Commit Graph

28 Commits

Author SHA1 Message Date
Bob Wilson d1b38e317d Combine the implementations of the core part of the SSAUpdater and
MachineSSAUpdater to avoid duplicating all the code.

llvm-svn: 103060
2010-05-04 23:18:19 +00:00
Bob Wilson 4c7f50afb8 Fix a performance problem with the new SSAUpdater. This showed up in the
GCCAS time for MultiSource/Benchmarks/ASCI_Purple/SMG2000.

llvm-svn: 102009
2010-04-21 18:39:03 +00:00
Bob Wilson ca51425d94 Re-commit my previous SSAUpdater changes. The previous version naively tried
to determine where to place PHIs by iteratively comparing reaching definitions
at each block.  That was just plain wrong.  This version now computes the
dominator tree within the subset of the CFG where PHIs may need to be placed,
and then places the PHIs in the iterated dominance frontier of each definition.
The rest of the patch is mostly the same, with a few more performance
improvements added in.

llvm-svn: 101612
2010-04-17 03:08:24 +00:00
Bob Wilson f1aa4743d9 Revert all my SSAUpdater patches. The PHI placement algorithm is not correct
(what was I thinking?) and there's also a problem with LCSSA.  I'll try again
later with fixes.

--- Reverse-merging r100263 into '.':
U    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100177 into '.':
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100148 into '.':
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100147 into '.':
U    include/llvm/Transforms/Utils/SSAUpdater.h
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100131 into '.':
G    include/llvm/Transforms/Utils/SSAUpdater.h
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100130 into '.':
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100126 into '.':
G    include/llvm/Transforms/Utils/SSAUpdater.h
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100050 into '.':
D    test/Transforms/GVN/2010-03-31-RedundantPHIs.ll
--- Reverse-merging r100047 into '.':
G    include/llvm/Transforms/Utils/SSAUpdater.h
G    lib/Transforms/Utils/SSAUpdater.cpp

llvm-svn: 100264
2010-04-03 03:50:38 +00:00
Bob Wilson 25f1aefd5b Add a DEBUG_TYPE for the SSAUpdater.
llvm-svn: 100263
2010-04-03 03:28:44 +00:00
Bob Wilson 3c54edf9b3 Recommit 100158 now that the buildbots are happy again.
llvm-svn: 100177
2010-04-02 05:09:46 +00:00
Bob Wilson 0389adcd73 Revert 100158 in case it is causing some of the buildbot problems.
llvm-svn: 100164
2010-04-02 01:22:49 +00:00
Bob Wilson 9af4e118c6 Check for terminating conditions before adding PHIs to the worklists.
This is more efficient than adding them to the worklist and then ignoring them.

llvm-svn: 100158
2010-04-02 00:10:41 +00:00
Bob Wilson 737195069a Remove trailing whitespace.
llvm-svn: 100148
2010-04-01 23:06:38 +00:00
Bob Wilson 37b73d9d3e Rewrite another SSAUpdater function to avoid recursion.
llvm-svn: 100147
2010-04-01 23:05:58 +00:00
Bob Wilson 8409feadf0 Change another SSAUpdater function to avoid recursion.
llvm-svn: 100131
2010-04-01 20:04:30 +00:00
Bob Wilson 043c0406f7 Simplify the code to check for existing PHIs, now that it is only used in
one place.  This removes the template function added in svn 94690.

llvm-svn: 100130
2010-04-01 19:53:48 +00:00
Bob Wilson 38fc88ee5d The SSAUpdater should avoid recursive traversals of the CFG, since that may
blow out the stack for really big functions.  Start by fixing an easy case.

llvm-svn: 100126
2010-04-01 18:46:59 +00:00
Bob Wilson ac229124f4 Rewrite part of the SSAUpdater to be more careful about inserting redundant
PHIs.  The previous algorithm was unable to reliably detect when existing
PHIs in a cycle can be reused.  I'm still working on reducing a testcase.
Radar 7711900.

llvm-svn: 100047
2010-03-31 20:51:00 +00:00
Bob Wilson 7577e948e4 Avoid creating redundant PHIs in SSAUpdater::GetValueInMiddleOfBlock.
This was already being done in SSAUpdater::GetValueAtEndOfBlock so I've
just changed SSAUpdater to check for existing PHIs in both places.

llvm-svn: 94690
2010-01-27 22:01:02 +00:00
David Greene 3774a38fdf Change errs() to dbgs().
llvm-svn: 92603
2010-01-05 01:26:49 +00:00
Chris Lattner eaa25da8bb improve indentation avoid a pointless conversion from weakvh to trackingvh,
no functionality change.

llvm-svn: 91848
2009-12-21 22:43:03 +00:00
Chris Lattner 8fb07c5a21 fix PR5837 by having SSAUpdate reuse phi nodes for the
'GetValueInMiddleOfBlock' case, instead of inserting 
duplicates.

A similar fix is almost certainly needed by the machine-level
SSAUpdate implementation.

llvm-svn: 91820
2009-12-21 07:16:11 +00:00
Chris Lattner 2bd9609992 add an assert to make it really clear what this is doing. Return singularval as
a compile time perf optimization to avoid a load.

llvm-svn: 90507
2009-12-04 01:03:32 +00:00
Chris Lattner 7f903681ac alternate fix for PR5258 which avoids worklist problems, with reduced testcase.
llvm-svn: 84667
2009-10-20 20:27:49 +00:00
Torok Edwin cf10ec951d Fix PR5258, jump-threading creating invalid PHIs.
When an incoming value for a PHI is updated, we must also updated all other
incoming values for the same BB to match, otherwise we create invalid PHIs.

llvm-svn: 84638
2009-10-20 15:42:00 +00:00
Duncan Sands 0058c7bcb0 Strip trailing white space.
llvm-svn: 84256
2009-10-16 15:20:13 +00:00
Chris Lattner 9c382cebc5 add a simple helper method.
llvm-svn: 83745
2009-10-10 23:41:48 +00:00
Chris Lattner 249265de06 add ability for clients of SSAUpdater to find out about the
PHI nodes inserted.

llvm-svn: 83744
2009-10-10 23:15:24 +00:00
Chris Lattner 67cdd8b567 add the ability to get a rewritten value from the middle of a block,
not just at the end.  Add a big comment explaining when this could
be useful (which never happens for jump threading).

llvm-svn: 83741
2009-10-10 23:00:11 +00:00
Chris Lattner e474a8d3a7 rename GetValueInBlock -> GetValueAtEndOfBlock to better reflect
what it does.

llvm-svn: 83740
2009-10-10 22:41:58 +00:00
Chris Lattner 65e69a77e1 use a typedef instead of spelling out an insane type. Yay for auto someday.
llvm-svn: 83707
2009-10-10 09:09:20 +00:00
Chris Lattner 60d4e69c81 Implement an efficient and fully general SSA update mechanism that
works on unstructured CFGs.  This implements PR217, our oldest open PR.

llvm-svn: 83705
2009-10-10 09:04:27 +00:00