Commit Graph

12 Commits

Author SHA1 Message Date
Jakob Stoklund Olesen 96eebf0b14 Convert RAGreedy to LiveRegMatrix interference checking.
Stop depending on the LiveIntervalUnions in RegAllocBase, they are about
to be removed.

The changes are mostly replacing register alias iterators with regunit
iterators, and querying LiveRegMatrix instrad of RegAllocBase.

InterferenceCache is converted to work with per-regunit
LiveIntervalUnions, and it checks fixed regunit interference separately,
using the fixed live intervals provided by LiveIntervalAnalysis.

The local splitting helper calcGapWeights() is also considering fixed
regunit interference which is kept on the side now.

llvm-svn: 158867
2012-06-20 22:52:26 +00:00
Jakob Stoklund Olesen a16ae59722 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.

llvm-svn: 150259
2012-02-10 18:58:34 +00:00
Jakob Stoklund Olesen b7c1715df1 Remove unused variable.
llvm-svn: 150258
2012-02-10 18:52:15 +00:00
Jakob Stoklund Olesen cacefc7dca Allow null interference cursors to be queried.
They always report 'no interference'.

llvm-svn: 135843
2011-07-23 03:10:17 +00:00
Jakob Stoklund Olesen a153ca5885 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.

llvm-svn: 135130
2011-07-14 05:35:11 +00:00
Jakob Stoklund Olesen 1d4badae74 Revert r135121 which broke a gcc-4.2 builder.
llvm-svn: 135122
2011-07-14 00:58:38 +00:00
Jakob Stoklund Olesen c270cb6e94 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.

llvm-svn: 135121
2011-07-14 00:31:14 +00:00
Jakob Stoklund Olesen d7e9937175 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.

llvm-svn: 135113
2011-07-14 00:17:10 +00:00
Jakob Stoklund Olesen fae30b240b Revert r135074 and r135080. They broke clamscan.
llvm-svn: 135096
2011-07-13 22:20:09 +00:00
Jakob Stoklund Olesen 7bb72e2824 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.

llvm-svn: 135074
2011-07-13 20:14:52 +00:00
Jakob Stoklund Olesen 4ad6c160a5 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.

llvm-svn: 129187
2011-04-09 02:59:05 +00:00
Jakob Stoklund Olesen 91cbcaf957 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.

llvm-svn: 128764
2011-04-02 06:03:35 +00:00