Move ecmult table computation code to separate file

Author: sipa

Makefile.am

@@ -26,6 +26,8 @@ noinst_HEADERS += src/eckey.h
 noinst_HEADERS += src/eckey_impl.h
 noinst_HEADERS += src/ecmult.h
 noinst_HEADERS += src/ecmult_impl.h
+noinst_HEADERS += src/ecmult_compute_table.h
+noinst_HEADERS += src/ecmult_compute_table_impl.h
 noinst_HEADERS += src/ecmult_const.h
 noinst_HEADERS += src/ecmult_const_impl.h
 noinst_HEADERS += src/ecmult_gen.h

src/ecmult_compute_table.h

@@ -0,0 +1,16 @@
+/*****************************************************************************************************
+ * Copyright (c) 2013, 2014, 2017, 2021 Pieter Wuille, Andrew Poelstra, Jonas Nick, Russell O'Connor *
+ * Distributed under the MIT software license, see the accompanying                                  *
+ * file COPYING or https://www.opensource.org/licenses/mit-license.php.                              *
+ *****************************************************************************************************/
+
+#ifndef SECP256K1_ECMULT_COMPUTE_TABLE_H
+#define SECP256K1_ECMULT_COMPUTE_TABLE_H
+
+/* Construct table of all odd multiples of gen in range 1..(2**(window_g-1)-1). */
+static void secp256k1_ecmult_compute_table(secp256k1_ge_storage* table, int window_g, const secp256k1_gej* gen);
+
+/* Like secp256k1_ecmult_compute_table, but one for both gen and gen*2^128. */
+static void secp256k1_ecmult_compute_two_tables(secp256k1_ge_storage* table, secp256k1_ge_storage* table_128, int window_g, const secp256k1_ge* gen);
+
+#endif /* SECP256K1_ECMULT_COMPUTE_TABLE_H */

src/ecmult_compute_table_impl.h

@@ -0,0 +1,49 @@
+/*****************************************************************************************************
+ * Copyright (c) 2013, 2014, 2017, 2021 Pieter Wuille, Andrew Poelstra, Jonas Nick, Russell O'Connor *
+ * Distributed under the MIT software license, see the accompanying                                  *
+ * file COPYING or https://www.opensource.org/licenses/mit-license.php.                              *
+ *****************************************************************************************************/
+
+#ifndef SECP256K1_ECMULT_COMPUTE_TABLE_IMPL_H
+#define SECP256K1_ECMULT_COMPUTE_TABLE_IMPL_H
+
+#include "ecmult_compute_table.h"
+#include "group_impl.h"
+#include "field_impl.h"
+#include "ecmult.h"
+#include "util.h"
+
+static void secp256k1_ecmult_compute_table(secp256k1_ge_storage* table, int window_g, const secp256k1_gej* gen) {
+    secp256k1_gej gj;
+    secp256k1_ge ge, dgen;
+    int j;
+
+    gj = *gen;
+    secp256k1_ge_set_gej_var(&ge, &gj);
+    secp256k1_ge_to_storage(&table[0], &ge);
+
+    secp256k1_gej_double_var(&gj, gen, NULL);
+    secp256k1_ge_set_gej_var(&dgen, &gj);
+
+    for (j = 1; j < ECMULT_TABLE_SIZE(window_g); ++j) {
+        secp256k1_gej_set_ge(&gj, &ge);
+        secp256k1_gej_add_ge_var(&gj, &gj, &dgen, NULL);
+        secp256k1_ge_set_gej_var(&ge, &gj);
+        secp256k1_ge_to_storage(&table[j], &ge);
+    }
+}
+
+/* Like secp256k1_ecmult_compute_table, but one for both gen and gen*2^128. */
+static void secp256k1_ecmult_compute_two_tables(secp256k1_ge_storage* table, secp256k1_ge_storage* table_128, int window_g, const secp256k1_ge* gen) {
+    secp256k1_gej gj;
+    int i;
+
+    secp256k1_gej_set_ge(&gj, gen);
+    secp256k1_ecmult_compute_table(table, window_g, &gj);
+    for (i = 0; i < 128; ++i) {
+        secp256k1_gej_double_var(&gj, &gj, NULL);
+    }
+    secp256k1_ecmult_compute_table(table_128, window_g, &gj);
+}
+
+#endif /* SECP256K1_ECMULT_COMPUTE_TABLE_IMPL_H */

src/precompute_ecmult.c

@@ -19,40 +19,7 @@
 #include "field_impl.h"
 #include "group_impl.h"
 #include "ecmult.h"
-
-/* Construct table of all odd multiples of gen in range 1..(2**(window_g-1)-1). */
-static void secp256k1_ecmult_compute_table(secp256k1_ge_storage* table, int window_g, const secp256k1_gej* gen) {
-    secp256k1_gej gj;
-    secp256k1_ge ge, dgen;
-    int j;
-
-    gj = *gen;
-    secp256k1_ge_set_gej_var(&ge, &gj);
-    secp256k1_ge_to_storage(&table[0], &ge);
-
-    secp256k1_gej_double_var(&gj, gen, NULL);
-    secp256k1_ge_set_gej_var(&dgen, &gj);
-
-    for (j = 1; j < ECMULT_TABLE_SIZE(window_g); ++j) {
-        secp256k1_gej_set_ge(&gj, &ge);
-        secp256k1_gej_add_ge_var(&gj, &gj, &dgen, NULL);
-        secp256k1_ge_set_gej_var(&ge, &gj);
-        secp256k1_ge_to_storage(&table[j], &ge);
-    }
-}
-
-/* Like secp256k1_ecmult_compute_table, but one for both gen and gen*2^128. */
-static void secp256k1_ecmult_compute_two_tables(secp256k1_ge_storage* table, secp256k1_ge_storage* table_128, int window_g, const secp256k1_ge* gen) {
-    secp256k1_gej gj;
-    int i;
-
-    secp256k1_gej_set_ge(&gj, gen);
-    secp256k1_ecmult_compute_table(table, window_g, &gj);
-    for (i = 0; i < 128; ++i) {
-        secp256k1_gej_double_var(&gj, &gj, NULL);
-    }
-    secp256k1_ecmult_compute_table(table_128, window_g, &gj);
-}
+#include "ecmult_compute_table_impl.h"
 
 static void print_table(FILE *fp, const char *name, int window_g, const secp256k1_ge_storage* table, int with_conditionals) {
     int j;