On Sun, Dec 28, 2014 at 7:28 AM, H.J. Lu <hjl.to...@gmail.com> wrote: > On Thu, Dec 18, 2014 at 12:52 PM, Vladimir Makarov <vmaka...@redhat.com> > wrote: >> The following patch solves >> >> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64291 >> >> It is a bug in a new rematerialization subpass of LRA. >> >> The patch was bootstrapped on x86/x86-64. >> >> Committed as rev. 218874. >> >> 2014-12-18 Vladimir Makarov <vmaka...@redhat.com> >> >> PR rtl-optimization/64291 >> * lra-remat.c (bad_for_rematerialization_p): Add UNPSEC_VLOATILE. >> (create_cands): Process only output reload insn with potential >> cands. >> >> 2014-12-18 Vladimir Makarov <vmaka...@redhat.com> >> >> PR rtl-optimization/64291 >> * testsuite/gcc.target/i386/pr64291-[12].c: New tests. >> > > There are a couple problems with the testcase: > > 1. It has > > typedef struct > { > int _mp_size; > unsigned long *_mp_d; > } __mpz_struct; > typedef __mpz_struct mpz_t[1]; > > int main () > { > mpz_t n, d; > long nn, dn; > unsigned long *np, *dup, *dnp, *qp; > long alloc, itch; > > f (n); > f (d); > qp = (unsigned long*)__builtin_alloca(4099*8) + 1; > dnp = (unsigned long*)__builtin_alloca (2049*8); > alloc = 1; > for (test = 0; test < 1; test++) > { > dn = d->_mp_size; > dup = d->_mp_d; > f (dnp, dup, dn); > dnp[dn - 1] |= 1UL<<63; > > For 32-bit targets, like -m32 and -mx32, GCC complains: > > /export/gnu/import/git/gcc/gcc/testsuite/gcc.target/i386/pr64291-1.c:33:25: > warning: left shift count >= width of type [-Wshift-count-overflow] > > 2. This program uses uninitialized stack variable n, d: > > void f(void*p,...){} > > The behavior of this testcase is totally undefined. >
I opened: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64291 -- H.J.
