arch/arc/lib/memcmp.S

   1 /*
   2  * Copyright (C) 2004, 2007-2010, 2011-2014 Synopsys, Inc. All rights reserved.
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #ifdef __LITTLE_ENDIAN__
   8 #define WORD2 r2
   9 #define SHIFT r3
  10 #else /* __BIG_ENDIAN__ */
  11 #define WORD2 r3
  12 #define SHIFT r2
  13 #endif /* _ENDIAN__ */
  14
  15 .global memcmp
  16 .align 4
  17 memcmp:
  18         or      %r12, %r0, %r1
  19         asl_s   %r12, %r12, 30
  20         sub     %r3, %r2, 1
  21         brls    %r2, %r12, .Lbytewise
  22         ld      %r4, [%r0, 0]
  23         ld      %r5, [%r1, 0]
  24         lsr.f   %lp_count, %r3, 3
  25         lpne    .Loop_end
  26         ld_s    WORD2, [%r0, 4]
  27         ld_s    %r12, [%r1, 4]
  28         brne    %r4, %r5, .Leven
  29         ld.a    %r4, [%r0, 8]
  30         ld.a    %r5, [%r1, 8]
  31         brne    WORD2, %r12, .Lodd
  32         nop
  33 .Loop_end:
  34         asl_s   SHIFT, SHIFT, 3
  35         bhs_s   .Last_cmp
  36         brne    %r4, %r5, .Leven
  37         ld      %r4, [%r0, 4]
  38         ld      %r5, [%r1, 4]
  39 #ifdef __LITTLE_ENDIAN__
  40         nop_s
  41         /* one more load latency cycle */
  42 .Last_cmp:
  43         xor     %r0, %r4, %r5
  44         bset    %r0, %r0, SHIFT
  45         sub_s   %r1, %r0, 1
  46         bic_s   %r1, %r1, %r0
  47         norm    %r1, %r1
  48         b.d     .Leven_cmp
  49         and     %r1, %r1, 24
  50 .Leven:
  51         xor     %r0, %r4, %r5
  52         sub_s   %r1, %r0, 1
  53         bic_s   %r1, %r1, %r0
  54         norm    %r1, %r1
  55         /* slow track insn */
  56         and     %r1, %r1, 24
  57 .Leven_cmp:
  58         asl     %r2, %r4, %r1
  59         asl     %r12, %r5, %r1
  60         lsr_s   %r2, %r2, 1
  61         lsr_s   %r12, %r12, 1
  62         j_s.d   [%blink]
  63         sub     %r0, %r2, %r12
  64         .balign 4
  65 .Lodd:
  66         xor     %r0, WORD2, %r12
  67         sub_s   %r1, %r0, 1
  68         bic_s   %r1, %r1, %r0
  69         norm    %r1, %r1
  70         /* slow track insn */
  71         and     %r1, %r1, 24
  72         asl_s   %r2, %r2, %r1
  73         asl_s   %r12, %r12, %r1
  74         lsr_s   %r2, %r2, 1
  75         lsr_s   %r12, %r12, 1
  76         j_s.d   [%blink]
  77         sub     %r0, %r2, %r12
  78 #else /* __BIG_ENDIAN__ */
  79 .Last_cmp:
  80         neg_s   SHIFT, SHIFT
  81         lsr     %r4, %r4, SHIFT
  82         lsr     %r5, %r5, SHIFT
  83         /* slow track insn */
  84 .Leven:
  85         sub.f   %r0, %r4, %r5
  86         mov.ne  %r0, 1
  87         j_s.d   [%blink]
  88         bset.cs %r0, %r0, 31
  89 .Lodd:
  90         cmp_s   WORD2, %r12
  91
  92         mov_s   %r0, 1
  93         j_s.d   [%blink]
  94         bset.cs %r0, %r0, 31
  95 #endif /* _ENDIAN__ */
  96         .balign 4
  97 .Lbytewise:
  98         breq    %r2, 0, .Lnil
  99         ldb     %r4, [%r0, 0]
 100         ldb     %r5, [%r1, 0]
 101         lsr.f   %lp_count, %r3
 102         lpne    .Lbyte_end
 103         ldb_s   %r3, [%r0, 1]
 104         ldb     %r12, [%r1, 1]
 105         brne    %r4, %r5, .Lbyte_even
 106         ldb.a   %r4, [%r0, 2]
 107         ldb.a   %r5, [%r1, 2]
 108         brne    %r3, %r12, .Lbyte_odd
 109         nop
 110 .Lbyte_end:
 111         bcc     .Lbyte_even
 112         brne    %r4, %r5, .Lbyte_even
 113         ldb_s   %r3, [%r0, 1]
 114         ldb_s   %r12, [%r1, 1]
 115 .Lbyte_odd:
 116         j_s.d   [%blink]
 117         sub     %r0, %r3, %r12
 118 .Lbyte_even:
 119         j_s.d   [%blink]
 120         sub     %r0, %r4, %r5
 121 .Lnil:
 122         j_s.d   [%blink]
 123         mov     %r0, 0