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-rw-r--r--src/hash/crc32/crc32_amd64.s279
1 files changed, 279 insertions, 0 deletions
diff --git a/src/hash/crc32/crc32_amd64.s b/src/hash/crc32/crc32_amd64.s
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+// Copyright 2011 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.
+
+#include "textflag.h"
+
+// castagnoliSSE42 updates the (non-inverted) crc with the given buffer.
+//
+// func castagnoliSSE42(crc uint32, p []byte) uint32
+TEXT ·castagnoliSSE42(SB),NOSPLIT,$0
+ MOVL crc+0(FP), AX // CRC value
+ MOVQ p+8(FP), SI // data pointer
+ MOVQ p_len+16(FP), CX // len(p)
+
+ // If there are fewer than 8 bytes to process, skip alignment.
+ CMPQ CX, $8
+ JL less_than_8
+
+ MOVQ SI, BX
+ ANDQ $7, BX
+ JZ aligned
+
+ // Process the first few bytes to 8-byte align the input.
+
+ // BX = 8 - BX. We need to process this many bytes to align.
+ SUBQ $1, BX
+ XORQ $7, BX
+
+ BTQ $0, BX
+ JNC align_2
+
+ CRC32B (SI), AX
+ DECQ CX
+ INCQ SI
+
+align_2:
+ BTQ $1, BX
+ JNC align_4
+
+ CRC32W (SI), AX
+
+ SUBQ $2, CX
+ ADDQ $2, SI
+
+align_4:
+ BTQ $2, BX
+ JNC aligned
+
+ CRC32L (SI), AX
+
+ SUBQ $4, CX
+ ADDQ $4, SI
+
+aligned:
+ // The input is now 8-byte aligned and we can process 8-byte chunks.
+ CMPQ CX, $8
+ JL less_than_8
+
+ CRC32Q (SI), AX
+ ADDQ $8, SI
+ SUBQ $8, CX
+ JMP aligned
+
+less_than_8:
+ // We may have some bytes left over; process 4 bytes, then 2, then 1.
+ BTQ $2, CX
+ JNC less_than_4
+
+ CRC32L (SI), AX
+ ADDQ $4, SI
+
+less_than_4:
+ BTQ $1, CX
+ JNC less_than_2
+
+ CRC32W (SI), AX
+ ADDQ $2, SI
+
+less_than_2:
+ BTQ $0, CX
+ JNC done
+
+ CRC32B (SI), AX
+
+done:
+ MOVL AX, ret+32(FP)
+ RET
+
+// castagnoliSSE42Triple updates three (non-inverted) crcs with (24*rounds)
+// bytes from each buffer.
+//
+// func castagnoliSSE42Triple(
+// crc1, crc2, crc3 uint32,
+// a, b, c []byte,
+// rounds uint32,
+// ) (retA uint32, retB uint32, retC uint32)
+TEXT ·castagnoliSSE42Triple(SB),NOSPLIT,$0
+ MOVL crcA+0(FP), AX
+ MOVL crcB+4(FP), CX
+ MOVL crcC+8(FP), DX
+
+ MOVQ a+16(FP), R8 // data pointer
+ MOVQ b+40(FP), R9 // data pointer
+ MOVQ c+64(FP), R10 // data pointer
+
+ MOVL rounds+88(FP), R11
+
+loop:
+ CRC32Q (R8), AX
+ CRC32Q (R9), CX
+ CRC32Q (R10), DX
+
+ CRC32Q 8(R8), AX
+ CRC32Q 8(R9), CX
+ CRC32Q 8(R10), DX
+
+ CRC32Q 16(R8), AX
+ CRC32Q 16(R9), CX
+ CRC32Q 16(R10), DX
+
+ ADDQ $24, R8
+ ADDQ $24, R9
+ ADDQ $24, R10
+
+ DECQ R11
+ JNZ loop
+
+ MOVL AX, retA+96(FP)
+ MOVL CX, retB+100(FP)
+ MOVL DX, retC+104(FP)
+ RET
+
+// CRC32 polynomial data
+//
+// These constants are lifted from the
+// Linux kernel, since they avoid the costly
+// PSHUFB 16 byte reversal proposed in the
+// original Intel paper.
+DATA r2r1<>+0(SB)/8, $0x154442bd4
+DATA r2r1<>+8(SB)/8, $0x1c6e41596
+DATA r4r3<>+0(SB)/8, $0x1751997d0
+DATA r4r3<>+8(SB)/8, $0x0ccaa009e
+DATA rupoly<>+0(SB)/8, $0x1db710641
+DATA rupoly<>+8(SB)/8, $0x1f7011641
+DATA r5<>+0(SB)/8, $0x163cd6124
+
+GLOBL r2r1<>(SB),RODATA,$16
+GLOBL r4r3<>(SB),RODATA,$16
+GLOBL rupoly<>(SB),RODATA,$16
+GLOBL r5<>(SB),RODATA,$8
+
+// Based on https://www.intel.com/content/dam/www/public/us/en/documents/white-papers/fast-crc-computation-generic-polynomials-pclmulqdq-paper.pdf
+// len(p) must be at least 64, and must be a multiple of 16.
+
+// func ieeeCLMUL(crc uint32, p []byte) uint32
+TEXT ·ieeeCLMUL(SB),NOSPLIT,$0
+ MOVL crc+0(FP), X0 // Initial CRC value
+ MOVQ p+8(FP), SI // data pointer
+ MOVQ p_len+16(FP), CX // len(p)
+
+ MOVOU (SI), X1
+ MOVOU 16(SI), X2
+ MOVOU 32(SI), X3
+ MOVOU 48(SI), X4
+ PXOR X0, X1
+ ADDQ $64, SI // buf+=64
+ SUBQ $64, CX // len-=64
+ CMPQ CX, $64 // Less than 64 bytes left
+ JB remain64
+
+ MOVOA r2r1<>+0(SB), X0
+loopback64:
+ MOVOA X1, X5
+ MOVOA X2, X6
+ MOVOA X3, X7
+ MOVOA X4, X8
+
+ PCLMULQDQ $0, X0, X1
+ PCLMULQDQ $0, X0, X2
+ PCLMULQDQ $0, X0, X3
+ PCLMULQDQ $0, X0, X4
+
+ /* Load next early */
+ MOVOU (SI), X11
+ MOVOU 16(SI), X12
+ MOVOU 32(SI), X13
+ MOVOU 48(SI), X14
+
+ PCLMULQDQ $0x11, X0, X5
+ PCLMULQDQ $0x11, X0, X6
+ PCLMULQDQ $0x11, X0, X7
+ PCLMULQDQ $0x11, X0, X8
+
+ PXOR X5, X1
+ PXOR X6, X2
+ PXOR X7, X3
+ PXOR X8, X4
+
+ PXOR X11, X1
+ PXOR X12, X2
+ PXOR X13, X3
+ PXOR X14, X4
+
+ ADDQ $0x40, DI
+ ADDQ $64, SI // buf+=64
+ SUBQ $64, CX // len-=64
+ CMPQ CX, $64 // Less than 64 bytes left?
+ JGE loopback64
+
+ /* Fold result into a single register (X1) */
+remain64:
+ MOVOA r4r3<>+0(SB), X0
+
+ MOVOA X1, X5
+ PCLMULQDQ $0, X0, X1
+ PCLMULQDQ $0x11, X0, X5
+ PXOR X5, X1
+ PXOR X2, X1
+
+ MOVOA X1, X5
+ PCLMULQDQ $0, X0, X1
+ PCLMULQDQ $0x11, X0, X5
+ PXOR X5, X1
+ PXOR X3, X1
+
+ MOVOA X1, X5
+ PCLMULQDQ $0, X0, X1
+ PCLMULQDQ $0x11, X0, X5
+ PXOR X5, X1
+ PXOR X4, X1
+
+ /* If there is less than 16 bytes left we are done */
+ CMPQ CX, $16
+ JB finish
+
+ /* Encode 16 bytes */
+remain16:
+ MOVOU (SI), X10
+ MOVOA X1, X5
+ PCLMULQDQ $0, X0, X1
+ PCLMULQDQ $0x11, X0, X5
+ PXOR X5, X1
+ PXOR X10, X1
+ SUBQ $16, CX
+ ADDQ $16, SI
+ CMPQ CX, $16
+ JGE remain16
+
+finish:
+ /* Fold final result into 32 bits and return it */
+ PCMPEQB X3, X3
+ PCLMULQDQ $1, X1, X0
+ PSRLDQ $8, X1
+ PXOR X0, X1
+
+ MOVOA X1, X2
+ MOVQ r5<>+0(SB), X0
+
+ /* Creates 32 bit mask. Note that we don't care about upper half. */
+ PSRLQ $32, X3
+
+ PSRLDQ $4, X2
+ PAND X3, X1
+ PCLMULQDQ $0, X0, X1
+ PXOR X2, X1
+
+ MOVOA rupoly<>+0(SB), X0
+
+ MOVOA X1, X2
+ PAND X3, X1
+ PCLMULQDQ $0x10, X0, X1
+ PAND X3, X1
+ PCLMULQDQ $0, X0, X1
+ PXOR X2, X1
+
+ PEXTRD $1, X1, AX
+ MOVL AX, ret+32(FP)
+
+ RET