diff options
Diffstat (limited to 'src/pkg/runtime/alg.c')
| -rw-r--r-- | src/pkg/runtime/alg.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/src/pkg/runtime/alg.c b/src/pkg/runtime/alg.c index ad85b43ae..2dc821256 100644 --- a/src/pkg/runtime/alg.c +++ b/src/pkg/runtime/alg.c @@ -8,6 +8,8 @@ #define M0 (sizeof(uintptr)==4 ? 2860486313UL : 33054211828000289ULL) #define M1 (sizeof(uintptr)==4 ? 3267000013UL : 23344194077549503ULL) +static bool use_aeshash; + /* * map and chan helpers for * dealing with unknown types @@ -17,6 +19,10 @@ runtime·memhash(uintptr *h, uintptr s, void *a) { byte *b; uintptr hash; + if(use_aeshash) { + runtime·aeshash(h, s, a); + return; + } b = a; hash = M0 ^ *h; @@ -467,6 +473,42 @@ runtime·algarray[] = // Runtime helpers. +// used in asm_{386,amd64}.s +byte runtime·aeskeysched[HashRandomBytes]; + +void +runtime·hashinit(void) +{ + // Install aes hash algorithm if we have the instructions we need + if((runtime·cpuid_ecx & (1 << 25)) != 0 && // aes (aesenc) + (runtime·cpuid_ecx & (1 << 9)) != 0 && // sse3 (pshufb) + (runtime·cpuid_ecx & (1 << 19)) != 0) { // sse4.1 (pinsr{d,q}) + byte *rnd; + int32 n; + use_aeshash = true; + runtime·algarray[AMEM].hash = runtime·aeshash; + runtime·algarray[AMEM8].hash = runtime·aeshash; + runtime·algarray[AMEM16].hash = runtime·aeshash; + runtime·algarray[AMEM32].hash = runtime·aeshash32; + runtime·algarray[AMEM64].hash = runtime·aeshash64; + runtime·algarray[AMEM128].hash = runtime·aeshash; + runtime·algarray[ASTRING].hash = runtime·aeshashstr; + + // Initialize with random data so hash collisions will be hard to engineer. + runtime·get_random_data(&rnd, &n); + if(n > HashRandomBytes) + n = HashRandomBytes; + runtime·memmove(runtime·aeskeysched, rnd, n); + if(n < HashRandomBytes) { + // Not very random, but better than nothing. + int64 t = runtime·nanotime(); + while (n < HashRandomBytes) { + runtime·aeskeysched[n++] = (int8)(t >> (8 * (n % 8))); + } + } + } +} + // func equal(t *Type, x T, y T) (ret bool) #pragma textflag 7 void |