fold: Unwrap MEM_REF after get_inner_reference in split_address_to_core_and_offset [PR121355]HEADtrunkmaster

Inside split_address_to_core_and_offset, this calls get_inner_reference.

Take:
```
  _6 = t_3(D) + 12;
  _8 = &MEM[(struct s1 *)t_3(D) + 4B].t;
  _1 = _6 - _8;
```

On the assignement of _8, get_inner_reference will return `MEM[(struct s1 *)t_3(D) + 4B]`
and an offset but that does not match up with `t_3(D)` which is how split_address_to_core_and_offset
handles pointer plus.
So this patch adds the unwrapping of the MEM_REF after the call to get_inner_reference
and have it act like a pointer plus.

Changes since v1:
* v2: Remove check on operand 1 for poly_int_tree_p, it is always.
      Add before the check to see if it fits in shwi instead of after.

Bootstrapped and tested on x86_64-linux-gnu.

	PR tree-optimization/121355

gcc/ChangeLog:

	* fold-const.cc (split_address_to_core_and_offset): Handle an MEM_REF after the call
	to get_inner_reference.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/ptrdiff-1.c: New test.

Signed-off-by: Andrew Pinski <andrew.pinski@oss.qualcomm.com>

0 files changed, 0 insertions, 0 deletions