Merge pull request #9398 from mikedn/switch-cast

Change switch value widening

2 files changed, 12 insertions, 22 deletions

diff --git a/src/jit/importer.cpp b/src/jit/importer.cpp
index b21fc12438..ef70d059ff 100644
--- a/src/jit/importer.cpp
+++ b/src/jit/importer.cpp
@@ -11575,22 +11575,6 @@ void Compiler::impImportBlockCode(BasicBlock* block)
                 op1 = impPopStack().val;
                 assertImp(genActualTypeIsIntOrI(op1->TypeGet()));
 
-#ifdef _TARGET_64BIT_
-                // Widen 'op1' on 64-bit targets
-                if (op1->TypeGet() != TYP_I_IMPL)
-                {
-                    if (op1->OperGet() == GT_CNS_INT)
-                    {
-                        op1->gtType = TYP_I_IMPL;
-                    }
-                    else
-                    {
-                        op1 = gtNewCastNode(TYP_I_IMPL, op1, TYP_I_IMPL);
-                    }
-                }
-#endif // _TARGET_64BIT_
-                assert(genActualType(op1->TypeGet()) == TYP_I_IMPL);
-
                 /* We can create a switch node */
 
                 op1 = gtNewOperNode(GT_SWITCH, TYP_VOID, op1);
@@ -15976,11 +15960,11 @@ SPILLSTACK:
                 }
                 else
                 {
-                    assert(addTree->gtOper == GT_SWITCH && genActualType(addTree->gtOp.gtOp1->gtType) == TYP_I_IMPL);
+                    assert(addTree->gtOper == GT_SWITCH && genActualTypeIsIntOrI(addTree->gtOp.gtOp1->TypeGet()));
 
                     unsigned temp = lvaGrabTemp(true DEBUGARG("spill addStmt SWITCH"));
                     impAssignTempGen(temp, addTree->gtOp.gtOp1, level);
-                    addTree->gtOp.gtOp1 = gtNewLclvNode(temp, TYP_I_IMPL);
+                    addTree->gtOp.gtOp1 = gtNewLclvNode(temp, genActualType(addTree->gtOp.gtOp1->TypeGet()));
                 }
             }
 
diff --git a/src/jit/lower.cpp b/src/jit/lower.cpp
index 2a65a949fd..9242c395a3 100644
--- a/src/jit/lower.cpp
+++ b/src/jit/lower.cpp
@@ -468,7 +468,7 @@ GenTree* Lowering::LowerSwitch(GenTree* node)
     // both GT_SWITCH lowering code paths.
     // This condition is of the form: if (temp > jumpTableLength - 2){ goto jumpTable[jumpTableLength - 1]; }
     GenTreePtr gtDefaultCaseCond = comp->gtNewOperNode(GT_GT, TYP_INT, comp->gtNewLclvNode(tempLclNum, tempLclType),
-                                                       comp->gtNewIconNode(jumpCnt - 2, TYP_INT));
+                                                       comp->gtNewIconNode(jumpCnt - 2, tempLclType));
 
     // Make sure we perform an unsigned comparison, just in case the switch index in 'temp'
     // is now less than zero 0 (that would also hit the default case).
@@ -681,9 +681,16 @@ GenTree* Lowering::LowerSwitch(GenTree* node)
 
         JITDUMP("Lowering switch BB%02u: using jump table expansion\n", originalSwitchBB->bbNum);
 
+        GenTree* switchValue = comp->gtNewLclvNode(tempLclNum, tempLclType);
+#ifdef _TARGET_64BIT_
+        if (tempLclType != TYP_I_IMPL)
+        {
+            // Note that the switch value is unsigned so the cast should be unsigned as well.
+            switchValue = comp->gtNewCastNode(TYP_I_IMPL, switchValue, TYP_U_IMPL);
+        }
+#endif
         GenTreePtr gtTableSwitch =
-            comp->gtNewOperNode(GT_SWITCH_TABLE, TYP_VOID, comp->gtNewLclvNode(tempLclNum, tempLclType),
-                                comp->gtNewJmpTableNode());
+            comp->gtNewOperNode(GT_SWITCH_TABLE, TYP_VOID, switchValue, comp->gtNewJmpTableNode());
         /* Increment the lvRefCnt and lvRefCntWtd for temp */
         tempVarDsc->incRefCnts(blockWeight, comp);
 
@@ -2257,7 +2264,6 @@ void Lowering::LowerCompare(GenTree* cmp)
             // automatically inserts a cast from int32 to long on 64 bit architectures. However, the JIT
             // accidentally generates int/long comparisons internally:
             //   - loop cloning compares int (and even small int) index limits against long constants
-            //   - switch lowering compares a 64 bit switch value against a int32 constant
             //
             // TODO-Cleanup: The above mentioned issues should be fixed and then the code below may be
             // replaced with an assert or at least simplified. The special casing of constants in code