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
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
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
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
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
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
