[coreboot] Incorrect casting in romcc.

[Andriy Gapon]

Sorry for top posting - did you by a chance confused '&' and '&&" as in 
your examples below?

on 12/09/2008 15:30 Mats Erik Andersson said the following:
> Hello all,
> 
> after much backtracking I have identified an unexpected case
> of (implicit) casting where romcc fails miserably.
> 
> I desire a computation 
> 
> 	uint16_t fn(uint8_t d);
> 
> 	uint8_t data;
> 
> 	data = 0;
> 	data += ( fn(0x10) >> 1 ) && 0x007f;
> 
> where fn(0x10) == 0x1010. However, the actual outcome of the previous
> calculation is the value 0x01, instead of the expected 0x08. I does
> not help to provide an explicit casting
> 
> 	data += (uint8_t) ( fn(0x10) >> 1) && 0x007f;
> 
> since provably the incorrect increment 0x01 is still produced.
> 
> The above code is to be used in i440bx/raminit.c, and if I make
> the only change in that code to replace the above calculation
> with the fixed, but intended case
> 
> 	data += 0x08;
> 
> then the full functionality is restored and coreboot can start.
> 
> In the light of all this, I mean to have found a bug in romcc,
> unless this can be viewed as a documented shortcoming.
> 
> Best regards,
> 
> Mats Erik Andersson
> 
> 
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> 


-- 
Andriy Gapon