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Re: peephole2: dead regs not marked as dead

On 10/27/2010 12:54 PM, Georg Lay wrote: 
reg 26 (Stackpointer) and reg 27 (return address) do not matter here.
The result ist

insn 10 (CALL) CURRENT = FIRST = 0xc008010 = {...,4,15}

Ok, this looks like a bug somewhere (either in DF or in your backend). 

hmmm. How could the backend introduce a bug in lifeness?
REG15 is special in some way

- it is call-saved
- it is neither an element of FUNCTION_ARG_REGNO_P nor of EPILOGUE_USES
   nor of CALL_[REALLY_]USED_REGISTERS

Looks fine.

However, your previous dump showed {2,26,27} for lr out, while this debug output shows {2,15,26,27} at the beginning of df_simulate_initialize_backwards.

I would then look at the dump for the previous pass, and/or put breakpoints before/after df_analyze to see why the two dumps differ.

Paolo

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