diff --git a/gcc/tree-ssa-phiopt.c b/gcc/tree-ssa-phiopt.c
index 0e339c46afa29fa97f90d9bc4394370cd9b4b396..1a2f9294e5c3e6a7fd5ade4c21cdedc44e70d911 100644
--- a/gcc/tree-ssa-phiopt.c
+++ b/gcc/tree-ssa-phiopt.c
@@ -2038,6 +2038,26 @@ spaceship_replacement (basic_block cond_bb, basic_block middle_bb,
   gimple *orig_use_stmt = use_stmt;
   tree orig_use_lhs = NULL_TREE;
   int prec = TYPE_PRECISION (TREE_TYPE (phires));
+
+  /* Deal with if match.pd has rewritten the (res & ~1) == 0
+     into res <= 1 and has left a type-cast for signed types.  */
+  if (gimple_assign_cast_p (use_stmt))
+    {
+      orig_use_lhs = gimple_assign_lhs (use_stmt);
+      /* Match.pd would have only done this for a signed type,
+	 so the conversion must be to an unsigned one.  */
+      if (!TYPE_UNSIGNED (TREE_TYPE (orig_use_lhs)))
+	return false;
+      if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (orig_use_lhs))
+	return false;
+      if (EDGE_COUNT (phi_bb->preds) != 4)
+	return false;
+      if (!TYPE_UNSIGNED (TREE_TYPE (orig_use_lhs)))
+	return false;
+      if (!single_imm_use (orig_use_lhs, &use_p, &use_stmt))
+	return false;
+    }
+
   if (is_gimple_assign (use_stmt)
       && gimple_assign_rhs_code (use_stmt) == BIT_AND_EXPR
       && TREE_CODE (gimple_assign_rhs2 (use_stmt)) == INTEGER_CST
@@ -2099,7 +2119,7 @@ spaceship_replacement (basic_block cond_bb, basic_block middle_bb,
       || !tree_fits_shwi_p (rhs)
       || !IN_RANGE (tree_to_shwi (rhs), -1, 1))
     return false;
-  if (orig_use_lhs)
+  if (orig_use_lhs && !integer_onep (rhs))
     {
       if ((cmp != EQ_EXPR && cmp != NE_EXPR) || !integer_zerop (rhs))
 	return false;
@@ -2345,6 +2365,8 @@ spaceship_replacement (basic_block cond_bb, basic_block middle_bb,
 	res_cmp = one_cmp == LT_EXPR ? GE_EXPR : LE_EXPR;
       else if (integer_minus_onep (rhs))
 	res_cmp = one_cmp == LT_EXPR ? GT_EXPR : LT_EXPR;
+      else if (integer_onep (rhs))
+	res_cmp = GE_EXPR;
       else
 	return false;
       break;
@@ -2353,6 +2375,8 @@ spaceship_replacement (basic_block cond_bb, basic_block middle_bb,
 	res_cmp = one_cmp == LT_EXPR ? LE_EXPR : GE_EXPR;
       else if (integer_zerop (rhs))
 	res_cmp = one_cmp;
+      else if (integer_onep (rhs))
+	res_cmp = one_cmp;
       else
 	return false;
       break;
@@ -2360,7 +2384,7 @@ spaceship_replacement (basic_block cond_bb, basic_block middle_bb,
       if (integer_zerop (rhs))
 	res_cmp = one_cmp == LT_EXPR ? LE_EXPR : GE_EXPR;
       else if (integer_onep (rhs))
-	res_cmp = one_cmp;
+	res_cmp = LE_EXPR;
       else
 	return false;
       break;