This prevents the behavior observed in llvm.org/PR22369. I am not sure
whether I am reading the code correctly, but the early exit based on
isLiveOutPastPHIs() seems to make the wrong assumption that
RegisterCoalescer won't be able to coalesce those copies later.
This change hides the new behavior behind -no-phi-elim-live-out-early-exit
as it currently breaks four tests:
* Assertion in:
CodeGen/Hexagon/hwloop-cleanup.ll
* Worse code in:
CodeGen/X86/coalescer-commute4.ll
CodeGen/X86/phys_subreg_coalesce-2.ll
CodeGen/X86/zlib-longest-match.ll
The root cause here seems to be that the heuristic that determines
the visitation order in RegisterCoalescer gets less lucky.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231064 91177308-0d34-0410-b5e6-96231b3b80d8
This is to be consistent with StringSet and ultimately with the standard
library's associative container insert function.
This lead to updating SmallSet::insert to return pair<iterator, bool>,
and then to update SmallPtrSet::insert to return pair<iterator, bool>,
and then to update all the existing users of those functions...
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222334 91177308-0d34-0410-b5e6-96231b3b80d8
shorter/easier and have the DAG use that to do the same lookup. This
can be used in the future for TargetMachine based caching lookups from
the MachineFunction easily.
Update the MIPS subtarget switching machinery to update this pointer
at the same time it runs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214838 91177308-0d34-0410-b5e6-96231b3b80d8
define below all header includes in the lib/CodeGen/... tree. While the
current modules implementation doesn't check for this kind of ODR
violation yet, it is likely to grow support for it in the future. It
also removes one layer of macro pollution across all the included
headers.
Other sub-trees will follow.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206837 91177308-0d34-0410-b5e6-96231b3b80d8
operator* on the by-operand iterators to return a MachineOperand& rather than
a MachineInstr&. At this point they almost behave like normal iterators!
Again, this requires making some existing loops more verbose, but should pave
the way for the big range-based for-loop cleanups in the future.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203865 91177308-0d34-0410-b5e6-96231b3b80d8
The Segment struct contains a single interval; multiple instances of this struct
are used to construct a live range, but the struct is not a live range by
itself.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192392 91177308-0d34-0410-b5e6-96231b3b80d8
When new virtual registers are created during splitting/spilling, defer
creation of the live interval until we need to use the live interval.
Along with the recent commits to notify LiveRangeEdit when new virtual
registers are created, this makes it possible for functions like
TargetInstrInfo::loadRegFromStackSlot() and
TargetInstrInfo::storeRegToStackSlot() to create multiple virtual
registers as part of the process of generating loads/stores for
different register classes, and then have the live intervals for those
new registers computed when they are needed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188437 91177308-0d34-0410-b5e6-96231b3b80d8
When phis get lowered, destination copies are inserted using an iterator that is
determined once for all phis in the block, which BuildMI interprets as a request
to insert an instruction directly before the iterator. In the case of a cyclic
phi, source copies may also be inserted directly before this iterator, which can
cause source copies to be inserted before destination copies. The fix is to keep
an iterator to the last phi and then advance it while lowering each phi in order
to insert destination copies directly after the phis.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185363 91177308-0d34-0410-b5e6-96231b3b80d8
Benjamin Kramer
Daniel Jasper
David Blaikie
Eric Christopher
Craig Topper
Alexey Samsonov
Chandler Carruth
Owen Anderson
Matt Arsenault
Matthias Braun
Mark Lacey
Cameron Zwarich