when compiling many small functions.

llvm-svn: 129321

weight limit has been exceeded.

llvm-svn: 129305

llvm-svn: 128634

The live range of a virtual register may change which invalidates the cached
interference information.

llvm-svn: 127772

Use the virtual register number as a cache tag instead. They are not reused.

llvm-svn: 127561

The tag is updated whenever the live interval union is changed, and it is tested
before using cached information.

llvm-svn: 125224

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.

llvm-svn: 122034

llvm-svn: 121783

LiveIntervalUnions.

llvm-svn: 121781

llvm-svn: 121410

heuristic to reshuffle register assignments when we can't find an
available reg.

llvm-svn: 121388

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.

llvm-svn: 121344

Minor optimization to the use of IntervalMap iterators. They are fairly
heavyweight, so prefer SI.valid() over SI != end().

llvm-svn: 121217

This speeds up RegAllocBasic by 20%, not counting releaseMemory which becomes
way faster.

llvm-svn: 121201

llvm-svn: 121098

in favor of the widespread llvm style. Capitalize variables and add
newlines for visual parsing. Rename variables for readability.
And other cleanup.

llvm-svn: 120490

it makes no sense for allocation_order iterators to visit reserved regs.
The inline spiller depends on AliasAnalysis.
Manage the Query state to avoid uninitialized or stale results.

llvm-svn: 118800

benchmarks hitting an assertion.
Adds LiveIntervalUnion::collectInterferingVRegs.
Fixes "late spilling" by checking for any unspillable live vregs among
all physReg aliases.

llvm-svn: 118701

(retry now that the windows build is green)

llvm-svn: 118630

-Wnon-virtual-dtor.

llvm-svn: 118616

llvm-svn: 118613

llvm-svn: 118604

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.

llvm-svn: 118423

them, but hopefully we won't. And this is not the right data structure
to do it anyway.

llvm-svn: 117412

llvm-svn: 117384

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.

llvm-svn: 117174