Commit Graph

11 Commits

Author SHA1 Message Date
Jakob Stoklund Olesen 9adf5e09cd Simplify LiveDebugVariables by storing MachineOperand copies locations instead
of using a Location class with the same information.

When making a copy of a MachineOperand that was already stored in a
MachineInstr, it is necessary to clear the parent pointer on the copy. Otherwise
the register use-def lists become inconsistent.

Add MachineOperand::clearParent() to do that. An alternative would be a custom
MachineOperand copy constructor that cleared ParentMI. I didn't want to do that
because of the performance impact.

llvm-svn: 123109
2011-01-09 05:33:21 +00:00
Jakob Stoklund Olesen 1331a15b0c Replace TargetRegisterInfo::printReg with a PrintReg class that also works without a TRI instance.
Print virtual registers numbered from 0 instead of the arbitrary
FirstVirtualRegister. The first virtual register is printed as %vreg0.
TRI::NoRegister is printed as %noreg.

llvm-svn: 123107
2011-01-09 03:05:53 +00:00
Devang Patel acbee0b0d9 Speculatively revert r123032.
llvm-svn: 123039
2011-01-07 22:33:41 +00:00
Devang Patel 6381e1584c Appropriately truncate debug info range in dwarf output.
Enable live debug variables pass.

llvm-svn: 123032
2011-01-07 21:30:41 +00:00
Jakob Stoklund Olesen 922e1fac6c Rename virtRegMap to avoid confusion with the VirtRegMap that it isn't.
llvm-svn: 120846
2010-12-03 22:25:09 +00:00
Jakob Stoklund Olesen 4408603a9e Coalesce debug locations when possible, causing less DBG_VALUE instructions to
be emitted.

llvm-svn: 120845
2010-12-03 22:25:07 +00:00
Jakob Stoklund Olesen afc2bc2c04 Emit DBG_VALUE instructions from LiveDebugVariables.
llvm-svn: 120842
2010-12-03 21:47:10 +00:00
Jakob Stoklund Olesen 25cde34ae4 Also update virtRegMap when renaming virtual registers.
llvm-svn: 120841
2010-12-03 21:47:08 +00:00
Jakob Stoklund Olesen 9ec20111c3 Update LiveDebugVariables during coalescing.
llvm-svn: 120720
2010-12-02 18:15:44 +00:00
Jakob Stoklund Olesen 4be0bd79a4 Implement the first half of LiveDebugVariables.
Scan the MachineFunction for DBG_VALUE instructions, and replace them with a
data structure similar to LiveIntervals. The live range of a DBG_VALUE is
determined by propagating it down the dominator tree until a new DBG_VALUE is
found. When a DBG_VALUE lives in a register, its live range is confined to the
live range of the register's value.

LiveDebugVariables runs before coalescing, so DBG_VALUEs are not artificially
extended when registers are joined.

The missing half will recreate DBG_VALUE instructions from the intervals when
register allocation is complete.

The pass is disabled by default. It can be enabled with the temporary command
line option -live-debug-variables.

llvm-svn: 120636
2010-12-02 00:37:37 +00:00
Jakob Stoklund Olesen d4900a644c Stub out a new LiveDebugVariables pass.
This analysis is going to run immediately after LiveIntervals. It will stay
alive during register allocation and keep track of user variables mentioned in
DBG_VALUE instructions.

When the register allocator is moving values between registers and the stack, it
is very hard to keep track of DBG_VALUE instructions. We usually get it wrong.
This analysis maintains a data structure that makes it easy to update DBG_VALUE
instructions.

llvm-svn: 120385
2010-11-30 02:17:10 +00:00