diff --git a/tcg/optimize.c b/tcg/optimize.c
index 0766a452b5..2f5030c899 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -1067,6 +1067,11 @@ static bool fold_masks_zs(OptContext *ctx, TCGOp *op,
     return true;
 }
 
+static bool fold_masks_z(OptContext *ctx, TCGOp *op, uint64_t z_mask)
+{
+    return fold_masks_zs(ctx, op, z_mask, 0);
+}
+
 static bool fold_masks(OptContext *ctx, TCGOp *op)
 {
     return fold_masks_zs(ctx, op, ctx->z_mask, ctx->s_mask);
@@ -1599,21 +1604,23 @@ static bool fold_count_zeros(OptContext *ctx, TCGOp *op)
 
 static bool fold_ctpop(OptContext *ctx, TCGOp *op)
 {
+    uint64_t z_mask;
+
     if (fold_const1(ctx, op)) {
         return true;
     }
 
     switch (ctx->type) {
     case TCG_TYPE_I32:
-        ctx->z_mask = 32 | 31;
+        z_mask = 32 | 31;
         break;
     case TCG_TYPE_I64:
-        ctx->z_mask = 64 | 63;
+        z_mask = 64 | 63;
         break;
     default:
         g_assert_not_reached();
     }
-    return false;
+    return fold_masks_z(ctx, op, z_mask);
 }
 
 static bool fold_deposit(OptContext *ctx, TCGOp *op)