+++ /dev/null
-/*
- * Calculate the checksum of data that is 16 byte aligned and a multiple of
- * 16 bytes.
- *
- * The first step is to reduce it to 1024 bits. We do this in 8 parallel
- * chunks in order to mask the latency of the vpmsum instructions. If we
- * have more than 32 kB of data to checksum we repeat this step multiple
- * times, passing in the previous 1024 bits.
- *
- * The next step is to reduce the 1024 bits to 64 bits. This step adds
- * 32 bits of 0s to the end - this matches what a CRC does. We just
- * calculate constants that land the data in this 32 bits.
- *
- * We then use fixed point Barrett reduction to compute a mod n over GF(2)
- * for n = CRC using POWER8 instructions. We use x = 32.
- *
- * http://en.wikipedia.org/wiki/Barrett_reduction
- *
- * Copyright (C) 2015 Anton Blanchard <anton@au.ibm.com>, IBM
- * Copyright (C) 2017 International Business Machines Corp.
- * All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- */
-#include <ppc-asm.h>
-#include "common/ppc-opcode.h"
-
-#undef toc
-
-#ifndef r1
-#define r1 1
-#endif
-
-#ifndef r2
-#define r2 2
-#endif
-
- .section .rodata
-.balign 16
-
-.byteswap_constant:
- /* byte reverse permute constant */
- .octa 0x0F0E0D0C0B0A09080706050403020100
-
-#define __ASSEMBLY__
-#include "crc32c_ppc_constants.h"
-
- .text
-
-#if defined(__BIG_ENDIAN__) && defined(REFLECT)
-#define BYTESWAP_DATA
-#elif defined(__LITTLE_ENDIAN__) && !defined(REFLECT)
-#define BYTESWAP_DATA
-#else
-#undef BYTESWAP_DATA
-#endif
-
-#define off16 r25
-#define off32 r26
-#define off48 r27
-#define off64 r28
-#define off80 r29
-#define off96 r30
-#define off112 r31
-
-#define const1 v24
-#define const2 v25
-
-#define byteswap v26
-#define mask_32bit v27
-#define mask_64bit v28
-#define zeroes v29
-
-#ifdef BYTESWAP_DATA
-#define VPERM(A, B, C, D) vperm A, B, C, D
-#else
-#define VPERM(A, B, C, D)
-#endif
-
-/* unsigned int __crc32_vpmsum(unsigned int crc, void *p, unsigned long len) */
-FUNC_START(__crc32_vpmsum)
- std r31,-8(r1)
- std r30,-16(r1)
- std r29,-24(r1)
- std r28,-32(r1)
- std r27,-40(r1)
- std r26,-48(r1)
- std r25,-56(r1)
-
- li off16,16
- li off32,32
- li off48,48
- li off64,64
- li off80,80
- li off96,96
- li off112,112
- li r0,0
-
- /* Enough room for saving 10 non volatile VMX registers */
- subi r6,r1,56+10*16
- subi r7,r1,56+2*16
-
- stvx v20,0,r6
- stvx v21,off16,r6
- stvx v22,off32,r6
- stvx v23,off48,r6
- stvx v24,off64,r6
- stvx v25,off80,r6
- stvx v26,off96,r6
- stvx v27,off112,r6
- stvx v28,0,r7
- stvx v29,off16,r7
-
- mr r10,r3
-
- vxor zeroes,zeroes,zeroes
- vspltisw v0,-1
-
- vsldoi mask_32bit,zeroes,v0,4
- vsldoi mask_64bit,zeroes,v0,8
-
- /* Get the initial value into v8 */
- vxor v8,v8,v8
- MTVRD(v8, r3)
-#ifdef REFLECT
- vsldoi v8,zeroes,v8,8 /* shift into bottom 32 bits */
-#else
- vsldoi v8,v8,zeroes,4 /* shift into top 32 bits */
-#endif
-
-#ifdef BYTESWAP_DATA
- addis r3,r2,.byteswap_constant@toc@ha
- addi r3,r3,.byteswap_constant@toc@l
-
- lvx byteswap,0,r3
- addi r3,r3,16
-#endif
-
- cmpdi r5,256
- blt .Lshort
-
- rldicr r6,r5,0,56
-
- /* Checksum in blocks of MAX_SIZE */
-1: lis r7,MAX_SIZE@h
- ori r7,r7,MAX_SIZE@l
- mr r9,r7
- cmpd r6,r7
- bgt 2f
- mr r7,r6
-2: subf r6,r7,r6
-
- /* our main loop does 128 bytes at a time */
- srdi r7,r7,7
-
- /*
- * Work out the offset into the constants table to start at. Each
- * constant is 16 bytes, and it is used against 128 bytes of input
- * data - 128 / 16 = 8
- */
- sldi r8,r7,4
- srdi r9,r9,3
- subf r8,r8,r9
-
- /* We reduce our final 128 bytes in a separate step */
- addi r7,r7,-1
- mtctr r7
-
- addis r3,r2,.constants@toc@ha
- addi r3,r3,.constants@toc@l
-
- /* Find the start of our constants */
- add r3,r3,r8
-
- /* zero v0-v7 which will contain our checksums */
- vxor v0,v0,v0
- vxor v1,v1,v1
- vxor v2,v2,v2
- vxor v3,v3,v3
- vxor v4,v4,v4
- vxor v5,v5,v5
- vxor v6,v6,v6
- vxor v7,v7,v7
-
- lvx const1,0,r3
-
- /*
- * If we are looping back to consume more data we use the values
- * already in v16-v23.
- */
- cmpdi r0,1
- beq 2f
-
- /* First warm up pass */
- lvx v16,0,r4
- lvx v17,off16,r4
- VPERM(v16,v16,v16,byteswap)
- VPERM(v17,v17,v17,byteswap)
- lvx v18,off32,r4
- lvx v19,off48,r4
- VPERM(v18,v18,v18,byteswap)
- VPERM(v19,v19,v19,byteswap)
- lvx v20,off64,r4
- lvx v21,off80,r4
- VPERM(v20,v20,v20,byteswap)
- VPERM(v21,v21,v21,byteswap)
- lvx v22,off96,r4
- lvx v23,off112,r4
- VPERM(v22,v22,v22,byteswap)
- VPERM(v23,v23,v23,byteswap)
- addi r4,r4,8*16
-
- /* xor in initial value */
- vxor v16,v16,v8
-
-2: bdz .Lfirst_warm_up_done
-
- addi r3,r3,16
- lvx const2,0,r3
-
- /* Second warm up pass */
- VPMSUMD(v8,v16,const1)
- lvx v16,0,r4
- VPERM(v16,v16,v16,byteswap)
- ori r2,r2,0
-
- VPMSUMD(v9,v17,const1)
- lvx v17,off16,r4
- VPERM(v17,v17,v17,byteswap)
- ori r2,r2,0
-
- VPMSUMD(v10,v18,const1)
- lvx v18,off32,r4
- VPERM(v18,v18,v18,byteswap)
- ori r2,r2,0
-
- VPMSUMD(v11,v19,const1)
- lvx v19,off48,r4
- VPERM(v19,v19,v19,byteswap)
- ori r2,r2,0
-
- VPMSUMD(v12,v20,const1)
- lvx v20,off64,r4
- VPERM(v20,v20,v20,byteswap)
- ori r2,r2,0
-
- VPMSUMD(v13,v21,const1)
- lvx v21,off80,r4
- VPERM(v21,v21,v21,byteswap)
- ori r2,r2,0
-
- VPMSUMD(v14,v22,const1)
- lvx v22,off96,r4
- VPERM(v22,v22,v22,byteswap)
- ori r2,r2,0
-
- VPMSUMD(v15,v23,const1)
- lvx v23,off112,r4
- VPERM(v23,v23,v23,byteswap)
-
- addi r4,r4,8*16
-
- bdz .Lfirst_cool_down
-
- /*
- * main loop. We modulo schedule it such that it takes three iterations
- * to complete - first iteration load, second iteration vpmsum, third
- * iteration xor.
- */
- .balign 16
-4: lvx const1,0,r3
- addi r3,r3,16
- ori r2,r2,0
-
- vxor v0,v0,v8
- VPMSUMD(v8,v16,const2)
- lvx v16,0,r4
- VPERM(v16,v16,v16,byteswap)
- ori r2,r2,0
-
- vxor v1,v1,v9
- VPMSUMD(v9,v17,const2)
- lvx v17,off16,r4
- VPERM(v17,v17,v17,byteswap)
- ori r2,r2,0
-
- vxor v2,v2,v10
- VPMSUMD(v10,v18,const2)
- lvx v18,off32,r4
- VPERM(v18,v18,v18,byteswap)
- ori r2,r2,0
-
- vxor v3,v3,v11
- VPMSUMD(v11,v19,const2)
- lvx v19,off48,r4
- VPERM(v19,v19,v19,byteswap)
- lvx const2,0,r3
- ori r2,r2,0
-
- vxor v4,v4,v12
- VPMSUMD(v12,v20,const1)
- lvx v20,off64,r4
- VPERM(v20,v20,v20,byteswap)
- ori r2,r2,0
-
- vxor v5,v5,v13
- VPMSUMD(v13,v21,const1)
- lvx v21,off80,r4
- VPERM(v21,v21,v21,byteswap)
- ori r2,r2,0
-
- vxor v6,v6,v14
- VPMSUMD(v14,v22,const1)
- lvx v22,off96,r4
- VPERM(v22,v22,v22,byteswap)
- ori r2,r2,0
-
- vxor v7,v7,v15
- VPMSUMD(v15,v23,const1)
- lvx v23,off112,r4
- VPERM(v23,v23,v23,byteswap)
-
- addi r4,r4,8*16
-
- bdnz 4b
-
-.Lfirst_cool_down:
- /* First cool down pass */
- lvx const1,0,r3
- addi r3,r3,16
-
- vxor v0,v0,v8
- VPMSUMD(v8,v16,const1)
- ori r2,r2,0
-
- vxor v1,v1,v9
- VPMSUMD(v9,v17,const1)
- ori r2,r2,0
-
- vxor v2,v2,v10
- VPMSUMD(v10,v18,const1)
- ori r2,r2,0
-
- vxor v3,v3,v11
- VPMSUMD(v11,v19,const1)
- ori r2,r2,0
-
- vxor v4,v4,v12
- VPMSUMD(v12,v20,const1)
- ori r2,r2,0
-
- vxor v5,v5,v13
- VPMSUMD(v13,v21,const1)
- ori r2,r2,0
-
- vxor v6,v6,v14
- VPMSUMD(v14,v22,const1)
- ori r2,r2,0
-
- vxor v7,v7,v15
- VPMSUMD(v15,v23,const1)
- ori r2,r2,0
-
-.Lsecond_cool_down:
- /* Second cool down pass */
- vxor v0,v0,v8
- vxor v1,v1,v9
- vxor v2,v2,v10
- vxor v3,v3,v11
- vxor v4,v4,v12
- vxor v5,v5,v13
- vxor v6,v6,v14
- vxor v7,v7,v15
-
-#ifdef REFLECT
- /*
- * vpmsumd produces a 96 bit result in the least significant bits
- * of the register. Since we are bit reflected we have to shift it
- * left 32 bits so it occupies the least significant bits in the
- * bit reflected domain.
- */
- vsldoi v0,v0,zeroes,4
- vsldoi v1,v1,zeroes,4
- vsldoi v2,v2,zeroes,4
- vsldoi v3,v3,zeroes,4
- vsldoi v4,v4,zeroes,4
- vsldoi v5,v5,zeroes,4
- vsldoi v6,v6,zeroes,4
- vsldoi v7,v7,zeroes,4
-#endif
-
- /* xor with last 1024 bits */
- lvx v8,0,r4
- lvx v9,off16,r4
- VPERM(v8,v8,v8,byteswap)
- VPERM(v9,v9,v9,byteswap)
- lvx v10,off32,r4
- lvx v11,off48,r4
- VPERM(v10,v10,v10,byteswap)
- VPERM(v11,v11,v11,byteswap)
- lvx v12,off64,r4
- lvx v13,off80,r4
- VPERM(v12,v12,v12,byteswap)
- VPERM(v13,v13,v13,byteswap)
- lvx v14,off96,r4
- lvx v15,off112,r4
- VPERM(v14,v14,v14,byteswap)
- VPERM(v15,v15,v15,byteswap)
-
- addi r4,r4,8*16
-
- vxor v16,v0,v8
- vxor v17,v1,v9
- vxor v18,v2,v10
- vxor v19,v3,v11
- vxor v20,v4,v12
- vxor v21,v5,v13
- vxor v22,v6,v14
- vxor v23,v7,v15
-
- li r0,1
- cmpdi r6,0
- addi r6,r6,128
- bne 1b
-
- /* Work out how many bytes we have left */
- andi. r5,r5,127
-
- /* Calculate where in the constant table we need to start */
- subfic r6,r5,128
- add r3,r3,r6
-
- /* How many 16 byte chunks are in the tail */
- srdi r7,r5,4
- mtctr r7
-
- /*
- * Reduce the previously calculated 1024 bits to 64 bits, shifting
- * 32 bits to include the trailing 32 bits of zeros
- */
- lvx v0,0,r3
- lvx v1,off16,r3
- lvx v2,off32,r3
- lvx v3,off48,r3
- lvx v4,off64,r3
- lvx v5,off80,r3
- lvx v6,off96,r3
- lvx v7,off112,r3
- addi r3,r3,8*16
-
- VPMSUMW(v0,v16,v0)
- VPMSUMW(v1,v17,v1)
- VPMSUMW(v2,v18,v2)
- VPMSUMW(v3,v19,v3)
- VPMSUMW(v4,v20,v4)
- VPMSUMW(v5,v21,v5)
- VPMSUMW(v6,v22,v6)
- VPMSUMW(v7,v23,v7)
-
- /* Now reduce the tail (0 - 112 bytes) */
- cmpdi r7,0
- beq 1f
-
- lvx v16,0,r4
- lvx v17,0,r3
- VPERM(v16,v16,v16,byteswap)
- VPMSUMW(v16,v16,v17)
- vxor v0,v0,v16
- bdz 1f
-
- lvx v16,off16,r4
- lvx v17,off16,r3
- VPERM(v16,v16,v16,byteswap)
- VPMSUMW(v16,v16,v17)
- vxor v0,v0,v16
- bdz 1f
-
- lvx v16,off32,r4
- lvx v17,off32,r3
- VPERM(v16,v16,v16,byteswap)
- VPMSUMW(v16,v16,v17)
- vxor v0,v0,v16
- bdz 1f
-
- lvx v16,off48,r4
- lvx v17,off48,r3
- VPERM(v16,v16,v16,byteswap)
- VPMSUMW(v16,v16,v17)
- vxor v0,v0,v16
- bdz 1f
-
- lvx v16,off64,r4
- lvx v17,off64,r3
- VPERM(v16,v16,v16,byteswap)
- VPMSUMW(v16,v16,v17)
- vxor v0,v0,v16
- bdz 1f
-
- lvx v16,off80,r4
- lvx v17,off80,r3
- VPERM(v16,v16,v16,byteswap)
- VPMSUMW(v16,v16,v17)
- vxor v0,v0,v16
- bdz 1f
-
- lvx v16,off96,r4
- lvx v17,off96,r3
- VPERM(v16,v16,v16,byteswap)
- VPMSUMW(v16,v16,v17)
- vxor v0,v0,v16
-
- /* Now xor all the parallel chunks together */
-1: vxor v0,v0,v1
- vxor v2,v2,v3
- vxor v4,v4,v5
- vxor v6,v6,v7
-
- vxor v0,v0,v2
- vxor v4,v4,v6
-
- vxor v0,v0,v4
-
-.Lbarrett_reduction:
- /* Barrett constants */
- addis r3,r2,.barrett_constants@toc@ha
- addi r3,r3,.barrett_constants@toc@l
-
- lvx const1,0,r3
- lvx const2,off16,r3
-
- vsldoi v1,v0,v0,8
- vxor v0,v0,v1 /* xor two 64 bit results together */
-
-#ifdef REFLECT
- /* shift left one bit */
- vspltisb v1,1
- vsl v0,v0,v1
-#endif
-
- vand v0,v0,mask_64bit
-
-#ifndef REFLECT
- /*
- * Now for the Barrett reduction algorithm. The idea is to calculate q,
- * the multiple of our polynomial that we need to subtract. By
- * doing the computation 2x bits higher (ie 64 bits) and shifting the
- * result back down 2x bits, we round down to the nearest multiple.
- */
- VPMSUMD(v1,v0,const1) /* ma */
- vsldoi v1,zeroes,v1,8 /* q = floor(ma/(2^64)) */
- VPMSUMD(v1,v1,const2) /* qn */
- vxor v0,v0,v1 /* a - qn, subtraction is xor in GF(2) */
-
- /*
- * Get the result into r3. We need to shift it left 8 bytes:
- * V0 [ 0 1 2 X ]
- * V0 [ 0 X 2 3 ]
- */
- vsldoi v0,v0,zeroes,8 /* shift result into top 64 bits */
-#else
- /*
- * The reflected version of Barrett reduction. Instead of bit
- * reflecting our data (which is expensive to do), we bit reflect our
- * constants and our algorithm, which means the intermediate data in
- * our vector registers goes from 0-63 instead of 63-0. We can reflect
- * the algorithm because we don't carry in mod 2 arithmetic.
- */
- vand v1,v0,mask_32bit /* bottom 32 bits of a */
- VPMSUMD(v1,v1,const1) /* ma */
- vand v1,v1,mask_32bit /* bottom 32bits of ma */
- VPMSUMD(v1,v1,const2) /* qn */
- vxor v0,v0,v1 /* a - qn, subtraction is xor in GF(2) */
-
- /*
- * Since we are bit reflected, the result (ie the low 32 bits) is in
- * the high 32 bits. We just need to shift it left 4 bytes
- * V0 [ 0 1 X 3 ]
- * V0 [ 0 X 2 3 ]
- */
- vsldoi v0,v0,zeroes,4 /* shift result into top 64 bits of */
-#endif
-
- /* Get it into r3 */
- MFVRD(r3, v0)
-
-.Lout:
- subi r6,r1,56+10*16
- subi r7,r1,56+2*16
-
- lvx v20,0,r6
- lvx v21,off16,r6
- lvx v22,off32,r6
- lvx v23,off48,r6
- lvx v24,off64,r6
- lvx v25,off80,r6
- lvx v26,off96,r6
- lvx v27,off112,r6
- lvx v28,0,r7
- lvx v29,off16,r7
-
- ld r31,-8(r1)
- ld r30,-16(r1)
- ld r29,-24(r1)
- ld r28,-32(r1)
- ld r27,-40(r1)
- ld r26,-48(r1)
- ld r25,-56(r1)
-
- blr
-
-.Lfirst_warm_up_done:
- lvx const1,0,r3
- addi r3,r3,16
-
- VPMSUMD(v8,v16,const1)
- VPMSUMD(v9,v17,const1)
- VPMSUMD(v10,v18,const1)
- VPMSUMD(v11,v19,const1)
- VPMSUMD(v12,v20,const1)
- VPMSUMD(v13,v21,const1)
- VPMSUMD(v14,v22,const1)
- VPMSUMD(v15,v23,const1)
-
- b .Lsecond_cool_down
-
-.Lshort:
- cmpdi r5,0
- beq .Lzero
-
- addis r3,r2,.short_constants@toc@ha
- addi r3,r3,.short_constants@toc@l
-
- /* Calculate where in the constant table we need to start */
- subfic r6,r5,256
- add r3,r3,r6
-
- /* How many 16 byte chunks? */
- srdi r7,r5,4
- mtctr r7
-
- vxor v19,v19,v19
- vxor v20,v20,v20
-
- lvx v0,0,r4
- lvx v16,0,r3
- VPERM(v0,v0,v16,byteswap)
- vxor v0,v0,v8 /* xor in initial value */
- VPMSUMW(v0,v0,v16)
- bdz .Lv0
-
- lvx v1,off16,r4
- lvx v17,off16,r3
- VPERM(v1,v1,v17,byteswap)
- VPMSUMW(v1,v1,v17)
- bdz .Lv1
-
- lvx v2,off32,r4
- lvx v16,off32,r3
- VPERM(v2,v2,v16,byteswap)
- VPMSUMW(v2,v2,v16)
- bdz .Lv2
-
- lvx v3,off48,r4
- lvx v17,off48,r3
- VPERM(v3,v3,v17,byteswap)
- VPMSUMW(v3,v3,v17)
- bdz .Lv3
-
- lvx v4,off64,r4
- lvx v16,off64,r3
- VPERM(v4,v4,v16,byteswap)
- VPMSUMW(v4,v4,v16)
- bdz .Lv4
-
- lvx v5,off80,r4
- lvx v17,off80,r3
- VPERM(v5,v5,v17,byteswap)
- VPMSUMW(v5,v5,v17)
- bdz .Lv5
-
- lvx v6,off96,r4
- lvx v16,off96,r3
- VPERM(v6,v6,v16,byteswap)
- VPMSUMW(v6,v6,v16)
- bdz .Lv6
-
- lvx v7,off112,r4
- lvx v17,off112,r3
- VPERM(v7,v7,v17,byteswap)
- VPMSUMW(v7,v7,v17)
- bdz .Lv7
-
- addi r3,r3,128
- addi r4,r4,128
-
- lvx v8,0,r4
- lvx v16,0,r3
- VPERM(v8,v8,v16,byteswap)
- VPMSUMW(v8,v8,v16)
- bdz .Lv8
-
- lvx v9,off16,r4
- lvx v17,off16,r3
- VPERM(v9,v9,v17,byteswap)
- VPMSUMW(v9,v9,v17)
- bdz .Lv9
-
- lvx v10,off32,r4
- lvx v16,off32,r3
- VPERM(v10,v10,v16,byteswap)
- VPMSUMW(v10,v10,v16)
- bdz .Lv10
-
- lvx v11,off48,r4
- lvx v17,off48,r3
- VPERM(v11,v11,v17,byteswap)
- VPMSUMW(v11,v11,v17)
- bdz .Lv11
-
- lvx v12,off64,r4
- lvx v16,off64,r3
- VPERM(v12,v12,v16,byteswap)
- VPMSUMW(v12,v12,v16)
- bdz .Lv12
-
- lvx v13,off80,r4
- lvx v17,off80,r3
- VPERM(v13,v13,v17,byteswap)
- VPMSUMW(v13,v13,v17)
- bdz .Lv13
-
- lvx v14,off96,r4
- lvx v16,off96,r3
- VPERM(v14,v14,v16,byteswap)
- VPMSUMW(v14,v14,v16)
- bdz .Lv14
-
- lvx v15,off112,r4
- lvx v17,off112,r3
- VPERM(v15,v15,v17,byteswap)
- VPMSUMW(v15,v15,v17)
-
-.Lv15: vxor v19,v19,v15
-.Lv14: vxor v20,v20,v14
-.Lv13: vxor v19,v19,v13
-.Lv12: vxor v20,v20,v12
-.Lv11: vxor v19,v19,v11
-.Lv10: vxor v20,v20,v10
-.Lv9: vxor v19,v19,v9
-.Lv8: vxor v20,v20,v8
-.Lv7: vxor v19,v19,v7
-.Lv6: vxor v20,v20,v6
-.Lv5: vxor v19,v19,v5
-.Lv4: vxor v20,v20,v4
-.Lv3: vxor v19,v19,v3
-.Lv2: vxor v20,v20,v2
-.Lv1: vxor v19,v19,v1
-.Lv0: vxor v20,v20,v0
-
- vxor v0,v19,v20
-
- b .Lbarrett_reduction
-
-.Lzero:
- mr r3,r10
- b .Lout
-
-FUNC_END(__crc32_vpmsum)
Code Review / stor4nfv.git / blobdiff