I think it's been fixed ages ado... can't remember when...
however, conversion from unsigned to signed may result in negative value of
destination if MSB of source is set in 1.
~d
On Monday 15 December 2003 22:46, Matthias Weingart wrote:
> Hi Dimitry,
>
> run the software below and at the end you get x=1 (should be 0!!)
>
> It seems that gcc uses the flags of sub for the next if(); but it should do
> a additional cmp !! (first it is a unsigned operation, then a signed)
>
> msp430-gcc main.c -mmcu=msp430x149 -g -O2 -ffunction-sections
> -Wl,--gc-sections,-uInterruptVectors -o main.elf (gcc from the download,
> maybe you have already fixed that bug??)
>
> #include <stdlib.h>
>
> int x=0;
>
> func1(uint a, uint b)
> {
> uint ud;
> int d;
>
> ud = a-b;
> d = ud;
> if ( d<0 )
> x|=1;
> }
>
> func2(uint a, uint b)
> {
> volatile uint ud;
> volatile int d;
>
> ud = a-b;
> d = ud;
> if ( d<0 )
> x|=2;
> }
>
> main()
> {
> func1(32768,20000);
> func2(32768,20000);
> }
>
> Matthias
>
>
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