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[/] [openrisc/] [trunk/] [gnu-src/] [newlib-1.17.0/] [newlib/] [libc/] [machine/] [hppa/] [strncmp.S] - Blame information for rev 158

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1 148 jeremybenn
/*
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 *  (c) Copyright 1986 HEWLETT-PACKARD COMPANY
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 *
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 *  To anyone who acknowledges that this file is provided "AS IS"
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 *  without any express or implied warranty:
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 *      permission to use, copy, modify, and distribute this file
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 *  for any purpose is hereby granted without fee, provided that
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 *  the above copyright notice and this notice appears in all
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 *  copies, and that the name of Hewlett-Packard Company not be
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 *  used in advertising or publicity pertaining to distribution
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 *  of the software without specific, written prior permission.
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 *  Hewlett-Packard Company makes no representations about the
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 *  suitability of this software for any purpose.
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 */
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/* strcmp(s1, s2) */
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/* returns integer: < 0 iff s1 lexicographically less than s2 */
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/*                  > 0 iff s1 lexicographically greater than s2 */
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/*                  = 0 iff s1 lexicographically equal to s2 */
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/*                  = 0 iff s1 lexicographically equal to s2 */
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/*                  quit after n charachters */
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#include "DEFS.h"
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#define s1        26
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#define s2        25
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#define tmp1      19
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#define s2word    20
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#define tmp3      21
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#define tmp7      22
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#define s1word    29
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#define save       1
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#define tmp6      23
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#define tmp5      28
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#define count     24
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ENTRY(strncmp)
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        combt,<,n       r0,count,search /* N <= 0 yields equality */
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        bv      r0(rp)                  /* */
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        copy    0,ret0                  /* return 0 (DELAY SLOT) */
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search: combf,=,n       s1,s2,findout   /* s1 != s2? */
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        bv      r0(rp)                  /* */
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        copy    0,ret0                  /* return 0 (delay slot)         */
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findout:
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        comibf,=,n      0,s1,checks1    /* s1 == NULL?   */
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        ldbs    0(0,s2),ret0            /* */
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        bv      r0(rp)                  /* */
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        subi    0,ret0,ret0             /* ret0 <- -*s2 */
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checks1:
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        comibf,=,n      0,s2,checkitout /* s2 == NULL?   */
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        bv      r0(rp)                  /* */
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        ldbs    0(0,s1),28              /* return *s1 */
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checkitout:
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        extru   s2,31,2,tmp1            /* Extract the low two bits of the s2. */
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        extru   s1,31,2,tmp5            /* Extract the low two bits of the s1 */
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        sub,=   tmp5,tmp1,tmp3          /* Are s1 & s2 aligned with each other? */
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        b       not_aligned             /* It's more complicated (not_aligned) */
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        dep     0,31,2,s1               /* Compute word address of s1 (DELAY SLOT) */
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        dep     0,31,2,s2               /* Compute word address of s2 */
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        ldwm    4(0,s1),s1word          /* get next s1 word  s1+=4 */
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        combt,= tmp5,r0,skipmask        /* skip masking, if we can */
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        ldwm    4(0,s2),s2word          /* get next s2 word  s2+=4 (DELAY SLOT) */
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        add     tmp5,count,count        /* bump count by the number of bytes */
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                                        /*  we are going to mask */
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        sh3add  tmp5,r0,save            /* save now has number of bits to mask */
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        mtctl   save,11
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        zvdepi  -2,32,save              /* load save with proper mask */
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        or      save,s1word,s1word      /* mask s1word (s1) */
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        or      save,s2word,s2word      /* mask s2word (s2) */
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skipmask:
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        combt,=,n       s1word,s2word,chknulls  /* are these words equal? */
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checkbyte:
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        extru   s1word,7,8,tmp3         /* get first byte (character) */
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ckbyte2:        extru   s2word,7,8,tmp7         /* get first byte (character) */
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        combf,= tmp3,tmp7,done          /* quit if first byte is not equal */
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        sub     tmp3,tmp7,ret0          /* return difference (delay slot) */
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        comibt,=,n      0,tmp3,done     /* have we reached the end of string */
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                                        /* if so done ret0 already has zero */
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        addibt,<=,n     -1,count,done   /* have we checked N chars? ret0 == 0 */
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        extru   s1word,15,8,tmp3        /* get second byte (character) */
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        extru   s2word,15,8,tmp7        /* get second byte (character)   */
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        combf,= tmp3,tmp7,done          /* quit if second byte is not equal */
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        sub     tmp3,tmp7,ret0          /* return difference (delay slot) */
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        comibt,=,n      0,tmp3,done     /* have we reached the end of string */
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                                        /* if so done ret0 already has zero */
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        addibt,<=,n     -1,count,done   /* have we checked N chars? */
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        extru   s1word,23,8,tmp3        /* get third byte (character) */
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        extru   s2word,23,8,tmp7        /* get third byte (character)    */
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        combf,= tmp3,tmp7,done          /* done if third byte is not equal */
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        sub     tmp3,tmp7,ret0          /* return difference (delay slot) */
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        comibt,=,n      0,tmp3,done     /* have we reached the end of string */
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                                        /* if so done ret0 already has zero */
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        addibt,<=,n     -1,count,done   /* have we checked N chars? */
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        extru   s1word,31,8,tmp3        /* get last byte (character) */
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        extru   s2word,31,8,tmp7        /* get last byte (character)     */
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        bv      r0(rp)                  /* */
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        sub     tmp3,tmp7,ret0          /*  the last characters in the word is */
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                                        /*   where the  difference is, so return */
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                                        /*    the difference and we're outta here */
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chknulls:
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        addibt,<=,n     -4,count,zero   /* have we checked N chars? */
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        uxor,nbz        s1word,0,0      /* don't have to check s2   Just quit */
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        bv      r0(rp)                  /* */
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        copy    0,28                    /* return 0 */
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        ldwm    4(0,s2),s2word          /* get next s2 word  s2+=4 */
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        b       skipmask                /* keep checking */
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        ldwm    4(0,s1),s1word          /* get next s1 word  s1+=4 */
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not_aligned:
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        dep     r0,31,2,s2              /* Compute word address of s2 */
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        combt,<,n       r0,tmp3,shifts1 /* Do we shift s1 or s2 */
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        sh3add  tmp3,r0,tmp3            /* eight bits per byte so mul by 8 */
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        ldwm    4(0,s1),s1word          /* get first word of s1 */
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        ldwm    4(0,s2),s2word          /* get first word or s2 */
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        combt,=,n       r0,tmp5,masks2  /* Do we need to mask beginning of s1 */
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        add     tmp5,count,count        /* bump count by the number of bytes */
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                                        /*  we are going to mask */
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        sh3add  tmp5,r0,save            /* save now has number of bits to mask */
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        mtctl   save,11
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        zvdepi  -2,32,save              /* load save with proper mask */
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        or      save,s1word,s1word      /* */
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masks2: sh3add  tmp1,r0,save            /* save now has number of bits to mask */
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        mtctl   save,11
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        zvdepi  -2,32,save              /* load save with proper mask */
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        or      save,s2word,s2word      /* */
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        mtctl   tmp3,11                 /* Move shift amount to CR11 */
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more:   uxor,nbz        s2word,r0,r0            /* Is there a null in first word         */
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        b,n     chunk1                  /* */
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        ldwm    4(0,s2),tmp7            /* load second word to enable us to shift */
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        vshd    s2word,tmp7,s2word      /* */
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        combf,=,n       s1word,s2word,ckbyte2   /* */
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        extru   s1word,7,8,tmp3         /* get first byte (DELAY SLOT) */
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        addibt,<=,n     -4,count,zero   /* have we checked N chars? */
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        uxor,nbz        s1word,0,0      /* even though they're equal we could be done */
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        b,n     zero
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        copy    tmp7,s2word             /* */
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        b       more                    /* keep checking */
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        ldwm    4(0,s1),s1word          /* get next s1 (DELAY SLOT) */
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chunk1:
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        vshd    s2word,r0,s2word        /* */
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        b       ckbyte2                 /* */
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        extru   s1word,7,8,tmp3         /* */
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shifts1:
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        sh3add  tmp3,r0,tmp3            /* eight bits per byte so mul by 4 */
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        sub     r0,tmp3,tmp3            /* Get negative value for left shift */
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        ldwm    4(0,s2),s2word          /* get first word of s2 */
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        ldwm    4(0,s1),s1word          /* get first word or s1 */
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        combt,=,n       r0,tmp1,masks1  /* Do we need to mask beginning of s2 */
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        add     tmp1,count,count        /* bump count by the number of bytes */
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                                        /*  we are going to mask */
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        sh3add  tmp1,r0,save            /* save now has number of bits to mask */
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        mtctl   save,11
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        zvdepi  -2,32,save              /* load save with proper mask */
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        or      save,s2word,s2word      /* */
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masks1: sh3add  tmp5,r0,save            /* save now has number of bits to mask */
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        mtctl   save,11
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        zvdepi  -2,32,save              /* load save with proper mask */
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        or      save,s1word,s1word      /* */
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        mtctl   tmp3,11                 /* Move shift amount to CR11 */
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more1:  uxor,nbz        s1word,r0,r0            /* Is there a null in first byte         */
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        b,n     chunk2                  /* */
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        ldwm    4(0,s1),tmp7            /* load second word to enable us to shift */
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        vshd    s1word,tmp7,s1word      /* */
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        combf,=,n       s2word,s1word,ckbyte2   /* */
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        extru   s1word,7,8,tmp3         /* get first byte (DELAY SLOT) */
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        addibt,<=,n     -4,count,zero   /* have we checked N chars? */
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        uxor,nbz        s2word,0,0      /* even though they're equal we could be done */
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        b,n     zero                    /* zero ret0 and quit */
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        copy    tmp7,s1word             /* */
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        b       more1                   /* keep checking */
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        ldwm    4(0,s2),s2word          /* get next s2 (DELAY SLOT) */
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chunk2:
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        vshd    s1word,r0,s1word        /* */
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        b       ckbyte2                 /* */
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        extru   s1word,7,8,tmp3         /* */
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zero:   copy    r0,ret0
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done:
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EXIT(strncmp)

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