Hello, I'm sorry to bother you. And I have some gcc compiler optimization
questions to ask you.
First of all, I used csmith tools to generate c files randomly. Meanwhile,
the final running result was the checksum for global variables in a c file.
For the two c files in the attachment, I performed the equivalent
transformation of loop from *initial.**c* to *transformed.c*. And the two
files produced different results (i.e. different checksum values) when
using *-Os* optimization level, while the results of both were the same
when using other levels of optimization such as *-O0*, -O1, -O2, -O3,
*-Ofast*.
Please help me to explain why this is, thank you.

command line: *gcc file.c -Os -lm -I $CSMITH_HOME/include && ./a.out*
version: gcc 12.2.0
os: ubuntu 22.04