crc32_loong64.s

Documentation: hash/crc32

     1// Copyright 2024 The Go Authors. All rights reserved.
     2// Use of this source code is governed by a BSD-style
     3// license that can be found in the LICENSE file.
     4
     5#include "textflag.h"
     6
     7// castagnoliUpdate updates the non-inverted crc with the given data.
     8
     9// func castagnoliUpdate(crc uint32, p []byte) uint32
    10TEXT ·castagnoliUpdate(SB),NOSPLIT,$0-36
    11	MOVWU	crc+0(FP), R4		// a0 = CRC value
    12	MOVV	p+8(FP), R5		// a1 = data pointer
    13	MOVV	p_len+16(FP), R6	// a2 = len(p)
    14
    15	SGT	$8, R6, R12
    16	BNE	R12, less_than_8
    17	AND	$7, R5, R12
    18	BEQ	R12, aligned
    19
    20	// Process the first few bytes to 8-byte align the input.
    21	// t0 = 8 - t0. We need to process this many bytes to align.
    22	SUB	$1, R12
    23	XOR	$7, R12
    24
    25	AND	$1, R12, R13
    26	BEQ	R13, align_2
    27	MOVB	(R5), R13
    28	CRCCWBW	R4, R13, R4
    29	ADDV	$1, R5
    30	ADDV	$-1, R6
    31
    32align_2:
    33	AND	$2, R12, R13
    34	BEQ	R13, align_4
    35	MOVH	(R5), R13
    36	CRCCWHW	R4, R13, R4
    37	ADDV	$2, R5
    38	ADDV	$-2, R6
    39
    40align_4:
    41	AND	$4, R12, R13
    42	BEQ	R13, aligned
    43	MOVW	(R5), R13
    44	CRCCWWW	R4, R13, R4
    45	ADDV	$4, R5
    46	ADDV	$-4, R6
    47
    48aligned:
    49	// The input is now 8-byte aligned and we can process 8-byte chunks.
    50	SGT	$8, R6, R12
    51	BNE	R12, less_than_8
    52	MOVV	(R5), R13
    53	CRCCWVW	R4, R13, R4
    54	ADDV	$8, R5
    55	ADDV	$-8, R6
    56	JMP	aligned
    57
    58less_than_8:
    59	// We may have some bytes left over; process 4 bytes, then 2, then 1.
    60	AND	$4, R6, R12
    61	BEQ	R12, less_than_4
    62	MOVW	(R5), R13
    63	CRCCWWW	R4, R13, R4
    64	ADDV	$4, R5
    65	ADDV	$-4, R6
    66
    67less_than_4:
    68	AND	$2, R6, R12
    69	BEQ	R12, less_than_2
    70	MOVH	(R5), R13
    71	CRCCWHW	R4, R13, R4
    72	ADDV	$2, R5
    73	ADDV	$-2, R6
    74
    75less_than_2:
    76	BEQ	R6, done
    77	MOVB	(R5), R13
    78	CRCCWBW	R4, R13, R4
    79
    80done:
    81	MOVW	R4, ret+32(FP)
    82	RET
    83
    84// ieeeUpdate updates the non-inverted crc with the given data.
    85
    86// func ieeeUpdate(crc uint32, p []byte) uint32
    87TEXT ·ieeeUpdate(SB),NOSPLIT,$0-36
    88	MOVWU	crc+0(FP), R4		// a0 = CRC value
    89	MOVV	p+8(FP), R5		// a1 = data pointer
    90	MOVV	p_len+16(FP), R6	// a2 = len(p)
    91
    92	SGT	$8, R6, R12
    93	BNE	R12, less_than_8
    94	AND	$7, R5, R12
    95	BEQ	R12, aligned
    96
    97	// Process the first few bytes to 8-byte align the input.
    98	// t0 = 8 - t0. We need to process this many bytes to align.
    99	SUB	$1, R12
   100	XOR	$7, R12
   101
   102	AND	$1, R12, R13
   103	BEQ	R13, align_2
   104	MOVB	(R5), R13
   105	CRCWBW	R4, R13, R4
   106	ADDV	$1, R5
   107	ADDV	$-1, R6
   108
   109align_2:
   110	AND	$2, R12, R13
   111	BEQ	R13, align_4
   112	MOVH	(R5), R13
   113	CRCWHW	R4, R13, R4
   114	ADDV	$2, R5
   115	ADDV	$-2, R6
   116
   117align_4:
   118	AND	$4, R12, R13
   119	BEQ	R13, aligned
   120	MOVW	(R5), R13
   121	CRCWWW	R4, R13, R4
   122	ADDV	$4, R5
   123	ADDV	$-4, R6
   124
   125aligned:
   126	// The input is now 8-byte aligned and we can process 8-byte chunks.
   127	SGT	$8, R6, R12
   128	BNE	R12, less_than_8
   129	MOVV	(R5), R13
   130	CRCWVW	R4, R13, R4
   131	ADDV	$8, R5
   132	ADDV	$-8, R6
   133	JMP	aligned
   134
   135less_than_8:
   136	// We may have some bytes left over; process 4 bytes, then 2, then 1.
   137	AND	$4, R6, R12
   138	BEQ	R12, less_than_4
   139	MOVW	(R5), R13
   140	CRCWWW	R4, R13, R4
   141	ADDV	$4, R5
   142	ADDV	$-4, R6
   143
   144less_than_4:
   145	AND	$2, R6, R12
   146	BEQ	R12, less_than_2
   147	MOVH	(R5), R13
   148	CRCWHW	R4, R13, R4
   149	ADDV	$2, R5
   150	ADDV	$-2, R6
   151
   152less_than_2:
   153	BEQ	R6, done
   154	MOVB	(R5), R13
   155	CRCWBW	R4, R13, R4
   156
   157done:
   158	MOVW	R4, ret+32(FP)
   159	RET
   160
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