Commit Graph

11 Commits

Author SHA1 Message Date
Jakob Stoklund Olesen
f4afdfc501 Build the Hopfield network incrementally when splitting global live ranges.
It is common for large live ranges to have few basic blocks with register uses
and many live-through blocks without any uses. This approach grows the Hopfield
network incrementally around the use blocks, completely avoiding checking
interference for some through blocks.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129188 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-09 02:59:09 +00:00
Jakob Stoklund Olesen
0bd2bd9ecc Prefer multiplications to divisions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129080 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-07 17:27:48 +00:00
Jakob Stoklund Olesen
7b41fbe872 Extract SpillPlacement::addLinks for handling the special transparent blocks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129079 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-07 17:27:46 +00:00
Jakob Stoklund Olesen
70d4370b47 Keep track of the number of positively biased nodes when adding constraints.
If there are no positive nodes, the algorithm can be aborted early.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129021 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-06 19:14:00 +00:00
Jakob Stoklund Olesen
9efa2a263e Break the spill placement algorithm into three parts: prepare, addConstraints, and finish.
This will allow us to abort the algorithm early if it is determined to be futile.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129020 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-06 19:13:57 +00:00
Jakob Stoklund Olesen
40a42a2cca Precompute block frequencies, pow() isn't free.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126975 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-04 00:58:40 +00:00
Jakob Stoklund Olesen
febb0bd0b9 Trim debugging output.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125802 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-18 00:32:47 +00:00
Jakob Stoklund Olesen
9590c7fbca Silence an MSVC warning
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124798 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-03 17:04:12 +00:00
Jakob Stoklund Olesen
fc7d775178 Divert Hopfield network debug output. It is very noisy.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123859 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-19 23:14:59 +00:00
Jakob Stoklund Olesen
b5fa933343 Add RAGreedy methods for splitting live ranges around regions.
Analyze the live range's behavior entering and leaving basic blocks. Compute an
interference pattern for each allocation candidate, and use SpillPlacement to
find an optimal region where that register can be live.

This code is still not enabled.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123774 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-18 21:13:27 +00:00
Jakob Stoklund Olesen
8bfe50871f Add the SpillPlacement analysis pass.
This pass precomputes CFG block frequency information that can be used by the
register allocator to find optimal spill code placement.

Given an interference pattern, placeSpills() will compute which basic blocks
should have the current variable enter or exit in a register, and which blocks
prefer the stack.

The algorithm is ready to consume block frequencies from profiling data, but for
now it gets by with the static estimates used for spill weights.

This is a work in progress and still not hooked up to RegAllocGreedy.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122938 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-06 01:21:53 +00:00