Re: [avr-gcc-list] Compiler bug ?

[E. Weddington]

On 16 Apr 2003 at 15:14, Larry Barello wrote:

> avr-gcc -S -Os -fno-reorder-blocks -Wall -g -mmcu=attiny26 foo.c -o
> foo.s foo.c: In function `DoDeadBand': foo.c:21: error: unable to
> generate reloads for: (insn:QI 31 28 32 2 006B7390 (set (cc0)
>         (compare (sign_extend:HI (reg/v:QI 24 r24 [42]))
>             (const_int -20 [0xffffffec]))) 94 {*cmpqi_sign_extend}
> (nil)
>     (nil))
> foo.c:21: internal compiler error: in find_reloads, at
> gcc/reload.c:3636
> Please submit a full bug report,
> with preprocessed source if appropriate.
> See <URL:http://www.gnu.org/software/gcc/bugs.html> for instructions.
> make: *** [foo.s] Error 1
> 
> 
> ---- Winavr Version -----
> 
> Reading specs from c:\WinAVR\bin\..\lib\gcc-lib\avr\3.3\specs
> Configured with:
> ../configure --prefix=/e/avrdev/install --target=avr --enable-language
> s=c,c++ --disable-nls Thread model: single gcc version 3.3 20030310
> (prerelease)
> 
> --- foo.c ---
> 
> #define DEADBAND_LOW (20)     // +/-20 us
> 
> char DoDeadBand(char raw)
> {
>     char deadband;
> 
>     deadband = DEADBAND_LOW;
> 
>     if (raw > deadband)
>     {
>         return raw - deadband;
>     }
>     else if (raw < -deadband)
>     {
>         return raw + deadband;
>     }
>     else
>     {
>         return 0;
>     }
> }
> 

I was able to reproduce it here, even with specifying -
mmcu=atmega128.

However, the error goes away if you specify
-funsigned-char.

I'm trying to get a new WinAVR release out this week to address 
another compiler bug that was reported on avr-gcc-list earlier. This 
new release of WinAVR is just to upgrade GCC and avr-libc only, 
however.

Eric Weddington