Dan Gohman
205b641954
Change tests from "opt %s" to "opt < %s" so that opt doesn't see the
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input filename so that opt doesn't print the input filename in the
output so that grep lines in the tests don't unintentionally match
strings in the input filename.
llvm-svn: 81537
2009-09-11 18:01:28 +00:00
Dan Gohman
142428ce64
Eliminate more uses of llvm-as and llvm-dis.
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llvm-svn: 81293
2009-09-09 00:09:15 +00:00
Dan Gohman
c95df8b6d8
Use opt -S instead of piping bitcode output through llvm-dis.
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llvm-svn: 81257
2009-09-08 22:34:10 +00:00
Dan Gohman
8d84372836
Change these tests to feed the assembly files to opt directly, instead
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of using llvm-as, now that opt supports this.
llvm-svn: 81226
2009-09-08 16:50:01 +00:00
Chris Lattner
8f6f044afd
make jump threading handle lexically identical compare instructions
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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.
llvm-svn: 73768
2009-06-19 16:27:56 +00:00
Nick Lewycky
a5f89b09c6
Teach jump threading to look at comparisons between phi nodes and non-constants.
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llvm-svn: 73755
2009-06-19 04:56:29 +00:00
Chris Lattner
6807ddd3d9
* Sink 4 duplicates of edge threading validity checks and DOUT prints into
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ThreadEdge directly. This shares the code, but is just a refactoring.
* Make JumpThreading compute the set of loop headers and avoid threading
across them. This prevents jump threading from forming irreducible
loops (goodness) but also prevents it from threading in other cases that
are beneficial (see the comment above FindFunctionBackedges).
llvm-svn: 70820
2009-05-04 02:28:08 +00:00
Chris Lattner
b88febb5cd
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
Chris Lattner
6140ea4f18
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
Chris Lattner
3f3717a4e2
testcase for br undef folding.
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llvm-svn: 60471
2008-12-03 07:48:27 +00:00
Chris Lattner
f00b2f3fb4
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
Chris Lattner
a854ab3760
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
Chris Lattner
73b251b3bf
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
Chris Lattner
532458b89f
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
Chris Lattner
50d16c2939
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
Chris Lattner
1a6268f776
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
Chris Lattner
e304ae5621
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
Chris Lattner
c59cf9c8da
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
Chris Lattner
dcbc6443ae
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
Chris Lattner
4638234905
add a basic testcase.
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llvm-svn: 50093
2008-04-22 06:35:14 +00:00