There was a big like this earlier but it's marked as resolved, so filing a new one.
reg...@john-home:~/volatile/bugs/tmp296$ current-gcc -O small.c -c small.c: In function main: small.c:5:5: internal compiler error: in gimple_rhs_has_side_effects, at gimple.c:2248 Please submit a full bug report, with preprocessed source if appropriate. See <http://gcc.gnu.org/bugs.html> for instructions. reg...@john-home:~/volatile/bugs/tmp296$ cat small.c volatile int g_2[7]; void foo (unsigned); int main (void) { int i_459 = 0; int t2818; int t2819; volatile char *t2820; int t2821; volatile char *t2822; int *t2823; unsigned t2824; LL655: t2822 = (volatile char *)g_2; t2821 = i_459; t2820 = t2822 + t2821; t2823 = (int *)t2820; t2824 = *t2823; foo (t2824); t2818 = i_459; t2819 = t2818 + 1; i_459 = t2819; goto LL655; } reg...@john-home:~/volatile/bugs/tmp296$ current-gcc -v Using built-in specs. COLLECT_GCC=current-gcc COLLECT_LTO_WRAPPER=/home/regehr/z/compiler-install/gcc-r157896-install/libexec/gcc/i686-pc-linux-gnu/4.5.0/lto-wrapper Target: i686-pc-linux-gnu Configured with: ../configure --with-libelf=/usr/local --enable-lto --prefix=/home/regehr/z/compiler-install/gcc-r157896-install --program-prefix=r157896- --enable-languages=c,c++ Thread model: posix gcc version 4.5.0 20100331 (experimental) (GCC) -- Summary: ice in gimple_rhs_has_side_effects, at gimple.c:2248 Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: c AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: regehr at cs dot utah dot edu GCC build triplet: i686-pc-linux-gnu GCC host triplet: i686-pc-linux-gnu GCC target triplet: i686-pc-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43614