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| author | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2011-09-14 16:45:39 +0000 |
|---|---|---|
| committer | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2011-09-14 16:45:39 +0000 |
| commit | a98af3985696a634295e93db390a18d91845cc27 (patch) | |
| tree | 9dcbe839e766147fd5d6cc189fa1733f854df43d /llvm/lib/CodeGen/MachineDominators.cpp | |
| parent | 1daf07338c43b37cc42f2d4df40e476f34cdcceb (diff) | |
| download | bcm5719-llvm-a98af3985696a634295e93db390a18d91845cc27.tar.gz bcm5719-llvm-a98af3985696a634295e93db390a18d91845cc27.zip | |
Hoist back-copies to the least busy dominator.
When a back-copy is hoisted to the nearest common dominator, keep
looking up the dominator tree for a less loopy dominator, and place the
back-copy there instead.
Don't do this when a single existing back-copy dominates all the others.
Assume the client knows what he is doing, and keep the dominating
back-copy.
This prevents us from hoisting back-copies into loops in most cases. If
a value is defined in a loop with multiple exits, we may still hoist
back-copies into that loop. That is the speed/size tradeoff.
llvm-svn: 139698
Diffstat (limited to 'llvm/lib/CodeGen/MachineDominators.cpp')
0 files changed, 0 insertions, 0 deletions
