siphash24: change result argument to uint64_t

Change the "out" parameter from uint8_t[8] to uint64_t. On architectures which
enforce pointer alignment this fixes crashes when we previously cast an
unaligned array to uint64_t*, and on others this should at least improve
performance as the compiler now aligns these properly.

This also simplifies the code in most cases by getting rid of typecasts. The
only place which we can't change is struct duid's en.id, as that is _packed_
and public API, so we can't enforce alignment of the "id" field and have to
use memcpy instead.

3 files changed, 5 insertions, 5 deletions

diff --git a/src/basic/hashmap.c b/src/basic/hashmap.c
index 4109a08c6c..d88ceb40aa 100644
--- a/src/basic/hashmap.c
+++ b/src/basic/hashmap.c
@@ -380,7 +380,7 @@ static unsigned base_bucket_hash(HashmapBase *h, const void *p) {
 
         h->hash_ops->hash(p, &state);
 
-        siphash24_finalize((uint8_t*)&hash, &state);
+        siphash24_finalize(&hash, &state);
 
         return (unsigned) (hash % n_buckets(h));
 }
diff --git a/src/basic/siphash24.c b/src/basic/siphash24.c
index 1da2d1a410..d7640d395d 100644
--- a/src/basic/siphash24.c
+++ b/src/basic/siphash24.c
@@ -141,7 +141,7 @@ void siphash24_compress(const void *_in, size_t inlen, struct siphash *state) {
         }
 }
 
-void siphash24_finalize(uint8_t out[8], struct siphash *state) {
+void siphash24_finalize(uint64_t *out, struct siphash *state) {
         uint64_t b;
 
         b = state->padding | (( ( uint64_t )state->inlen ) << 56);
@@ -174,7 +174,7 @@ void siphash24_finalize(uint8_t out[8], struct siphash *state) {
 }
 
 /* SipHash-2-4 */
-void siphash24(uint8_t out[8], const void *_in, size_t inlen, const uint8_t k[16]) {
+void siphash24(uint64_t *out, const void *_in, size_t inlen, const uint8_t k[16]) {
         struct siphash state;
 
         siphash24_init(&state, k);
diff --git a/src/basic/siphash24.h b/src/basic/siphash24.h
index 6c5cd98ee8..dc08077d53 100644
--- a/src/basic/siphash24.h
+++ b/src/basic/siphash24.h
@@ -14,6 +14,6 @@ struct siphash {
 
 void siphash24_init(struct siphash *state, const uint8_t k[16]);
 void siphash24_compress(const void *in, size_t inlen, struct siphash *state);
-void siphash24_finalize(uint8_t out[8], struct siphash *state);
+void siphash24_finalize(uint64_t *out, struct siphash *state);
 
-void siphash24(uint8_t out[8], const void *in, size_t inlen, const uint8_t k[16]);
+void siphash24(uint64_t *out, const void *in, size_t inlen, const uint8_t k[16]);