It seems like there's a whole range of issues once boolean_true_node (or any such global tree node) has been clobbered.
#include <stdbool.h> int main (int argc, char **argv) { if ((bool)((1527719483 + 1477819644))) { } return 0; } bool t1 = true; --- [EMAIL PROTECTED] gcc]$ ./xgcc -B./ -O3 -S foo2.c -save-temps -pedantic foo2.c: In function `main': foo2.c:6: warning: integer overflow in expression foo2.c: At top level: foo2.c:12: warning: overflow in constant expression [EMAIL PROTECTED] gcc]$ ./xgcc -B./ -v Reading specs from ./specs Target: i686-pc-linux-gnu Configured with: ./configure --prefix=/tmp/junk Thread model: posix gcc version 4.1.0 20051026 (experimental) [EMAIL PROTECTED] gcc]$