When a physical register is in use, some alias of that register has a live
interval with a relevant live range. That is the sad state of intervals after
physreg coalescing of subregs, and it is good enough for correct register
allocation.
llvm-svn: 110452
LiveVariables becomes horribly wrong while the coalescer is running, but the
analysis is not zapped until after the coalescer pass has run. This causes tons
of false reports when calling verify form the coalescer.
llvm-svn: 110402
We verify that the LiveInterval is live at uses and defs, and that all
instructions have a SlotIndex.
Stuff we don't check yet:
- Is the LiveInterval minimal?
- Do all defs correspond to instructions or phis?
- Do all defs dominate all their live ranges?
- Are all live ranges continually reachable from their def?
llvm-svn: 110386
be killed before being redefined.
These checks are usually disabled, and usually fail when enabled. We de facto
allow live registers to be redefined without a kill, the corresponding
assertions in RegScavenger were removed long ago.
llvm-svn: 110362
- This fixed a number of bugs in if-converter, tail merging, and post-allocation
scheduler. If-converter now runs branch folding / tail merging first to
maximize if-conversion opportunities.
- Also changed the t2IT instruction slightly. It now defines the ITSTATE
register which is read by instructions in the IT block.
- Added Thumb2 specific hazard recognizer to ensure the scheduler doesn't
change the instruction ordering in the IT block (since IT mask has been
finalized). It also ensures no other instructions can be scheduled between
instructions in the IT block.
This is not yet enabled.
llvm-svn: 106344
- Kill is implicit when use and def registers are identical.
- Only virtual registers can differ.
Add a -verify-fast-regalloc to run the verifier before the fast allocator.
llvm-svn: 103797
MachineBasicBlock::livein_iterator a const_iterator, because
clients shouldn't ever be using the iterator interface to
mutate the livein set.
llvm-svn: 101147
into TargetOpcodes.h. #include the new TargetOpcodes.h
into MachineInstr. Add new inline accessors (like isPHI())
to MachineInstr, and start using them throughout the
codebase.
llvm-svn: 95687
A phi operand that is implicitly defined in a predecessor becomes an undefined
register after phi elimination. This causes a lot of false positives when the
verifier is checking if live-in registers are live-out from all predecessors.
Removing the verifier checks seems like a better solution than insisting on
IMPLICIT_DEF instructions in predecessor blocks.
llvm-svn: 92769
These checks would often trigger on unreachable statements inserted by
bugpoint, leading it astray.
It would be nice if we could distinguish unreachable blocks from errors.
llvm-svn: 91923
Owen Anderson
Bill Wendling
Jakob Stoklund Olesen
Evan Cheng
Dan Gohman
Chris Lattner