gcc: AArch64 - Fix strict-align cpymem/setmem

The cpymemdi/setmemdi implementation doesn't fully support strict alignment.
Block the expansion if the alignment is less than 16 with STRICT_ALIGNMENT.
Clean up the condition when to use MOPS.

Upstream-Status: Backport [https://gcc.gnu.org/cgit/gcc/commit/?id=b9d16d8361a9e3a82a2f21e759e760d235d43322]

Signed-off-by: Wilco Dijkstra <wilco.dijkstra@arm.com>
Signed-off-by: Sundeep KOKKONDA <sundeep.kokkonda@windriver.com>
---
--- a/gcc/config/aarch64/aarch64.c	2025-05-08 20:40:10.969865898 -0700
+++ b/gcc/config/aarch64/aarch64.c	2025-05-13 23:11:07.006796627 -0700
@@ -23621,14 +23621,15 @@
   int mode_bits;
   rtx dst = operands[0];
   rtx src = operands[1];
+  unsigned align = UINTVAL (operands[3]);
   rtx base;
   machine_mode cur_mode = BLKmode;
 
   /* Only expand fixed-size copies.  */
-  if (!CONST_INT_P (operands[2]))
+  if (!CONST_INT_P (operands[2]) || (STRICT_ALIGNMENT && align < 16))
     return false;
 
-  unsigned HOST_WIDE_INT size = INTVAL (operands[2]);
+  unsigned HOST_WIDE_INT size = UINTVAL (operands[2]);
 
   /* Inline up to 256 bytes when optimizing for speed.  */
   unsigned HOST_WIDE_INT max_copy_size = 256;
@@ -23750,11 +23751,12 @@
   unsigned HOST_WIDE_INT len;
   rtx dst = operands[0];
   rtx val = operands[2], src;
+  unsigned align = UINTVAL (operands[3]);
   rtx base;
   machine_mode cur_mode = BLKmode, next_mode;
 
   /* We can't do anything smart if the amount to copy is not constant.  */
-  if (!CONST_INT_P (operands[1]))
+  if (!CONST_INT_P (operands[1]) || (STRICT_ALIGNMENT && align < 16))
     return false;
 
   bool speed_p = !optimize_function_for_size_p (cfun);