I typed in the examples from the paper and tried them out with the Digital Mars C compiler. They all passed, as well as http://blog.regehr.org/archives/482. I hope the authors will try to break dmc with their test suite generator, and look forward to fixing any issues they find.
regehr@home:~/volatile/bugs/tmp007$ cparser --version
cparser (0.9.11) using libFirm (1.18)
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
regehr@home:~/volatile/bugs/tmp007$ cparser -c small.c
cparser: ast2firm.c:3197: conditional_to_firm: Assertion `get_irn_mode(false_val) == mode' failed.
Aborted
regehr@home:~/volatile/bugs/tmp007$ cat small.c
unsigned char foo (int ui1, unsigned char ui2)
{
return ui2 ? : ui1 + ui2;
}