Devang Patel
dd14e0f7fa
Use IRBuilder while simplifying return instruction.
...
llvm-svn: 131580
2011-05-18 21:33:11 +00:00
Devang Patel
583805530c
Spread use of IRBuilder even more.
...
llvm-svn: 131571
2011-05-18 20:53:17 +00:00
Devang Patel
a7ec47d23c
Use IRBuilder while simplifying switch instruction.
...
llvm-svn: 131566
2011-05-18 20:35:38 +00:00
Devang Patel
0b373dca1f
Use IRBuilder while simplifying unwind.
...
llvm-svn: 131561
2011-05-18 20:01:18 +00:00
Devang Patel
2c2ea226b7
Use IRBuilder while simplifying terminator.
...
llvm-svn: 131552
2011-05-18 18:43:31 +00:00
Devang Patel
767f6930bc
Use IRBuilder while simplifying unconditional branch.
...
llvm-svn: 131551
2011-05-18 18:28:48 +00:00
Devang Patel
5c810ce4a3
Use IRBuilder while folding two entry PHINode.
...
llvm-svn: 131548
2011-05-18 18:16:44 +00:00
Devang Patel
15ad6761da
Set up IRBuilder for use during simplification.
...
llvm-svn: 131545
2011-05-18 18:01:27 +00:00
Matt Beaumont-Gay
8fa6ebf975
fix typo
...
llvm-svn: 131543
2011-05-18 17:37:10 +00:00
Devang Patel
1fabbe921b
Use IRBuiler while constant folding terminator.
...
llvm-svn: 131541
2011-05-18 17:26:46 +00:00
Devang Patel
b849cd511b
Preseve line numbers while simplifying CFG.
...
llvm-svn: 131508
2011-05-17 23:29:05 +00:00
Devang Patel
c23bcbc498
Preserve line number information.
...
llvm-svn: 131480
2011-05-17 19:43:06 +00:00
Devang Patel
a0b682db62
There is no need to force DebugLoc on a PHI at this point.
...
llvm-svn: 131427
2011-05-16 22:05:03 +00:00
Devang Patel
8e60ff11db
Preserve debug info for unused zero extended boolean argument.
...
Radar 9422775.
llvm-svn: 131422
2011-05-16 21:24:05 +00:00
Benjamin Kramer
d96205c4e5
SimplifyCFG: Use ComputeMaskedBits to prune dead cases from switch instructions.
...
llvm-svn: 131345
2011-05-14 15:57:25 +00:00
Devang Patel
ac794d46bf
Set debug location for new PHI nodes created in exit block.
...
llvm-svn: 130894
2011-05-04 23:58:22 +00:00
Devang Patel
bb35e8ba88
Scanning entire basic block may be too expensive in terms of compile time. Instead, just use whatever location info first non-phi instruction has.
...
llvm-svn: 130729
2011-05-02 21:57:00 +00:00
Devang Patel
a8e7411c74
Assing line number info to new PHIs created by SSA updater.
...
llvm-svn: 130551
2011-04-29 22:28:59 +00:00
Peter Collingbourne
616044acd5
SimplifyCFG: Expose phi node folding cost threshold as command line parameter
...
llvm-svn: 130528
2011-04-29 18:47:38 +00:00
Peter Collingbourne
e3511e15e0
SimplifyCFG: Add CostRemaining parameter to DominatesMergePoint
...
llvm-svn: 130527
2011-04-29 18:47:31 +00:00
Peter Collingbourne
61f6602acd
SimplifyCFG: Add Trunc, ZExt and SExt to the list of cheap instructions for phi node folding
...
llvm-svn: 130526
2011-04-29 18:47:25 +00:00
Devang Patel
72aa1a8a68
Remove DbgDeclare only if all uses are converted.
...
llvm-svn: 130431
2011-04-28 20:32:02 +00:00
Jay Foad
1a180156b6
Remove unused STL header includes.
...
llvm-svn: 130068
2011-04-23 19:53:52 +00:00
Jay Foad
5514afe6b2
PR9214: Convert Metadata API to use ArrayRef.
...
llvm-svn: 129932
2011-04-21 19:59:31 +00:00
Jay Foad
6a85be25a4
Trivial simplification.
...
llvm-svn: 129759
2011-04-19 15:23:29 +00:00
Chris Lattner
0ab5e2cded
Fix a ton of comment typos found by codespell. Patch by
...
Luis Felipe Strano Moraes!
llvm-svn: 129558
2011-04-15 05:18:47 +00:00
Chris Lattner
fba5cdfce1
rework FoldBranchToCommonDest to exit earlier when there is a bonus
...
instruction around, reducing work.
Greatly simplify handling of debug instructions. There is no need to
build up a vector of them and then move them into the one predecessor
if we're processing a block. Instead just rescan the block and *copy*
them into the pred. If a block gets merged into multiple preds, this
will retain more debug info.
llvm-svn: 129502
2011-04-14 02:44:53 +00:00
Chris Lattner
7d4cdae564
comment cleanup, use moveBefore instead of removeFromParent+insertBefore.
...
llvm-svn: 129319
2011-04-11 23:24:57 +00:00
Jay Foad
7c14a558fe
Don't include Operator.h from InstrTypes.h.
...
llvm-svn: 129271
2011-04-11 09:35:34 +00:00
Devang Patel
bc3d8b212f
Do not let debug info interfer with branch folding.
...
llvm-svn: 129114
2011-04-07 23:11:25 +00:00
Devang Patel
197c35298a
While hoisting common code from if/else, hoist debug info intrinsics if they match.
...
llvm-svn: 129078
2011-04-07 17:27:36 +00:00
Devang Patel
e48ddf863b
Simplify. isIdenticalToWhenDefined() checks opcode.
...
llvm-svn: 129041
2011-04-07 00:30:15 +00:00
Devang Patel
d715ec82b4
While folding branch to a common destination into a predecessor, copy dbg values also.
...
llvm-svn: 129035
2011-04-06 22:37:20 +00:00
Eli Friedman
b85c0caf7d
Attempt to fix breakage from r128782 reported by Francois Pichet on
...
llvm-commits. (Not sure why it only breaks on Windows; maybe it has
something to do with the iterator representation...)
llvm-svn: 128802
2011-04-04 00:37:38 +00:00
Eli Friedman
17bf4922c9
PR9446: RecursivelyDeleteTriviallyDeadInstructions can delete the instruction
...
after the given instruction; make sure to handle that case correctly.
(It's difficult to trigger; the included testcase involves a dead
block, but I don't think that's a requirement.)
While I'm here, get rid of the unnecessary warning about
SimplifyInstructionsInBlock, since it should work correctly as far as I know.
llvm-svn: 128782
2011-04-02 22:45:17 +00:00
Jay Foad
52131344a2
Remove PHINode::reserveOperandSpace(). Instead, add a parameter to
...
PHINode::Create() giving the (known or expected) number of operands.
llvm-svn: 128537
2011-03-30 11:28:46 +00:00
Jay Foad
e0938d8a87
(Almost) always call reserveOperandSpace() on newly created PHINodes.
...
llvm-svn: 128535
2011-03-30 11:19:20 +00:00
Devang Patel
17bbd7f495
Simplify.
...
llvm-svn: 128030
2011-03-21 22:04:45 +00:00
Devang Patel
2c7ee2700c
If an AllocaInst referred by DbgDeclareInst is used by a LoadInst then the LoadInst should also get a corresponding llvm.dbg.value intrinsic.
...
llvm-svn: 127924
2011-03-18 23:45:43 +00:00
Devang Patel
3ac171d49a
Remove dead code.
...
llvm-svn: 127923
2011-03-18 23:33:58 +00:00
Devang Patel
c1431e6e84
Consider debug info intrinsics pointing to null value as dead instructions.
...
llvm-svn: 127922
2011-03-18 23:28:02 +00:00
Devang Patel
aad34d882d
Try to not lose variable's debug info during instcombine.
...
This is done by lowering dbg.declare intrinsic into dbg.value intrinsic.
Radar 9143931.
llvm-svn: 127834
2011-03-17 22:18:16 +00:00
Devang Patel
8c0b16b0aa
Refactor into a separate utility function.
...
llvm-svn: 127832
2011-03-17 21:58:19 +00:00
Cameron Zwarich
dbb27393cc
Clean up something noticed by Fritz.
...
llvm-svn: 127684
2011-03-15 18:42:33 +00:00
Cameron Zwarich
0b8cdfb6ec
Do not add PHIs with no users when creating LCSSA form. Patch by Andrew Clinton.
...
llvm-svn: 127674
2011-03-15 07:41:25 +00:00
Eli Friedman
c4414c6e92
PR9450: Make switch optimization in SimplifyCFG not dependent on the ordering
...
of pointers in an std::map.
llvm-svn: 127650
2011-03-15 02:23:35 +00:00
Eli Friedman
aac35b3fbb
PR9420; an instruction before an unreachable is guaranteed not to have any
...
reachable uses, but there still might be uses in dead blocks. Use the
standard solution of replacing all the uses with undef. This is
a rare case because it's very sensitive to phase ordering in SimplifyCFG.
llvm-svn: 127299
2011-03-09 00:48:33 +00:00
Jakob Stoklund Olesen
e2017b6f2e
DenseMap<uintptr_t,...> doesn't allow all values as keys.
...
Avoid colliding with the sentinels, hopefully unbreaking
llvm-gcc-x86_64-linux-selfhost.
llvm-svn: 126982
2011-03-04 02:48:56 +00:00
Frits van Bommel
8ae07996c9
Teach SimplifyCFG that (switch (select cond, X, Y)) is better expressed as a branch.
...
Based on a patch by Alistair Lynn.
llvm-svn: 126647
2011-02-28 09:44:07 +00:00
Benjamin Kramer
ceb5daa567
Revert "SimplifyCFG: GEPs with just one non-constant index are also cheap."
...
Yes, there are other types than i8* and GEPs on them can produce an add+multiply.
We don't consider that cheap enough to be speculatively executed.
llvm-svn: 126481
2011-02-25 10:33:33 +00:00
Benjamin Kramer
dfdca1a14d
SimplifyCFG: GEPs with just one non-constant index are also cheap.
...
llvm-svn: 126452
2011-02-24 23:26:09 +00:00
Benjamin Kramer
27361a7124
SimplifyCFG: GEPs with constant indices are cheap enough to be executed unconditionally.
...
llvm-svn: 126445
2011-02-24 22:46:11 +00:00
Devang Patel
cedf928743
Do not use DIFactory. Use DIBuilder.
...
llvm-svn: 126398
2011-02-24 18:49:55 +00:00
Duncan Sands
ecbbf0825b
If the phi node was used by an unreachable instruction that ends up using
...
itself without going via a phi node then we could return false here in
spite of making a change. Also, tweak the comment because this method
can (and always could) return true without deleting the original phi node.
For example, if the phi node was used by a read-only invoke instruction
which is used by another phi node phi2 which is only used by and only uses
the invoke, then phi2 would be deleted but not the invoke instruction and
not the original phi node.
llvm-svn: 126129
2011-02-21 17:32:05 +00:00
Duncan Sands
6dcd49bc2b
Simplify RecursivelyDeleteDeadPHINode. The only functionality change
...
should be that if the phi is used by a side-effect free instruction with
no uses then the phi and the instruction now get zapped (checked by the
unittest).
llvm-svn: 126124
2011-02-21 16:27:36 +00:00
Nick Lewycky
183c24c51b
Make RecursivelyDeleteDeadPHINode delete a phi node that has no users and add a
...
test for that. With this change, test/CodeGen/X86/codegen-dce.ll no longer finds
any instructions to DCE, so delete the test.
Also renamed J and JP to I and IP in RecursivelyDeleteDeadPHINode.
llvm-svn: 126088
2011-02-20 18:05:56 +00:00
Nick Lewycky
c8a1569950
Teach RecursivelyDeleteDeadPHINodes to handle multiple self-references. Patch
...
by Andrew Clinton!
llvm-svn: 126077
2011-02-20 08:38:20 +00:00
Chris Lattner
4a14fbc50c
Don't unroll loops whose header block's address is taken.
...
This is part of a futile attempt to not "break" bizzaro
code like this:
l1:
printf("l1: %p\n", &&l1);
++x;
if( x < 3 ) goto l1;
Previously we'd fold &&l1 to 1, which is fine per our semantics
but not helpful to the user.
llvm-svn: 125827
2011-02-18 04:25:21 +00:00
Cameron Zwarich
d8e66038f4
Rename 'loopsimplify' to 'loop-simplify'.
...
llvm-svn: 125317
2011-02-10 23:38:10 +00:00
Benjamin Kramer
8d6a8c130b
SimplifyCFG: Track the number of used icmps when turning a icmp chain into a switch. If we used only one icmp, don't turn it into a switch.
...
Also prevent the switch-to-icmp transform from creating identity adds, noticed by Marius Wachtler.
llvm-svn: 125056
2011-02-07 22:37:28 +00:00
Benjamin Kramer
62aa46b852
SimplifyCFG: Also transform switches that represent a range comparison but are not sorted into sub+icmp.
...
This transforms another 1000 switches in gcc.c.
llvm-svn: 124826
2011-02-03 22:51:41 +00:00
Benjamin Kramer
f4ea1d5f79
SimplifyCFG: Turn switches into sub+icmp+branch if possible.
...
This makes the job of the later optzn passes easier, allowing the vast amount of
icmp transforms to chew on it.
We transform 840 switches in gcc.c, leading to a 16k byte shrink of the resulting
binary on i386-linux.
The testcase from README.txt now compiles into
decl %edi
cmpl $3, %edi
sbbl %eax, %eax
andl $1, %eax
ret
llvm-svn: 124724
2011-02-02 15:56:22 +00:00
Evan Cheng
d983eba7dc
Re-apply r124518 with fix. Watch out for invalidated iterator.
...
llvm-svn: 124526
2011-01-29 04:46:23 +00:00
Evan Cheng
65b8ccf6ac
Revert r124518. It broke Linux self-host.
...
llvm-svn: 124522
2011-01-29 02:43:04 +00:00
Evan Cheng
d4eff31476
Re-commit r124462 with fixes. Tail recursion elim will now dup ret into unconditional predecessor to enable TCE on demand.
...
llvm-svn: 124518
2011-01-29 01:29:26 +00:00
Evan Cheng
aaa9606b2f
Revert r124462. There are a few big regressions that I need to fix first.
...
llvm-svn: 124478
2011-01-28 07:12:38 +00:00
Evan Cheng
417fca86c4
- Stop simplifycfg from duplicating "ret" instructions into unconditional
...
branches. PR8575, rdar://5134905, rdar://8911460.
- Allow codegen tail duplication to dup small return blocks after register
allocation is done.
llvm-svn: 124462
2011-01-28 02:19:21 +00:00
Chris Lattner
b4017769ae
fix PR9017, a bug where we'd assert when promoting in unreachable
...
code.
llvm-svn: 124100
2011-01-24 03:29:07 +00:00
Chris Lattner
23289c385a
fix PR9015, a crash linking recursive metadata.
...
llvm-svn: 124099
2011-01-24 03:18:24 +00:00
Cameron Zwarich
07d6fe34b3
Convert two std::vectors to SmallVectors for a 3.4% speedup running -scalarrepl
...
on test-suite + SPEC2000 & SPEC2006.
llvm-svn: 124068
2011-01-23 08:03:04 +00:00
Cameron Zwarich
fc210c79b7
Convert a std::map to a DenseMap for another 1.7% speedup on -scalarrepl.
...
llvm-svn: 123732
2011-01-18 04:50:38 +00:00
Cameron Zwarich
6968c41ac8
Make a std::vector a SmallVector<*, 32> like the other vectors in the same
...
function. This seems to be about a 1.5% speedup of -scalarrepl on test-suite
with SPEC2000 and SPEC2006.
llvm-svn: 123731
2011-01-18 04:41:32 +00:00
Cameron Zwarich
b703654edc
Remove code for updating dominance frontiers and some outdated references to
...
dominance and post-dominance frontiers.
llvm-svn: 123725
2011-01-18 04:11:31 +00:00
Cameron Zwarich
4694e69540
Remove outdated references to dominance frontiers.
...
llvm-svn: 123724
2011-01-18 03:53:26 +00:00
Cameron Zwarich
b410858a5f
Roll r123609 back in with two changes that fix test failures with expensive
...
checks enabled:
1) Use '<' to compare integers in a comparison function rather than '<='.
2) Use the uniqued set DefBlocks rather than Info.DefiningBlocks to initialize
the priority queue.
The speedup of scalarrepl on test-suite + SPEC2000 + SPEC2006 is a bit less, at
just under 16% rather than 17%.
llvm-svn: 123662
2011-01-17 17:38:41 +00:00
Cameron Zwarich
67431d7943
Roll out r123609 due to failures on the llvm-x86_64-linux-checks bot.
...
llvm-svn: 123618
2011-01-17 07:26:51 +00:00
Cameron Zwarich
814cd9233e
Eliminate the use of dominance frontiers in PromoteMemToReg. In addition to
...
eliminating a potentially quadratic data structure, this also gives a 17%
speedup when running -scalarrepl on test-suite + SPEC2000 + SPEC2006. My initial
experiment gave a greater speedup around 25%, but I moved the dominator tree
level computation from dominator tree construction to PromoteMemToReg.
Since this approach to computing IDFs has a much lower overhead than the old
code using precomputed DFs, it is worth looking at using this new code for the
second scalarrepl pass as well.
llvm-svn: 123609
2011-01-17 01:08:59 +00:00
Chris Lattner
b68ec5c339
Generalize LoadAndStorePromoter a bit and switch LICM
...
to use it.
llvm-svn: 123501
2011-01-15 00:12:35 +00:00
Chris Lattner
95294b8796
Add a new LoadAndStorePromoter class, which implements the general
...
"promote a bunch of load and stores" logic, allowing the code to
be shared and reused.
llvm-svn: 123456
2011-01-14 19:36:13 +00:00
Chris Lattner
90f3a9a1c7
indentation
...
llvm-svn: 123426
2011-01-14 04:23:53 +00:00
Jakob Stoklund Olesen
f2407aa98b
Fix a non-deterministic loop in llvm::MergeBlockIntoPredecessor.
...
DT->changeImmediateDominator() trivially ignores identity updates, so there is
really no need for the uniqueing provided by SmallPtrSet.
I expect this to fix PR8954.
llvm-svn: 123286
2011-01-11 22:54:38 +00:00
Chris Lattner
d41db8f9cb
this pass claims to preserve scev, make sure to tell it about deletions.
...
llvm-svn: 123247
2011-01-11 18:14:50 +00:00
Frits van Bommel
8e158495f1
Factor the actual simplification out of SimplifyIndirectBrOnSelect and into a new helper function so it can be reused in e.g. an upcoming SimplifySwitchOnSelect.
...
No functional change.
llvm-svn: 123234
2011-01-11 12:52:11 +00:00
Chris Lattner
e2523b287c
when MergeBlockIntoPredecessor merges two blocks, update MemDep if it
...
is floating around in the ether.
llvm-svn: 123223
2011-01-11 08:16:49 +00:00
Chris Lattner
f6ae904e34
Fix FoldSingleEntryPHINodes to update memdep and AA when it deletes
...
phi nodes. It is called from MergeBlockIntoPredecessor which is
called from GVN, which claims to preserve these.
I'm skeptical that this is the actual problem behind PR8954, but
this is a stab in the right direction.
llvm-svn: 123222
2011-01-11 08:13:40 +00:00
Chris Lattner
dfcfcb49fa
random cleanups
...
llvm-svn: 123221
2011-01-11 08:00:40 +00:00
Chris Lattner
930b716e1b
various code cleanups, enhance MergeBlockIntoPredecessor to preserve
...
loop info.
llvm-svn: 123074
2011-01-08 19:08:40 +00:00
Chris Lattner
30d95f9f87
reduce nesting.
...
llvm-svn: 123071
2011-01-08 18:47:43 +00:00
Cameron Zwarich
84986b298a
Make more passes preserve dominators (or state that they preserve dominators if
...
they all ready do). This removes two dominator recomputations prior to isel,
which is a 1% improvement in total llc time for 403.gcc.
The only potentially suspect thing is making GCStrategy recompute dominators if
it used a custom lowering strategy.
llvm-svn: 123064
2011-01-08 17:01:52 +00:00
Chris Lattner
43f8d16482
Revamp the ValueMapper interfaces in a couple ways:
...
1. Take a flags argument instead of a bool. This makes
it more clear to the reader what it is used for.
2. Add a flag that says that "remapping a value not in the
map is ok".
3. Reimplement MapValue to share a bunch of code and be a lot
more efficient. For lookup failures, don't drop null values
into the map.
4. Using the new flag a bunch of code can vaporize in LinkModules
and LoopUnswitch, kill it.
No functionality change.
llvm-svn: 123058
2011-01-08 08:15:20 +00:00
Jay Foad
89afb43b1e
Remove all uses of the "ugly" method BranchInst::setUnconditionalDest().
...
llvm-svn: 123025
2011-01-07 20:25:56 +00:00
Duncan Sands
697de77339
Speed up instsimplify by about 10-15% by not bothering to retry
...
InstructionSimplify on instructions that didn't change since the
last time round the loop.
llvm-svn: 122745
2011-01-03 10:50:04 +00:00
Chris Lattner
bf0aa927cc
split dom frontier handling stuff out to its own DominanceFrontier header,
...
so that Dominators.h is *just* domtree. Also prune #includes a bit.
llvm-svn: 122714
2011-01-02 22:09:33 +00:00
Duncan Sands
64f1c0dcda
Fix PR8702 by not having LoopSimplify claim to preserve LCSSA form. As described
...
in the PR, the pass could break LCSSA form when inserting preheaders. It probably
would be easy enough to fix this, but since currently we always go into LCSSA form
after running this pass, doing so is not urgent.
llvm-svn: 122695
2011-01-02 13:38:21 +00:00
Duncan Sands
2c440fa403
Simplify this pass by using a depth-first iterator to ensure that all
...
operands are visited before the instructions themselves.
llvm-svn: 122647
2010-12-31 17:49:05 +00:00
Duncan Sands
6cc7126ed9
Zap dead instructions harder.
...
llvm-svn: 122645
2010-12-31 16:17:54 +00:00
Benjamin Kramer
570dd787a6
Make a bunch of symbols internal.
...
llvm-svn: 122642
2010-12-30 22:34:44 +00:00
Benjamin Kramer
84bd73c527
BuildLibCalls: Nuke EmitMemCpy, EmitMemMove and EmitMemSet. They are dead and superseded by IRBuilder.
...
llvm-svn: 122576
2010-12-27 00:25:32 +00:00
Chris Lattner
d729d0dcdb
don't lose TD info
...
llvm-svn: 122556
2010-12-25 20:52:04 +00:00
Chris Lattner
20fca48341
switch the inliner alignment enforcement stuff to use the
...
getOrEnforceKnownAlignment function, which simplifies the code
and makes it stronger.
llvm-svn: 122555
2010-12-25 20:42:38 +00:00
Chris Lattner
6fcd32e7d7
Move getOrEnforceKnownAlignment out of instcombine into Transforms/Utils.
...
llvm-svn: 122554
2010-12-25 20:37:57 +00:00
Jeffrey Yasskin
9b43f33620
Change all self assignments X=X to (void)X, so that we can turn on a
...
new gcc warning that complains on self-assignments and
self-initializations.
llvm-svn: 122458
2010-12-23 00:58:24 +00:00
Duncan Sands
3b8af41a3e
Visit instructions deterministically. Use a FIFO so as to approximately
...
visit instructions before their uses, since InstructionSimplify does a
better job in that case. All this prompted by Frits van Bommel.
llvm-svn: 122343
2010-12-21 17:08:55 +00:00
Duncan Sands
e7cbb64ec0
If an instruction simplifies, try again to simplify any uses of it. This is
...
not very important since the pass is only used for testing, but it does make
it more realistic. Suggested by Frits van Bommel.
llvm-svn: 122336
2010-12-21 16:12:03 +00:00
Duncan Sands
eaff500c7b
Oops, forgot to add the pass itself!
...
llvm-svn: 122265
2010-12-20 21:07:42 +00:00
Duncan Sands
a436cbe4bf
Add a new convenience pass for testing InstructionSimplify. Previously
...
it could only be tested indirectly, via instcombine, gvn or some other
pass that makes use of InstructionSimplify, which means that testcases
had to be carefully contrived to dance around any other transformations
that that pass did.
llvm-svn: 122264
2010-12-20 20:54:37 +00:00
Chris Lattner
0f11495289
when eliding a byval copy due to inlining a readonly function, we have
...
to make sure that the reused alloca has sufficient alignment.
llvm-svn: 122236
2010-12-20 08:10:40 +00:00
Chris Lattner
0099744506
pull byval processing out to its own helper function.
...
llvm-svn: 122235
2010-12-20 07:57:41 +00:00
Chris Lattner
7394680a00
fix PR8769, a miscompilation by inliner when inlining a function with a byval
...
argument. The generated alloca has to have at least the alignment of the
byval, if not, the client may be making assumptions that the new alloca won't
satisfy.
llvm-svn: 122234
2010-12-20 07:45:28 +00:00
Chris Lattner
6b8b4855ff
simplify this a bit.
...
llvm-svn: 122156
2010-12-18 20:22:49 +00:00
Benjamin Kramer
e5f49c4ff2
SimplifyCFG: Ranges can be larger than 64 bits. Fixes Release-selfhost build.
...
llvm-svn: 122054
2010-12-17 10:48:14 +00:00
Chris Lattner
d14b0f1db7
improve switch formation to handle small range
...
comparisons formed by comparisons. For example,
this:
void foo(unsigned x) {
if (x == 0 || x == 1 || x == 3 || x == 4 || x == 6)
bar();
}
compiles into:
_foo: ## @foo
## BB#0: ## %entry
cmpl $6, %edi
ja LBB0_2
## BB#1: ## %entry
movl %edi, %eax
movl $91, %ecx
btq %rax, %rcx
jb LBB0_3
instead of:
_foo: ## @foo
## BB#0: ## %entry
cmpl $2, %edi
jb LBB0_4
## BB#1: ## %switch.early.test
cmpl $6, %edi
ja LBB0_3
## BB#2: ## %switch.early.test
movl %edi, %eax
movl $88, %ecx
btq %rax, %rcx
jb LBB0_4
This catches a bunch of cases in GCC, which look like this:
%804 = load i32* @which_alternative, align 4, !tbaa !0
%805 = icmp ult i32 %804, 2
%806 = icmp eq i32 %804, 3
%or.cond121 = or i1 %805, %806
%807 = icmp eq i32 %804, 4
%or.cond124 = or i1 %or.cond121, %807
br i1 %or.cond124, label %.thread, label %808
turning this into a range comparison.
llvm-svn: 122045
2010-12-17 06:20:15 +00:00
Chris Lattner
e893e2601e
make qsort predicate more conformant by returning 0 for equal values.
...
llvm-svn: 121838
2010-12-15 04:52:41 +00:00
Chris Lattner
7499b452c1
- Insert new instructions before DomBlock's terminator,
...
which is simpler than finding a place to insert in BB.
- Don't perform the 'if condition hoisting' xform on certain
i1 PHIs, as it interferes with switch formation.
This re-fixes "example 7", without breaking the world hopefully.
llvm-svn: 121764
2010-12-14 08:46:09 +00:00
Chris Lattner
335f0e4ad4
fix two significant issues with FoldTwoEntryPHINode:
...
first, it can kick in on blocks whose conditions have been
folded to a constant, even though one of the edges will be
trivially folded.
second, it doesn't clean up the "if diamond" that it just
eliminated away. This is a problem because other simplifycfg
xforms kick in depending on the order of block visitation,
causing pointless work.
llvm-svn: 121762
2010-12-14 08:01:53 +00:00
Chris Lattner
dc20a7d38c
remove the instsimplify logic I added in r121754. It is apparently
...
breaking the selfhost builds, though I can't fathom how.
llvm-svn: 121761
2010-12-14 07:53:03 +00:00
Chris Lattner
9ac168d0ab
clean up logic, convert std::set to SmallPtrSet, handle the case
...
when all 2-entry phis are simplified away.
llvm-svn: 121760
2010-12-14 07:41:39 +00:00
Chris Lattner
9fd838d31b
tidy up a bit, move DEBUG down to when we commit to doing the transform so we
...
don't print it unless the xform happens.
llvm-svn: 121758
2010-12-14 07:23:10 +00:00
Chris Lattner
b42d293faa
use SimplifyInstruction instead of reimplementing part of it.
...
llvm-svn: 121757
2010-12-14 07:20:29 +00:00
Chris Lattner
fb73de482c
simplify GetIfCondition by using getSinglePredecessor.
...
llvm-svn: 121756
2010-12-14 07:15:21 +00:00
Chris Lattner
0f4d67bd88
use AddPredecessorToBlock in 3 places instead of a manual loop.
...
llvm-svn: 121755
2010-12-14 07:09:42 +00:00
Chris Lattner
a07cc6f4fd
make FoldTwoEntryPHINode use instsimplify a bit, make
...
GetIfCondition faster by avoiding pred_iterator. No
really interesting change.
llvm-svn: 121754
2010-12-14 07:00:00 +00:00
Chris Lattner
afd2a8cfbb
remove the dead (and terrible) llvm::RemoveSuccessor function.
...
llvm-svn: 121753
2010-12-14 06:51:55 +00:00
Chris Lattner
d7beca3782
improve DEBUG's a bit, switch to eraseFromParent() to simplify
...
code a bit, switch from constant folding to instsimplify.
llvm-svn: 121751
2010-12-14 06:17:25 +00:00
Chris Lattner
5a9d59d918
reapply my recent change that disables a piece of the switch formation
...
work, but fixes 400.perlbmk.
llvm-svn: 121749
2010-12-14 05:57:30 +00:00
Owen Anderson
3e5648896e
Fix recent buildbot breakage by pulling SimplifyCFG back to its state as of r121694, the most recent state
...
where I'm confident there were no crashes or miscompilations. XFAIL the test added since then for now.
llvm-svn: 121733
2010-12-13 23:49:28 +00:00
Chris Lattner
a6e5d5694a
temporarily disable part of my previous patch, which causes an iterator invalidation issue, causing a crash on some versions of perlbmk.
...
llvm-svn: 121728
2010-12-13 23:02:19 +00:00
Chris Lattner
2d434e594e
add some DEBUG's.
...
llvm-svn: 121711
2010-12-13 19:55:30 +00:00
Benjamin Kramer
1e155ab7e1
Fix sort predicate. qsort(3)'s predicate semantics differ from std::sort's. Fixes PR 8780.
...
llvm-svn: 121705
2010-12-13 18:20:38 +00:00
Chris Lattner
fb836f8c1a
reinstate my patch: the miscompile was caused by an inverted branch in the
...
'and' case.
llvm-svn: 121695
2010-12-13 08:12:19 +00:00
Chris Lattner
79db357d80
Completely disable the optimization I added in r121680 until
...
I can track down a miscompile. This should bring the buildbots
back to life
llvm-svn: 121693
2010-12-13 07:41:29 +00:00
Chris Lattner
fbeb55844b
Make simplifycfg reprocess newly formed "br (cond1 | cond2)" conditions
...
when simplifying, allowing them to be eagerly turned into switches. This
is the last step required to get "Example 7" from this blog post:
http://blog.regehr.org/archives/320
On X86, we now generate this machine code, which (to my eye) seems better
than the ICC generated code:
_crud: ## @crud
## BB#0: ## %entry
cmpb $33, %dil
jb LBB0_4
## BB#1: ## %switch.early.test
addb $-34, %dil
cmpb $58, %dil
ja LBB0_3
## BB#2: ## %switch.early.test
movzbl %dil, %eax
movabsq $288230376537592865, %rcx ## imm = 0x400000017001421
btq %rax, %rcx
jb LBB0_4
LBB0_3: ## %lor.rhs
xorl %eax, %eax
ret
LBB0_4: ## %lor.end
movl $1, %eax
ret
llvm-svn: 121690
2010-12-13 07:00:06 +00:00
Chris Lattner
1d05761df4
make this logic a bit simpler.
...
llvm-svn: 121689
2010-12-13 06:36:51 +00:00
Chris Lattner
25c3af35d8
split all the guts of SimplifyCFGOpt::run out into one function
...
per terminator kind.
llvm-svn: 121688
2010-12-13 06:25:44 +00:00
Chris Lattner
cb570f87e5
fix a bug in r121680 that upset the various buildbots.
...
llvm-svn: 121687
2010-12-13 05:34:18 +00:00
Chris Lattner
a6db741f3d
refactor the speculative execution logic to be factored into the cond branch code instead of
...
doing a cfg search for every block simplified.
llvm-svn: 121686
2010-12-13 05:26:52 +00:00
Chris Lattner
466f54ffcf
simplify a bunch of code.
...
llvm-svn: 121685
2010-12-13 05:20:28 +00:00
Chris Lattner
6df7bdd810
move HoistThenElseCodeToIf up to a more logical and efficient-to-handle place.
...
llvm-svn: 121684
2010-12-13 05:15:29 +00:00
Chris Lattner
2e3832d9a0
move 'MergeBlocksIntoPredecessor' call earlier. Use
...
getSinglePredecessor to simplify code.
llvm-svn: 121683
2010-12-13 05:10:48 +00:00
Chris Lattner
a69c443459
factor new code out to a SimplifyBranchOnICmpChain helper function.
...
llvm-svn: 121681
2010-12-13 05:03:41 +00:00
Chris Lattner
a442f24a36
enhance the "change or icmp's into switch" xform to handle one value in an
...
'or sequence' that it doesn't understand. This allows us to optimize
something insane like this:
int crud (unsigned char c, unsigned x)
{
if(((((((((( (int) c <= 32 ||
(int) c == 46) || (int) c == 44)
|| (int) c == 58) || (int) c == 59) || (int) c == 60)
|| (int) c == 62) || (int) c == 34) || (int) c == 92)
|| (int) c == 39) != 0)
foo();
}
into:
define i32 @crud(i8 zeroext %c, i32 %x) nounwind ssp noredzone {
entry:
%cmp = icmp ult i8 %c, 33
br i1 %cmp, label %if.then, label %switch.early.test
switch.early.test: ; preds = %entry
switch i8 %c, label %if.end [
i8 39, label %if.then
i8 44, label %if.then
i8 58, label %if.then
i8 59, label %if.then
i8 60, label %if.then
i8 62, label %if.then
i8 46, label %if.then
i8 92, label %if.then
i8 34, label %if.then
]
by pulling the < comparison out ahead of the newly formed switch.
llvm-svn: 121680
2010-12-13 04:50:38 +00:00
Chris Lattner
5a177e681e
merge two very similar functions into one that has a bool argument.
...
llvm-svn: 121678
2010-12-13 04:26:26 +00:00
Chris Lattner
9b1af510cb
don't bother handling non-canonical icmp's
...
llvm-svn: 121676
2010-12-13 04:18:32 +00:00
Chris Lattner
395252d93e
inline a function, making the result much simpler.
...
llvm-svn: 121675
2010-12-13 04:15:19 +00:00
Chris Lattner
62cc76e9cc
Fix my previous patch to handle a degenerate case that the llvm-gcc
...
bootstrap buildbot tripped over.
llvm-svn: 121674
2010-12-13 03:43:57 +00:00
Chris Lattner
11dafaa3ec
convert some methods to be static functions
...
llvm-svn: 121673
2010-12-13 03:30:12 +00:00
Chris Lattner
4642d79fb0
zap two more std::sorts.
...
llvm-svn: 121672
2010-12-13 03:24:30 +00:00
Chris Lattner
d9bacc088a
fix a fairly serious oversight with switch formation from
...
or'd conditions. Previously we'd compile something like this:
int crud (unsigned char c) {
return c == 62 || c == 34 || c == 92;
}
into:
switch i8 %c, label %lor.rhs [
i8 62, label %lor.end
i8 34, label %lor.end
]
lor.rhs: ; preds = %entry
%cmp8 = icmp eq i8 %c, 92
br label %lor.end
lor.end: ; preds = %entry, %entry, %lor.rhs
%0 = phi i1 [ true, %entry ], [ %cmp8, %lor.rhs ], [ true, %entry ]
%lor.ext = zext i1 %0 to i32
ret i32 %lor.ext
which failed to merge the compare-with-92 into the switch. With this patch
we simplify this all the way to:
switch i8 %c, label %lor.rhs [
i8 62, label %lor.end
i8 34, label %lor.end
i8 92, label %lor.end
]
lor.rhs: ; preds = %entry
br label %lor.end
lor.end: ; preds = %entry, %entry, %entry, %lor.rhs
%0 = phi i1 [ true, %entry ], [ false, %lor.rhs ], [ true, %entry ], [ true, %entry ]
%lor.ext = zext i1 %0 to i32
ret i32 %lor.ext
which is much better for codegen's switch lowering stuff. This kicks in 33 times
on 176.gcc (for example) cutting 103 instructions off the generated code.
llvm-svn: 121671
2010-12-13 03:18:54 +00:00
Chris Lattner
7c8e6047d6
convert an std::sort to array_pod_sort.
...
llvm-svn: 121669
2010-12-13 02:00:58 +00:00
Chris Lattner
1475987634
move the "br (X == 0 | X == 1), T, F" -> switch optimization to a new
...
location in simplifycfg. In the old days, SimplifyCFG was never run on
the entry block, so we had to scan over all preds of the BB passed into
simplifycfg to do this xform, now we can just check blocks ending with
a condbranch. This avoids a scan over all preds of every simplified
block, which should be a significant compile-time perf win on functions
with lots of edges. No functionality change.
llvm-svn: 121668
2010-12-13 01:57:34 +00:00
Chris Lattner
4088e2b8e4
reduce indentation and generally simplify code, no functionality change.
...
llvm-svn: 121667
2010-12-13 01:47:07 +00:00
Chris Lattner
7cb7867d7a
use getFirstNonPHIOrDbg to simplify this code.
...
llvm-svn: 121664
2010-12-13 01:28:06 +00:00
Chris Lattner
cd3af96a8f
improve comment
...
llvm-svn: 120994
2010-12-06 07:43:04 +00:00
Frits van Bommel
8fb69ee805
Teach SimplifyCFG to turn
...
(indirectbr (select cond, blockaddress(@fn, BlockA),
blockaddress(@fn, BlockB)))
into
(br cond, BlockA, BlockB).
llvm-svn: 120943
2010-12-05 18:29:03 +00:00
Chris Lattner
b438ef236c
remove the pointless check of MemoryUseIntrinsic from
...
is trivially dead, since these have side effects. This makes the
(misnamed) MemoryUseIntrinsic class dead, so remove it.
llvm-svn: 120382
2010-11-30 02:03:47 +00:00
Duncan Sands
433c1679cf
Replace calls to ConstantFoldInstruction with calls to SimplifyInstruction
...
in two places that are really interested in simplified instructions, not
constants.
llvm-svn: 120044
2010-11-23 20:26:33 +00:00
Duncan Sands
c6648eb4c3
Don't keep track of inserted phis in PromoteMemoryToRegister: the information
...
is never used. Patch by Cameron Zwarich.
llvm-svn: 119963
2010-11-22 09:41:24 +00:00
Benjamin Kramer
ddd1b7b801
Simplify code. No change in functionality.
...
llvm-svn: 119908
2010-11-20 18:43:35 +00:00
Duncan Sands
aef146b890
Factor code for testing whether replacing one value with another
...
preserves LCSSA form out of ScalarEvolution and into the LoopInfo
class. Use it to check that SimplifyInstruction simplifications
are not breaking LCSSA form. Fixes PR8622.
llvm-svn: 119727
2010-11-18 19:59:41 +00:00
Duncan Sands
9d9a4e2ca2
Have InlineFunction use SimplifyInstruction rather than
...
hasConstantValue. I was leery of using SimplifyInstruction
while the IR was still in a half-baked state, which is the
reason for delaying the simplification until the IR is fully
cooked.
llvm-svn: 119494
2010-11-17 11:16:23 +00:00
Duncan Sands
ba0b22c785
Have RemovePredecessorAndSimplify you SimplifyInstruction
...
rather than hasConstantValue.
llvm-svn: 119457
2010-11-17 04:12:05 +00:00
Duncan Sands
637049515f
Have a few places that want to simplify phi nodes use SimplifyInstruction
...
rather than calling hasConstantValue. No intended functionality change.
llvm-svn: 119352
2010-11-16 17:41:24 +00:00
John Thompson
e8360b7182
Inline asm multiple alternative constraints development phase 2 - improved basic logic, added initial platform support.
...
llvm-svn: 117667
2010-10-29 17:29:13 +00:00
Duncan Sands
31c803b2ba
Fix PR8445: a block with no predecessors may be the entry block, in which case
...
it isn't unreachable and should not be zapped. The check for the entry block
was missing in one case: a block containing a unwind instruction. While there,
do some small cleanups: "M" is not a great name for a Function* (it would be
more appropriate for a Module*), change it to "Fn"; use Fn in more places.
llvm-svn: 117224
2010-10-24 12:23:30 +00:00
Chandler Carruth
88c54b82c1
Switch attribute macros to use 'LLVM_' as a prefix. We retain the old names
...
until other LLVM projects using these are cleaned up.
llvm-svn: 117200
2010-10-23 08:10:43 +00:00
Owen Anderson
a4fefc1949
Passes do not need to recursively initialize passes that they preserve, if
...
they do not also require them. This allows us to reduce inter-pass linkage
dependencies.
llvm-svn: 116854
2010-10-19 20:08:44 +00:00
Owen Anderson
6c18d1aac0
Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which
...
must be called in the pass's constructor. This function uses static dependency declarations to recursively initialize
the pass's dependencies.
Clients that only create passes through the createFooPass() APIs will require no changes. Clients that want to use the
CommandLine options for passes will need to manually call the appropriate initialization functions in PassInitialization.h
before parsing commandline arguments.
I have tested this with all standard configurations of clang and llvm-gcc on Darwin. It is possible that there are problems
with the static dependencies that will only be visible with non-standard options. If you encounter any crash in pass
registration/creation, please send the testcase to me directly.
llvm-svn: 116820
2010-10-19 17:21:58 +00:00
Devang Patel
218f3206fa
Transfer debug loc to lowered call.
...
Patch by Alexander Herz!
llvm-svn: 116733
2010-10-18 18:53:44 +00:00
Rafael Espindola
c2240adcc7
Fix PR8313 by changing ValueToValueMap use a TrackingVH.
...
llvm-svn: 116390
2010-10-13 02:08:17 +00:00
Rafael Espindola
229e38f0fe
Be more consistent in using ValueToValueMapTy.
...
llvm-svn: 116387
2010-10-13 01:36:30 +00:00
Owen Anderson
8ac477ffb5
Begin adding static dependence information to passes, which will allow us to
...
perform initialization without static constructors AND without explicit initialization
by the client. For the moment, passes are required to initialize both their
(potential) dependencies and any passes they preserve. I hope to be able to relax
the latter requirement in the future.
llvm-svn: 116334
2010-10-12 19:48:12 +00:00
Owen Anderson
df7a4f2515
Now with fewer extraneous semicolons!
...
llvm-svn: 115996
2010-10-07 22:25:06 +00:00
Owen Anderson
4698c5d7f7
Next step on the getting-rid-of-static-ctors train: begin adding per-library
...
initialization functions that initialize the set of passes implemented in
that library. Add C bindings for these functions as well.
llvm-svn: 115927
2010-10-07 17:55:47 +00:00
Owen Anderson
5e19bfcde3
Move the pass initialization helper functions into the llvm namespace, and add
...
a header declaring them all. This is also where we will declare per-library pass-set
initializer functions down the road.
llvm-svn: 115900
2010-10-07 04:13:08 +00:00
Oscar Fuentes
b4b12535e8
Removed a bunch of unnecessary target_link_libraries.
...
llvm-svn: 114999
2010-09-28 22:39:14 +00:00
Michael J. Spencer
ded5f66813
Get rid of pop_macro warnings on MSVC.
...
llvm-svn: 114750
2010-09-24 19:48:47 +00:00
Michael J. Spencer
93c9b2ea93
Revert "CMake: Get rid of LLVMLibDeps.cmake and export the libraries normally."
...
This reverts commit r113632
Conflicts:
cmake/modules/AddLLVM.cmake
llvm-svn: 113819
2010-09-13 23:59:48 +00:00
John Thompson
1094c80281
Added skeleton for inline asm multiple alternative constraint support.
...
llvm-svn: 113766
2010-09-13 18:15:37 +00:00
Gabor Greif
2f5f696b66
typoes
...
llvm-svn: 113647
2010-09-10 22:25:58 +00:00
Michael J. Spencer
dc38d36ccb
CMake: Get rid of LLVMLibDeps.cmake and export the libraries normally.
...
llvm-svn: 113632
2010-09-10 21:14:25 +00:00
Dan Gohman
487e250109
Fix LoopSimplify to notify ScalarEvolution when splitting a loop backedge
...
into an inner loop, as the new loop iteration may differ substantially.
This fixes PR8078.
llvm-svn: 113057
2010-09-04 02:42:48 +00:00
Duncan Sands
6778149f7e
Reapply commit 112699, speculatively reverted by echristo, since
...
I'm sure it is harmless. Original commit message:
If PrototypeValue is erased in the middle of using the SSAUpdator
then the SSAUpdator may access freed memory. Instead, simply pass
in the type and name explicitly, which is all that was used anyway.
llvm-svn: 112810
2010-09-02 08:14:03 +00:00
Eric Christopher
a5d315c665
Speculatively revert 112699 and 112702, they seem to be causing
...
self host errors on clang-x86-64.
llvm-svn: 112719
2010-09-01 17:29:10 +00:00
Duncan Sands
f7b18437b5
If PrototypeValue is erased in the middle of using the SSAUpdator
...
then the SSAUpdator may access freed memory. Instead, simply pass
in the type and name explicitly, which is all that was used anyway.
llvm-svn: 112699
2010-09-01 10:29:33 +00:00
Chris Lattner
c3fb03e289
implement SSAUpdater::RewriteUseAfterInsertions, a helpful form of RewriteUse.
...
llvm-svn: 112409
2010-08-29 04:54:06 +00:00
Chris Lattner
504e5100d3
remove the ABCD and SSI passes. They don't have any clients that
...
I'm aware of, aren't maintained, and LVI will be replacing their value.
nlewycky approved this on irc.
llvm-svn: 112355
2010-08-28 03:51:24 +00:00
Dan Gohman
ca26f79051
Reapply r112091 and r111922, support for metadata linking, with a
...
fix: add a flag to MapValue and friends which indicates whether
any module-level mappings are being made. In the common case of
inlining, no module-level mappings are needed, so MapValue doesn't
need to examine non-function-local metadata, which can be very
expensive in the case of a large module with really deep metadata
(e.g. a large C++ program compiled with -g).
This flag is a little awkward; perhaps eventually it can be moved
into the ClonedCodeInfo class.
llvm-svn: 112190
2010-08-26 15:41:53 +00:00
Daniel Dunbar
ce45863f0d
Revert r111922, "MapValue support for MDNodes. This is similar to r109117,
...
except ...", it is causing *massive* performance regressions when building Clang
with itself (-O3 -g).
llvm-svn: 112158
2010-08-26 03:48:11 +00:00
Daniel Dunbar
95fe13c720
Revert r112091, "Remap metadata attached to instructions when remapping
...
individual ...", which depends on r111922, which I am reverting.
llvm-svn: 112157
2010-08-26 03:48:08 +00:00
Dan Gohman
fd824487a3
Remap metadata attached to instructions when remapping individual
...
instructions, not when remapping modules.
llvm-svn: 112091
2010-08-25 21:36:50 +00:00
Dan Gohman
a209503467
Use MapValue in the Linker instead of having a private function
...
which does the same thing. This eliminates redundant code and
handles MDNodes better. MDNode linking still doesn't fully
work yet though.
llvm-svn: 111941
2010-08-24 18:50:07 +00:00
Dan Gohman
6901283544
MapValue support for MDNodes. This is similar to r109117, except
...
that it avoids a lot of unnecessary cloning by avoiding remapping
MDNode cycles when none of the nodes in the cycle actually need to
be remapped. Also it uses the new temporary MDNode mechanism.
llvm-svn: 111922
2010-08-24 17:10:10 +00:00
Owen Anderson
d31d82d75c
Now that PassInfo and Pass::ID have been separated, move the rest of the passes over to the new registration API.
...
llvm-svn: 111815
2010-08-23 17:52:01 +00:00
Chris Lattner
f0b5b67ba5
fit in 80 cols
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llvm-svn: 111348
2010-08-18 03:13:35 +00:00
Chris Lattner
b45de95345
remove some dead code.
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llvm-svn: 111344
2010-08-18 02:41:56 +00:00
Dan Gohman
941020ed72
Use the getUniquePredecessor() utility function, instead of doing
...
what it does manually.
llvm-svn: 111248
2010-08-17 17:07:02 +00:00
Dan Gohman
6e964c7fb4
Avoid #include <ScalarEvolution.h> in LoopSimplify.cpp, which doesn't
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actually use ScalarEvolution.
llvm-svn: 111124
2010-08-16 14:44:03 +00:00
Dan Gohman
250b754428
Instead, teach SimplifyCFG to trim non-address-taken blocks from
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indirectbr destination lists.
llvm-svn: 111122
2010-08-16 14:41:14 +00:00
Dan Gohman
aa445c0751
LoopSimplify shouldn't split loop backedges that use indirectbr. PR7867.
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llvm-svn: 111061
2010-08-14 00:43:09 +00:00
Dan Gohman
4a63fad976
Teach SimplifyCFG how to simplify indirectbr instructions.
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- Eliminate redundant successors.
- Convert an indirectbr with one successor into a direct branch.
Also, generalize SimplifyCFG to be able to be run on a function entry block.
It knows quite a few simplifications which are applicable to the entry
block, and it only needs a few checks to avoid trouble with the entry block.
llvm-svn: 111060
2010-08-14 00:29:42 +00:00