The PREAMBLE macro sets up the SipHash initial internal state. It also
defines that state as a variable, which isn't macro hygeinic. With
previous changes simplifying this premable, it's now possible to replace it
with a macro which simply expands to a C initialisedrfor that state.
Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au>
---
siphash.c | 29 ++++++++++++-----------------
1 file changed, 12 insertions(+), 17 deletions(-)
diff --git a/siphash.c b/siphash.c
index 6932da2..21c560d 100644
--- a/siphash.c
+++ b/siphash.c
@@ -58,15 +58,12 @@
#define ROTL(x, b) (uint64_t)(((x) << (b)) | ((x) >> (64 - (b))))
-#define PREAMBLE \
- uint64_t v[4] = { 0x736f6d6570736575ULL, 0x646f72616e646f6dULL, \
- 0x6c7967656e657261ULL, 0x7465646279746573ULL }; \
- int __i; \
- \
- do { \
- for (__i = sizeof(v) / sizeof(v[0]) - 1; __i >= 0; __i--) \
- v[__i] ^= k[__i % 2]; \
- } while (0)
+#define SIPHASH_INIT(k) { \
+ 0x736f6d6570736575ULL ^ (k)[0], \
+ 0x646f72616e646f6dULL ^ (k)[1], \
+ 0x6c7967656e657261ULL ^ (k)[0], \
+ 0x7465646279746573ULL ^ (k)[1] \
+ }
/**
* sipround() - Perform rounds of SipHash scrambling
@@ -140,7 +137,8 @@ __attribute__((optimize("-fno-strict-aliasing")))
/* cppcheck-suppress unusedFunction */
uint64_t siphash_8b(const uint8_t *in, const uint64_t *k)
{
- PREAMBLE;
+ uint64_t v[4] = SIPHASH_INIT(k);
+
siphash_feed(v, *(uint64_t *)in);
@@ -160,8 +158,8 @@ __attribute__((optimize("-fno-strict-aliasing"))) /* See
siphash_8b() */
uint64_t siphash_12b(const uint8_t *in, const uint64_t *k)
{
uint32_t *in32 = (uint32_t *)in;
+ uint64_t v[4] = SIPHASH_INIT(k);
- PREAMBLE;
siphash_feed(v, (uint64_t)(*(in32 + 1)) << 32 | *in32);
return siphash_final(v, 12, *(in32 + 2));
@@ -179,10 +177,9 @@ __attribute__((optimize("-fno-strict-aliasing"))) /* See
siphash_8b() */
uint64_t siphash_20b(const uint8_t *in, const uint64_t *k)
{
uint32_t *in32 = (uint32_t *)in;
+ uint64_t v[4] = SIPHASH_INIT(k);
int i;
- PREAMBLE;
-
for (i = 0; i < 2; i++, in32 += 2)
siphash_feed(v, (uint64_t)(*(in32 + 1)) << 32 | *in32);
@@ -202,10 +199,9 @@ __attribute__((optimize("-fno-strict-aliasing"))) /* See
siphash_8b() */
uint64_t siphash_32b(const uint8_t *in, const uint64_t *k)
{
uint64_t *in64 = (uint64_t *)in;
+ uint64_t v[4] = SIPHASH_INIT(k);
int i;
- PREAMBLE;
-
for (i = 0; i < 4; i++, in64++)
siphash_feed(v, *in64);
@@ -224,10 +220,9 @@ __attribute__((optimize("-fno-strict-aliasing"))) /* See
siphash_8b() */
uint64_t siphash_36b(const uint8_t *in, const uint64_t *k)
{
uint32_t *in32 = (uint32_t *)in;
+ uint64_t v[4] = SIPHASH_INIT(k);
int i;
- PREAMBLE;
-
for (i = 0; i < 4; i++, in32 += 2)
siphash_feed(v, (uint64_t)(*(in32 + 1)) << 32 | *in32);
--
2.41.0