Extract the updateSSA() method from the too long extendRange().
LiveOutCache can be shared among all the new intervals since there is at most
one of the new ranges live out from each basic block.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126818 91177308-0d34-0410-b5e6-96231b3b80d8
This method could probably be used by LiveIntervalAnalysis::shrinkToUses, and
now it can use extendIntervalEndTo() which coalesces ranges.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126803 91177308-0d34-0410-b5e6-96231b3b80d8
The value map is currently not used, all values are 'complex mapped' and
LiveIntervalMap::mapValue is used to dig them out.
This is the first step in a series changes leading to the removal of
LiveIntervalMap. Its data structures can be shared among all the live intervals
created by a split, so it is wasteful to create a copy for each.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126800 91177308-0d34-0410-b5e6-96231b3b80d8
An original endpoint is an instruction that killed or defined the original live
range before any live ranges were split.
When splitting global live ranges, avoid creating local live ranges without any
original endpoints. We may still create global live ranges without original
endpoints, but such a range won't be split again, and live range splitting still
terminates.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126151 91177308-0d34-0410-b5e6-96231b3b80d8
Loop splitting is better handled by the more generic global region splitting
based on the edge bundle graph.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125243 91177308-0d34-0410-b5e6-96231b3b80d8
If a live range is used by a terminator instruction, and that live range needs
to leave the block on the stack or in a different register, it can be necessary
to have both sides of the split live at the terminator instruction.
Example:
%vreg2 = COPY %vreg1
JMP %vreg1
Becomes after spilling %vreg2:
SPILL %vreg1
JMP %vreg1
The spill doesn't kill the register as is normally the case.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125102 91177308-0d34-0410-b5e6-96231b3b80d8
A live range cannot be split everywhere in a basic block. A split must go before
the first terminator, and if the variable is live into a landing pad, the split
must happen before the call that can throw.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124894 91177308-0d34-0410-b5e6-96231b3b80d8
If the found value is not live-through the block, we should only add liveness up
to the requested slot index. When the value is live-through, the whole block
should be colored.
Bug found by SSA verification in the machine code verifier.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124812 91177308-0d34-0410-b5e6-96231b3b80d8
These end points come from the inserted copies, and can be passed directly to
useIntv. This simplifies the coloring code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124799 91177308-0d34-0410-b5e6-96231b3b80d8
The greedy register allocator revealed some problems with the value mapping in
SplitKit. We would sometimes start mapping values before all defs were known,
and that could change a value from a simple 1-1 mapping to a multi-def mapping
that requires ssa update.
The new approach collects all defs and register assignments first without
filling in any live intervals. Only when finish() is called, do we compute
liveness and mapped values. At this time we know with certainty which values map
to multiple values in a split range.
This also has the advantage that we can compute live ranges based on the
remaining uses after rematerializing at split points.
The current implementation has many opportunities for compile time optimization.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124765 91177308-0d34-0410-b5e6-96231b3b80d8
Jakob Stoklund Olesen
Eric Christopher