[avr-gcc-list] ASM Label address problem

[Steven Bromley]

Hey all,

 

Here is a small piece of code I’m having trouble with:

 

  subi ZL,pm_lo8(-.Last+6)

  sbci ZH,pm_hi8(-.Last+6)

 

  ... more code here ...

 

  .Last:

 

  ... more code here ...

 

 

My intention is to add (.Last-6) to Z (where .Last is a just a label in the
code).  Since the AVR instruction set doesn’t provide us with "addi"/"adci"
I must use subi/sbci instead.  No problems there.

 

The trouble arises when I attempt to subtract from .Last producing a
negative address, to which the compiler generates:

 

  Error: can't resolve `0' {.text section} - `.Last' {.text section}

 

I realise I could expand the code so I don’t need the subtraction, but at
the cost of more cycles and ROM.  Eg:

 

  ldi YL,pm_lo8(.Last-6)

  add ZL,YL

  ldi YL,pm_hi8(.Last-6)

  adc ZH,YL

 

I would much prefer just to use first block of code though.  Does anyone
have a solution to this?

BTW, I’m using WinAVR-20040720.

 

Cheers


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