diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 3afdb09f0726bbc03d403a5bcfa93b984f0caac8..2842a7f4cfc7a07dd7aec78323bc79587aaa673d 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2019-09-18  Richard Sandiford  <richard.sandiford@arm.com>
+
+	* gimplify.c (gimplify_decl_expr): Use poly_int_tree_p instead
+	of checking specifically for INTEGER_CST.
+
 2019-09-18  Richard Sandiford  <richard.sandiford@arm.com>
 
 	* stor-layout.c (compute_record_mode): Operate on poly_uint64
diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index daa0b71c191e6d92387180e927b818517b8b58a7..623cdbfed7c758611466a2955c047ad3b6abf936 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -1754,11 +1754,12 @@ gimplify_decl_expr (tree *stmt_p, gimple_seq *seq_p)
       tree init = DECL_INITIAL (decl);
       bool is_vla = false;
 
-      if (TREE_CODE (DECL_SIZE_UNIT (decl)) != INTEGER_CST
+      poly_uint64 size;
+      if (!poly_int_tree_p (DECL_SIZE_UNIT (decl), &size)
 	  || (!TREE_STATIC (decl)
 	      && flag_stack_check == GENERIC_STACK_CHECK
-	      && compare_tree_int (DECL_SIZE_UNIT (decl),
-				   STACK_CHECK_MAX_VAR_SIZE) > 0))
+	      && maybe_gt (size,
+			   (unsigned HOST_WIDE_INT) STACK_CHECK_MAX_VAR_SIZE)))
 	{
 	  gimplify_vla_decl (decl, seq_p);
 	  is_vla = true;