[Bug rtl-optimization/66444] New: [5/6 Regression] Miscompilation of Xen since r211078

["jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66444

            Bug ID: 66444
           Summary: [5/6 Regression] Miscompilation of Xen since r211078
           Product: gcc
           Version: 5.1.1
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jakub at gcc dot gnu.org
                CC: vmakarov at gcc dot gnu.org, vries at gcc dot gnu.org
  Target Milestone: ---

void foo (unsigned long);
int bar (unsigned long);
unsigned long a, c, d, f, g;
volatile void *b;
int e;
struct S { unsigned long p, q, r; void *v; };
void fn2 (struct S *x);

__attribute__((noinline, noclone)) void *
fn1 (struct S *x)
{
  unsigned long y = x->q;
  unsigned long z = a;
  do
    {
      if ((x->q + 2 & 1UL << 63 - 10) <= 2)
return (void *) 0;
    }
  while (y = z != x->q);
  return x->v ? x->v : (void *) 0;
}

int
baz (void)
{
  foo (f);
  struct S *x = (struct S *) 0xe000000000UL;
  x += bar (f);
  fn1 (x);
  fn2 (x);
  return 0;
}

reduced from Xen is miscompiled at -O2 starting with r211078 on x86_64-linux.
Still in *.optimized dump we have:
  _6 = bar (f.0_4);
  _7 = (long unsigned int) _6;
  _8 = _7 * 32;
  x_9 = 962072674304B + _8;
  fn1 (x_9);
  fn2 (x_9);
(note the same value, constant + 32 * result of bar) is passed to both fn1 and
fn2.
But starting with *.reload we get:
        movabsq $962072674304, %r8
        salq    $5, %rax
        leaq    (%r8,%rax), %rdi
        call    fn1
        movq    %r8, %rdi
        call    fn2
which is wrong, it passes just the constant, without the added 32 * bar (), to
the second function.