| //go:build !appengine && gc && !purego |
| // +build !appengine |
| // +build gc |
| // +build !purego |
| |
| #include "textflag.h" |
| |
| // Registers: |
| #define digest R1 |
| #define h R2 // return value |
| #define p R3 // input pointer |
| #define n R4 // input length |
| #define nblocks R5 // n / 32 |
| #define prime1 R7 |
| #define prime2 R8 |
| #define prime3 R9 |
| #define prime4 R10 |
| #define prime5 R11 |
| #define v1 R12 |
| #define v2 R13 |
| #define v3 R14 |
| #define v4 R15 |
| #define x1 R20 |
| #define x2 R21 |
| #define x3 R22 |
| #define x4 R23 |
| |
| #define round(acc, x) \ |
| MADD prime2, acc, x, acc \ |
| ROR $64-31, acc \ |
| MUL prime1, acc |
| |
| // round0 performs the operation x = round(0, x). |
| #define round0(x) \ |
| MUL prime2, x \ |
| ROR $64-31, x \ |
| MUL prime1, x |
| |
| #define mergeRound(acc, x) \ |
| round0(x) \ |
| EOR x, acc \ |
| MADD acc, prime4, prime1, acc |
| |
| // blockLoop processes as many 32-byte blocks as possible, |
| // updating v1, v2, v3, and v4. It assumes that n >= 32. |
| #define blockLoop() \ |
| LSR $5, n, nblocks \ |
| PCALIGN $16 \ |
| loop: \ |
| LDP.P 16(p), (x1, x2) \ |
| LDP.P 16(p), (x3, x4) \ |
| round(v1, x1) \ |
| round(v2, x2) \ |
| round(v3, x3) \ |
| round(v4, x4) \ |
| SUB $1, nblocks \ |
| CBNZ nblocks, loop |
| |
| // func Sum64(b []byte) uint64 |
| TEXT ·Sum64(SB), NOSPLIT|NOFRAME, $0-32 |
| LDP b_base+0(FP), (p, n) |
| |
| LDP ·primes+0(SB), (prime1, prime2) |
| LDP ·primes+16(SB), (prime3, prime4) |
| MOVD ·primes+32(SB), prime5 |
| |
| CMP $32, n |
| CSEL LT, prime5, ZR, h // if n < 32 { h = prime5 } else { h = 0 } |
| BLT afterLoop |
| |
| ADD prime1, prime2, v1 |
| MOVD prime2, v2 |
| MOVD $0, v3 |
| NEG prime1, v4 |
| |
| blockLoop() |
| |
| ROR $64-1, v1, x1 |
| ROR $64-7, v2, x2 |
| ADD x1, x2 |
| ROR $64-12, v3, x3 |
| ROR $64-18, v4, x4 |
| ADD x3, x4 |
| ADD x2, x4, h |
| |
| mergeRound(h, v1) |
| mergeRound(h, v2) |
| mergeRound(h, v3) |
| mergeRound(h, v4) |
| |
| afterLoop: |
| ADD n, h |
| |
| TBZ $4, n, try8 |
| LDP.P 16(p), (x1, x2) |
| |
| round0(x1) |
| |
| // NOTE: here and below, sequencing the EOR after the ROR (using a |
| // rotated register) is worth a small but measurable speedup for small |
| // inputs. |
| ROR $64-27, h |
| EOR x1 @> 64-27, h, h |
| MADD h, prime4, prime1, h |
| |
| round0(x2) |
| ROR $64-27, h |
| EOR x2 @> 64-27, h, h |
| MADD h, prime4, prime1, h |
| |
| try8: |
| TBZ $3, n, try4 |
| MOVD.P 8(p), x1 |
| |
| round0(x1) |
| ROR $64-27, h |
| EOR x1 @> 64-27, h, h |
| MADD h, prime4, prime1, h |
| |
| try4: |
| TBZ $2, n, try2 |
| MOVWU.P 4(p), x2 |
| |
| MUL prime1, x2 |
| ROR $64-23, h |
| EOR x2 @> 64-23, h, h |
| MADD h, prime3, prime2, h |
| |
| try2: |
| TBZ $1, n, try1 |
| MOVHU.P 2(p), x3 |
| AND $255, x3, x1 |
| LSR $8, x3, x2 |
| |
| MUL prime5, x1 |
| ROR $64-11, h |
| EOR x1 @> 64-11, h, h |
| MUL prime1, h |
| |
| MUL prime5, x2 |
| ROR $64-11, h |
| EOR x2 @> 64-11, h, h |
| MUL prime1, h |
| |
| try1: |
| TBZ $0, n, finalize |
| MOVBU (p), x4 |
| |
| MUL prime5, x4 |
| ROR $64-11, h |
| EOR x4 @> 64-11, h, h |
| MUL prime1, h |
| |
| finalize: |
| EOR h >> 33, h |
| MUL prime2, h |
| EOR h >> 29, h |
| MUL prime3, h |
| EOR h >> 32, h |
| |
| MOVD h, ret+24(FP) |
| RET |
| |
| // func writeBlocks(d *Digest, b []byte) int |
| TEXT ·writeBlocks(SB), NOSPLIT|NOFRAME, $0-40 |
| LDP ·primes+0(SB), (prime1, prime2) |
| |
| // Load state. Assume v[1-4] are stored contiguously. |
| MOVD d+0(FP), digest |
| LDP 0(digest), (v1, v2) |
| LDP 16(digest), (v3, v4) |
| |
| LDP b_base+8(FP), (p, n) |
| |
| blockLoop() |
| |
| // Store updated state. |
| STP (v1, v2), 0(digest) |
| STP (v3, v4), 16(digest) |
| |
| BIC $31, n |
| MOVD n, ret+32(FP) |
| RET |