Intel® oneAPI DPC++/C++ Compiler

Developer Guide and Reference

ID 767253
Date 3/31/2025
Public
Document Table of Contents

Modify makefiles for Microsoft Applications

If you use makefiles to build your Microsoft* application, you need to change the value for the compiler variable to use the Intel® oneAPI DPC++/C++ Compiler. You may also want to review the options specified by CPPFLAGS.

For example, a sample Microsoft makefile:

# name of the program 
  PROGRAM = area.exe 

# names of source files 
  CPPSOURCES = area_main.cpp area_functions.cpp 

# names of object files 
  CPPOBJECTS = area_main.obj area_functions.obj 

# Microsoft(R) compiler options 
  CPPFLAGS = /RTC1 /EHsc 

# Use Microsoft C++(R)  
  CPP = cl 

# link objects 
  $(PROGRAM): $(CPPOBJECTS)
     link.exe /out:$@ $(CPPOBJECTS) 

# build objects 
  area_main.obj: area_main.cpp area_headers.h 
  area_functions.obj: area_functions.cpp area_headers.h 

# clean 
  clean:  del  $(CPPOBJECTS) $(PROGRAM)

Modified makefiles for the Intel® oneAPI DPC++/C++ Compiler

Before you can run nmake with the Intel® oneAPI DPC++/C++ Compiler, you need to set the proper environment. In this example, only the name of the compiler changes to use icx:

# name of the program 
  PROGRAM = area.exe 

# names of source files 
  CPPSOURCES = area_main.cpp area_functions.cpp 

# names of object files 
  CPPOBJECTS = area_main.obj area_functions.obj 

# Intel oneAPI DPC++/C++ Compiler options
  CPPFLAGS = /RTC1 /EHsc 

# Use the Intel oneAPI DPC++/C++ Compiler
  CPP = icx

# link objects 
  $(PROGRAM): $(CPPOBJECTS)
     link.exe /out:$@ $(CPPOBJECTS) 

# build objects 
  area_main.obj: area_main.cpp area_headers.h 
  area_functions.obj: area_functions.cpp area_headers.h 

# clean 
  clean:  del  $(CPPOBJECTS) $(PROGRAM)

With the modified makefile, the output of nmake is similar to the following:

Microsoft (R) Program Maintenance Utility Version 8.00.50727.42 
Copyright (C) Microsoft Corporation. All rights reserved.

        icx /RTC1 /EHsc  /c area_main.cpp area_functions.cpp 

Intel(R) Compiler for applications running on IA-64
Copyright (C) 1985-2006 Intel Corporation. All rights reserved. 

area_main.cpp 
area_functions.cpp
        link.exe /out:area.exe area_main.obj area_functions.obj 

Microsoft (R) Incremental Linker Version 8.00.50727.42 
Copyright (C) Microsoft Corporation. All rights reserved.

Use IPO in makefiles

By default, IPO generates dummy object files containing interprocedural information used by the compiler. To link or create static libraries with these object files requires specific LLVM-provided tools. To use them in your makefile, replace references to link with lld-link and references to lib with llvm-lib. For example:

 # name of the program 
  PROGRAM = area.exe 

# names of source files 
  CPPSOURCES = area_main.cpp area_functions.cpp 

# names of object files 
  CPPOBJECTS = area_main.obj area_functions.obj 

# Intel oneAPI DPC++/C++ Compiler options
  CPPFLAGS = /RTC1 /EHsc /Qipo

# Use the Intel oneAPI DPC++/C++ Compiler
  CPP = icx

# link objects 
  $(PROGRAM): $(CPPOBJECTS)
     lld-link.exe /out:$@ $(CPPOBJECTS) 

# build objects 
  area_main.obj: area_main.cpp area_headers.h 
  area_functions.obj: area_functions.cpp area_headers.h 

# clean 
  clean:  del  $(CPPOBJECTS) $(PROGRAM)