[csmith-dev] Some random questions

[Vikram KS <ksvikram@gmail.com>]

Hello,

I have some random questions.

1. How to find bugs other than compiler crash/ICE. i.e. wrong codegen bugs using csmith generated tests? 
    I learnt from "scripts/compiler_test.pl" that, a wrong code bug is determined by comparing the checksum output value generated across 
    different optimization levels. So if a compiler wrong-code bug exists across all optimization, how do i find it?

2. Suppose if set "bitfields_creation_prob=100" (100% probability?) in my configuration file and use it to generate a testcase, should the generated 
    testcase contain atleast one bitfield structure in it? For me, setting "bitfields_creation_prob=100" didn't create any testcase with bitfield in it. i'm bit
    unclear about

3. What is the the ideal timeout value for csmith to generate a testcase. Can i consider $CSMITH_TIMEOUT = 90; itself? or it may take more than that also?

4. I'm not able to understand some of the statistics generated at the end of each test case. i.e.
        XXX max struct depth: 1
       breakdown:
       depth: 0, occurrence: 412
       depth: 1, occurrence: 37

       XXX max _expression_ depth: 2
       breakdown:
       depth: 0, occurrence: 417
       depth: 1, occurrence: 35
       depth: 2, occurrence: 2
 
     etc

Please correct me if i'm wrong anywhere. Also please let me know if i'm not clear enough.

Thanks
Vikram