Commit Graph

16 Commits

Author SHA1 Message Date
Bob Wilson
cb44b28f4d Treat indirect branches specially only during pre-regalloc tail duplication,
not during the later post-alloc tail duplication.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93600 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-16 00:42:25 +00:00
Jakob Stoklund Olesen
057d53993c Simplify logic. Any functional change is unintended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93540 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-15 19:59:57 +00:00
Bob Wilson
bfdcf3bd49 Change pre-regalloc tail duplication to only duplicate indirect branch blocks.
The pre-regalloc pass caused some regressions in both compile time and
performance of the generated code, and it did not improve performance, except
for indirect branches.  I also moved the check for single-block loops to speed
up the common case when running the taildup pass before reg allocation.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93505 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-15 06:29:17 +00:00
Jakob Stoklund Olesen
30ac0467ce Add Target hook to duplicate machine instructions.
Some instructions refer to unique labels, and so cannot be trivially cloned
with CloneMachineInstr.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92873 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-06 23:47:07 +00:00
David Greene
00dec1bbf9 Change errs() to dbgs().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92582 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 01:25:15 +00:00
Evan Cheng
3466f13f38 Tail duplication should zap a copy it inserted for SSA update if the copy is the only use of its source.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91390 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-15 01:44:10 +00:00
Evan Cheng
80564f761a Delete code accidentally left behind.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90804 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-07 21:19:33 +00:00
Evan Cheng
75eb535843 Pre-regalloc tale duplication. Work in progress.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90759 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-07 10:15:19 +00:00
Evan Cheng
11572babb1 Handle recursive PHI's.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90575 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-04 19:09:10 +00:00
Evan Cheng
79fc6f44b6 Add a pre-regalloc tail duplication pass.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90567 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-04 09:42:45 +00:00
Evan Cheng
111e7629cc Teach tail duplication to update SSA form. Work in progress.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90432 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-03 08:43:53 +00:00
Bob Wilson
f1e01dcc94 Don't count PHI instructions toward the limit for tail duplicating a block.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90326 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-02 17:15:24 +00:00
Bob Wilson
3858225afc Reprioritize tests for tail duplication to be aggressive about indirect
branches even when optimizing for code size.  Unless we find evidence to the
contrary in the future, the special treatment for indirect branches does not
have a significant effect on code size, and performance still matters with -Os.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90147 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-30 18:56:45 +00:00
Bob Wilson
15217e63bc Remove isProfitableToDuplicateIndirectBranch target hook. It is profitable
for all the processors where I have tried it, and even when it might not help
performance, the cost is quite low.  The opportunities for duplicating
indirect branches are limited by other factors so code size does not change
much due to tail duplicating indirect branches aggressively.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90144 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-30 18:35:03 +00:00
Bob Wilson
2d521e51ac Rename new TailDuplicationPass to avoid name conflict with the old one.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89968 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-26 21:38:41 +00:00
Bob Wilson
15acadde5f Split tail duplication into a separate pass. This is needed to avoid
running tail duplication when doing branch folding for if-conversion, and
we also want to be able to run tail duplication earlier to fix some
reg alloc problems.  Move the CanFallThrough function from BranchFolding
to MachineBasicBlock so that it can be shared by TailDuplication.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89904 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-26 00:32:21 +00:00