Chris Lattner
bbc25ff5cc
if jump threading is able to infer interesting values on both
...
the LHS and RHS of an and/or instruction, don't multiply add
known predecessor values. This fixes the crash on testcase
from PR7498
llvm-svn: 108114
2010-07-12 00:47:34 +00:00
Chris Lattner
329ea064ed
jump threading can't split a critical edge from an indirectbr. This
...
fixes PR7356.
llvm-svn: 105950
2010-06-14 19:45:43 +00:00
Dan Gohman
826bdf8c10
Move FindAvailableLoadedValue isSafeToLoadUnconditionally out of
...
lib/Transforms/Utils and into lib/Analysis so that Analysis passes
can use them.
llvm-svn: 104949
2010-05-28 16:19:17 +00:00
Chris Lattner
9ae28b141f
fix PR6743, a case where we'd delete an instruction before using it
...
in some cases.
llvm-svn: 100937
2010-04-10 18:26:57 +00:00
Duncan Sands
19d0b47b1f
There are two ways of checking for a given type, for example isa<PointerType>(T)
...
and T->isPointerTy(). Convert most instances of the first form to the second form.
Requested by Chris.
llvm-svn: 96344
2010-02-16 11:11:14 +00:00
Duncan Sands
9dff9bec31
Uniformize the names of type predicates: rather than having isFloatTy and
...
isInteger, we now have isFloatTy and isIntegerTy. Requested by Chris!
llvm-svn: 96223
2010-02-15 16:12:20 +00:00
Chris Lattner
d924f63692
Make jump threading honor x|undef -> true and x&undef -> false,
...
instead of considering x|undef -> x, which may not be true.
llvm-svn: 95850
2010-02-11 04:40:44 +00:00
Chris Lattner
29b15c5cfd
third bug from PR6119: the xor dupe extension allows
...
for arbitrary terminators in predecessors, don't assume
it is a conditional or uncond branch. The testcase shows
an example where they can happen with switches.
llvm-svn: 94323
2010-01-23 19:21:31 +00:00
Chris Lattner
ba2d0b89ff
add an early out to ProcessBranchOnXOR to speed it up,
...
handle the case when we can infer an input to the xor
from all inputs that agree, instead of going into an
infinite loop. Another part of PR6199
llvm-svn: 94321
2010-01-23 19:16:25 +00:00
Chris Lattner
de5ab4860f
fix a crash in jump threading, PR6119
...
llvm-svn: 94319
2010-01-23 18:56:07 +00:00
Chris Lattner
573da8ac90
1) Use the new SimplifyInstructionsInBlock routine instead of the copy
...
in JT.
2) When cloning blocks for PHI or xor conditions, use
instsimplify to simplify the code as we go. This allows us to
squish common cases early in JT which opens up opportunities for
subsequent iterations, and allows it to completely simplify the
testcase.
llvm-svn: 93253
2010-01-12 20:41:47 +00:00
Chris Lattner
af7855d571
tidy up
...
llvm-svn: 93222
2010-01-12 02:07:50 +00:00
Chris Lattner
eb73bdb2e1
Teach jump threading to duplicate small blocks when the branch
...
condition is a xor with a phi node. This eliminates nonsense
like this from 176.gcc in several places:
LBB166_84:
testl %eax, %eax
- setne %al
- xorb %cl, %al
- notb %al
- testb $1, %al
- je LBB166_85
+ je LBB166_69
+ jmp LBB166_85
This is rdar://7391699
llvm-svn: 93221
2010-01-12 02:07:17 +00:00
Chris Lattner
6a19ed0b86
some cleanup, and make it obvious that ProcessJumpOnPHI only works
...
on branches by renaming it and checking for a branch at the call site.
llvm-svn: 93208
2010-01-11 23:41:09 +00:00
Benjamin Kramer
76e2766442
Use a do-while loop instead of while + boolean.
...
llvm-svn: 92912
2010-01-07 13:50:07 +00:00
David Greene
1efdb45562
Change errs() to dbgs().
...
llvm-svn: 92614
2010-01-05 01:27:19 +00:00
Chris Lattner
f8d22fc77d
Metadata.h doesn't need to include ValueHandle.h anymore.
...
llvm-svn: 92211
2009-12-28 08:20:46 +00:00
Chris Lattner
6d6f10fe91
fix PR5698
...
llvm-svn: 90708
2009-12-06 17:17:23 +00:00
Chris Lattner
3c9aca9079
fix PR5640 by tracking whether a block is the header of a loop more
...
precisely, which prevents us from infinitely peeling the loop.
llvm-svn: 90211
2009-12-01 06:04:43 +00:00
Chris Lattner
9d9812a636
make PRE of loads preserve the alignment of the moved load instruction.
...
llvm-svn: 88865
2009-11-15 19:58:31 +00:00
Chris Lattner
5f037b6439
fix a bug handling 'not x' when x is undef.
...
llvm-svn: 88864
2009-11-15 19:57:43 +00:00
Chris Lattner
5f6b8b2bcb
use getPredicateOnEdge to fold comparisons through PHI nodes,
...
which implements GCC PR18046. This also gets us 360 more
jump threads on 176.gcc.
llvm-svn: 86953
2009-11-12 05:24:05 +00:00
Chris Lattner
22db4b5e0c
various fixes to the lattice transfer functions.
...
llvm-svn: 86952
2009-11-12 04:57:13 +00:00
Chris Lattner
c893c4ed10
switch jump threading to use getPredicateOnEdge in one place
...
making the new LVI stuff smart enough to subsume some special
cases in the old code. Disable them when LVI is around, the
testcase still passes.
llvm-svn: 86951
2009-11-12 04:37:50 +00:00
Chris Lattner
ba45616958
with the new code we can thread non-instruction values. This
...
allows us to handle the test10 testcase.
llvm-svn: 86924
2009-11-12 01:41:34 +00:00
Chris Lattner
3f80d85191
this argument can be an arbitrary value, it doesn't need to be an instruction.
...
llvm-svn: 86923
2009-11-12 01:37:43 +00:00
Chris Lattner
d5e25436a1
expose edge information and switch j-t to use it.
...
llvm-svn: 86920
2009-11-12 01:29:10 +00:00
Chris Lattner
67146695b6
pass TD into a SimplifyCmpInst call. Add another case that
...
uses LVI info when -enable-jump-threading-lvi is passed.
llvm-svn: 86886
2009-11-11 22:31:38 +00:00
Chris Lattner
fde1f8d0d8
stub out some LazyValueInfo interfaces, and have JumpThreading
...
start using them in a trivial way when -enable-jump-threading-lvi
is passed. enable-jump-threading-lvi will be my playground for
awhile.
llvm-svn: 86789
2009-11-11 02:08:33 +00:00
Chris Lattner
3a2ae908fe
add a fixme
...
llvm-svn: 86766
2009-11-11 00:21:58 +00:00
Chris Lattner
9518fbb54e
implement a TODO by teaching jump threading about "xor x, 1".
...
llvm-svn: 86739
2009-11-10 22:39:16 +00:00
Chris Lattner
852d6d64ff
move some generally useful functions out of jump threading
...
into libanalysis and transformutils.
llvm-svn: 86735
2009-11-10 22:26:15 +00:00
Chris Lattner
40b15f220d
improve comment.
...
llvm-svn: 86723
2009-11-10 21:45:09 +00:00
Chris Lattner
80e7e5a429
Make jump threading eliminate blocks that just contain phi nodes,
...
debug intrinsics, and an unconditional branch when possible. This
reuses the TryToSimplifyUncondBranchFromEmptyBlock function split
out of simplifycfg.
llvm-svn: 86722
2009-11-10 21:40:01 +00:00
Chris Lattner
38c44ea6b0
make jump threading recursively simplify expressions instead of doing it
...
just one level deep. On the testcase we go from getting this:
F1: ; preds = %T2
%F = and i1 true, %cond ; <i1> [#uses=1]
br i1 %F, label %X, label %Y
to a fully threaded:
F1: ; preds = %T2
br label %Y
This changes gets us to the point where we're forming (too many) switch
instructions on doug's strswitch testcase.
llvm-svn: 86646
2009-11-10 01:57:31 +00:00
Chris Lattner
be11db6894
don't invalidate PN, rewrite of this code is in progress anyway.
...
llvm-svn: 86639
2009-11-10 01:19:06 +00:00
Chris Lattner
fb7f87d5a3
add a new SimplifyInstruction API, which is like ConstantFoldInstruction,
...
except that the result may not be a constant. Switch jump threading to
use it so that it gets things like (X & 0) -> 0, which occur when phi preds
are deleted and the remaining phi pred was a zero.
llvm-svn: 86637
2009-11-10 01:08:51 +00:00
Chris Lattner
c1f19071f8
rename SimplifyCompare -> SimplifyCmpInst and split it into
...
Simplify[IF]Cmp pieces. Add some predicates to CmpInst to
determine whether a predicate is fp or int.
llvm-svn: 86624
2009-11-09 23:28:39 +00:00
Chris Lattner
800aad3dda
use instructionsimplify instead of a weak clone of ad-hoc folding stuff.
...
llvm-svn: 86616
2009-11-09 23:00:14 +00:00
Chris Lattner
2978ca7b79
stub out a new form of BasicBlock::RemovePredecessorAndSimplify which
...
simplifies instruction users of PHIs when the phi is eliminated. This
will be moved to transforms/utils after some other refactoring.
llvm-svn: 86603
2009-11-09 22:32:36 +00:00
Chris Lattner
ea465e221e
comment typos pointed out by Duncan
...
llvm-svn: 86497
2009-11-09 00:41:49 +00:00
Chris Lattner
5ff7f5672e
reapply 86289, 86278, 86270, 86267, 86266 & 86264 plus a fix
...
(making pred factoring only happen if threading is guaranteed
to be successful).
This now survives an X86-64 bootstrap of llvm-gcc.
llvm-svn: 86355
2009-11-07 08:05:03 +00:00
Devang Patel
3a42e7ac65
Revert following patches to fix llvmgcc bootstrap.
...
86289, 86278, 86270, 86267, 86266 & 86264
Chris, please take a look.
llvm-svn: 86321
2009-11-07 01:32:59 +00:00
Jeffrey Yasskin
8f77e948e5
Avoid "ambiguous 'else'" warning from gcc.
...
llvm-svn: 86314
2009-11-07 00:26:47 +00:00
Chris Lattner
eb690feaef
Fix a bug where we'd call SplitBlockPredecessors with a pred in the
...
set only once even if it has multiple edges to BB.
llvm-svn: 86299
2009-11-06 23:19:58 +00:00
Eli Friedman
a70917b2f4
Remove function left over from other jump threading cleanup.
...
llvm-svn: 86289
2009-11-06 21:24:57 +00:00
Chris Lattner
a8b9ce3f07
Fix a problem discovered on self host.
...
llvm-svn: 86278
2009-11-06 19:21:48 +00:00
Chris Lattner
d91a7960bf
remove more code subsumed by r86264
...
llvm-svn: 86270
2009-11-06 18:24:32 +00:00
Chris Lattner
899ef22acb
eliminate some more code subsumed by r86264
...
llvm-svn: 86267
2009-11-06 18:22:54 +00:00
Chris Lattner
2f6184f6aa
remove now redundant code, r86264 handles this case.
...
llvm-svn: 86266
2009-11-06 18:20:58 +00:00
Chris Lattner
68d2417e05
Extend jump threading to support much more general threading
...
predicates. This allows us to jump thread things like:
_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit119:
%tmp1.i24166 = phi i8 [ 1, %bb5.i117 ], [ %tmp1.i24165, %_Z....exit ], [ %tmp1.i24165, %bb4.i114 ]
%toBoolnot.i87 = icmp eq i8 %tmp1.i24166, 0 ; <i1> [#uses=1]
%tmp4.i90 = icmp eq i32 %tmp2.i, 6 ; <i1> [#uses=1]
%or.cond173 = and i1 %toBoolnot.i87, %tmp4.i90 ; <i1> [#uses=1]
br i1 %or.cond173, label %bb4.i96, label %_ZN12...
Where it is "obvious" that when coming from %bb5.i117 that the 'and' is always
false. This triggers a surprisingly high number of times in the testsuite,
and gets us closer to generating good code for doug's strswitch testcase.
This also make a bunch of other code in jump threading redundant, I'll rip
out in the next patch. This survived an enable-checking llvm-gcc bootstrap.
llvm-svn: 86264
2009-11-06 18:15:14 +00:00
Chris Lattner
46b5c642b9
remove a bunch of extraneous LLVMContext arguments
...
from various APIs, addressing PR5325.
llvm-svn: 86231
2009-11-06 04:27:31 +00:00
Chris Lattner
a09062758b
improve DSE when TargetData is not around, based on work by
...
Hans Wennborg!
llvm-svn: 86067
2009-11-04 23:20:12 +00:00
Chris Lattner
85c85c5e04
when folding duplicate conditions, delete the
...
now-probably-dead instruction tree feeding it.
llvm-svn: 83778
2009-10-11 18:39:58 +00:00
Chris Lattner
97b1405207
implement a transformation in jump threading that is currently
...
done by condprop, but do it in a much more general form. The
basic idea is that we can do a limited form of tail duplication
in the case when we have a branch on a phi. Moving the branch
up in to the predecessor block makes instruction selection
much easier and encourages chained jump threadings.
llvm-svn: 83759
2009-10-11 07:24:57 +00:00
Chris Lattner
6ce85e85f5
restructure some code, no functionality change.
...
llvm-svn: 83756
2009-10-11 04:40:21 +00:00
Chris Lattner
f466bc84c9
factor some code better and move a function, no functionality change.
...
llvm-svn: 83755
2009-10-11 04:33:43 +00:00
Chris Lattner
f99a74e24b
make jump threading on a phi with undef inputs happen.
...
llvm-svn: 83754
2009-10-11 04:18:15 +00:00
Chris Lattner
84095071ea
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).
llvm-svn: 83706
2009-10-10 09:05:58 +00:00
Nick Lewycky
42fb7452df
Instruction::clone does not need to take an LLVMContext&. Remove that and
...
update all the callers.
llvm-svn: 82889
2009-09-27 07:38:41 +00:00
Chris Lattner
2dd09dbdf7
eliminate VISIBILITY_HIDDEN from Transforms/Scalar. PR4861
...
llvm-svn: 80766
2009-09-02 06:11:42 +00:00
Owen Anderson
55f1c09e31
Push LLVMContexts through the IntegerType APIs.
...
llvm-svn: 78948
2009-08-13 21:58:54 +00:00
Owen Anderson
23a204d91b
Move getTrue() and getFalse() to 2.5-like APIs.
...
llvm-svn: 77685
2009-07-31 17:39:07 +00:00
Owen Anderson
b292b8ce70
Move more code back to 2.5 APIs.
...
llvm-svn: 77635
2009-07-30 23:03:37 +00:00
Owen Anderson
487375e9a2
Move ConstantExpr to 2.5 API.
...
llvm-svn: 77494
2009-07-29 18:55:55 +00:00
Daniel Dunbar
6115b39ffd
Remove Value::getName{Start,End}, the last of the old Name APIs.
...
llvm-svn: 77152
2009-07-26 09:48:23 +00:00
Daniel Dunbar
9813b0b025
Eliminate some uses of DOUT, cerr, and getNameStart().
...
llvm-svn: 77145
2009-07-26 07:49:05 +00:00
Owen Anderson
edb4a70325
Revert the ConstantInt constructors back to their 2.5 forms where possible, thanks to contexts-on-types. More to come.
...
llvm-svn: 77011
2009-07-24 23:12:02 +00:00
Dan Gohman
67243a4bec
Convert several more passes to use getAnalysisIfAvailable<TargetData>()
...
instead of getAnalysis<TargetData>().
llvm-svn: 76982
2009-07-24 18:13:53 +00:00
Owen Anderson
47db941fd3
Get rid of the Pass+Context magic.
...
llvm-svn: 76702
2009-07-22 00:24:57 +00:00
Owen Anderson
c37bc69e91
Rename getConstantInt{True|False} to get{True|False} at Chris' behest.
...
llvm-svn: 76598
2009-07-21 18:03:38 +00:00
Owen Anderson
4fdeba9706
Revert yesterday's change by removing the LLVMContext parameter to AllocaInst and MallocInst.
...
llvm-svn: 75863
2009-07-15 23:53:25 +00:00
Owen Anderson
b6b2530000
Move EVER MORE stuff over to LLVMContext.
...
llvm-svn: 75703
2009-07-14 23:09:55 +00:00
Owen Anderson
1e5f00e7a7
This started as a small change, I swear. Unfortunately, lots of things call the [I|F]CmpInst constructors. Who knew!?
...
llvm-svn: 75200
2009-07-09 23:48:35 +00:00
Owen Anderson
38264b1554
"LLVMContext* " --> "LLVMContext *"
...
llvm-svn: 74878
2009-07-06 23:00:19 +00:00
Owen Anderson
39f00cc1d4
Thread LLVMContext through the constant folding APIs, which touches a lot of files.
...
llvm-svn: 74844
2009-07-06 18:42:36 +00:00
Owen Anderson
80baed63b4
Second batch of passes using LLVMContext.
...
llvm-svn: 74753
2009-07-03 00:54:20 +00:00
Chris Lattner
f3f6aaa2c3
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.
llvm-svn: 74698
2009-07-02 15:39:39 +00:00
Dan Gohman
43f33dd550
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.
llvm-svn: 74676
2009-07-02 00:17:47 +00:00
Chris Lattner
d0a363e03b
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.
llvm-svn: 73768
2009-06-19 16:27:56 +00:00
Nick Lewycky
77585a24ac
Teach jump threading to look at comparisons between phi nodes and non-constants.
...
llvm-svn: 73755
2009-06-19 04:56:29 +00:00
Chris Lattner
fa552d728d
fix some problems spotted by Duncan and Nicolas Geoffray
...
llvm-svn: 70872
2009-05-04 16:29:24 +00:00
Chris Lattner
d579cb1167
* Sink 4 duplicates of edge threading validity checks and DOUT prints into
...
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
Dale Johannesen
87077356be
Fix a debug info dependency in jump threading.
...
llvm-svn: 67064
2009-03-17 00:38:24 +00:00
Chris Lattner
e6d1e8d0cc
this wasn't intended to go in.
...
llvm-svn: 66252
2009-03-06 05:42:30 +00:00
Chris Lattner
e3fc2d13be
Change various llvm utilities to use PrettyStackTraceProgram in
...
their main routines. This makes the tools print their argc/argv
commands if they crash.
llvm-svn: 66248
2009-03-06 05:34:10 +00:00
Chris Lattner
6f34e317e9
Fix PR3353, infinitely jump threading an infinite loop make from switches.
...
llvm-svn: 62529
2009-01-19 21:20:34 +00:00
Chris Lattner
482eb70a10
Fix PR3298, a crash in Jump Threading. Apparently even
...
jump threading can have bugs, who knew? ;-)
llvm-svn: 61983
2009-01-09 06:08:12 +00:00
Chris Lattner
e598370ae9
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! ;-)
llvm-svn: 60725
2008-12-08 22:44:07 +00:00
Chris Lattner
8f723670ce
Start simplifying a switch that has a successor that is a switch.
...
llvm-svn: 60534
2008-12-04 06:31:07 +00:00
Chris Lattner
75c2661d24
add a debugging option to help track down j-t problems.
...
llvm-svn: 60514
2008-12-04 00:07:59 +00:00
Chris Lattner
595c7279bd
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.
llvm-svn: 60470
2008-12-03 07:48:08 +00:00
Chris Lattner
2b07d3ccde
switch a couple more calls to use array_pod_sort.
...
llvm-svn: 60337
2008-12-01 06:52:57 +00:00
Chris Lattner
88a1f0213d
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.
llvm-svn: 60327
2008-12-01 04:48:07 +00:00
Chris Lattner
8a172daa55
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.
llvm-svn: 60210
2008-11-28 19:54:49 +00:00
Chris Lattner
5dfbfcd80d
Fix PR3138: if we merge the entry block into another block, make sure to
...
move the other block back up into the entry position!
llvm-svn: 60179
2008-11-27 19:25:19 +00:00
Chris Lattner
72f16e70f0
move FindAvailableLoadedValue from JumpThreading to Transforms/Utils.
...
llvm-svn: 60166
2008-11-27 08:10:05 +00:00
Chris Lattner
99d6809ac1
move MergeBasicBlockIntoOnlyPred to Transforms/Utils.
...
llvm-svn: 60162
2008-11-27 07:43:12 +00:00
Chris Lattner
240051aace
rename ThreadBlock to ProcessBlock, since it does other things than
...
just simple threading.
llvm-svn: 60157
2008-11-27 07:20:04 +00:00
Chris Lattner
98d89d1b1b
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.
llvm-svn: 60148
2008-11-27 05:07:53 +00:00
Dan Gohman
a79db30d28
Tidy up several unbeseeming casts from pointer to intptr_t.
...
llvm-svn: 55779
2008-09-04 17:05:41 +00:00
Dan Gohman
fa1211f69b
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.
llvm-svn: 53941
2008-07-23 00:34:11 +00:00
Duncan Sands
698348dfac
Fix some constructs that gcc-4.4 warns about.
...
llvm-svn: 51591
2008-05-27 11:50:51 +00:00
Dan Gohman
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
Matthijs Kooijman
5148a4ba66
Fix typo.
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llvm-svn: 51303
2008-05-20 07:26:45 +00:00
Dan Gohman
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
Chris Lattner
e7f0afe168
restore doxygen comment.
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llvm-svn: 50881
2008-05-09 04:43:13 +00:00
Gordon Henriksen
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
Chris Lattner
de68fabb35
fix typo Duncan noticed
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llvm-svn: 50699
2008-05-06 02:31:18 +00:00
Chris Lattner
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
Chris Lattner
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
Chris Lattner
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
Chris Lattner
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
Chris Lattner
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
Chris Lattner
e369c35a84
refactor some code, no functionality change.
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llvm-svn: 50094
2008-04-22 06:36:15 +00:00
Chris Lattner
bab7bec9c8
fix grammar-o, thanks to Duncan for noticing.
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llvm-svn: 50047
2008-04-21 18:25:01 +00:00
Chris Lattner
f6236cc2e9
Use the new SplitBlockPredecessors to implement a todo.
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llvm-svn: 50022
2008-04-21 02:57:57 +00:00
Chris Lattner
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
Chris Lattner
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
Chris Lattner
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
Chris Lattner
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