I believe this is “fixed” in commit 05b1f8. What I did is actually disable structures containing bit-fields inside unions. This is an example that Csmith has to sacrifice expressiveness in order to maintain unambiguity: How to allocate bit-fields is very much implementation dependent, and we found some differences among compilers.
From: Pascal Cuoq [mailto:email@example.com]
Sent: Thursday, August 18, 2011 11:24 AM
To: Xuejun Yang
Subject: Re: [csmith-bugs] pragma pack and unions
Sorry, I indeed attached the wrong file.
The one with the union U5 and the g_85 is:
* This is a RANDOMLY GENERATED PROGRAM.
* Generator: csmith 2.1.0
* Options: --max-pointer-depth 3 --max-funcs 2 --max-array-dim 2 --max-array-
len-per-dim 3 --max-struct-fields 5 --no-volatiles --no-argc --unions