Commit Graph

91 Commits

Author SHA1 Message Date
Devang Patel
3fc178ffda Do not hoist @llvm.dbg.value. Here, @llvm.dbg.value is "referring" a value that is modified inside loop.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125529 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-14 23:03:23 +00:00
Chris Lattner
93767fdb61 remove a bogus assertion: the latch block of a loop is not
neccesarily an uncond branch to the header.  This fixes 
PR8955 (the assertion tripping).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123219 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-11 07:47:59 +00:00
Chris Lattner
5d37370a6f When loop rotation happens, it is *very* common for the duplicated condbr
to be foldable into an uncond branch.  When this happens, we can make a
much simpler CFG for the loop, which is important for nested loop cases
where we want the outer loop to be aggressively optimized.

Handle this case more aggressively.  For example, previously on
phi-duplicate.ll we would get this:


define void @test(i32 %N, double* %G) nounwind ssp {
entry:
  %cmp1 = icmp slt i64 1, 1000
  br i1 %cmp1, label %bb.nph, label %for.end

bb.nph:                                           ; preds = %entry
  br label %for.body

for.body:                                         ; preds = %bb.nph, %for.cond
  %j.02 = phi i64 [ 1, %bb.nph ], [ %inc, %for.cond ]
  %arrayidx = getelementptr inbounds double* %G, i64 %j.02
  %tmp3 = load double* %arrayidx
  %sub = sub i64 %j.02, 1
  %arrayidx6 = getelementptr inbounds double* %G, i64 %sub
  %tmp7 = load double* %arrayidx6
  %add = fadd double %tmp3, %tmp7
  %arrayidx10 = getelementptr inbounds double* %G, i64 %j.02
  store double %add, double* %arrayidx10
  %inc = add nsw i64 %j.02, 1
  br label %for.cond

for.cond:                                         ; preds = %for.body
  %cmp = icmp slt i64 %inc, 1000
  br i1 %cmp, label %for.body, label %for.cond.for.end_crit_edge

for.cond.for.end_crit_edge:                       ; preds = %for.cond
  br label %for.end

for.end:                                          ; preds = %for.cond.for.end_crit_edge, %entry
  ret void
}

Now we get the much nicer:

define void @test(i32 %N, double* %G) nounwind ssp {
entry:
  br label %for.body

for.body:                                         ; preds = %entry, %for.body
  %j.01 = phi i64 [ 1, %entry ], [ %inc, %for.body ]
  %arrayidx = getelementptr inbounds double* %G, i64 %j.01
  %tmp3 = load double* %arrayidx
  %sub = sub i64 %j.01, 1
  %arrayidx6 = getelementptr inbounds double* %G, i64 %sub
  %tmp7 = load double* %arrayidx6
  %add = fadd double %tmp3, %tmp7
  %arrayidx10 = getelementptr inbounds double* %G, i64 %j.01
  store double %add, double* %arrayidx10
  %inc = add nsw i64 %j.01, 1
  %cmp = icmp slt i64 %inc, 1000
  br i1 %cmp, label %for.body, label %for.end

for.end:                                          ; preds = %for.body
  ret void
}

With all of these recent changes, we are now able to compile:

void foo(char *X) {
 for (int i = 0; i != 100; ++i) 
   for (int j = 0; j != 100; ++j)
     X[j+i*100] = 0;
}

into a single memset of 10000 bytes.  This series of changes
should also be helpful for other nested loop scenarios as well.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123079 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-08 19:59:06 +00:00
Chris Lattner
64c24db959 split ssa updating code out to its own helper function. Don't bother
moving the OrigHeader block anymore: we just merge it away anyway so
its code layout doesn't matter.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123077 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-08 19:26:33 +00:00
Chris Lattner
883401a72f Implement a TODO: Enhance loopinfo to merge away the unconditional branch
that it was leaving in loops after rotation (between the original latch
block and the original header.

With this change, it is possible for rotated loops to have just a single
basic block, which is useful.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123075 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-08 19:10:28 +00:00
Chris Lattner
a1ae0c74af inline preserveCanonicalLoopForm now that it is simple.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123073 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-08 18:55:50 +00:00
Chris Lattner
0e4a1543ab Three major changes:
1. Rip out LoopRotate's domfrontier updating code.  It isn't
   needed now that LICM doesn't use DF and it is super complex
   and gross.
2. Make DomTree updating code a lot simpler and faster.  The 
   old loop over all the blocks was just to find a block??
3. Change the code that inserts the new preheader to just use
   SplitCriticalEdge instead of doing an overcomplex 
   reimplementation of it.

No behavior change, except for the name of the inserted preheader.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123072 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-08 18:52:51 +00:00
Chris Lattner
2aa6908231 LoopRotate requires canonical loop form, so it always has preheaders
and latch blocks.  Reorder entry conditions to make hte pass faster
and more logical.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123069 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-08 18:06:22 +00:00
Chris Lattner
66fe0ded05 use the LI ivar.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123068 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-08 17:49:51 +00:00
Chris Lattner
4aefc9bf1b some cleanups: remove dead arguments and eliminate ivars
that are just passed to one function.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123067 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-08 17:48:33 +00:00
Chris Lattner
012ca949af fix an issue duncan pointed out, which could cause loop rotate
to violate LCSSA form


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123066 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-08 17:38:45 +00:00
Chris Lattner
d9ec3572f3 Have loop-rotate simplify instructions (yay instsimplify!) as it clones
them into the loop preheader, eliminating silly instructions like
"icmp i32 0, 100" in fixed tripcount loops.  This also better exposes the 
bigger problem with loop rotate that I'd like to fix: once this has been
folded, the duplicated conditional branch *often* turns into an uncond branch.

Not aggressively handling this is pessimizing later loop optimizations 
somethin' fierce by making "dominates all exit blocks" checks fail.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123060 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-08 08:24:46 +00:00
Chris Lattner
b5fa5fcecc Revamp the ValueMapper interfaces in a couple ways:
1. Take a flags argument instead of a bool.  This makes
   it more clear to the reader what it is used for.
2. Add a flag that says that "remapping a value not in the
   map is ok".
3. Reimplement MapValue to share a bunch of code and be a lot
   more efficient.  For lookup failures, don't drop null values
   into the map.
4. Using the new flag a bunch of code can vaporize in LinkModules
   and LoopUnswitch, kill it.

No functionality change.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123058 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-08 08:15:20 +00:00
Chris Lattner
6ccb365293 two minor changes: switch to the standard ValueToValueMapTy
map from ValueMapper.h (giving us access to its utilities)
and add a fastpath in the loop rotation code, avoiding expensive
ssa updator manipulation for values with nothing to update.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123057 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-08 07:21:31 +00:00
Chris Lattner
9fc5cdf77c split dom frontier handling stuff out to its own DominanceFrontier header,
so that Dominators.h is *just* domtree.  Also prune #includes a bit.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122714 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 22:09:33 +00:00
Chris Lattner
d9e079706e improve loop rotation to use CodeMetrics to analyze the
size of a loop header instead of its own code size estimator.
This allows it to handle bitcasts etc more precisely.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122681 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 07:35:53 +00:00
Owen Anderson
205942a4a5 Passes do not need to recursively initialize passes that they preserve, if
they do not also require them.  This allows us to reduce inter-pass linkage
dependencies.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116854 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-19 20:08:44 +00:00
Owen Anderson
081c34b725 Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which
must be called in the pass's constructor.  This function uses static dependency declarations to recursively initialize
the pass's dependencies.

Clients that only create passes through the createFooPass() APIs will require no changes.  Clients that want to use the
CommandLine options for passes will need to manually call the appropriate initialization functions in PassInitialization.h
before parsing commandline arguments.

I have tested this with all standard configurations of clang and llvm-gcc on Darwin.  It is possible that there are problems
with the static dependencies that will only be visible with non-standard options.  If you encounter any crash in pass
registration/creation, please send the testcase to me directly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116820 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-19 17:21:58 +00:00
Owen Anderson
2ab36d3502 Begin adding static dependence information to passes, which will allow us to
perform initialization without static constructors AND without explicit initialization
by the client.  For the moment, passes are required to initialize both their
(potential) dependencies and any passes they preserve.  I hope to be able to relax
the latter requirement in the future.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116334 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-12 19:48:12 +00:00
Owen Anderson
ce665bd2e2 Now with fewer extraneous semicolons!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115996 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-07 22:25:06 +00:00
Chris Lattner
50fb46983c Teach loop rotate to hoist trivially invariant instructions
in the duplicated block instead of duplicating them.  

Duplicating them into the end of the loop and the preheader 
means that we got a phi node in the header of the loop, 
which prevented LICM from hoisting them.  GVN would
usually come around later and merge the duplicated 
instructions so we'd get reasonable output... except that
anything dependent on the shoulda-been-hoisted value can't
be hoisted.  In PR5319 (which this fixes), a memory value
didn't get promoted.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113134 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-06 01:10:22 +00:00
Duncan Sands
fc6e29d4ab Reapply commit 112699, speculatively reverted by echristo, since
I'm sure it is harmless.  Original commit message:
If PrototypeValue is erased in the middle of using the SSAUpdator
then the SSAUpdator may access freed memory.  Instead, simply pass
in the type and name explicitly, which is all that was used anyway.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112810 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-02 08:14:03 +00:00
Eric Christopher
adc581f5cb Speculatively revert 112699 and 112702, they seem to be causing
self host errors on clang-x86-64.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112719 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-01 17:29:10 +00:00
Duncan Sands
4d588bceb0 If PrototypeValue is erased in the middle of using the SSAUpdator
then the SSAUpdator may access freed memory.  Instead, simply pass
in the type and name explicitly, which is all that was used anyway.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112699 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-01 10:29:33 +00:00
Dan Gohman
fc8042a122 When rotating loops, put the original header at the bottom of the
loop, making the resulting loop significantly less ugly.  Also, zap
its trivial PHI nodes, since it's easy.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111255 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-17 17:39:21 +00:00
Owen Anderson
90c579de5a Reapply r110396, with fixes to appease the Linux buildbot gods.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110460 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-06 18:33:48 +00:00
Owen Anderson
1f74590e9d Revert r110396 to fix buildbots.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110410 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-06 00:23:35 +00:00
Owen Anderson
9ccaf53ada Don't use PassInfo* as a type identifier for passes. Instead, use the address of the static
ID member as the sole unique type identifier.  Clean up APIs related to this change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110396 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-05 23:42:04 +00:00
Owen Anderson
d13db2c59c Fix batch of converting RegisterPass<> to INTIALIZE_PASS().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109045 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-21 22:09:45 +00:00
Dan Gohman
1e381fcd55 Reorder the contents of various getAnalysisUsage functions, eliminating
a redundant loopsimplify run from the default -O2 sequence.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108539 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-16 17:58:45 +00:00
Dan Gohman
fe60104ac9 Use pre-increment instead of post-increment when the result is not used.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106542 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-22 15:08:57 +00:00
Dan Gohman
03e896bd60 Update various Loop optimization passes to cope with the possibility that
LoopSimplify form may not be available.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86175 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-05 21:11:53 +00:00
Dan Gohman
6a02fc3070 Call getAnalysis<LoopInfo> the normal way, instead of asking passed-in
LoopPassManager for it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86163 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-05 19:43:25 +00:00
Dan Gohman
4c7279ac72 Rename forgetLoopBackedgeTakenCount to forgetLoop, because it
clears out more information than just the stored backedge taken count.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85664 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-31 15:04:55 +00:00
Dan Gohman
440e251c75 Fix a typo in a comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85120 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-26 15:55:24 +00:00
Dan Gohman
32663b719b Rename isLoopExit to isLoopExiting, for consistency with the wording
used elsewhere - an exit block is a block outside the loop branched to
from within the loop. An exiting block is a block inside the loop that
branches out.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85019 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-24 23:34:26 +00:00
Dan Gohman
e6e37b94e8 Rewrite LoopRotation's SSA updating code using SSAUpdater.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85016 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-24 23:19:52 +00:00
Dan Gohman
e6fe67b2fb Tell ScalarEvolution to forget everything it knows about a loop before
rotating the loop, since loop rotation is a very significant change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82901 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-27 15:37:03 +00:00
Nick Lewycky
6776064d19 Instruction::clone does not need to take an LLVMContext&. Remove that and
update all the callers.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82889 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-27 07:38:41 +00:00
Dan Gohman
c292caf55c Fix SplitCriticalEdge to properly update LCSSA form when splitting a
loop exit edge -- new PHIs may be needed not only for the additional
splits that are made to preserve LoopSimplify form, but also for the
original split. Factor out the code that inserts new PHIs so that it
can be used for both. Remove LoopRotation.cpp's code for manually
updating LCSSA form, as it is now redundant. This fixes PR4934.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81363 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-09 18:18:18 +00:00
Chris Lattner
3e8b6631e6 eliminate VISIBILITY_HIDDEN from Transforms/Scalar. PR4861
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80766 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-02 06:11:42 +00:00
Owen Anderson
1d0be15f89 Push LLVMContexts through the IntegerType APIs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78948 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-13 21:58:54 +00:00
Devang Patel
b7f40c1a2a Fix dom frontier update. This fixes PR4667.
Patch by Jakub Staszak.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78388 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-07 17:16:44 +00:00
Owen Anderson
e922c02019 Get rid of the Pass+Context magic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76702 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-22 00:24:57 +00:00
Owen Anderson
333c400965 This started as a small change, I swear. Unfortunately, lots of things call the [I|F]CmpInst constructors. Who knew!?
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75200 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-09 23:48:35 +00:00
Dan Gohman
cfb32203bc More minor code simplifications.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74395 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-27 21:23:40 +00:00
Dan Gohman
e1047fbb97 Change this code to a form about which VC++ reportedly isn't unhappy.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74243 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-26 00:35:12 +00:00
Dan Gohman
30d670f51f Minor code simplification.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74240 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-26 00:26:03 +00:00
Dan Gohman
cc4e605721 Reword a few comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74146 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-25 00:22:44 +00:00
Devang Patel
3f43a7021f Do not count DbgInfoIntrinsic while estimating loop header size.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66245 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-06 03:51:30 +00:00