libgomp: alloc* test fixes [PR102628, PR102668]

libgomp: alloc* test fixes [PR102628, PR102668]

As reported, the alloc-9.c test and alloc-{1,2,3}.F* and alloc-11.f90
tests fail on powerpc64-linux with -m32.
The reason why it fails just there is that malloc doesn't guarantee there
128-bit alignment (historically glibc guaranteed 2 * sizeof (void *)
alignment from malloc).

There are two separate issues.
One is a thinko on my side.
In this part of alloc-9.c test (copied to alloc-11.f90), we have
2 allocators, a with pool size 1024B and alignment 16B and default fallback
and a2 with pool size 512B and alignment 32B and a as fallback allocator.
We start at no allocations in both at line 194 and do:
  p = (int *) omp_alloc (sizeof (int), a2);
// This succeeds in a2 and needs 4+overhead bytes (which includes the 32B alignment)
  p = (int *) omp_realloc (p, 420, a, a2);
// This allocates 420 bytes+overhead in a, with 16B alignment and deallocates the above
  q = (int *) omp_alloc (sizeof (int), a);
// This allocates 4+overhead bytes in a, with 16B alignment
  q = (int *) omp_realloc (q, 420, a2, a);
// This allocates 420+overhead in a2 with 32B alignment
  q = (int *) omp_realloc (q, 768, a2, a2);
// This attempts to reallocate, but as there are elevated alignment
// requirements doesn't try to just realloc (even if it wanted to try that
// a2 is almost full, with 512-420-overhead bytes left in it), so it
// tries to alloc in a2, but there is no space left in the pool, falls
// back to a, which already has 420+overhead bytes allocated in it and
// 1024-420-overhead bytes left and so fails too and fails to default
// non-pool allocator that allocates it, but doesn't guarantee alignment
// higher than malloc guarantees.
// But, the test expected 16B alignment.

So, I've slightly lowered the allocation sizes in that part of the test
420->320 and 768 -> 568, so that the last test still fails to allocate
in a2 (568 > 512-320-overhead) but succeeds in a as fallback, which was
the intent of the test.

Another thing is that alloc-1.F90 seems to be transcription of
libgomp.c-c++-common/alloc-1.c into Fortran, but alloc-1.c had:
  q = (int *) omp_alloc (768, a2);
  if ((((uintptr_t) q) % 16) != 0)
    abort ();
  q[0] = 7;
  q[767 / sizeof (int)] = 8;
  r = (int *) omp_alloc (512, a2);
  if ((((uintptr_t) r) % __alignof (int)) != 0)
    abort ();
there but Fortran has:
        cq = omp_alloc (768_c_size_t, a2)
        if (mod (transfer (cq, intptr), 16_c_intptr_t) /= 0) stop 12
        call c_f_pointer (cq, q, [768 / c_sizeof (i)])
        q(1) = 7
        q(768 / c_sizeof (i)) = 8
        cr = omp_alloc (512_c_size_t, a2)
        if (mod (transfer (cr, intptr), 16_c_intptr_t) /= 0) stop 13
I'm changing the latter to 4_c_intptr_t because other spots in the
testcase do that, Fortran sadly doesn't have c_alignof, but strictly
speaking it isn't correct, __alignof (int) could be on some architectures
smaller than 4.
So probably alloc-1.F90 etc. should also have
! { dg-additional-sources alloc-7.c }
! { dg-prune-output "command-line option '-fintrinsic-modules-path=.*' is valid for Fortran but not for C" }
and use get__alignof_int.

2021-10-12  Jakub Jelinek  <jakub@redhat.com>

	PR libgomp/102628
	PR libgomp/102668
	* testsuite/libgomp.c-c++-common/alloc-9.c (main): Decrease
	allocation sizes from 420 to 320 and from 768 to 568.
	* testsuite/libgomp.fortran/alloc-11.f90: Likewise.
	* testsuite/libgomp.fortran/alloc-1.F90: Change expected alignment
	for cr from 16 to 4.