I figured out that they are generated during RTL passes that run after whole program analysis and partitioning. The file names have extension .su. But they have ltrans#.ltrans added to the name as well. # is the partition number. Since all the ltrans files are temporary, I had to add –save-temps to my link command for them to be kept around. Did you see this problem? If yes, how did you solve/worked around it? I am on GCC 8.3.1 Thanks, Visda