https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78543
--- Comment #10 from Matthias Klose <doko at gcc dot gnu.org> --- here is one more build failure seen with 20170221, with -O1 (works with -O0), seen in the gtk-gnutella package: $ gcc-6 -c -O1 -msecure-plt -mcpu=power8 fileinfo.i fileinfo.c: In function 'file_info_retrieve_binary': fileinfo.c:2113:1: internal compiler error: in push_reload, at reload.c:1349 Please submit a full bug report, with preprocessed source if appropriate. $ cat fileinfo.i typedef long a; enum c { e, f, g, h, i, ab } j(); int l, n, o, p; a q, r; void *memcpy(); void b(); static int k(int *s) { int m; if (j(&m)) *s = m; return !0; } void d(char s) { int af[4]; int ag; enum c ah; char ai[24 << 11]; unsigned aj; if (!k(&aj)) goto ak; for (;;) { if (!k(&ag)) goto ak; switch (ah) { case e: b(""); b("bad length %d for GUID in fileinfo v%u for \"%s\""); case i: b("bad length %d for TTH in fileinfo v%u for \"%s\"", aj); case ab: if (ag % 24) b("for \"%s\"", s); case f: if (20 == ag) case h: if (20 == ag) o = 0; break; case g: memcpy(af, ai, sizeof af); b(); if (p) { a al, am; r = al << 2 | am; n = af[2]; al = n; l = __builtin_bswap32(af[3]); am = q = n | l; } default: b("%s0 unhandled field ID %u 0", __func__); } } ak:; }