Abstract: The Fortran language is widely applied in scientific and engineering computing domains.However,general-purpose digital signal processors(GPDSPs)currently rely primarily on C or assembly languages for programming,lacking Fortran support at present.Addressing this gap,this paper investigates the implementation technology of Fortran compilers targeting CPU-DSP he-terogeneous processors.Based on the LLVM Flang compiler framework,it designs and implements a Fortran compiler prototype named mtFortran,completing the Flang frontend migration while focusing on resolving compilation and runtime support challenges for Fortran programs in heterogeneous architectures.Key issues addressed include program loading/execution,syntax compatibility,built-in function implementation,and input/output(I/O)system adaptation.Experimental results demonstrate that this Fortran compiler successfully supports the syntactic features of the GUIDE F90 test suite within the commercial U_F90_TS_LITE benchmark collection.Among the 176 test programs are evaluated,all 102 programs with supported runtime libraries are passed heterogeneous compilation and execution validation.The implementation rate for built-in functions across major categories reaches 79.38%,enabling support for typical high-performance computing applications(e.g.,the NPB-EP benchmark program).This work establishes foundational runtime capabilities for Fortran programs on CPU-DSP heterogeneous processor architectures,laying the groundwork for subsequent enhancements in standard compliance,performance optimization,and parallelization extensions.

Key words: CPU-DSP heterogeneous processors, Fortran compiler, Fortran runtime, LLVM, Flang