[LLVMdev] Double spills with Greedy regalloc

[Borja Ferrer]

Hello,

I noticed the following interesting code sequence while compiling a piece
of code with the backend I'm developing. Probably this issue is for Jakob,
but anyways this is what I'm getting:

    STDWPtrQRr <fi#12>, 0, %R25R24; mem:ST2[FixedStack12](align=1)
    STDWPtrQRr <fi#12>, 0, %R25R24; mem:ST2[FixedStack12](align=1)
    STDWPtrQRr <fi#13>, 0, %R23R22; mem:ST2[FixedStack13](align=1)
    STDWPtrQRr <fi#13>, 0, %R23R22; mem:ST2[FixedStack13](align=1)
    STDWPtrQRr <fi#14>, 0, %R21R20; mem:ST2[FixedStack14](align=1)
    STDWPtrQRr <fi#14>, 0, %R21R20; mem:ST2[FixedStack14](align=1)
    STDWPtrQRr <fi#15>, 0, %R19R18; mem:ST2[FixedStack15](align=1)
    STDWPtrQRr <fi#15>, 0, %R19R18; mem:ST2[FixedStack15](align=1)

Each STDWPtrQRr is a spill instruction, but notice that it's spilling
everything twice to each frame index. I'm only getting this with the Greedy
regalloc, PBQP will not duplicate the spills.
Is there something here that I'm missing or could it be a bug? I haven't
attached the C code now to not spam the message or the huge debug output of
the regalloc, but I will supply any information as requested.

Thanks
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