Preview: crc32_amd64.s
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/proc/thread-self/root/opt/golang/1.22.0/src/hash/crc32/crc32_amd64.s
// 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
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