Before revision:  First solutions to this problem have been proposed, such as TVM  or ISAMIR, which work on a loop-level representation of operators and rewrite the program before an instruction embedding into the operator is performed .
After revision:  First solutions to this problem have been proposed, such as TVM , UNIT or ISAMIR, which work on a loop-level representation of operators and rewrite the program before an instruction embedding into the operator is performed .