toolchain/gcc/newlib/libc/machine/sh/strcmp.S

   1 ! SH5 code Copyright 2002 SuperH Ltd.
   2
   3 #include "asm.h"
   4
   5 ENTRY(strcmp)
   6
   7 #if __SHMEDIA__
   8         ld.ub   r2,0,r4
   9         pt/l    quickret0,tr0
  10         ld.ub   r3,0,r5
  11         ptabs   r18,tr2
  12         beqi/u  r4,0,tr0
  13         ld.ub   r2,1,r6
  14         bne/u   r4,r5,tr0
  15         pt/l    quickret1,tr1
  16         ld.ub   r3,1,r7
  17         beqi/u  r6,0,tr1
  18         ld.ub   r2,2,r4
  19         bne/u   r6,r7,tr1
  20         ld.ub   r3,2,r5
  21         beqi/u  r4,0,tr0
  22         ld.ub   r2,3,r6
  23         bne/u   r4,r5,tr0
  24         ld.ub   r3,3,r7
  25         beqi/u  r6,0,tr1
  26         ld.ub   r2,4,r4
  27         bne/u   r6,r7,tr1
  28         ld.ub   r3,4,r5
  29         beqi/u  r4,0,tr0
  30         ld.ub   r2,5,r6
  31         bne/u   r4,r5,tr0
  32         ld.ub   r3,5,r7
  33         beqi/u  r6,0,tr1
  34         ld.ub   r2,6,r4
  35         bne/u   r6,r7,tr1
  36         ld.ub   r3,6,r5
  37         beqi/u  r4,0,tr0
  38         ld.ub   r2,7,r6
  39         bne/u   r4,r5,tr0
  40         ld.ub   r3,7,r7
  41         beqi/u  r6,0,tr1
  42         sub     r3,r2,r3
  43         bne/u   r6,r7,tr1
  44
  45         andi    r2,-8,r2
  46         add     r3,r2,r3
  47         ldlo.q  r3,8,r23
  48         pt      r23_zero,tr0
  49         shlli   r3,3,r22
  50         sub     r63,r22,r20
  51         movi    0x101,r6
  52         mperm.w r6,r63,r6
  53         SHLO    r6,r22,r7
  54         msubs.ub r7,r23,r8
  55         pt      loop,tr1
  56         bnei/u  r8,0,tr0 // r23_zero
  57         pt      found_zero,tr0
  58         addi    r3,15,r3
  59         andi    r3,-8,r3
  60         sub     r3,r2,r3
  61         bne/l   r7,r6,tr1 // loop
  62         /* The strings are aligned to each other.  */
  63         /* It is possible to have a loop with six cycles / iteration
  64            by re-ordering the exit conditions, but then it needs extra
  65            time and/or code to sort out the r4 != r5 case.  */
  66         pt      al_loop,tr1
  67         pt      al_found_zero,tr0
  68 al_loop:
  69         ld.q    r2,8,r4
  70         ldx.q   r2,r3,r5
  71         addi    r2,8,r2
  72         mcmpeq.b r63,r4,r8
  73         pt      cmp_quad,tr3
  74         bnei/u  r8,0,tr0  // al_found_zero
  75         beq/l   r4,r5,tr1 // al_loop
  76         blink   tr3,r63   // cmp_quad
  77
  78         .balign 8
  79 quickret0:
  80         sub     r4,r5,r2
  81         blink   tr2,r63
  82 quickret1:
  83         sub     r6,r7,r2
  84         blink   tr2,r63
  85
  86 loop:
  87         ld.q    r2,8,r4
  88         ldx.q   r2,r3,r19
  89         addi    r2,8,r2
  90         msubs.ub r6,r4,r8
  91         mcmpeq.b r63,r19,r9
  92         SHHI    r19,r20,r21
  93         or      r21,r23,r5
  94         SHLO    r19,r22,r23
  95         bne/u   r8,r9,tr0 // found_zero
  96         beq/l   r4,r5,tr1 // loop
  97 cmp_quad:
  98 #ifdef __LITTLE_ENDIAN__
  99         byterev r4,r4
 100         byterev r5,r5
 101 #endif
 102         cmpgtu  r4,r5,r6
 103         cmpgtu  r5,r4,r7
 104         sub     r6,r7,r2
 105         blink tr2,r63
 106 found_zero:
 107         pt      zero_now,tr0
 108         pt      cmp_quad,tr1
 109         SHHI    r9,r20,r7
 110         bne/u   r8,r7,tr0 // zero_now
 111         bne/u   r4,r5,tr1 // cmp_quad
 112         SHLO    r9,r22,r8
 113 r23_zero:
 114         ld.q    r2,8,r4
 115         add     r23,r63,r5
 116 zero_now:
 117 al_found_zero:
 118 /* We konw that one of the values has at lest one zero, and r8 holds
 119    an 0x01 or 0xff mask for every zero found in one of the operands.
 120    If both operands have the first zero in the same place, this mask
 121    allows us to truncate the comparison to the valid bytes in the
 122    strings.  If the first zero is in different places, it doesn't
 123    matter if some invalid bytes are included, since the comparison
 124    of the zero with the non-zero will determine the outcome.  */
 125 #ifdef __LITTLE_ENDIAN__
 126         shlli   r8,8,r8
 127         addi    r8,-1,r9
 128         andc    r9,r8,r8
 129         and     r8,r4,r4
 130         and     r8,r5,r5
 131 #else
 132         shlri r8,1,r8
 133         nsb     r8,r8
 134         addi    r8,8,r8
 135         andi    r8,56,r8
 136         sub     r63,r8,r8
 137         shlrd   r4,r8,r4
 138         shlrd   r5,r8,r5
 139 #endif
 140 #ifdef __LITTLE_ENDIAN__
 141         byterev r4,r4
 142         byterev r5,r5
 143 #endif
 144         cmpgtu  r4,r5,r6
 145         cmpgtu  r5,r4,r7
 146         sub     r6,r7,r2
 147         blink tr2,r63
 148
 149 #else /* ! __SHMEDIA__, i.e. SH 1..4 / SHcompact */
 150
 151 #ifdef __SH5__
 152 #define STR1 r2
 153 #define STR2 r3
 154 #define RESULT r2
 155 #define TMP r4
 156 #else
 157 ! Entry: r4: string1
 158 !        r5: string2
 159 ! Exit:  r0: result
 160 !        r1-r2,r4-r5: clobbered
 161 #define STR1 r4
 162 #define STR2 r5
 163 #define RESULT r0
 164 #define TMP r2
 165 #endif /* __SH5__ */
 166
 167         mov     STR1,r0
 168         or      STR2,r0
 169         tst     #3,r0
 170         bf      L_setup_char_loop
 171         mov     #0,r0
 172 #ifdef DELAYED_BRANCHES
 173         mov.l   @STR1+,r1
 174         .align  2
 175 Longword_loop:
 176         mov.l   @STR2+,TMP
 177         cmp/str r0,r1
 178         bt      Longword_loop_end
 179         cmp/eq  r1,TMP
 180         bt.s    Longword_loop
 181         mov.l   @STR1+,r1
 182         add #-4, STR1
 183 Longword_loop_end:
 184         add #-4, STR1
 185         add #-4, STR2
 186 L_setup_char_loop:
 187         mov.b   @STR1+,r0
 188         .align  2
 189 L_char_loop:
 190         mov.b   @STR2+,r1
 191         tst     r0,r0
 192         bt      L_return
 193         cmp/eq  r0,r1
 194         bt.s L_char_loop
 195         mov.b   @STR1+,r0
 196         add     #-2,STR1
 197         mov.b   @STR1,r0
 198 #else /* ! DELAYED_BRANCHES */
 199         .align  2
 200 Longword_loop:
 201         mov.l   @r4+,r1
 202         mov.l   @r5+,r2
 203         cmp/str r0,r1
 204         bt      Longword_loop_end
 205         cmp/eq  r1,r2
 206         bt      Longword_loop
 207 Longword_loop_end:
 208         add #-4, r4
 209         add #-4, r5
 210         .align  2
 211 L_setup_char_loop:
 212 L_char_loop:
 213         mov.b   @r4+,r0
 214         mov.b   @r5+,r1
 215         tst     r0,r0
 216         bt      L_return
 217         cmp/eq  r0,r1
 218         bt L_char_loop
 219 #endif
 220 L_return:
 221         extu.b  r0,RESULT
 222         extu.b  r1,r1
 223         rts
 224         sub     r1,RESULT
 225 #endif /* ! __SHMEDIA__ */