rfv2.h

// RainForest hash algorithm
// Author: Bill Schneider
// Date: Feb 13th, 2018
//
// RainForest uses native integer operations which are extremely fast on
// modern 64-bit processors, significantly slower on 32-bit processors such
// as GPUs, and extremely slow if at all implementable on FPGAs and ASICs.
// It makes an intensive use of the L1 cache to maintain a heavy intermediary
// state favoring modern CPUs compared to GPUs (small L1 cache shared by many
// shaders) or FPGAs (very hard to implement the required low-latency cache)
// when scanning ranges for nonces. The purpose is to create a fair balance
// between all mining equipments, from mobile phones to extreme performance
// GPUs and to rule out farming factories relying on ASICs and FPGAs. The
// CRC32 instruction is used a lot as it is extremely fast on low-power ARM
// chips and allows such devices to rival high-end PCs mining performance.
//
// Tests on various devices have shown the following performance :
// +--------------------------------------------------------------------------+
// | CPU/GPU       Clock Threads Full hash  Nonce scan  Watts   Cost          |
// |               (MHz)         (80 bytes) (4 bytes)   total                 |
// | Core i7-6700k  4000      8   390 kH/s  1642 kH/s     200  ~$350+PC       |
// | Radeon RX560   1300   1024  1100 kH/s  1650 kH/s     300  ~$180+PC       |
// | RK3368 (8*A53) 1416      8   534 kH/s  1582 kH/s       6   $60 (Geekbox) |
// +--------------------------------------------------------------------------+
//
// Build instructions on Ubuntu 16.04 :
//   - on x86:   use gcc -march=native or -maes to enable AES-NI
//   - on ARMv8: use gcc -march=native or -march=armv8-a+crypto+crc to enable
//               CRC32 and AES extensions.
//
// Note: always use the same options to build all files!
//

#ifndef RAINFOREST
#define RAINFOREST

#include <stdint.h>
#include <stddef.h>

#define RFV2_RAMBOX_SIZE (96*1024*1024/8)

int rfv2_hash(void *out, const void *in, size_t len, void *rambox, const void *rambox_template);
int rfv2_hash2(void *out, const void *in, size_t len, void *rambox, const void *rambox_template, uint32_t seed);
void rfv2_raminit(void *area);

#endif