Displaying 3 results from an estimated 3 matches for "subregh".
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subregs
2008 Jan 23
1
[LLVMdev] LiveInterval Splitting & SubRegisters
...rrect live interval for a virtual register in
> > the case
> > where a subregister extract was coalesced.
>
> Right. That has been removed because it's surprisingly painful to
> maintain that information. Now subreg index lives on MachineOperand.
Yep, I saw that. Does the subregh index in the MachineOperand tell the
asm printer what name to output for a register operand? How else is
it used?
> > That information appears to now be in RegSubIdxMap, which is local to
> > runOnMachineFunction, so it's lost after the coalescer runs. Do I
> > not need
>...
2008 Jan 23
0
[LLVMdev] LiveInterval Splitting & SubRegisters
On Jan 22, 2008, at 12:23 PM, David Greene wrote:
> Evan,
>
> Can you explain the basic mechanics of the live interval splitting
> code?
> Is it all in LiveIntervalAnalysis.cpp under addIntervalsForSpills
> and child
> routines? What is it trying to do?
It's splitting live intervals that span multiple basic blocks. That
is, when an interval is spilled, it
2008 Jan 22
4
[LLVMdev] LiveInterval Splitting & SubRegisters
Evan,
Can you explain the basic mechanics of the live interval splitting code?
Is it all in LiveIntervalAnalysis.cpp under addIntervalsForSpills and child
routines? What is it trying to do?
Also, in the ancient subregister coalescing code, there used to be an update
of the SSARegMap to point subregisters to the superregister they were
coalesced to (IIRC). That has since gone away. I used to