mg2d: actually initialize u to zero as documented

1 files changed, 3 insertions, 0 deletions

diff --git a/mg2d.c b/mg2d.c
index 73157f5..7dacece 100644
--- a/mg2d.c
+++ b/mg2d.c
@@ -450,6 +450,9 @@ MG2DContext *mg2d_solver_alloc(size_t domain_size)
 
     ctx->u          = priv->root->solver->u;
     ctx->u_stride   = priv->root->solver->u_stride;
+    /* initialize the initial guess to zero */
+    memset(ctx->u, 0, sizeof(*ctx->u) * ctx->u_stride * ctx->domain_size);
+
     ctx->rhs        = priv->root->solver->rhs;
     ctx->rhs_stride = priv->root->solver->rhs_stride;