Hello,
I'd like to know why the first generated rtl files of compiling the same program with different optimization levels are syntactically different. For example, suppose my file is file.c, and I do the following compilations:
gcc -dr file.c (a), and
gcc -O2 -dr file.c (b).
Suppose (a) is the rtl file of the first compilation and (b) is that of the second compilation. According to my observation, (a) and (b) have the same basic-block structure, but they are syntactically different. Does gcc perform something else, when the option -O2 is used, before generating the first rtl file?
Rgds,
Iman Narasamdya
