6f34e317e9
Fix PR3353, infinitely jump threading an infinite loop make from switches.
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llvm-svn: 62529
2009-01-19 21:20:34 +00:00
482eb70a10
Fix PR3298, a crash in Jump Threading. Apparently even
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jump threading can have bugs, who knew? ;-)
llvm-svn: 61983
2009-01-09 06:08:12 +00:00
e598370ae9
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! ;-)
llvm-svn: 60725
2008-12-08 22:44:07 +00:00
8f723670ce
Start simplifying a switch that has a successor that is a switch.
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llvm-svn: 60534
2008-12-04 06:31:07 +00:00
75c2661d24
add a debugging option to help track down j-t problems.
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llvm-svn: 60514
2008-12-04 00:07:59 +00:00
595c7279bd
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.
llvm-svn: 60470
2008-12-03 07:48:08 +00:00
2b07d3ccde
switch a couple more calls to use array_pod_sort.
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llvm-svn: 60337
2008-12-01 06:52:57 +00:00
88a1f0213d
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.
llvm-svn: 60327
2008-12-01 04:48:07 +00:00
8a172daa55
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.
llvm-svn: 60210
2008-11-28 19:54:49 +00:00
5dfbfcd80d
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!
llvm-svn: 60179
2008-11-27 19:25:19 +00:00
72f16e70f0
move FindAvailableLoadedValue from JumpThreading to Transforms/Utils.
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llvm-svn: 60166
2008-11-27 08:10:05 +00:00
99d6809ac1
move MergeBasicBlockIntoOnlyPred to Transforms/Utils.
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llvm-svn: 60162
2008-11-27 07:43:12 +00:00
240051aace
rename ThreadBlock to ProcessBlock, since it does other things than
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just simple threading.
llvm-svn: 60157
2008-11-27 07:20:04 +00:00
98d89d1b1b
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.
llvm-svn: 60148
2008-11-27 05:07:53 +00:00
a79db30d28
Tidy up several unbeseeming casts from pointer to intptr_t.
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llvm-svn: 55779
2008-09-04 17:05:41 +00:00
fa1211f69b
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.
llvm-svn: 53941
2008-07-23 00:34:11 +00:00
698348dfac
Fix some constructs that gcc-4.4 warns about.
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llvm-svn: 51591
2008-05-27 11:50:51 +00:00
f96e1371e8
Tidy up BasicBlock::getFirstNonPHI, and change a bunch of places to
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use it instead of duplicating its functionality.
llvm-svn: 51499
2008-05-23 21:05:58 +00:00
5148a4ba66
Fix typo.
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llvm-svn: 51303
2008-05-20 07:26:45 +00:00
d78c400b5b
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.
llvm-svn: 51017
2008-05-13 00:00:25 +00:00
e7f0afe168
restore doxygen comment.
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llvm-svn: 50881
2008-05-09 04:43:13 +00:00
829046b0b4
Improve pass documentation and comments.
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Patch by Matthijs Kooijman!
llvm-svn: 50861
2008-05-08 17:46:35 +00:00
de68fabb35
fix typo Duncan noticed
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llvm-svn: 50699
2008-05-06 02:31:18 +00:00
8ed8e3d0e6
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.
llvm-svn: 50667
2008-05-05 20:21:22 +00:00
f7de528463
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
llvm-svn: 50251
2008-04-25 04:12:29 +00:00
37e9c187b0
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.
llvm-svn: 50110
2008-04-22 21:40:39 +00:00
d5425e8f8d
Dig through multiple levels of AND to thread jumps if needed.
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llvm-svn: 50106
2008-04-22 20:46:09 +00:00
3df4c15dc7
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.
llvm-svn: 50096
2008-04-22 07:05:46 +00:00
e369c35a84
refactor some code, no functionality change.
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llvm-svn: 50094
2008-04-22 06:36:15 +00:00
bab7bec9c8
fix grammar-o, thanks to Duncan for noticing.
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llvm-svn: 50047
2008-04-21 18:25:01 +00:00
f6236cc2e9
Use the new SplitBlockPredecessors to implement a todo.
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llvm-svn: 50022
2008-04-21 02:57:57 +00:00
ff1c6e388c
finish the first cut of a jump threading pass implementation.
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llvm-svn: 50006
2008-04-20 22:39:42 +00:00
9c1f1a82bf
we can only thread blocks when there is a pred we can determine the succ of.
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llvm-svn: 50003
2008-04-20 21:18:09 +00:00
2115722ffa
improve comments, infrastructure, and add some validity checks for threading.
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Add a cost function.
llvm-svn: 50002
2008-04-20 21:13:06 +00:00
b3b6007c8b
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. :)
llvm-svn: 50000
2008-04-20 20:35:01 +00:00
Chris Lattner