Builds/RandomWOW
1
0
Fork 0
mirror of https://codeberg.org/wownero/RandomWOW synced 2026-03-05 14:17:33 -05:00
Code Issues Packages Projects Releases Wiki Activity

Optimized randomx_reciprocal

Browse Source 
Also limited it to 32 bit because it's supposed to work only with 32-bit values, according to the specs.
This commit is contained in:
SChernykh
2023-10-20 10:54:25 +02:00
parent 5fc512e71c
commit 5c49ab12a0
8 changed files with 23 additions and 42 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
src/jit_compiler_a64.cpp
View File

@@ -686,7 +686,7 @@ void JitCompilerA64::h_ISMULH_M(Instruction& instr, uint32_t& codePos)
void JitCompilerA64::h_IMUL_RCP(Instruction& instr, uint32_t& codePos)
{
const uint64_t divisor = instr.getImm32();
const uint32_t divisor = instr.getImm32();
if (isZeroOrPowerOf2(divisor))
return;
@@ -695,22 +695,11 @@ void JitCompilerA64::h_IMUL_RCP(Instruction& instr, uint32_t& codePos)
constexpr uint32_t tmp_reg = 20;
const uint32_t dst = IntRegMap[instr.dst];
constexpr uint64_t N = 1ULL << 63;
const uint64_t q = N / divisor;
const uint64_t r = N % divisor;
#ifdef __GNUC__
const uint64_t shift = 64 - __builtin_clzll(divisor);
#else
uint64_t shift = 32;
for (uint64_t k = 1U << 31; (k & divisor) == 0; k >>= 1)
--shift;
#endif
const uint32_t literal_id = (ImulRcpLiteralsEnd - literalPos) / sizeof(uint64_t);
literalPos -= sizeof(uint64_t);
const uint64_t randomx_reciprocal = (q << shift) + ((r << shift) / divisor);
memcpy(code + literalPos, &randomx_reciprocal, sizeof(randomx_reciprocal));
const uint64_t reciprocal = randomx_reciprocal_fast(divisor);
memcpy(code + literalPos, &reciprocal, sizeof(reciprocal));
if (literal_id < 12)
{