arch/arc/lib/memcpy-archs.S

   1 /*
   2  * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/linkage.h>
  10
  11 #ifdef __LITTLE_ENDIAN__
  12 # define SHIFT_1(RX,RY,IMM)     asl     RX, RY, IMM     ; <<
  13 # define SHIFT_2(RX,RY,IMM)     lsr     RX, RY, IMM     ; >>
  14 # define MERGE_1(RX,RY,IMM)     asl     RX, RY, IMM
  15 # define MERGE_2(RX,RY,IMM)
  16 # define EXTRACT_1(RX,RY,IMM)   and     RX, RY, 0xFFFF
  17 # define EXTRACT_2(RX,RY,IMM)   lsr     RX, RY, IMM
  18 #else
  19 # define SHIFT_1(RX,RY,IMM)     lsr     RX, RY, IMM     ; >>
  20 # define SHIFT_2(RX,RY,IMM)     asl     RX, RY, IMM     ; <<
  21 # define MERGE_1(RX,RY,IMM)     asl     RX, RY, IMM     ; <<
  22 # define MERGE_2(RX,RY,IMM)     asl     RX, RY, IMM     ; <<
  23 # define EXTRACT_1(RX,RY,IMM)   lsr     RX, RY, IMM
  24 # define EXTRACT_2(RX,RY,IMM)   lsr     RX, RY, 0x08
  25 #endif
  26
  27 #ifdef CONFIG_ARC_HAS_LL64
  28 # define PREFETCH_READ(RX)      prefetch    [RX, 56]
  29 # define PREFETCH_WRITE(RX)     prefetchw   [RX, 64]
  30 # define LOADX(DST,RX)          ldd.ab  DST, [RX, 8]
  31 # define STOREX(SRC,RX)         std.ab  SRC, [RX, 8]
  32 # define ZOLSHFT                5
  33 # define ZOLAND                 0x1F
  34 #else
  35 # define PREFETCH_READ(RX)      prefetch    [RX, 28]
  36 # define PREFETCH_WRITE(RX)     prefetchw   [RX, 32]
  37 # define LOADX(DST,RX)          ld.ab   DST, [RX, 4]
  38 # define STOREX(SRC,RX)         st.ab   SRC, [RX, 4]
  39 # define ZOLSHFT                4
  40 # define ZOLAND                 0xF
  41 #endif
  42
  43 ENTRY(memcpy)
  44         prefetch [r1]           ; Prefetch the read location
  45         prefetchw [r0]          ; Prefetch the write location
  46         mov.f   0, r2
  47 ;;; if size is zero
  48         jz.d    [blink]
  49         mov     r3, r0          ; don;t clobber ret val
  50
  51 ;;; if size <= 8
  52         cmp     r2, 8
  53         bls.d   @.Lsmallchunk
  54         mov.f   lp_count, r2
  55
  56         and.f   r4, r0, 0x03
  57         rsub    lp_count, r4, 4
  58         lpnz    @.Laligndestination
  59         ;; LOOP BEGIN
  60         ldb.ab  r5, [r1,1]
  61         sub     r2, r2, 1
  62         stb.ab  r5, [r3,1]
  63 .Laligndestination:
  64
  65 ;;; Check the alignment of the source
  66         and.f   r4, r1, 0x03
  67         bnz.d   @.Lsourceunaligned
  68
  69 ;;; CASE 0: Both source and destination are 32bit aligned
  70 ;;; Convert len to Dwords, unfold x4
  71         lsr.f   lp_count, r2, ZOLSHFT
  72         lpnz    @.Lcopy32_64bytes
  73         ;; LOOP START
  74         LOADX (r6, r1)
  75         PREFETCH_READ (r1)
  76         PREFETCH_WRITE (r3)
  77         LOADX (r8, r1)
  78         LOADX (r10, r1)
  79         LOADX (r4, r1)
  80         STOREX (r6, r3)
  81         STOREX (r8, r3)
  82         STOREX (r10, r3)
  83         STOREX (r4, r3)
  84 .Lcopy32_64bytes:
  85
  86         and.f   lp_count, r2, ZOLAND ;Last remaining 31 bytes
  87 .Lsmallchunk:
  88         lpnz    @.Lcopyremainingbytes
  89         ;; LOOP START
  90         ldb.ab  r5, [r1,1]
  91         stb.ab  r5, [r3,1]
  92 .Lcopyremainingbytes:
  93
  94         j       [blink]
  95 ;;; END CASE 0
  96
  97 .Lsourceunaligned:
  98         cmp     r4, 2
  99         beq.d   @.LunalignedOffby2
 100         sub     r2, r2, 1
 101
 102         bhi.d   @.LunalignedOffby3
 103         ldb.ab  r5, [r1, 1]
 104
 105 ;;; CASE 1: The source is unaligned, off by 1
 106         ;; Hence I need to read 1 byte for a 16bit alignment
 107         ;; and 2bytes to reach 32bit alignment
 108         ldh.ab  r6, [r1, 2]
 109         sub     r2, r2, 2
 110         ;; Convert to words, unfold x2
 111         lsr.f   lp_count, r2, 3
 112         MERGE_1 (r6, r6, 8)
 113         MERGE_2 (r5, r5, 24)
 114         or      r5, r5, r6
 115
 116         ;; Both src and dst are aligned
 117         lpnz    @.Lcopy8bytes_1
 118         ;; LOOP START
 119         ld.ab   r6, [r1, 4]
 120         prefetch [r1, 28]       ;Prefetch the next read location
 121         ld.ab   r8, [r1,4]
 122         prefetchw [r3, 32]      ;Prefetch the next write location
 123
 124         SHIFT_1 (r7, r6, 24)
 125         or      r7, r7, r5
 126         SHIFT_2 (r5, r6, 8)
 127
 128         SHIFT_1 (r9, r8, 24)
 129         or      r9, r9, r5
 130         SHIFT_2 (r5, r8, 8)
 131
 132         st.ab   r7, [r3, 4]
 133         st.ab   r9, [r3, 4]
 134 .Lcopy8bytes_1:
 135
 136         ;; Write back the remaining 16bits
 137         EXTRACT_1 (r6, r5, 16)
 138         sth.ab  r6, [r3, 2]
 139         ;; Write back the remaining 8bits
 140         EXTRACT_2 (r5, r5, 16)
 141         stb.ab  r5, [r3, 1]
 142
 143         and.f   lp_count, r2, 0x07 ;Last 8bytes
 144         lpnz    @.Lcopybytewise_1
 145         ;; LOOP START
 146         ldb.ab  r6, [r1,1]
 147         stb.ab  r6, [r3,1]
 148 .Lcopybytewise_1:
 149         j       [blink]
 150
 151 .LunalignedOffby2:
 152 ;;; CASE 2: The source is unaligned, off by 2
 153         ldh.ab  r5, [r1, 2]
 154         sub     r2, r2, 1
 155
 156         ;; Both src and dst are aligned
 157         ;; Convert to words, unfold x2
 158         lsr.f   lp_count, r2, 3
 159 #ifdef __BIG_ENDIAN__
 160         asl.nz  r5, r5, 16
 161 #endif
 162         lpnz    @.Lcopy8bytes_2
 163         ;; LOOP START
 164         ld.ab   r6, [r1, 4]
 165         prefetch [r1, 28]       ;Prefetch the next read location
 166         ld.ab   r8, [r1,4]
 167         prefetchw [r3, 32]      ;Prefetch the next write location
 168
 169         SHIFT_1 (r7, r6, 16)
 170         or      r7, r7, r5
 171         SHIFT_2 (r5, r6, 16)
 172
 173         SHIFT_1 (r9, r8, 16)
 174         or      r9, r9, r5
 175         SHIFT_2 (r5, r8, 16)
 176
 177         st.ab   r7, [r3, 4]
 178         st.ab   r9, [r3, 4]
 179 .Lcopy8bytes_2:
 180
 181 #ifdef __BIG_ENDIAN__
 182         lsr.nz  r5, r5, 16
 183 #endif
 184         sth.ab  r5, [r3, 2]
 185
 186         and.f   lp_count, r2, 0x07 ;Last 8bytes
 187         lpnz    @.Lcopybytewise_2
 188         ;; LOOP START
 189         ldb.ab  r6, [r1,1]
 190         stb.ab  r6, [r3,1]
 191 .Lcopybytewise_2:
 192         j       [blink]
 193
 194 .LunalignedOffby3:
 195 ;;; CASE 3: The source is unaligned, off by 3
 196 ;;; Hence, I need to read 1byte for achieve the 32bit alignment
 197
 198         ;; Both src and dst are aligned
 199         ;; Convert to words, unfold x2
 200         lsr.f   lp_count, r2, 3
 201 #ifdef __BIG_ENDIAN__
 202         asl.ne  r5, r5, 24
 203 #endif
 204         lpnz    @.Lcopy8bytes_3
 205         ;; LOOP START
 206         ld.ab   r6, [r1, 4]
 207         prefetch [r1, 28]       ;Prefetch the next read location
 208         ld.ab   r8, [r1,4]
 209         prefetchw [r3, 32]      ;Prefetch the next write location
 210
 211         SHIFT_1 (r7, r6, 8)
 212         or      r7, r7, r5
 213         SHIFT_2 (r5, r6, 24)
 214
 215         SHIFT_1 (r9, r8, 8)
 216         or      r9, r9, r5
 217         SHIFT_2 (r5, r8, 24)
 218
 219         st.ab   r7, [r3, 4]
 220         st.ab   r9, [r3, 4]
 221 .Lcopy8bytes_3:
 222
 223 #ifdef __BIG_ENDIAN__
 224         lsr.nz  r5, r5, 24
 225 #endif
 226         stb.ab  r5, [r3, 1]
 227
 228         and.f   lp_count, r2, 0x07 ;Last 8bytes
 229         lpnz    @.Lcopybytewise_3
 230         ;; LOOP START
 231         ldb.ab  r6, [r1,1]
 232         stb.ab  r6, [r3,1]
 233 .Lcopybytewise_3:
 234         j       [blink]
 235
 236 END(memcpy)