Linux kernel, in particularly xen-blkfront.c, doesn't compile with GCC trunk. 4.5.0 20090625 was still fine, 4.5.0 20090630 is already wrong.
Simplified testcase: #define M1(x) (((x) & 0x00000002) ? 0x2 : ((x) & 0x1)) #define M2(x) (((x) & 0x0000000c) ? M1 ((x) >> 2) << 2 : M1 (x)) struct A { char f[1]; }; char a[M2 (4096UL - (long)&((struct A *) 16)->f)]; -- Summary: [4.5 Regression] Endless recursion between fold_ternary and fold_cond_expr_with_comparison Product: gcc Version: 4.5.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: middle-end AssignedTo: jakub at gcc dot gnu dot org ReportedBy: jakub at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40692