Hi,

as you know we use FreePascal with our OpenXP Project (www.openxp.de/.com). We found, that after compiling our release version, an important function doesn't work anymore. After long search, I found, that compiling with R- instead of R+ is the reason. There is a bug in fpc. See the following code:

compiled with R+

# [904] zlen:=FindUmbruch(cont[offset],zlen); { in EDITOR.ASM } movl -20(%ebp),%edx
movl %ebx,%eax
movzwl -8(%ebp),%esi

> movl %esi,%ecx

cmpl $65500,%ecx
jbe .Lj1668
call FPC_RANGEERROR
.Lj1668:
leal 16(%eax,%esi,1),%eax
call EDITOR_FINDUMBRUCH$formal$LONGINT$$LONGINT

compiled with R-

# [904] zlen:=FindUmbruch(cont[offset],zlen); { in EDITOR.ASM } movl -20(%ebp),%edx
movl %ebx,%eax
movzwl -8(%ebp),%ecx
leal 16(%eax,%ecx,1),%eax
call EDITOR_FINDUMBRUCH$formal$LONGINT$$LONGINT

start of FindUmbruch:

DITOR_FINDUMBRUCH$formal$LONGINT$$LONGINT:
.stabs "FINDUMBRUCH:f6",36,0,254,EDITOR_FINDUMBRUCH$formal$LONGINT$$LONGINT .stabs "DATA:rv35",64,0,254,0
.stabs "ZLEN:rp6",64,0,254,2
# Temps allocated between ebp-4 and ebp-4
.stabs "editor.pas",132,0,0,.Lf2
.Lf2:
.stabn 68,0,306,.Ll48 - EDITOR_FINDUMBRUCH$formal$LONGINT$$LONGINT .Ll48:
pushl %ebp
movl %esp,%ebp
subl $4,%esp
# Var data located in register
# Var zlen located in register
# Var $result 68,0,257,.Ll49 - EDITOR_FINDUMBRUCH$formal$LONGINT$$LONGINT .Ll49:
# [257] mov esi,data
movl %eax,%esi
.stabn 68,0,258,.Ll50 - EDITOR_FINDUMBRUCH$formal$LONGINT$$LONGINT .Ll50:
# [258] mov ebx,zlen
movl %edx,%ebx
.stabn 68,0,259,.Ll51 - EDITOR_FINDUMBRUCH$formal$LONGINT$$LONGINT

Findumbruch awaits the "data" in esi. With the R+ version, the value is loaded to esi before range check. In the R- version the value is located in ecx and not been copied to esi, which is the bug.

You may test this bug with the openxp source
(ftp://www.openxp.de/openxp/openxp-4.0.7144.src.tar.bz2), file is editor.pas. R- can be changed in xpdefine.pas. Source compiled with -O1

If you need more information, I'll do as much as I can.

P.S. Pascal snippet of FindUmbruch

unction FindUmbruch(var data; zlen:integer):integer; assembler; {&uses ebx, esi}
{ rckw„rts von data[zlen] bis data[0] nach erster Umbruchstelle suchen } asm
mov esi,data
mov ebx,zlen
test ebx, ebx
jz @ufound
@floop:
mov al,[esi+ebx]
cmp al,' ' { ' ' -> unbedingter Umbruch } jz @ufound

cmp al,'-' { '-' -> Umbruch, falls alphanum. } jnz @testslash { Zeichen folgt: } mov al,[esi+ebx+1]
cmp al,'0' { '0'..'9' }
jb @fnext
cmp al,'9'
jbe @ufound
cmp al,'A' { 'A'..'Z' }
jb @fnext
cmp al,'Z'
jbe @ufound
cmp al,'a' { 'a'..'z' }
jb @fnext
cmp al,'z'
jbe @ufound
cmp al,'€' { '€'..'¥' }
jb @fnext
cmp al,'¥'
jbe @ufound
jmp @fnext

@testslash:
cmp ebx,1
ja @testslash2
mov ebx,0
jmp @ufound
@testslash2:
cmp al,'/' { '/' -> Umbruch, falls kein } jnz @fnext { Trennzeichen vorausgeht } cmp byte ptr [esi+ebx-1],' '
jz @fnext
cmp byte ptr [esi+ebx-1],'-'
jnz @ufound

  @fnext:
            dec   ebx
            jnz   @floop
  @ufound:
            mov   eax,ebx
{$IFDEF FPC }
end ['EAX', 'EBX', 'ESI'];
{$ELSE }
end;
{$ENDIF }