diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8118e14b563..f346dd5ced7 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2019-10-11  Richard Sandiford  <richard.sandiford@arm.com>
+
+	* expr.c (store_expr): Use rtx_to_poly_int64 rather than
+	INTVAL when calling store_bit_field.
+
 2019-10-11  Wilco Dijkstra  <wdijkstr@arm.com>
 
 	* config/arm/arm.h (HONOR_REG_ALLOC_ORDER): Set when optimizing for
diff --git a/gcc/expr.c b/gcc/expr.c
index 124144d9b1e..b54bf1d3dc5 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -5790,7 +5790,8 @@ store_expr (tree exp, rtx target, int call_param_p,
 		copy_blkmode_from_reg (target, temp, TREE_TYPE (exp));
 	      else
 		store_bit_field (target,
-				 INTVAL (expr_size (exp)) * BITS_PER_UNIT,
+				 rtx_to_poly_int64 (expr_size (exp))
+				 * BITS_PER_UNIT,
 				 0, 0, 0, GET_MODE (temp), temp, reverse);
 	    }
 	  else