Compilation warnings on OpenBSD

Replaces unnecessary aligned(32) with aligned(16) instead.

cbits/decaf/include/decaf/point_448.h

@@ -34,7 +34,7 @@ extern "C" {
 /** @brief Galois field element internal structure */
 typedef struct cryptonite_gf_448_s {
     cryptonite_decaf_word_t limb[512/CRYPTONITE_DECAF_WORD_BITS];
-} __attribute__((aligned(32))) cryptonite_gf_448_s, cryptonite_gf_448_t[1];
+} __attribute__((aligned(16))) cryptonite_gf_448_s, cryptonite_gf_448_t[1];
 #endif /* __CRYPTONITE_DECAF_448_GF_DEFINED__ */
 /** @endcond */
 

cbits/decaf/p448/f_field.h

@@ -27,7 +27,7 @@
 #define SER_BYTES 56
 typedef struct cryptonite_gf_448_s {
     word_t limb[NLIMBS];
-} __attribute__((aligned(32))) cryptonite_gf_448_s, cryptonite_gf_448_t[1];
+} __attribute__((aligned(16))) cryptonite_gf_448_s, cryptonite_gf_448_t[1];
 
 #define GF_LIT_LIMB_BITS  56
 #define GF_BITS           448

cbits/decaf/tools/generate.sh

@@ -21,6 +21,11 @@
 #
 # * code related to SHAKE is replaced by cryptonite code, referenced from
 #   a custom shake.h.  As a consequence, portable_endian.h is not needed.
+#
+# * aligned(32) attributes used for stack alignment are replaced by
+#   aligned(16).  This removes warnings on OpenBSD with GCC 4.2.1, and makes
+#   sure we get at least 16-byte alignment.  32-byte alignment is necessary
+#   only for AVX2 and arch_x86_64, which we don't have.
 
 SRC_DIR="$1/src"
 DEST_DIR="`dirname "$0"`"/..
@@ -33,7 +38,16 @@ fi
 
 convert() {
   local FILE_NAME="`basename "$1"`"
+  local REPL
+
+  if [ "$FILE_NAME" = word.h ]; then
+    REPL='__attribute__((aligned(32)))'
+  else
+    REPL='__attribute__((aligned(16)))'
+  fi
+
   sed <"$1" >"$2/$FILE_NAME" \
+    -e "s/__attribute__((aligned(32)))/$REPL/g" \
     -e 's/decaf_/cryptonite_decaf_/g' \
     -e 's/DECAF_/CRYPTONITE_DECAF_/g' \
     -e 's/gf_/cryptonite_gf_/g' \