fpc/rtl/powerpc/strings.inc
2001-02-23 14:05:33 +00:00

475 lines
14 KiB
PHP

{
$Id$
This file is part of the Free Pascal run time library.
Copyright (c) 2000 by Jonas Maebe, member of the
Free Pascal development team
Processor dependent part of strings.pp, that can be shared with
sysutils unit.
See the file COPYING.FPC, included in this distribution,
for details about the copyright.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
**********************************************************************}
{ Note: the implementation of these routines is for BIG ENDIAN only!! (JM) }
function strcopy(dest,source : pchar) : pchar;assembler;
{ in: dest in r3, source in r4 }
{ out: result (dest) in r3 }
asm
{ in: dest in r3, source in r4 }
{ out: result (dest) in r3 }
{ get # of misaligned bytes }
rlwinm. r30,r4,0,31-2,31
subfic r30,r30,4
mtctr r30
{ since we have to return dest intact, use another register for }
{ dest in the copy loop }
subi r29,r3,1
subi r4,r4,1
beq LStrCopyAligned
LStrCopyAlignLoop:
{ load next byte }
lbzu r28,1(r4)
{ end of string? }
cmpli cr0,r28,0
{ store byte }
stbu r28,1(r29)
{ loop if misaligned bytes left and not end of string found }
bdnzf eq,LStrCopyAlignLoop
beq LStrCopyDone
LStrCopyAligned:
subi r4,r4,3
subi r29,r29,3
{ setup magic constants }
li r27,0x0feff
addis r27,r27,0x0feff
li r26,0x08080
addis r26,r26,0x08081
LStrCopyAlignedLoop:
{ load next 4 bytes }
lwzu r28,4(r4)
{ test for zero byte }
add r30,r28,r27
andc r30,r30,r28
and. r30,r30,r26
bne LStrCopyEndFound
stwu r28,4(r29)
b LStrCopyAlignedLoop
LStrCopyEndFound:
{ result is either 0, 8, 16 or 24 depending on which byte is zero }
cntlzw r30,r30
addi r29,r29,3
LStrCopyWrapUpLoop:
subic. r30,r30,8
rlwinm r28,r28,8,0,31
stbu r28,1(r29)
bge LStrCopyWrapUpLoop
LStrCopyDone:
{ r3 still contains dest here }
end ['r4','r26','r27','r28','r29','r30','cr0','ctr'];
function strecopy(dest,source : pchar) : pchar;assembler;
{ in: dest in r3, source in r4 }
{ out: result (end of new dest) in r3 }
asm
{ get # of misaligned bytes }
rlwinm. r30,r4,0,31-2,31
subfic r30,r30,4
mtctr r30
subi r3,r3,1
subi r4,r4,1
beq LStrCopyAligned
LStrCopyAlignLoop:
{ load next byte }
lbzu r28,1(r4)
{ end of string? }
cmpli cr0,r28,0
{ store byte }
stbu r28,1(r3)
{ loop if misaligned bytes left and not end of string found }
bdnzf eq,LStrCopyAlignLoop
beq LStrCopyDone
LStrCopyAligned:
subi r4,r4,3
subi r3,r3,3
{ setup magic constants }
li r27,0x0feff
addis r27,r27,0x0feff
li r29,0x08080
addis r29,r29,0x08081
LStrCopyAlignedLoop:
{ load next 4 bytes }
lwzu r28,4(r4)
{ test for zero byte }
add r30,r28,r27
andc r30,r30,r28
and. r30,r30,r29
bne LStrCopyEndFound
stwu r28,4(r3)
b LStrCopyAlignedLoop
LStrCopyEndFound:
{ result is either 0, 8, 16 or 24 depending on which byte is zero }
cntlzw r30,r30
addi r3,r3,3
LStrCopyWrapUpLoop:
subic. r30,r30,8
rlwinm r28,r28,8,0,31
stbu r28,1(r3)
bge LStrCopyWrapUpLoop
LStrCopyDone:
{ r3 contains new dest here }
end ['r3','r4','r27','r28','r3','r30','cr0','ctr'];
function strlcopy(dest,source : pchar;maxlen : longint) : pchar;assembler;
{ in: dest in r3, source in r4, maxlen in r5 }
{ out: result (dest) in r3 }
asm
mtctr r5
subi r4,r4,1
subi r29,r3,1
LStrlCopyLoop:
lbzu r30,1(r4)
cmpli r30,0
stbu r30,1(r29)
bdnzne LStrlCopyLoop
{ if we stopped because we copied a #0, we're done }
beq LStrlCopyDone
{ otherwise add the #0 }
li r30,0
stb r30,1(r29)
LStrlCopyDone:
end ['r4','r29','r30','cr0'];
function strlen(p : pchar) : longint;assembler;
{ in: p in r3 }
{ out: result (length) in r3 }
asm
{ empty/invalid string? }
cmpli r3,0
{ if yes, do nothing }
beq LStrLenDone
subi r29,r3,1
LStrLenLoop:
lbzu r30,1(r29)
cmpli r30,0
bne LStrLenLoop
sub r3,r29,r3
LStrLenDone:
end ['r3','r4','r29','r30','cr0'];
function strend(p : pchar) : pchar;assembler;
{ in: p in r3 }
{ out: result (end of p) in r3 }
asm
{ empty/invalid string? }
cmpli r3,0
{ if yes, do nothing }
beq LStrEndDone
subi r3,r3,1
LStrEndLoop:
lbzu r30,1(r3)
cmpli r30,0
bne LStrEndLoop
LStrEndDone:
end ['r3','r4','r30','cr0'];
function strcomp(str1,str2 : pchar) : longint;assembler;
{ in: str1 in r3, str2 in r4 }
{ out: result (= 0 if strings equal, < 0 if str1 < str2, > 0 if str1 > str2 }
{ in r3 }
asm
{ use r28 instead of r3 for str1 since r3 contains result }
subi r28,r3,1
subi r4,r4,1
LStrCompLoop:
{ load next chars }
lbzu r29,1(r28)
{ check if one is zero }
cmpli cr1,r29,0
lbzu r30,1(r4)
{ calculate difference }
sub. r3,r29,r30
{ if chars not equal, we're ready }
bne LStrCompDone
{ if they are equal and one is zero, then the other one is zero too }
{ and we're done as well (r3 also contains 0 then) }
{ otherwise loop }
bne cr1,LStrCompLoop
LStrCompDone:
end ['r3','r4','r28','r29','r30','cr0','cr1'];
function strlcomp(str1,str2 : pchar;l : longint) : longint;assembler;
{ (same as strcomp, but maximally compare until l'th character) }
{ in: str1 in r3, str2 in r4, l in r5 }
{ out: result (= 0 if strings equal, < 0 if str1 < str2, > 0 if str1 > str2 }
{ in r3 }
asm
{ use r28 instead of r3 for str1 since r3 contains result }
cmpl r5,0
subi r28,r3,1
li r3,0
beq LStrlCompDone
mtctr r5
subi r4,r4,1
LStrlCompLoop:
{ load next chars }
lbzu r29,1(r28)
{ check if one is zero }
cmpli cr1,r29,0
lbzu r30,1(r4)
{ calculate difference }
sub. r3,r29,r30
{ if chars not equal, we're ready }
bne LStrlCompDone
{ if they are equal and one is zero, then the other one is zero too }
{ and we're done as well (r3 also contains 0 then) }
{ otherwise loop (if ctr <> 0) }
bdnzne cr1,LStrlCompLoop
LStrlCompDone:
end ['r3','r4','r28','r29','r30','cr0','cr1','ctr'];
function stricomp(str1,str2 : pchar) : longint;assembler;
{ in: str1 in r3, str2 in r4 }
{ out: result of case insensitive comparison (< 0, = 0, > 0) }
asm
{ use r28 instead of r3 for str1 since r3 contains result }
subi r28,r3,1
subi r4,r4,1
LStriCompLoop:
{ load next chars }
lbzu r29,1(r28)
{ check if one is zero }
cmpli cr1,r29,0
lbzu r30,1(r4)
{ calculate difference }
sub. r3,r29,r30
{ if chars are equal, no further test is necessary }
beq+ LStriCompEqual
{ make both lowercase, no branches }
li r27,0
li r25,0
{ r3 := r29 - 'A' }
subic r3,r29,'A'
{ if r29 < 'A' then r27 := 0 else r27 := $ffffffff }
addme r27,r27
{ same for r30 }
subic r3,r30,'A'
addme r25,r25
{ r3 := 'Z' - r29 }
subfic r3,r29,'Z'
{ if r29 < 'A' then r27 := 0 else r27 := $20 }
andi r27,r27,0x020
{ if r29 > Z then r26 := 0 else r26 := $ffffffff
subfe r26,r26,r26
{ same for r30 }
subfic r3,r30,'Z'
andi r25,r25,0x020
subfe r24,r24,r24
{ if (r29 in ['A'..'Z'] then r27 := $20 else r27 := 0 }
and r27,r27,r26
{ same for r30 }
and r25,r25,r24
{ make lowercase }
add r29,r29,r27
{ same for r30 }
add r30,r30,r25
{ compare again }
sub. r3,r29,r30
bne LStrCompDone
LStriCompEqual:
{ if they are equal and one is zero, then the other one is zero too }
{ and we're done as well (r3 also contains 0 then) }
{ otherwise loop }
bne LStriCompLoop
LStriCompDone:
end ['r3','r4','r26','r27','r28','r29','r30','cr0','cr1'];
function strlicomp(str1,str2 : pchar;l : longint) : longint;assembler;
{ (same as stricomp, but maximally compare until l'th character) }
{ in: str1 in r3, str2 in r4, l in r5 }
{ out: result of case insensitive comparison (< 0, = 0, > 0) }
asm
{ use r28 instead of r3 for str1 since r3 contains result }
cmpl r5,0
subi r28,r3,1
li r3,0
beq LStrlCompDone
mtctr r5
subi r4,r4,1
LStriCompLoop:
{ load next chars }
lbzu r29,1(r28)
{ check if one is zero }
cmpli cr1,r29,0
lbzu r30,1(r4)
{ calculate difference }
sub. r3,r29,r30
{ if chars are equal, no further test is necessary }
beq+ LStriCompEqual
{ see stricomp for explanation }
li r27,0
li r25,0
subic r3,r29,'A'
addme r27,r27
subic r3,r30,'A'
addme r25,r25
subfic r3,r29,'Z'
andi r27,r27,0x020
subfe r26,r26,r26
subfic r3,r30,'Z'
andi r25,r25,0x020
subfe r24,r24,r24
and r27,r27,r26
and r25,r25,r24
add r29,r29,r27
add r30,r30,r25
{ compare again }
sub. r3,r29,r30
bne LStrCompDone
LStriCompEqual:
{ if they are equal and one is zero, then the other one is zero too }
{ and we're done as well (r3 also contains 0 then) }
{ otherwise loop (if ctr <> 0) }
bdnzne cr1,LStriCompLoop
LStriCompDone:
end ['r3','r4','r26','r27','r28','r29','r30','cr0','cr1','ctr'];
function strscan(p : pchar;c : char) : pchar;assembler;
asm
{ empty/invalid string? }
cmpli r3,0
{ if yes, do nothing }
beq LStrScanDone
subi r3,r3,1
LStrScanLoop:
lbzu r30,1(r3)
cmpl cr1,r30,r4
cmpli r30,0
beq cr1,LStrScanDone
bne LStrScanLoop
LStrScanDone:
end ['r3','r4','r30','cr0','cr1'];
function strrscan(p : pchar;c : char) : pchar;assembler;
asm
{ empty/invalid string? }
cmpli r3,0
{ if yes, do nothing }
beq LStrrScanDone
{ make r29 $ffffffff, later on we take min(r29,r3) }
li r29,0x0ffff
subi r3,r3,1
LStrrScanLoop:
lbzu r30,1(r3)
cmpl cr1,r30,r4
cmpli cr0,r30,0
bne+ cr1,LStrrScanNotFound
{ store address of found position }
mr r29,r3
LStrrScanNotFound:
bne LStrrScanLoop
{ Select min of r3 and r29 -> end of string or found position }
{ From the PPC compiler writer's guide, not sure if I could ever }
{ come up with something like this :) }
subfc r30,r3,r29 { r30 = r29 - r3, CA = (r29 >= r3) ? 1 : 0 }
subfe r29,r29,r29 { r29' = (r29 >= r3) ? 0 : -1 }
and r30,r30,r29 { r30 = (r29 >= r3) ? 0 : r29 - r3 }
add r3,r30,r3 { r3 = (r29 >= r3) ? r3 : r29 }
LStrrScanDone:
end ['r3','r4','r29','r30','cr0','cr1'];
function strupper(p : pchar) : pchar;assembler;
asm
cmpli r3,0
beq LStrUpperNil
subi r29,r3,1
LStrUpperLoop:
lbzu r30,1(r29)
{ a <= x <= b <=> cardinal(x-a) <= cardinal(b-a) }
subi r28,r30,97
cmpli r28,122-97
cmpli cr1,r30,0
subi r30,r30,0x20
bgt LStrUpper1
stb r30,0(r29)
LStrUpper1:
bne cr1,LStrUpperLoop
LStrUpperNil:
end ['r28','r29','r30','cr0','cr1'];
function strlower(p : pchar) : pchar;assembler;
asm
cmpli r3,0
beq LStrLowerNil
subi r29,r3,1
LStrLowerLoop:
lbzu r30,1(r29)
{ a <= x <= b <=> cardinal(x-a) <= cardinal(b-a) }
subi r28,r30,65
cmpli r28,90-65
cmpli cr1,r30,0
addi r30,r30,0x20
bgt LStrLower1
stb r30,0(r29)
LStrLower1:
bne cr1,LStrLowerLoop
LStrLowerNil:
end ['r28','r29','r30','cr0','cr1'];
{
$Log$
Revision 1.6 2001-02-23 14:05:33 jonas
* optimized strcopy/strecopy
Revision 1.5 2001/02/11 17:59:14 jonas
* fixed bug in strscan
Revision 1.4 2001/02/11 12:15:03 jonas
* some small optimizations and bugfixes
Revision 1.3 2001/02/10 16:09:43 jonas
+ implemented all missing routines and changed reg allocation to follow ABI
Revision 1.2 2001/02/10 12:28:22 jonas
* fixed some bugs, simplified/optimized already implemented routines and code some more
Revision 1.1 2000/11/05 17:17:08 jonas
+ first implementation, not yet finished
}