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[/] [openrisc/] [trunk/] [gnu-src/] [newlib-1.17.0/] [newlib/] [libc/] [machine/] [hppa/] [strcmp.S] - Blame information for rev 171

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Line No. Rev Author Line
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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/*
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        strcmp
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20
        Jerry Huck
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        Edgar Circenis
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*/
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/*
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 * strcmp(s1, s2)
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 *
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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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 */
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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   23
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#define save      1
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#define tmp6     24
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#define tmp5     28
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ENTRY(strcmp)
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        comb,=,n   s1,s2,samestring
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        comib,=,n  0,s1,s1isnull
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        comib,=,n  0,s2,s2isnull
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/* Hope for word alignment.  Pick up low two bits of each adress */
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        extru,<>   s1,31,2,tmp1
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        ldwm       4(s1),s1word
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        dep,=      s2,29,2,tmp1
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        b,n        case_analysis
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/* Start looping until null is found in s1 or they mis-compare */
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loop:
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        ldwm       4(s2),s2word
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loop_plus:
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        uxor,nbz   s1word,r0,r0   /* Null in this? */
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        b,n        nullins1
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        comb,=,n   s1word,s2word,loop
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        ldwm       4(s1),s1word
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/* The words do not compare equal and s1 does not have a null.
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   Need to treat words as unsigned and generate either a positive
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   or negative return value */
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wordcomparereturn:
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        comclr,>>  s1word,s2word,ret0    /*Set ret0 to 0 and skip if greater*/
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        ldi        -2,ret0           /*Set ret0 to -2 when less */
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        bv         r0(rp)
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        addi       1,ret0,ret0           /*Fix return value to be -1 or +1 */
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/* s1 has a null.  s2 has not been checked. */
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nullins1:
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        /*If s2 has no nulls this is simple, but assume that it might
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          and fix up s1 to allow the word comparision to work by
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          scanning s1 and duplicating all the bytes in s2 below that byte into
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          the remainder of s1.  A remainder only exists if the zero byte
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          is found in the upper three bytes */
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        extru,<>   s1word,7,8,r0         /*in the first byte? */
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        dep,tr     s2word,31,24,s1word   /*copy low 3 bytes of *s2 into *s1 */
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        extru,<>   s1word,15,8,r0         /*in the second byte? */
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        dep,tr     s2word,31,16,s1word   /*copy low 2 bytes of *s2 into *s1 */
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        extru,<>   s1word,23,8,r0         /*in the third byte? */
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        dep        s2word,31,8,s1word   /*copy low 1 byte of *s2 into *s1 */
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        /* Do the normal unsigned compare and return */
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        comclr,<>  s1word,s2word,ret0    /*Set ret0 to 0 and skip if not equal */
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        bv,n       r0(rp)
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        comclr,>>  s1word,s2word,ret0    /*Set ret0 to 0 and skip if greater*/
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        ldi        -2,ret0           /*Set ret0 to -2 when less */
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        bv         r0(rp)
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        addi       1,ret0,ret0           /*Fix return value to be -1 or +1 */
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/* s1 and s2 are the same string and therefore equal */
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samestring:
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        bv      r0(rp)
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        copy    r0,ret0
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/* s1 is null.  Treat as string of nulls.  Therefore return
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   the negative of s2's first byte.  s2 cannot be zero. */
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s1isnull:
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        ldbs    0(0,s2),ret0
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        bv      r0(rp)
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        sub     0,ret0,ret0
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/* s2 is null.  Treat as string of nulls.  Therefore return
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   s1's first byte.  s1 cannot be zero. */
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s2isnull:
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        bv      r0(rp)
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        ldbs    0(0,s1),ret0
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110
case_analysis:
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        blr     tmp1,r0
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        nop
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        /*
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           Case statement for non-aligned cases (we've already
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           checked the aligned case.
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           NOTE: for non-aligned cases, the absolute shift value
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           gets loaded into tmp3.
119
        */
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121
                                /* S2 S1 */
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        nop                     /* 00 00 can't happen */
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        nop
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        b       shifts2         /* 00 01 */
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        ldi     8,tmp3          /* load shift count (delay slot) */
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        b       shifts2         /* 00 10 */
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        ldi     16,tmp3         /* load shift count (delay slot) */
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        b       shifts2         /* 00 11 */
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        ldi     24,tmp3         /* load shift count (delay slot) */
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        b       shifts1_0       /* 01 00 */
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        ldi     8,tmp3          /* load shift count (delay slot) */
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        b       eq_align1       /* 01 01 */
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        ldbs,ma 1(s1),s1word
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        b       shifts2         /* 01 10 */
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        ldi     8,tmp3          /* load shift count (delay slot) */
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        b       shifts2         /* 01 11 */
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        ldi     16,tmp3         /* load shift count (delay slot) */
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        b       shifts1_0       /* 10 00 */
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        ldi     16,tmp3         /* load shift count (delay slot) */
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        b       shifts1         /* 10 01 */
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        ldi     8,tmp3          /* load shift count (delay slot) */
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        b       eq_align2       /* 10 10 */
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        ldhs,ma 2(s1),s1word
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        b       shifts2         /* 10 11 */
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        ldi     8,tmp3          /* load shift count (delay slot) */
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        b       shifts1_0       /* 11 00 */
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        ldi     24,tmp3         /* load shift count (delay slot) */
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        b       shifts1         /* 11 01 */
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        ldi     16,tmp3         /* load shift count (delay slot) */
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        b       shifts1         /* 11 10 */
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        ldi     8,tmp3          /* load shift count (delay slot) */
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        ldbs,ma 1(s1),s1word    /* 11 11 */
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        ldbs,ma 1(s2),s2word
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        sub,=   s1word,s2word,ret0      /* if not equal, we can return now */
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        bv,n    r0(rp)
156
        comclr,<>       s1word,r0,ret0
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        bv,n    r0(rp)
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        b       loop                    /* fall into main loop */
159
        ldwm    4(s1),s1word
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161
eq_align1:
162
        ldbs,ma 1(s2),s2word
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        sub,=   s1word,s2word,ret0      /* if not equal, we can return now */
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        bv,n    r0(rp)
165
        comclr,<>       s1word,r0,ret0
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        bv,n    r0(rp)
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        /* fall through to half-word aligned case */
168
        ldhs,ma 2(s1),s1word            /* load next halfword */
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eq_align2:
170
        ldhs,ma 2(s2),s2word            /* load next halfword */
171
        /* form the mask: 0xffff0000 and mask leading nulls in s1word and s2word
172
           so that we can fall into the main loop with word aligned data */
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        ldi     16,save
174
        mtctl   save,r11
175
        zvdepi  -2,32,save
176
        or      save,s1word,s1word
177
        b       loop_plus               /* fall into main loop */
178
        or      save,s2word,s2word
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180
/* s2's alignment is greater than s1's alignment, so we will shift s1 */
181
shifts1_0:
182
        addi    -4,s1,s1                /* fix up s1 due to earlier read */
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shifts1:
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        extru   s1,31,2,tmp1
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        extru   s2,31,2,tmp5
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        dep     r0,31,2,s1              /* Compute word address of s1 */
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        dep     r0,31,2,s2              /* Compute word address of s2 */
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        ldwm    4(s1),s1word            /* get first word of s1 */
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        ldwm    4(s2),s2word            /* get first word of s2 */
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        combt,=,n       r0,tmp1,masks2  /* Do we need to mask beginning of s1 */
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        sh3add  tmp1,r0,save            /* save now has number of bits to mask */
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        mtctl   save,r11
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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:
196
        sh3add  tmp5,r0,save            /* save now has number of bits to mask */
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        mtctl   save,r11
198
        zvdepi  -2,32,save              /* load save with proper mask */
199
        or      save,s2word,s2word
200
        ldi     -1,tmp7                 /* load tmp7 with 0xffffffff */
201
        mtctl   tmp3,r11                /* Move shift amount to CR11 */
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more:   uxor,nbz        s1word,r0,r0    /* Is there a null in s1? */
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        b       ends1
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        vshd    tmp7,s1word,save
205
        combf,=,n       save,s2word,cmps1
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        ldwm    4(s1),tmp7
207
        ldwm    4(s2),s2word
208
        uxor,nbz        tmp7,r0,r0      /* is there a null in s1? */
209
        b       ends1_0
210
        vshd    s1word,tmp7,save
211
        combf,=,n       save,s2word,cmps1
212
        ldwm    4(s1),s1word
213
        b       more
214
        ldwm    4(s2),s2word
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216
cmps1:  movb,tr         save,s1word,wordcomparereturn
217
        nop
218
 
219
ends1_0:
220
        copy    tmp7,s1word                     /* move tmp7 to s1word */
221
ends1:
222
        combf,=,n       save,s2word,nullins1    /* branch if no match */
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        copy    save,s1word                     /* delay slot */
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/* At this point, we know that we've read a null */
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/* from s1, so we can't read more from s1 */
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        uxor,nbz        save,r0,r0              /* are the strings equal? */
227
        b,n     samestring
228
        vshd    s1word,r0,s1word
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        b       nullins1
230
        ldwm    4(s2),s2word
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232
/* s1's alignment is greater than s2's alignment, so we will shift s2 */
233
shifts2:
234
        extru   s1,31,2,tmp1
235
        extru   s2,31,2,tmp5
236
        dep     r0,31,2,s1              /* Compute word address of s1 */
237
        dep     r0,31,2,s2              /* Compute word address of s2 */
238
        ldwm    4(s2),s2word            /* get first word of s2 */
239
        ldwm    4(s1),s1word            /* get first word of s1 */
240
        combt,=,n       r0,tmp5,masks1  /* Do we need to mask beginning of s2 */
241
        sh3add  tmp5,r0,save            /* save now has number of bits to mask */
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        mtctl   save,r11
243
        zvdepi  -2,32,save              /* load save with proper mask */
244
        or      save,s2word,s2word
245
masks1:
246
        sh3add  tmp1,r0,save            /* save now has number of bits to mask */
247
        mtctl   save,r11
248
        zvdepi  -2,32,save              /* load save with proper mask */
249
        or      save,s1word,s1word
250
        ldi     -1,tmp7                 /* load tmp7 with 0xffffffff */
251
        mtctl   tmp3,r11                /* Move shift amount to CR11 */
252
more1:  uxor,nbz        s2word,r0,r0    /* is there a null in s2? */
253
        b       ends2
254
        vshd    tmp7,s2word,save
255
        combf,=,n       s1word,save,cmps2
256
        ldwm    4(s2),tmp7
257
        ldwm    4(s1),s1word
258
        uxor,nbz        tmp7,r0,r0      /* is there a null in s2? */
259
        b       ends2_0
260
        vshd    s2word,tmp7,save
261
        combf,=,n       s1word,save,cmps2
262
        ldwm    4(s2),s2word
263
        b       more1
264
        ldwm    4(s1),s1word
265
 
266
cmps2:  movb,tr         save,s2word,wordcomparereturn
267
        nop
268
 
269
ends2_0:
270
        copy    tmp7,s2word                     /* move tmp7 to s2word */
271
ends2:
272
        combf,=,n       s1word,save,nullins1    /* branch if no match */
273
        copy    save,s2word                     /* delay slot */
274
/* At this point, we know that we've read a null */
275
/* from s2, so we can't read more from s2 */
276
        uxor,nbz        save,r0,r0              /* are the strings equal? */
277
        b,n     samestring
278
        vshd    s2word,r0,s2word
279
        b       nullins1
280
        ldwm    4(s1),s1word
281
 
282
EXIT(strcmp)

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