Chris Lattner
20fa76ef6f
remove DebugIterations option. Despite the accusations,
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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.
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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.
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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:
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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.
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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
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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
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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
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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.
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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.
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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
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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:
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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.
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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.
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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.
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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
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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.
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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
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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.
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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.
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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
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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.
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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
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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
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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.
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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:
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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.
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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.
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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.
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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.
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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.
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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.
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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
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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