diff options
Diffstat (limited to 'newlib/libc/machine/hppa/memcmp.S')
| -rw-r--r-- | newlib/libc/machine/hppa/memcmp.S | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/newlib/libc/machine/hppa/memcmp.S b/newlib/libc/machine/hppa/memcmp.S new file mode 100644 index 0000000..babb207 --- /dev/null +++ b/newlib/libc/machine/hppa/memcmp.S @@ -0,0 +1,183 @@ +/* + * (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. + */ + +/* memcmp(s1, s2, n) */ +/* 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 */ +#ifndef _NAMESPACE_CLEAN +#define NOSECDEF /* prevents _memcmp from becoming primary entry */ +#endif + +#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(memcmp) + combt,<,n r0,count,search /*N <= 0 yields equality */ + b done /**/ + copy 0,ret0 /*return 0 (DELAY SLOT) */ +search: combf,=,n s1,s2,findout /*s1 != s2? */ + b done + copy 0,ret0 /*return 0 (delay slot) */ +findout: + comibf,=,n 0,s1,checks1 /*s1 == NULL? */ + ldbs 0(0,s2),ret0 /**/ + b done /*quit */ + sub 0,ret0,ret0 /*ret0 <- -*s2 */ +checks1: + comibf,=,n 0,s2,checkitout /*s2 == NULL? */ + b done /* quit */ + 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,checkN /* We may be done */ + +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) */ + 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) */ + 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) */ + 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) */ + b done /* if we reach this point we know that */ + sub tmp3,tmp7,ret0 /* the last character in the word is */ + /* where the difference is, so return */ + /* the difference and we're outta here */ + + +checkN: + addibt,<=,n -4,count,zero /* have we checked N chars? */ + 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 /**/ + subi 4,tmp1,tmp1 /* tmp1 now has the number of byte that */ + /* are valid in s2word before the vshd */ + mtctl tmp3,11 /* Move shift amount to CR11 */ +more: combt,<=,n count,tmp1,chunk1 /* Can we do the vshd? */ + 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? */ + copy tmp7,s2word /**/ + b more /* keep checking */ + ldwm 4(0,s1),s1word /* get next s1 (DELAY SLOT) */ + +chunk1: + vshd s2word,r0,s2word /* do an arithmetic shift left to position data */ + b ckbyte2 /**/ + extru s1word,7,8,tmp3 /**/ + + +shifts1: + sh3add tmp3,r0,tmp3 /* eight bits per byte so mul by 8 */ + sub r0,tmp3,tmp3 /* Get negative value for left shift */ + dep r0,31,2,s2 /* Compute word address of s2 */ + 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 /**/ + subi 4,tmp5,tmp5 /*tmp5 now has the number of byte that */ + /*are valid in s1word before the vshd */ + mtctl tmp3,11 /*Move shift amount to CR11 */ +more1: combt,<=,n count,tmp5,chunk2 /*Can we do the vshd? */ + 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? */ + 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(memcmp) |