http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55940
Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|WAITING |NEW Target Milestone|--- |4.7.3 Summary|Incorrect code for |[4.7/4.8 Regression] |accessing parameters with |Incorrect code for |32-bit Intel hosts |accessing parameters with | |32-bit Intel hosts --- Comment #11 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-01-15 17:45:48 UTC --- Sounds like shrink-wrapping bug to me: /* { dg-options "-Os" } */ /* { dg-additional-options "-mpreferred-stack-boundary=2" { target { { i?86-*-* x86_64-*-* } && ia32 } } } */ struct S { int s; unsigned long t; }; __attribute__ ((visibility ("hidden"))) unsigned long long bar (struct S *x, unsigned long y); unsigned long long foo (struct S *x, unsigned long y) { unsigned long a; if (__builtin_expect (((unsigned long) (x) + 0x1000U < 0x2000U), 0)) return ~0ULL; if (__builtin_expect (x->s <= 0 || x->s > 9, 0)) return ~0ULL; a = x->t >> 12; if (y >= a && y == a) return ~0ULL; if (x->s == 3) return x->t + y * 4096; return bar (x, y); } The pre-prologue code can't use registers initialized in the prologue.