| // Copyright 2018 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // +build ppc64 ppc64le |
| |
| #include "textflag.h" |
| |
| // func xorBytesVSX(dst, a, b *byte, n int) |
| TEXT ·xorBytesVSX(SB), NOSPLIT, $0 |
| MOVD dst+0(FP), R3 // R3 = dst |
| MOVD a+8(FP), R4 // R4 = a |
| MOVD b+16(FP), R5 // R5 = b |
| MOVD n+24(FP), R6 // R6 = n |
| |
| CMPU R6, $16, CR7 // Check if n ≥ 16 bytes |
| MOVD R0, R8 // R8 = index |
| CMPU R6, $8, CR6 // Check if 8 ≤ n < 16 bytes |
| BGE CR7, preloop16 |
| BLT CR6, small |
| |
| // Case for 8 ≤ n < 16 bytes |
| MOVD (R4)(R8), R14 // R14 = a[i,...,i+7] |
| MOVD (R5)(R8), R15 // R15 = b[i,...,i+7] |
| XOR R14, R15, R16 // R16 = a[] ^ b[] |
| SUB $8, R6 // n = n - 8 |
| MOVD R16, (R3)(R8) // Store to dst |
| ADD $8, R8 |
| |
| // Check if we're finished |
| CMP R6, R0 |
| BGT small |
| JMP done |
| |
| // Case for n ≥ 16 bytes |
| preloop16: |
| SRD $4, R6, R7 // Setup loop counter |
| MOVD R7, CTR |
| ANDCC $15, R6, R9 // Check for tailing bytes for later |
| loop16: |
| LXVD2X (R4)(R8), VS32 // VS32 = a[i,...,i+15] |
| LXVD2X (R5)(R8), VS33 // VS33 = b[i,...,i+15] |
| XXLXOR VS32, VS33, VS34 // VS34 = a[] ^ b[] |
| STXVD2X VS34, (R3)(R8) // Store to dst |
| ADD $16, R8 // Update index |
| BC 16, 0, loop16 // bdnz loop16 |
| |
| BEQ CR0, done |
| SLD $4, R7 |
| SUB R7, R6 // R6 = n - (R7 * 16) |
| |
| // Case for n < 8 bytes and tailing bytes from the |
| // previous cases. |
| small: |
| MOVD R6, CTR // Setup loop counter |
| |
| loop: |
| MOVBZ (R4)(R8), R14 // R14 = a[i] |
| MOVBZ (R5)(R8), R15 // R15 = b[i] |
| XOR R14, R15, R16 // R16 = a[i] ^ b[i] |
| MOVB R16, (R3)(R8) // Store to dst |
| ADD $1, R8 |
| BC 16, 0, loop // bdnz loop |
| |
| done: |
| RET |
