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Diffstat (limited to 'newlib/libc/machine/hppa/strcmp.S')
| -rw-r--r-- | newlib/libc/machine/hppa/strcmp.S | 282 |
1 files changed, 282 insertions, 0 deletions
diff --git a/newlib/libc/machine/hppa/strcmp.S b/newlib/libc/machine/hppa/strcmp.S new file mode 100644 index 00000000000..007a648492d --- /dev/null +++ b/newlib/libc/machine/hppa/strcmp.S @@ -0,0 +1,282 @@ +/* + * (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 + + Jerry Huck + Edgar Circenis + +*/ +/* + * 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 + */ + +#include "DEFS.h" + +#define s1 26 +#define s2 25 +#define tmp1 19 +#define s2word 20 +#define tmp3 21 +#define tmp7 22 +#define s1word 23 +#define save 1 +#define tmp6 24 +#define tmp5 28 + +ENTRY(strcmp) + comb,=,n s1,s2,samestring + comib,=,n 0,s1,s1isnull + comib,=,n 0,s2,s2isnull +/* Hope for word alignment. Pick up low two bits of each adress */ + extru,<> s1,31,2,tmp1 + ldwm 4(s1),s1word + dep,= s2,29,2,tmp1 + b,n case_analysis + +/* Start looping until null is found in s1 or they mis-compare */ +loop: + ldwm 4(s2),s2word +loop_plus: + uxor,nbz s1word,r0,r0 /* Null in this? */ + b,n nullins1 + comb,=,n s1word,s2word,loop + ldwm 4(s1),s1word + +/* The words do not compare equal and s1 does not have a null. + Need to treat words as unsigned and generate either a positive + or negative return value */ +wordcomparereturn: + comclr,>> s1word,s2word,ret0 /*Set ret0 to 0 and skip if greater*/ + ldi -2,ret0 /*Set ret0 to -2 when less */ + bv r0(rp) + addi 1,ret0,ret0 /*Fix return value to be -1 or +1 */ + +/* s1 has a null. s2 has not been checked. */ +nullins1: + /*If s2 has no nulls this is simple, but assume that it might + and fix up s1 to allow the word comparision to work by + scanning s1 and duplicating all the bytes in s2 below that byte into + the remainder of s1. A remainder only exists if the zero byte + is found in the upper three bytes */ + extru,<> s1word,7,8,r0 /*in the first byte? */ + dep,tr s2word,31,24,s1word /*copy low 3 bytes of *s2 into *s1 */ + extru,<> s1word,15,8,r0 /*in the second byte? */ + dep,tr s2word,31,16,s1word /*copy low 2 bytes of *s2 into *s1 */ + extru,<> s1word,23,8,r0 /*in the third byte? */ + dep s2word,31,8,s1word /*copy low 1 byte of *s2 into *s1 */ + /* Do the normal unsigned compare and return */ + comclr,<> s1word,s2word,ret0 /*Set ret0 to 0 and skip if not equal */ + bv,n r0(rp) + comclr,>> s1word,s2word,ret0 /*Set ret0 to 0 and skip if greater*/ + ldi -2,ret0 /*Set ret0 to -2 when less */ + bv r0(rp) + addi 1,ret0,ret0 /*Fix return value to be -1 or +1 */ + +/* s1 and s2 are the same string and therefore equal */ +samestring: + bv r0(rp) + copy r0,ret0 +/* s1 is null. Treat as string of nulls. Therefore return + the negative of s2's first byte. s2 cannot be zero. */ +s1isnull: + ldbs 0(0,s2),ret0 + bv r0(rp) + sub 0,ret0,ret0 +/* s2 is null. Treat as string of nulls. Therefore return + s1's first byte. s1 cannot be zero. */ +s2isnull: + bv r0(rp) + ldbs 0(0,s1),ret0 + +case_analysis: + blr tmp1,r0 + nop + + /* + Case statement for non-aligned cases (we've already + checked the aligned case. + NOTE: for non-aligned cases, the absolute shift value + gets loaded into tmp3. + */ + + /* S2 S1 */ + nop /* 00 00 can't happen */ + nop + b shifts2 /* 00 01 */ + ldi 8,tmp3 /* load shift count (delay slot) */ + b shifts2 /* 00 10 */ + ldi 16,tmp3 /* load shift count (delay slot) */ + b shifts2 /* 00 11 */ + ldi 24,tmp3 /* load shift count (delay slot) */ + b shifts1_0 /* 01 00 */ + ldi 8,tmp3 /* load shift count (delay slot) */ + b eq_align1 /* 01 01 */ + ldbs,ma 1(s1),s1word + b shifts2 /* 01 10 */ + ldi 8,tmp3 /* load shift count (delay slot) */ + b shifts2 /* 01 11 */ + ldi 16,tmp3 /* load shift count (delay slot) */ + b shifts1_0 /* 10 00 */ + ldi 16,tmp3 /* load shift count (delay slot) */ + b shifts1 /* 10 01 */ + ldi 8,tmp3 /* load shift count (delay slot) */ + b eq_align2 /* 10 10 */ + ldhs,ma 2(s1),s1word + b shifts2 /* 10 11 */ + ldi 8,tmp3 /* load shift count (delay slot) */ + b shifts1_0 /* 11 00 */ + ldi 24,tmp3 /* load shift count (delay slot) */ + b shifts1 /* 11 01 */ + ldi 16,tmp3 /* load shift count (delay slot) */ + b shifts1 /* 11 10 */ + ldi 8,tmp3 /* load shift count (delay slot) */ + ldbs,ma 1(s1),s1word /* 11 11 */ + ldbs,ma 1(s2),s2word + sub,= s1word,s2word,ret0 /* if not equal, we can return now */ + bv,n r0(rp) + comclr,<> s1word,r0,ret0 + bv,n r0(rp) + b loop /* fall into main loop */ + ldwm 4(s1),s1word + +eq_align1: + ldbs,ma 1(s2),s2word + sub,= s1word,s2word,ret0 /* if not equal, we can return now */ + bv,n r0(rp) + comclr,<> s1word,r0,ret0 + bv,n r0(rp) + /* fall through to half-word aligned case */ + ldhs,ma 2(s1),s1word /* load next halfword */ +eq_align2: + ldhs,ma 2(s2),s2word /* load next halfword */ + /* form the mask: 0xffff0000 and mask leading nulls in s1word and s2word + so that we can fall into the main loop with word aligned data */ + ldi 16,save + mtctl save,r11 + zvdepi -2,32,save + or save,s1word,s1word + b loop_plus /* fall into main loop */ + or save,s2word,s2word + +/* s2's alignment is greater than s1's alignment, so we will shift s1 */ +shifts1_0: + addi -4,s1,s1 /* fix up s1 due to earlier read */ +shifts1: + extru s1,31,2,tmp1 + extru s2,31,2,tmp5 + dep r0,31,2,s1 /* Compute word address of s1 */ + dep r0,31,2,s2 /* Compute word address of s2 */ + ldwm 4(s1),s1word /* get first word of s1 */ + ldwm 4(s2),s2word /* get first word of s2 */ + combt,=,n r0,tmp1,masks2 /* Do we need to mask beginning of s1 */ + sh3add tmp1,r0,save /* save now has number of bits to mask */ + mtctl save,r11 + zvdepi -2,32,save /* load save with proper mask */ + or save,s1word,s1word +masks2: + sh3add tmp5,r0,save /* save now has number of bits to mask */ + mtctl save,r11 + zvdepi -2,32,save /* load save with proper mask */ + or save,s2word,s2word + ldi -1,tmp7 /* load tmp7 with 0xffffffff */ + mtctl tmp3,r11 /* Move shift amount to CR11 */ +more: uxor,nbz s1word,r0,r0 /* Is there a null in s1? */ + b ends1 + vshd tmp7,s1word,save + combf,=,n save,s2word,cmps1 + ldwm 4(s1),tmp7 + ldwm 4(s2),s2word + uxor,nbz tmp7,r0,r0 /* is there a null in s1? */ + b ends1_0 + vshd s1word,tmp7,save + combf,=,n save,s2word,cmps1 + ldwm 4(s1),s1word + b more + ldwm 4(s2),s2word + +cmps1: movb,tr save,s1word,wordcomparereturn + nop + +ends1_0: + copy tmp7,s1word /* move tmp7 to s1word */ +ends1: + combf,=,n save,s2word,nullins1 /* branch if no match */ + copy save,s1word /* delay slot */ +/* At this point, we know that we've read a null */ +/* from s1, so we can't read more from s1 */ + uxor,nbz save,r0,r0 /* are the strings equal? */ + b,n samestring + vshd s1word,r0,s1word + b nullins1 + ldwm 4(s2),s2word + +/* s1's alignment is greater than s2's alignment, so we will shift s2 */ +shifts2: + extru s1,31,2,tmp1 + extru s2,31,2,tmp5 + dep r0,31,2,s1 /* Compute word address of s1 */ + dep r0,31,2,s2 /* Compute word address of s2 */ + ldwm 4(s2),s2word /* get first word of s2 */ + ldwm 4(s1),s1word /* get first word of s1 */ + combt,=,n r0,tmp5,masks1 /* Do we need to mask beginning of s2 */ + sh3add tmp5,r0,save /* save now has number of bits to mask */ + mtctl save,r11 + zvdepi -2,32,save /* load save with proper mask */ + or save,s2word,s2word +masks1: + sh3add tmp1,r0,save /* save now has number of bits to mask */ + mtctl save,r11 + zvdepi -2,32,save /* load save with proper mask */ + or save,s1word,s1word + ldi -1,tmp7 /* load tmp7 with 0xffffffff */ + mtctl tmp3,r11 /* Move shift amount to CR11 */ +more1: uxor,nbz s2word,r0,r0 /* is there a null in s2? */ + b ends2 + vshd tmp7,s2word,save + combf,=,n s1word,save,cmps2 + ldwm 4(s2),tmp7 + ldwm 4(s1),s1word + uxor,nbz tmp7,r0,r0 /* is there a null in s2? */ + b ends2_0 + vshd s2word,tmp7,save + combf,=,n s1word,save,cmps2 + ldwm 4(s2),s2word + b more1 + ldwm 4(s1),s1word + +cmps2: movb,tr save,s2word,wordcomparereturn + nop + +ends2_0: + copy tmp7,s2word /* move tmp7 to s2word */ +ends2: + combf,=,n s1word,save,nullins1 /* branch if no match */ + copy save,s2word /* delay slot */ +/* At this point, we know that we've read a null */ +/* from s2, so we can't read more from s2 */ + uxor,nbz save,r0,r0 /* are the strings equal? */ + b,n samestring + vshd s2word,r0,s2word + b nullins1 + ldwm 4(s1),s1word + +EXIT(strcmp) |