diff --git a/gcc/tree-ssa-math-opts.cc b/gcc/tree-ssa-math-opts.cc
index 7555793948e..232e903b0d2 100644
--- a/gcc/tree-ssa-math-opts.cc
+++ b/gcc/tree-ssa-math-opts.cc
@@ -1495,7 +1495,7 @@ powi_cost (HOST_WIDE_INT n)
 
 static tree
 powi_as_mults_1 (gimple_stmt_iterator *gsi, location_t loc, tree type,
-		 HOST_WIDE_INT n, tree *cache)
+		 unsigned HOST_WIDE_INT n, tree *cache)
 {
   tree op0, op1, ssa_target;
   unsigned HOST_WIDE_INT digit;
@@ -1548,7 +1548,7 @@ powi_as_mults (gimple_stmt_iterator *gsi, location_t loc,
   memset (cache, 0, sizeof (cache));
   cache[1] = arg0;
 
-  result = powi_as_mults_1 (gsi, loc, type, (n < 0) ? -n : n, cache);
+  result = powi_as_mults_1 (gsi, loc, type, absu_hwi (n), cache);
   if (n >= 0)
     return result;
 
@@ -1572,11 +1572,9 @@ static tree
 gimple_expand_builtin_powi (gimple_stmt_iterator *gsi, location_t loc, 
 			    tree arg0, HOST_WIDE_INT n)
 {
-  /* Avoid largest negative number.  */
-  if (n != -n
-      && ((n >= -1 && n <= 2)
-	  || (optimize_function_for_speed_p (cfun)
-	      && powi_cost (n) <= POWI_MAX_MULTS)))
+  if ((n >= -1 && n <= 2)
+      || (optimize_function_for_speed_p (cfun)
+	  && powi_cost (n) <= POWI_MAX_MULTS))
     return powi_as_mults (gsi, loc, arg0, n);
 
   return NULL_TREE;