Commit Graph

11 Commits

Author SHA1 Message Date
Jakob Stoklund Olesen
6ef7da0197 Add register mask support to InterferenceCache.
This makes global live range splitting behave identically with and
without register mask operands.

This is not necessarily the best way of using register masks for live
range splitting.  It would be more efficient to first split global live
ranges around calls (i.e., register masks), and reserve the fine grained
per-physreg interference guidance for global live ranges that do not
cross calls.

For now the goal is to produce identical assembly when enabling register
masks.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150259 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-10 18:58:34 +00:00
Jakob Stoklund Olesen
3bf7a1cc3c Remove unused variable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150258 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-10 18:52:15 +00:00
Jakob Stoklund Olesen
c7931fd725 Allow null interference cursors to be queried.
They always report 'no interference'.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135843 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-23 03:10:17 +00:00
Jakob Stoklund Olesen
f1c709837b Reapply r135121 with a fixed copy constructor.
Original commit message:

Count references to interference cache entries.

Each InterferenceCache::Cursor instance references a cache entry. A
non-zero reference count guarantees that the entry won't be reused for a
new register.

This makes it possible to have multiple live cursors examining
interference for different physregs.

The total number of live cursors into a cache must be kept below
InterferenceCache::getMaxCursors().

Code generation should be unaffected by this change, and it doesn't seem
to affect the cache replacement strategy either.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135130 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-14 05:35:11 +00:00
Jakob Stoklund Olesen
4fcfcf4984 Revert r135121 which broke a gcc-4.2 builder.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135122 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-14 00:58:38 +00:00
Jakob Stoklund Olesen
6a9feaac93 Count references to interference cache entries.
Each InterferenceCache::Cursor instance references a cache entry. A
non-zero reference count guarantees that the entry won't be reused for a
new register.

This makes it possible to have multiple live cursors examining
interference for different physregs.

The total number of live cursors into a cache must be kept below
InterferenceCache::getMaxCursors().

Code generation should be unaffected by this change, and it doesn't seem
to affect the cache replacement strategy either.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135121 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-14 00:31:14 +00:00
Jakob Stoklund Olesen
c66a37df73 Reapply r135074 and r135080 with a fix.
The cache entry referenced by the best split candidate could become
clobbered by an unsuccessful candidate.

The correct fix here is to use reference counts on the cache entries.
Coming up.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135113 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-14 00:17:10 +00:00
Jakob Stoklund Olesen
54c74e906a Revert r135074 and r135080. They broke clamscan.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135096 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-13 22:20:09 +00:00
Jakob Stoklund Olesen
1337e2b75a Move the InterferenceCache cursor into the GlobalSplitCand struct.
This is in preparation of supporting multiple global split candidates in
a single live range split operation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135074 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-13 20:14:52 +00:00
Jakob Stoklund Olesen
9d29cbad32 Precompute interference for neighbor blocks as long as there is no interference.
This doesn't require seeking in the live interval union, so it is very cheap.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129187 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-09 02:59:05 +00:00
Jakob Stoklund Olesen
5907d86365 Add an InterferenceCache class for caching per-block interference ranges.
When the greedy register allocator is splitting multiple global live ranges, it
tends to look at the same interference data many times. The InterferenceCache
class caches queries for unaltered LiveIntervalUnions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128764 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-02 06:03:35 +00:00