ell_grid_solve: split residual computation into its own file

1 files changed, 77 insertions, 0 deletions

diff --git a/residual_calc.h b/residual_calc.h
new file mode 100644
index 0000000..af1bf39
--- /dev/null
+++ b/residual_calc.h
@@ -0,0 +1,77 @@
+/*
+ * Copyright 2019 Anton Khirnov <anton@khirnov.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef MG2D_RESIDUAL_CALC_H
+#define MG2D_RESIDUAL_CALC_H
+
+#include <stddef.h>
+
+#include <threadpool.h>
+
+typedef struct ResidualCalcInternal ResidualCalcInternal;
+
+/**
+ * Context for computing the residual, allocated by mg2di_residual_calc_alloc(),
+ * freed by mg2di_residual_calc_free()
+ */
+typedef struct ResidualCalcContext {
+    ResidualCalcInternal *priv;
+
+    /**
+     * The thread pool, must be set by the caller before
+     * mg2di_residual_calc_init().
+     */
+    TPContext *tp;
+
+    /**
+     * FD stencil size, must be set by the caller before
+     * mg2di_residual_calc_init().
+     */
+    size_t fd_stencil;
+
+    /**
+     * Flags indicating supported CPU features,  must be set by the caller
+     * before mg2di_residual_calc_init().
+     */
+    int cpuflags;
+} ResidualCalcContext;
+
+/**
+ * Allocate and retur a new ResidualCalcContext.
+ */
+ResidualCalcContext *mg2di_residual_calc_alloc(void);
+/**
+ * Free a ResidualCalcContext and write NULL into the supplied pointer.
+ */
+void mg2di_residual_calc_free(ResidualCalcContext **ctx);
+
+/**
+ * Reinitialize the context for updated parameters. Must be called at least once
+ * before mg2di_residual_calc().
+ */
+int mg2di_residual_calc_init(ResidualCalcContext *ctx);
+
+/**
+ * Calculate the residual.
+ */
+int mg2di_residual_calc(ResidualCalcContext *ctx, size_t size[2], ptrdiff_t stride,
+                        double *res_max,
+                        double *dst, const double *u, const double *rhs,
+                        const double * const diff_coeffs[MG2D_DIFF_COEFF_NB],
+                        const double *fd_factors);
+
+#endif // MG2D_RESIDUAL_CALC_H