romcc error in smbus code

[Eric W. Biederman]

Stefan Reinauer <stepan at suse.de> writes:

> Hi Eric,
> 
> I recently added the function smbus_write_byte() to 
> src/southbridge/amd/amd8111/amd8111_early_smbus.c. 
> if the code within #if 0 in that function is enabled, I get the
> following internal compiler error:
> 
> ./romcc -mcpu=k8  -O ./auto.E > auto.inc
> <built-in>:1.0: warning: edge: 
> <built-in>:1.0: warning:  0x2fe7e40 __inw
> amd8111_early_smbus.c:120.39: warning: edge: 
> amd8111_early_smbus.c:120.39: warning:  0x2fe80e0 copy
> <built-in>:1.0: warning: edge: 
> <built-in>:1.0: warning:  0x3126060 copy
> <built-in>:1.0: warning: edge: 
> <built-in>:1.0: warning:  0x2fea8d0 __inw
> amd8111_early_smbus.c:125.63: warning: edge: 
> amd8111_early_smbus.c:125.63: warning:  0x2feab70 copy
> <built-in>:1.0: warning: edge: 
> <built-in>:1.0: warning:  0x2feba50 __inw
> io.h:39.1: warning: edge: 
> io.h:39.1: warning:  0x2febb70 copy
> amd8111_early_smbus.c:128.48: warning:  0x2febcf0 copy
> <built-in>:1.0: warning: edge: 
> <built-in>:1.0: warning:  0x2fe6450 __inw
> auto.c:102.45: warning: def: 
> auto.c:102.45: warning:  0x2fe5020 copy
> amd8111_early_smbus.c:131.33: warning:  0x2fec520 copy
> auto.c:102.45: 0x2fe5020 copy Internal compiler error: live range with
> already used color %ax
> 
> Is the code running out of registers? What's happening here?

Yes the compiler ran out of registers.  

Although in this case it looks like this was cause by a compiler bug.

The compiler tried to assign %ax to two variables simultaneously.

Eric