romcc error in smbus code

[Stefan Reinauer]

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?

Stefan

Stefan Reinauer  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

[Stefan Reinauer]

* Eric W. Biederman  [031007 23:00]:
> Stefan Reinauer  writes:
> > ./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.

Hm. ok. Does this code suite you as a testsuite, or can I do anything to
provide such?

Stefan

Stefan Reinauer  writes:
> Hm. ok. Does this code suite you as a testsuite, or can I do anything to
> provide such?

If you can find the minimal sequence of code that causes this error I would
appreciate it.

That is how must of my test cases have been built of for romcc.  I find
a bug and then strip it down as far as I can go.  A number of cases actually
involve some pretty subtle interactions between the various pieces so
finding a minimal case might be tricky.

I suggest you start with the preprocessed output and go from there.

I have a major bugfix release sitting in the wings that I will get out
shortly.  I have tested everything except if LinuxBIOS itself will compile
with it :)

Do you need smbus_write_byte to set the position of the i2c mux?

Eric

[Stefan Reinauer]

* Eric W. Biederman  [031009 03:50]:
> Do you need smbus_write_byte to set the position of the i2c mux?

yes

Stefan