The Query class now holds two iterators instead of an InterferenceResult
instance. The iterators are used as bookmarks for repeated
collectInterferingVRegs calls.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137380 91177308-0d34-0410-b5e6-96231b3b80d8
The InterferenceResult iterator turned out to be less important than we
thought it would be. LiveIntervalUnion clients want higher level
information, like the list of interfering virtual registers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137346 91177308-0d34-0410-b5e6-96231b3b80d8
RAGreedy::tryAssign will now evict interference from the preferred
register even when another register is free.
To support this, add the EvictionCost struct that counts how many hints
are broken by an eviction. We don't want to break one hint just to
satisfy another.
Rename canEvict to shouldEvict, and add the first bit of eviction policy
that doesn't depend on spill weights: Always make room in the preferred
register as long as the evictees can be split and aren't already
assigned to their preferred register.
Also make the CSR avoidance more accurate. When looking for a cheaper
register it is OK to use a new volatile register. Only CSR aliases that
have never been used before should be avoided.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134735 91177308-0d34-0410-b5e6-96231b3b80d8
The tag is updated whenever the live interval union is changed, and it is tested
before using cached information.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125224 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123107 91177308-0d34-0410-b5e6-96231b3b80d8
This is a three-way interval list intersection between a virtual register, a
live interval union, and a loop. It will be used to identify interference-free
loops for live range splitting.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122034 91177308-0d34-0410-b5e6-96231b3b80d8
live range splitting around loops guided by register pressure.
So far, trySplit() simply prints a lot of debug output.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121918 91177308-0d34-0410-b5e6-96231b3b80d8
references instead.
Similarly, IntervalMap::begin() is almost as expensive as find(), so use find(x)
instead of begin().advanceTo(x);
This makes RegAllocBasic run another 5% faster.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121344 91177308-0d34-0410-b5e6-96231b3b80d8
in favor of the widespread llvm style. Capitalize variables and add
newlines for visual parsing. Rename variables for readability.
And other cleanup.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120490 91177308-0d34-0410-b5e6-96231b3b80d8
benchmarks hitting an assertion.
Adds LiveIntervalUnion::collectInterferingVRegs.
Fixes "late spilling" by checking for any unspillable live vregs among
all physReg aliases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118701 91177308-0d34-0410-b5e6-96231b3b80d8
handle cases in which a register is unavailable for spill code.
Adds LiveIntervalUnion::extract. While processing interferences on a
live virtual register, reuses the same Query object for each
physcial reg.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118423 91177308-0d34-0410-b5e6-96231b3b80d8
framework. It's purpose is not to improve register allocation per se,
but to make it easier to develop powerful live range splitting. I call
it the basic allocator because it is as simple as a global allocator
can be but provides the building blocks for sophisticated register
allocation with live range splitting.
A minimal implementation is provided that trivially spills whenever it
runs out of registers. I'm checking in now to get high-level design
and style feedback. I've only done minimal testing. The next step is
implementing a "greedy" allocation algorithm that does some register
reassignment and makes better splitting decisions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117174 91177308-0d34-0410-b5e6-96231b3b80d8
