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siphash: Use more hygienic state initialiser

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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@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
David Gibson 2023-09-28 11:20:58 +10:00 committed by Stefano Brivio
parent 5cc843521d
commit fcec3f6f9d
1 changed files with 12 additions and 17 deletions
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29
siphash.c
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@ -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);