[Bug bootstrap/102681] [12 Regression] AArch64 bootstrap failure

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102681

--- Comment #3 from Martin Sebor <msebor at gcc dot gnu.org> ---
Simply initializing the variable as in the patch below avoids the warning.  The
control flow in the code is sufficiently opaque to make it worthwhile from a
readability point irrespective of whether or not the variable can, in fact, be
used uninitialized.

index e50d3fc3b62..c7f0a405ff6 100644
--- a/gcc/calls.c
+++ b/gcc/calls.c
@@ -199,7 +199,7 @@ stack_region_maybe_used_p (poly_uint64 lower_bound,
poly_uint64 upper_bound,
 static void
 mark_stack_region_used (poly_uint64 lower_bound, poly_uint64 upper_bound)
 {
-  unsigned HOST_WIDE_INT const_lower, const_upper;
+  unsigned HOST_WIDE_INT const_lower, const_upper = 0;
   const_lower = constant_lower_bound (lower_bound);
   if (upper_bound.is_constant (&const_upper))
     for (unsigned HOST_WIDE_INT i = const_lower; i < const_upper; ++i)