Commit Graph

162 Commits

Author SHA1 Message Date
Chris Lattner
433a0dbb26 Change jump threading to use the new SSAUpdater class instead of
DemoteRegToStack.  This makes it more efficient (because it isn't
creating a ton of load/stores that are eventually removed by a later
mem2reg), and more slightly more effective (because those load/stores
don't get in the way of threading).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83706 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-10 09:05:58 +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
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
Owen Anderson
5defacc6e6 Move getTrue() and getFalse() to 2.5-like APIs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77685 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-31 17:39:07 +00:00
Owen Anderson
9e9a0d5fc2 Move more code back to 2.5 APIs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77635 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-30 23:03:37 +00:00
Owen Anderson
baf3c40440 Move ConstantExpr to 2.5 API.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77494 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-29 18:55:55 +00:00
Daniel Dunbar
460f656475 Remove Value::getName{Start,End}, the last of the old Name APIs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77152 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-26 09:48:23 +00:00
Daniel Dunbar
93b67e40de Eliminate some uses of DOUT, cerr, and getNameStart().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77145 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-26 07:49:05 +00:00
Owen Anderson
eed707b1e6 Revert the ConstantInt constructors back to their 2.5 forms where possible, thanks to contexts-on-types. More to come.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77011 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-24 23:12:02 +00:00
Dan Gohman
02a436c48e Convert several more passes to use getAnalysisIfAvailable<TargetData>()
instead of getAnalysis<TargetData>().


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76982 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-24 18:13:53 +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
b3056faa55 Rename getConstantInt{True|False} to get{True|False} at Chris' behest.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76598 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-21 18:03:38 +00:00
Owen Anderson
50dead06ff Revert yesterday's change by removing the LLVMContext parameter to AllocaInst and MallocInst.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75863 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-15 23:53:25 +00:00
Owen Anderson
9adc0abad3 Move EVER MORE stuff over to LLVMContext.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75703 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-14 23:09:55 +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
Owen Anderson
07cf79ef53 "LLVMContext* " --> "LLVMContext *"
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74878 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-06 23:00:19 +00:00
Owen Anderson
508955156a Thread LLVMContext through the constant folding APIs, which touches a lot of files.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74844 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-06 18:42:36 +00:00
Owen Anderson
1ff50b380e Second batch of passes using LLVMContext.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74753 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-03 00:54:20 +00:00
Chris Lattner
62c762f329 fix inverted logic pointed out by John McCall, noticed by inspection.
This was considering vector intrinsics to have cost 2, but non-vector
intrinsics to have cost 1, which is backward.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74698 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-02 15:39:39 +00:00
Dan Gohman
f530c92cd5 Fix a bunch of other places that used operator[] to test whether
a key is present in a std::map or DenseMap to use find instead.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74676 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-02 00:17:47 +00:00
Chris Lattner
79c740ff47 make jump threading handle lexically identical compare instructions
as if they were multiple uses of the same instruction.  This interacts
well with the existing loadpre that j-t does to open up many new jump
threads earlier.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73768 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-19 16:27:56 +00:00
Nick Lewycky
9683f18174 Teach jump threading to look at comparisons between phi nodes and non-constants.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73755 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-19 04:56:29 +00:00
Mike Stump
fe095f39e7 Restore minor deletion.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70892 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-04 18:40:41 +00:00
Dale Johannesen
6b23339502 Fix a debug info dependency in jump threading.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67064 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-17 00:38:24 +00:00
Chris Lattner
0070ce511e this wasn't intended to go in.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66252 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-06 05:42:30 +00:00
Chris Lattner
cc14d25dd9 Change various llvm utilities to use PrettyStackTraceProgram in
their main routines.  This makes the tools print their argc/argv
commands if they crash.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66248 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-06 05:34:10 +00:00
Chris Lattner
2c7ed11d93 Fix PR3353, infinitely jump threading an infinite loop make from switches.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62529 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-19 21:20:34 +00:00
Chris Lattner
2a99b482a6 Fix PR3298, a crash in Jump Threading. Apparently even
jump threading can have bugs, who knew? ;-)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61983 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-09 06:08:12 +00:00
Chris Lattner
20fa76ef6f remove DebugIterations option. Despite the accusations,
jump threading has been shown to only expose problems not
have bugs itself.  I'm sure it's completely bug free! ;-)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60725 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-08 22:44:07 +00:00
Chris Lattner
3cda3cdab1 Start simplifying a switch that has a successor that is a switch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60534 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-04 06:31:07 +00:00
Chris Lattner
77ee977fcf add a debugging option to help track down j-t problems.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60514 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-04 00:07:59 +00:00
Chris Lattner
421fa9e32e Teach jump threading some more simple tricks:
1) have it fold "br undef", which does occur with
   surprising frequency as jump threading iterates.
2) teach j-t to delete dead blocks.  This removes the successor
   edges, reducing the in-edges of other blocks, allowing 
   recursive simplification.
3) Fold things like:
     br COND, BBX, BBY
  BBX:
     br COND, BBZ, BBW

   which also happens because jump threading iterates.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60470 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-03 07:48:08 +00:00
Chris Lattner
a3522000ab switch a couple more calls to use array_pod_sort.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60337 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-01 06:52:57 +00:00
Chris Lattner
ef0c6744d5 Teach jump threading to clean up after itself, DCE and constfolding the
new instructions it simplifies.  Because we're threading jumps on edges
with constants coming in from PHI's, we inherently are exposing a lot more
constants to the new block.  Folding them and deleting dead conditions
allows the cost model in jump threading to be more accurate as it iterates.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60327 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-01 04:48:07 +00:00
Chris Lattner
f5102a0f08 don't call MergeBasicBlockIntoOnlyPred on a block whose only
predecessor is itself.  This doesn't make sense, and this is
a dead infinite loop anyway.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60210 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-28 19:54:49 +00:00
Chris Lattner
3d86d242c6 Fix PR3138: if we merge the entry block into another block, make sure to
move the other block back up into the entry position!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60179 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-27 19:25:19 +00:00
Chris Lattner
52c95856b4 move FindAvailableLoadedValue from JumpThreading to Transforms/Utils.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60166 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-27 08:10:05 +00:00
Chris Lattner
b29714a10a move MergeBasicBlockIntoOnlyPred to Transforms/Utils.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60162 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-27 07:43:12 +00:00
Chris Lattner
c7bcbf6903 rename ThreadBlock to ProcessBlock, since it does other things than
just simple threading.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60157 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-27 07:20:04 +00:00
Chris Lattner
69e067fdd8 Make jump threading substantially more powerful, in the following ways:
1. Make it fold blocks separated by an unconditional branch.  This enables
   jump threading to see a broader scope.
2. Make jump threading able to eliminate locally redundant loads when they
   feed the branch condition of a block.  This frequently occurs due to
   reg2mem running.
3. Make jump threading able to eliminate *partially redundant* loads when
   they feed the branch condition of a block.  This is common in code with
   lots of loads and stores like C++ code and 255.vortex.

This implements thread-loads.ll and rdar://6402033.

Per the fixme's, several pieces of this should be moved into Transforms/Utils.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60148 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-27 05:07:53 +00:00
Dan Gohman
ae73dc1448 Tidy up several unbeseeming casts from pointer to intptr_t.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55779 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-04 17:05:41 +00:00
Dan Gohman
fc74abfba5 Enable first-class aggregates support.
Remove the GetResultInst instruction. It is still accepted in LLVM assembly
and bitcode, where it is now auto-upgraded to ExtractValueInst. Also, remove
support for return instructions with multiple values. These are auto-upgraded
to use InsertValueInst instructions.

The IRBuilder still accepts multiple-value returns, and auto-upgrades them
to InsertValueInst instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53941 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-23 00:34:11 +00:00
Duncan Sands
43e2a03530 Fix some constructs that gcc-4.4 warns about.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51591 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-27 11:50:51 +00:00
Dan Gohman
02dea8b39f Tidy up BasicBlock::getFirstNonPHI, and change a bunch of places to
use it instead of duplicating its functionality.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51499 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23 21:05:58 +00:00
Matthijs Kooijman
6e7b322d36 Fix typo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51303 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-20 07:26:45 +00:00
Dan Gohman
844731a7f1 Clean up the use of static and anonymous namespaces. This turned up
several things that were neither in an anonymous namespace nor static
but not intended to be global.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51017 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-13 00:00:25 +00:00
Chris Lattner
94019f8e06 restore doxygen comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50881 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-09 04:43:13 +00:00
Gordon Henriksen
a8a118b68f Improve pass documentation and comments.
Patch by Matthijs Kooijman!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50861 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-08 17:46:35 +00:00
Chris Lattner
9b34849a6b fix typo Duncan noticed
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50699 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-06 02:31:18 +00:00
Chris Lattner
8554cc2ea7 Fix a crash when threading a block that includes a MRV call result.
DemoteRegToStack doesn't work with MRVs yet, because it relies on the
ability to load/store things.

This fixes PR2285.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50667 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-05 20:21:22 +00:00
Chris Lattner
eede65ce6c Don't infininitely thread branches when a threaded edge
goes back to the block, e.g.:

  Threading edge through bool from 'bb37.us.thread3829' to 'bb37.us' with cost: 1, across block:

bb37.us:		; preds = %bb37.us.thread3829, %bb37.us, %bb33
	%D1361.1.us = phi i32 [ %tmp36, %bb33 ], [ %D1361.1.us, %bb37.us ], [ 0, %bb37.us.thread3829 ]		; <i32> [#uses=2]
	%tmp39.us = icmp eq i32 %D1361.1.us, 0		; <i1> [#uses=1]
	br i1 %tmp39.us, label %bb37.us, label %bb42.us



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50251 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-25 04:12:29 +00:00
Chris Lattner
a5ddb59a13 Start doing the significantly useful part of jump threading: handle cases
where a comparison has a phi input and that phi is a constant.  For example,
stuff like:

  Threading edge through bool from 'bb2149' to 'bb2231' with cost: 1, across block:
bb2237:		; preds = %bb2231, %bb2149
	%tmp2328.rle = phi i32 [ %tmp2232, %bb2231 ], [ %tmp2232439, %bb2149 ]		; <i32> [#uses=2]
	%done.0 = phi i32 [ %done.2, %bb2231 ], [ 0, %bb2149 ]		; <i32> [#uses=1]
	%tmp2239 = icmp eq i32 %done.0, 0		; <i1> [#uses=1]
	br i1 %tmp2239, label %bb2231, label %bb2327

or

bb38.i298:		; preds = %bb33.i295, %bb1693
	%tmp39.i296.rle = phi %struct.ibox* [ null, %bb1693 ], [ %tmp39.i296.rle1109, %bb33.i295 ]		; <%struct.ibox*> [#uses=2]
	%minspan.1.i291.reg2mem.1 = phi i32 [ 32000, %bb1693 ], [ %minspan.0.i288, %bb33.i295 ]		; <i32> [#uses=1]
	%tmp40.i297 = icmp eq %struct.ibox* %tmp39.i296.rle, null		; <i1> [#uses=1]
	br i1 %tmp40.i297, label %implfeeds.exit311, label %bb43.i301

This triggers thousands of times in spec.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50110 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-22 21:40:39 +00:00
Chris Lattner
ae65b3c791 Dig through multiple levels of AND to thread jumps if needed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50106 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-22 20:46:09 +00:00
Chris Lattner
6bf77500c6 Teach jump threading to thread through blocks like:
br (and X, phi(Y, Z, false)), label L1, label L2

This triggers once on 252.eon and 6 times on 176.gcc.  Blocks 
in question often look like this:

bb262:		; preds = %bb261, %bb248
	%iftmp.251.0 = phi i1 [ true, %bb261 ], [ false, %bb248 ]		; <i1> [#uses=4]
	%tmp270 = icmp eq %struct.rtx_def* %tmp.0.i, null		; <i1> [#uses=1]
	%bothcond = or i1 %iftmp.251.0, %tmp270		; <i1> [#uses=1]
	br i1 %bothcond, label %bb288, label %bb273

In this case, it is clear that it doesn't matter if tmp.0.i is null when coming from bb261.  When coming from bb248, it is all that matters.


Another random example:

check_asm_operands.exit:		; preds = %check_asm_operands.exit.thr_comm, %bb30.i, %bb12.i, %bb6.i413
	%tmp.0.i420 = phi i1 [ true, %bb6.i413 ], [ true, %bb12.i ], [ true, %bb30.i ], [ false, %check_asm_operands.exit.thr_comm ; <i1> [#uses=1]
	call void @llvm.stackrestore( i8* %savedstack ) nounwind 
	%tmp4389 = icmp eq i32 %added_sets_1.0, 0		; <i1> [#uses=1]
	%tmp4394 = icmp eq i32 %added_sets_2.0, 0		; <i1> [#uses=1]
	%bothcond80 = and i1 %tmp4389, %tmp4394		; <i1> [#uses=1]
	%bothcond81 = and i1 %bothcond80, %tmp.0.i420		; <i1> [#uses=1]
	br i1 %bothcond81, label %bb4398, label %bb4397

Here is the case from 252.eon:

bb290.i.i:		; preds = %bb23.i57.i.i, %bb8.i39.i.i, %bb100.i.i, %bb100.i.i, %bb85.i.i110
	%myEOF.1.i.i = phi i1 [ true, %bb100.i.i ], [ true, %bb100.i.i ], [ true, %bb85.i.i110 ], [ true, %bb8.i39.i.i ], [ false, %bb23.i57.i.i ]		; <i1> [#uses=2]
	%i.4.i.i = phi i32 [ %i.1.i.i, %bb85.i.i110 ], [ %i.0.i.i, %bb100.i.i ], [ %i.0.i.i, %bb100.i.i ], [ %i.3.i.i, %bb8.i39.i.i ], [ %i.3.i.i, %bb23.i57.i.i ]		; <i32> [#uses=3]
	%tmp292.i.i = load i8* %tmp16.i.i100, align 1		; <i8> [#uses=1]
	%tmp293.not.i.i = icmp ne i8 %tmp292.i.i, 0		; <i1> [#uses=1]
	%bothcond.i.i = and i1 %tmp293.not.i.i, %myEOF.1.i.i		; <i1> [#uses=1]
	br i1 %bothcond.i.i, label %bb202.i.i, label %bb301.i.i
  Factoring out 3 common predecessors.

On the path from any blocks other than bb23.i57.i.i, the load and compare 
are dead.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50096 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-22 07:05:46 +00:00
Chris Lattner
d38c14e6ed refactor some code, no functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50094 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-22 06:36:15 +00:00
Chris Lattner
037c781de7 fix grammar-o, thanks to Duncan for noticing.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50047 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-21 18:25:01 +00:00
Chris Lattner
2cc675180b Use the new SplitBlockPredecessors to implement a todo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50022 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-21 02:57:57 +00:00
Chris Lattner
bd3401fa98 finish the first cut of a jump threading pass implementation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50006 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-20 22:39:42 +00:00
Chris Lattner
f9065a904f we can only thread blocks when there is a pred we can determine the succ of.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50003 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-20 21:18:09 +00:00
Chris Lattner
177480b7ed improve comments, infrastructure, and add some validity checks for threading.
Add a cost function.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50002 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-20 21:13:06 +00:00
Chris Lattner
8383a7b7a6 Add a new Jump Threading pass, which will handle cases
such as those in PR2235.  Right now the pass is not very
effective. :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50000 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-20 20:35:01 +00:00