diff options
Diffstat (limited to 'newlib/libc/machine/hppa/strncmp.S')
| -rw-r--r-- | newlib/libc/machine/hppa/strncmp.S | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/newlib/libc/machine/hppa/strncmp.S b/newlib/libc/machine/hppa/strncmp.S new file mode 100644 index 0000000..222384e --- /dev/null +++ b/newlib/libc/machine/hppa/strncmp.S @@ -0,0 +1,189 @@ +/* + * (c) Copyright 1986 HEWLETT-PACKARD COMPANY + * + * To anyone who acknowledges that this file is provided "AS IS" + * without any express or implied warranty: + * permission to use, copy, modify, and distribute this file + * for any purpose is hereby granted without fee, provided that + * the above copyright notice and this notice appears in all + * copies, and that the name of Hewlett-Packard Company not be + * used in advertising or publicity pertaining to distribution + * of the software without specific, written prior permission. + * Hewlett-Packard Company makes no representations about the + * suitability of this software for any purpose. + */ + +/* strcmp(s1, s2) */ +/* returns integer: < 0 iff s1 lexicographically less than s2 */ +/* > 0 iff s1 lexicographically greater than s2 */ +/* = 0 iff s1 lexicographically equal to s2 */ +/* = 0 iff s1 lexicographically equal to s2 */ +/* quit after n charachters */ +#include "DEFS.h" + +#define s1 26 +#define s2 25 +#define tmp1 19 +#define s2word 20 +#define tmp3 21 +#define tmp7 22 +#define s1word 29 +#define save 1 +#define tmp6 23 +#define tmp5 28 +#define count 24 + +ENTRY(strncmp) + combt,<,n r0,count,search /* N <= 0 yields equality */ + bv r0(rp) /* */ + copy 0,ret0 /* return 0 (DELAY SLOT) */ +search: combf,=,n s1,s2,findout /* s1 != s2? */ + bv r0(rp) /* */ + copy 0,ret0 /* return 0 (delay slot) */ +findout: + comibf,=,n 0,s1,checks1 /* s1 == NULL? */ + ldbs 0(0,s2),ret0 /* */ + bv r0(rp) /* */ + subi 0,ret0,ret0 /* ret0 <- -*s2 */ +checks1: + comibf,=,n 0,s2,checkitout /* s2 == NULL? */ + bv r0(rp) /* */ + ldbs 0(0,s1),28 /* return *s1 */ + +checkitout: + extru s2,31,2,tmp1 /* Extract the low two bits of the s2. */ + extru s1,31,2,tmp5 /* Extract the low two bits of the s1 */ + sub,= tmp5,tmp1,tmp3 /* Are s1 & s2 aligned with each other? */ + b not_aligned /* It's more complicated (not_aligned) */ + dep 0,31,2,s1 /* Compute word address of s1 (DELAY SLOT) */ + dep 0,31,2,s2 /* Compute word address of s2 */ + ldwm 4(0,s1),s1word /* get next s1 word s1+=4 */ + combt,= tmp5,r0,skipmask /* skip masking, if we can */ + ldwm 4(0,s2),s2word /* get next s2 word s2+=4 (DELAY SLOT) */ + add tmp5,count,count /* bump count by the number of bytes */ + /* we are going to mask */ + sh3add tmp5,r0,save /* save now has number of bits to mask */ + mtctl save,11 + zvdepi -2,32,save /* load save with proper mask */ + or save,s1word,s1word /* mask s1word (s1) */ + or save,s2word,s2word /* mask s2word (s2) */ + + +skipmask: + combt,=,n s1word,s2word,chknulls /* are these words equal? */ + +checkbyte: + extru s1word,7,8,tmp3 /* get first byte (character) */ +ckbyte2: extru s2word,7,8,tmp7 /* get first byte (character) */ + combf,= tmp3,tmp7,done /* quit if first byte is not equal */ + sub tmp3,tmp7,ret0 /* return difference (delay slot) */ + comibt,=,n 0,tmp3,done /* have we reached the end of string */ + /* if so done ret0 already has zero */ + addibt,<=,n -1,count,done /* have we checked N chars? ret0 == 0 */ + extru s1word,15,8,tmp3 /* get second byte (character) */ + extru s2word,15,8,tmp7 /* get second byte (character) */ + combf,= tmp3,tmp7,done /* quit if second byte is not equal */ + sub tmp3,tmp7,ret0 /* return difference (delay slot) */ + comibt,=,n 0,tmp3,done /* have we reached the end of string */ + /* if so done ret0 already has zero */ + addibt,<=,n -1,count,done /* have we checked N chars? */ + extru s1word,23,8,tmp3 /* get third byte (character) */ + extru s2word,23,8,tmp7 /* get third byte (character) */ + combf,= tmp3,tmp7,done /* done if third byte is not equal */ + sub tmp3,tmp7,ret0 /* return difference (delay slot) */ + comibt,=,n 0,tmp3,done /* have we reached the end of string */ + /* if so done ret0 already has zero */ + addibt,<=,n -1,count,done /* have we checked N chars? */ + extru s1word,31,8,tmp3 /* get last byte (character) */ + extru s2word,31,8,tmp7 /* get last byte (character) */ + bv r0(rp) /* */ + sub tmp3,tmp7,ret0 /* the last characters in the word is */ + /* where the difference is, so return */ + /* the difference and we're outta here */ + + +chknulls: + addibt,<=,n -4,count,zero /* have we checked N chars? */ + uxor,nbz s1word,0,0 /* don't have to check s2 Just quit */ + bv r0(rp) /* */ + copy 0,28 /* return 0 */ + ldwm 4(0,s2),s2word /* get next s2 word s2+=4 */ + b skipmask /* keep checking */ + ldwm 4(0,s1),s1word /* get next s1 word s1+=4 */ + + +not_aligned: + dep r0,31,2,s2 /* Compute word address of s2 */ + combt,<,n r0,tmp3,shifts1 /* Do we shift s1 or s2 */ + sh3add tmp3,r0,tmp3 /* eight bits per byte so mul by 8 */ + ldwm 4(0,s1),s1word /* get first word of s1 */ + ldwm 4(0,s2),s2word /* get first word or s2 */ + combt,=,n r0,tmp5,masks2 /* Do we need to mask beginning of s1 */ + add tmp5,count,count /* bump count by the number of bytes */ + /* we are going to mask */ + sh3add tmp5,r0,save /* save now has number of bits to mask */ + mtctl save,11 + zvdepi -2,32,save /* load save with proper mask */ + or save,s1word,s1word /* */ +masks2: sh3add tmp1,r0,save /* save now has number of bits to mask */ + mtctl save,11 + zvdepi -2,32,save /* load save with proper mask */ + or save,s2word,s2word /* */ + mtctl tmp3,11 /* Move shift amount to CR11 */ +more: uxor,nbz s2word,r0,r0 /* Is there a null in first word */ + b,n chunk1 /* */ + ldwm 4(0,s2),tmp7 /* load second word to enable us to shift */ + vshd s2word,tmp7,s2word /* */ + combf,=,n s1word,s2word,ckbyte2 /* */ + extru s1word,7,8,tmp3 /* get first byte (DELAY SLOT) */ + addibt,<=,n -4,count,zero /* have we checked N chars? */ + uxor,nbz s1word,0,0 /* even though they're equal we could be done */ + b,n zero + copy tmp7,s2word /* */ + b more /* keep checking */ + ldwm 4(0,s1),s1word /* get next s1 (DELAY SLOT) */ + +chunk1: + vshd s2word,r0,s2word /* */ + b ckbyte2 /* */ + extru s1word,7,8,tmp3 /* */ + + +shifts1: + sh3add tmp3,r0,tmp3 /* eight bits per byte so mul by 4 */ + sub r0,tmp3,tmp3 /* Get negative value for left shift */ + ldwm 4(0,s2),s2word /* get first word of s2 */ + ldwm 4(0,s1),s1word /* get first word or s1 */ + combt,=,n r0,tmp1,masks1 /* Do we need to mask beginning of s2 */ + add tmp1,count,count /* bump count by the number of bytes */ + /* we are going to mask */ + sh3add tmp1,r0,save /* save now has number of bits to mask */ + mtctl save,11 + zvdepi -2,32,save /* load save with proper mask */ + or save,s2word,s2word /* */ +masks1: sh3add tmp5,r0,save /* save now has number of bits to mask */ + mtctl save,11 + zvdepi -2,32,save /* load save with proper mask */ + or save,s1word,s1word /* */ + mtctl tmp3,11 /* Move shift amount to CR11 */ +more1: uxor,nbz s1word,r0,r0 /* Is there a null in first byte */ + b,n chunk2 /* */ + ldwm 4(0,s1),tmp7 /* load second word to enable us to shift */ + vshd s1word,tmp7,s1word /* */ + combf,=,n s2word,s1word,ckbyte2 /* */ + extru s1word,7,8,tmp3 /* get first byte (DELAY SLOT) */ + addibt,<=,n -4,count,zero /* have we checked N chars? */ + uxor,nbz s2word,0,0 /* even though they're equal we could be done */ + b,n zero /* zero ret0 and quit */ + copy tmp7,s1word /* */ + b more1 /* keep checking */ + ldwm 4(0,s2),s2word /* get next s2 (DELAY SLOT) */ + +chunk2: + vshd s1word,r0,s1word /* */ + b ckbyte2 /* */ + extru s1word,7,8,tmp3 /* */ + +zero: copy r0,ret0 +done: +EXIT(strncmp) |