[sdcc-devel] [ sdcc-Bugs-800998 ] Write result back to BROKEN HL address

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Bugs item #800998, was opened at 2003-09-05 05:50
Message generated for change (Comment added) made by epetrich
You can respond by visiting: 
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Category: z80 port
>Group: fixed
>Status: Closed
>Resolution: Fixed
Priority: 5
Submitted By: Akiya ISHIDA (akiya-i)
>Assigned to: Erik Petrich (epetrich)
Summary: Write result back to BROKEN HL address

Initial Comment:
I found Z80 code generator bug on 

  SDCC : 

mcs51/gbz80/z80/avr/ds390/pic14/pic16/TININative/xa51

/ds400 2.3.5 (Aug 18 2003) (UNIX) 



I attach two files, source and asm, asm file was 

generated by the compiler with the command...

 % sdcc -c -mz80 -I../include bug.c



Brief overview of the problem:



The C statement 

{

     global_struct.char_member --;

}



compiled into following Z80 code.



	ld	hl, #{ADDR of struct}	; load HL 

pointer to struct.

	ld	l,(hl)			; load 

char_member to L. 

					; HL pair 

was BROKEN.

	ld	a,l

	add	a,#0xFF			; doing --

	ld	c,a			; c = 

char_member -1;



	ld	(hl),c		; <<<< Write C to 

address of BROKEN HL pair !!



The code write back result to WRONG address of 

BROKEN HL pair.





I looked into z80/gen.c, but couldn't figure out how to 

fix.



Hoping this helps somenoe....



----------------------------------------------------------------------

>Comment By: Erik Petrich (epetrich)
Date: 2003-09-06 12:46

Message:
Logged In: YES 
user_id=635249

Fixed in src/z80/gen.c 1.117



----------------------------------------------------------------------

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