX_LEN | BBF_HAS_NULLCHECK | BBF_HAS_NEWOBJ | BBF_HAS_NEWARRAY))
+    if (auto copyFlags = bTest->bbFlags & (BBF_HAS_IDX_LEN | BBF_HAS_NULLCHECK | BBF_HAS_NEWOBJ | BBF_HAS_NEWARRAY))
     {
         block->bbFlags |= copyFlags;
     }