Take MachineInstr by reference instead of by pointer in SlotIndexes and
the SlotIndex wrappers in LiveIntervals. The MachineInstrs here are
never null, so this cleans up the API a bit. It also incidentally
removes a few implicit conversions from MachineInstrBundleIterator to
MachineInstr* (see PR26753).
At a couple of call sites it was convenient to convert to a range-based
for loop over MachineBasicBlock::instr_begin/instr_end, so I added
MachineBasicBlock::instrs.
llvm-svn: 262115
This renaming is necessary to avoid a subregister aware scheduler
accidentally creating liveness "holes" which are rejected by the
MachineVerifier.
Explanation as found in this patch:
Helper class that can divide MachineOperands of a virtual register into
equivalence classes of connected components.
MachineOperands belong to the same equivalence class when they are part of
the same SubRange segment or adjacent segments (adjacent in control
flow); Different subranges affected by the same MachineOperand belong to
the same equivalence class.
Example:
vreg0:sub0 = ...
vreg0:sub1 = ...
vreg0:sub2 = ...
...
xxx = op vreg0:sub1
vreg0:sub1 = ...
store vreg0:sub0_sub1
The example contains 3 different equivalence classes:
- One for the (dead) vreg0:sub2 definition
- One containing the first vreg0:sub1 definition and its use,
but not the second definition!
- The remaining class contains all other operands involving vreg0.
We provide a utility function here to rename disjunct classes to different
virtual registers.
Differential Revision: http://reviews.llvm.org/D16126
llvm-svn: 258257
This improves ConnectedVNInfoEqClasses::Distribute() to distribute the
segments and value numbers in the subranges instead of conservatively
clearing all subregister info.
No separate test here, just clearing the subrange instead of properly
distributing them would however break my upcoming fix regarding dead super
register definitions.
Differential Revision: http://reviews.llvm.org/D13075
llvm-svn: 248334
Empty subranges are not allowed in a LiveInterval and must be removed
instead: Check this in the verifiers, put a reminder for this in the
comment of the shrinkToUses variant for a single lane and make it
automatic for the shrinkToUses variant for a LiveInterval.
llvm-svn: 242431
If two livesegments from different subranges happened to have the same
definition they could possibly end up as two adjacent segments in the
main liverange with the same value number which is not allowed. Detect
such cases and fix them in the 2nd pass of computeFromMainRange() if
necessary.
No testcase as there is only an out-of-tree target where I can sensibly
come up with one.
llvm-svn: 234382
GCC 4.7's libstdc++ doesn't have std::map::emplace, but it does have
std::unordered_map::emplace, and the use case here doesn't appear to
need ordering. The container has been changed in a separate/precursor
patch, and now this patch should hopefully build cleanly even with
GCC 4.7.
& then I realized the order of the container did matter, so extra
handling of ordering was added in r231189.
Original commit message:
This makes LiveRange non-copyable, and LiveInterval is already
non-movable (due to the explicit dtor), so now it's non-copyable and
non-movable.
Fix the one case where we were relying on the (deprecated in C++11)
implicit copy ctor of LiveInterval (which happened to work because the
ctor created an object with a null segmentSet, so double-deleting the
null pointer was fine).
llvm-svn: 231192
Apparently something does care about ordering of LiveIntervals... so
revert all that stuff (r231175, r231176, r231177) & take some time to
re-evaluate.
llvm-svn: 231184
GCC 4.7's libstdc++ doesn't have std::map::emplace, but it does have
std::unordered_map::emplace, and the use case here doesn't appear to
need ordering. The container has been changed in a separate/precursor
patch, and now this patch should hopefully build cleanly even with
GCC 4.7.
Original commit message:
This makes LiveRange non-copyable, and LiveInterval is already
non-movable (due to the explicit dtor), so now it's non-copyable and
non-movable.
Fix the one case where we were relying on the (deprecated in C++11)
implicit copy ctor of LiveInterval (which happened to work because the
ctor created an object with a null segmentSet, so double-deleting the
null pointer was fine).
llvm-svn: 231176
This makes LiveRange non-copyable, and LiveInterval is already
non-movable (due to the explicit dtor), so now it's non-copyable and
non-movable.
Fix the one case where we were relying on the (deprecated in C++11)
implicit copy ctor of LiveInterval (which happened to work because the
ctor created an object with a null segmentSet, so double-deleting the
null pointer was fine).
llvm-svn: 231168
Accidentally committed a few more of these cleanup changes than
intended. Still breaking these out & tidying them up.
This reverts commit r231135.
llvm-svn: 231136
There doesn't seem to be any need to assert that iterator assignment is
between iterators over the same node - if you want to reuse an iterator
variable to iterate another node, that's perfectly acceptable. Just
don't mix comparisons between iterators into disjoint sequences, as
usual.
llvm-svn: 231135
by using a segment set.
The patch addresses a compile-time performance regression in the LiveIntervals
analysis pass (see http://llvm.org/bugs/show_bug.cgi?id=18580). This regression
is especially critical when compiling long functions. Our analysis had shown
that the most of time is taken for generation of live intervals for physical
registers. Insertions in the middle of the array of live ranges cause quadratic
algorithmic complexity, which is apparently the main reason for the slow-down.
Overview of changes:
- The patch introduces an additional std::set<Segment>* member in LiveRange for
storing segments in the phase of initial creation. The set is used if this
member is not NULL, otherwise everything works the old way.
- The set of operations on LiveRange used during initial creation (i.e. used by
createDeadDefs and extendToUses) have been reimplemented to use the segment
set if it is available.
- After a live range is created the contents of the set are flushed to the
segment vector, because the set is not as efficient as the vector for the
later uses of the live range. After the flushing, the set is deleted and
cannot be used again.
- The set is only for live ranges computed in
LiveIntervalAnalysis::computeLiveInRegUnits() and getRegUnit() but not in
computeVirtRegs(), because I did not bring any performance benefits to
computeVirtRegs() and for some examples even brought a slow down.
Patch by Vaidas Gasiunas <vaidas.gasiunas@sap.com>
Differential Revision: http://reviews.llvm.org/D6013
llvm-svn: 228421
This function constructs the main liverange by merging all subranges if
subregister liveness tracking is available. This should be slightly
faster to compute instead of performing the liveness calculation again
for the main range. More importantly it avoids cases where the main
liverange would cover positions where no subrange was live. These cases
happened for partial definitions where the actual defined part was dead
and only the undefined parts used later.
The register coalescing requires that every part covered by the main
live range has at least one subrange live.
I also expect this function to become usefull later for places where the
subranges are modified in a way that it is hard to correctly fix the
main liverange in the machine scheduler, we can simply reconstruct it
from subranges then.
llvm-svn: 224806
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...
llvm-svn: 222334
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.
llvm-svn: 203865
LiveRange just manages a list of segments and a list of value numbers
now as LiveInterval did previously, but without having details like spill
weight or a fixed register number.
LiveInterval is now a subclass of LiveRange and simply adds the spill weight
and the register number.
llvm-svn: 192393
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.
llvm-svn: 192392
Now that the LiveDebugVariables pass is running *after* register
coalescing, the ConnectedVNInfoEqClasses class needs to deal with
DBG_VALUE instructions.
This only comes up when rematerialization during coalescing causes the
remaining live range of a virtual register to separate into two
connected components.
llvm-svn: 182592
Rewrite value numbers directly in the 'Other' LiveInterval which is
moribund anyway. This avoids allocating the OtherAssignments vector.
llvm-svn: 175690
