[llvm-commits] [llvm] r77904 - in /llvm/trunk: include/llvm/CodeGen/RegisterScavenging.h lib/CodeGen/RegisterScavenging.cpp test/CodeGen/Blackfin/load-intr.ll

[Jakob Stoklund Olesen]

On 03/08/2009, at 04.03, Evan Cheng wrote:

>
> On Aug 2, 2009, at 11:28 AM, Jakob Stoklund Olesen wrote:
>
>>
>> /// setUsed - Set the register and its sub-registers as being used.
>> void RegScavenger::setUsed(unsigned Reg) {
>>  RegsAvailable.reset(Reg);
>> @@ -218,7 +226,7 @@
>>    const MachineOperand MO = *UseMOs[i].first;
>>    unsigned Reg = MO.getReg();
>>
>> -    assert(isUsed(Reg) && "Using an undefined register!");
>> +    assert((MO.isImplicit() || isUsed(Reg)) && "Using an undefined
>> register!");
>
> Hi Jakob,
>
> I don't understand why this is necessary. It's seems like it will end
> up letting a lot of real errors go through.

Clearly I was too quick to commit this part. Sorry about that.

I will try to make it work with the stricter rule. Then I can back out  
this part.

>> @@ -269,7 +277,8 @@
>>
>>    // Implicit def is allowed to "re-define" any register. Similarly,
>>    // implicitly defined registers can be clobbered.
>> -    assert((isReserved(Reg) || isUnused(Reg) ||
>> +    assert((MO.isImplicit() || isReserved(Reg) || isUnused(Reg) ||
>> +            isSuperRegUsed(Reg) ||
>>            isLiveInButUnusedBefore(Reg, MI, MBB, TRI, MRI)) &&
>>           "Re-defining a live register!");
>>    setUsed(Reg);

But this part is OK, right? <imp-def> can redefine a live register.

/jakob