!fixup move extends to CG.

Author: fhahn

clang/lib/CodeGen/CGExpr.cpp

@@ -4348,8 +4348,18 @@ LValue CodeGenFunction::EmitMatrixSubscriptExpr(const MatrixSubscriptExpr *E) {
       !E->isIncomplete() &&
       "incomplete matrix subscript expressions should be rejected during Sema");
   LValue Base = EmitLValue(E->getBase());
-  llvm::Value *RowIdx = EmitScalarExpr(E->getRowIdx());
-  llvm::Value *ColIdx = EmitScalarExpr(E->getColumnIdx());
+
+  // Extend or truncate the index type to 32 or 64-bits.
+  auto EmitIndex = [this](const Expr *E) {
+    llvm::Value *Idx = EmitScalarExpr(E);
+    bool IsSigned = E->getType()->isSignedIntegerOrEnumerationType();
+    if (Idx->getType() != IntPtrTy)
+      Idx = Builder.CreateIntCast(Idx, IntPtrTy, IsSigned);
+    return Idx;
+  };
+  llvm::Value *RowIdx = EmitIndex(E->getRowIdx());
+  llvm::Value *ColIdx = EmitIndex(E->getColumnIdx());
+
   llvm::Value *NumRows = Builder.getIntN(
       RowIdx->getType()->getScalarSizeInBits(),
       E->getBase()->getType()->castAs<ConstantMatrixType>()->getNumRows());

clang/lib/CodeGen/CGExprScalar.cpp

@@ -2007,8 +2007,15 @@ Value *ScalarExprEmitter::VisitMatrixSubscriptExpr(MatrixSubscriptExpr *E) {
 
   // Handle the vector case.  The base must be a vector, the index must be an
   // integer value.
-  Value *RowIdx = Visit(E->getRowIdx());
-  Value *ColumnIdx = Visit(E->getColumnIdx());
+  auto VisitIndex = [this](Expr *E) {
+    llvm::Value *Idx = Visit(E);
+    bool IsSigned = E->getType()->isSignedIntegerOrEnumerationType();
+    if (Idx->getType() != CGF.IntPtrTy)
+      Idx = Builder.CreateIntCast(Idx, CGF.IntPtrTy, IsSigned);
+    return Idx;
+  };
+  Value *RowIdx = VisitIndex(E->getRowIdx());
+  Value *ColumnIdx = VisitIndex(E->getColumnIdx());
 
   const auto *MatrixTy = E->getBase()->getType()->castAs<ConstantMatrixType>();
   unsigned NumRows = MatrixTy->getNumRows();

clang/lib/Sema/SemaExpr.cpp

@@ -5025,10 +5025,7 @@ ExprResult Sema::CreateBuiltinMatrixSubscriptExpr(Expr *Base, Expr *RowIdx,
       }
     }
 
-    ExprResult ConvExpr = tryConvertExprToType(
-        IndexExpr, IndexExpr->getType()->isSignedIntegerType()
-                       ? Context.getSignedSizeType()
-                       : Context.getSizeType());
+    ExprResult ConvExpr = IndexExpr;
     assert(!ConvExpr.isInvalid() &&
            "should be able to convert any integer type to size type");
     return ConvExpr.get();