Commit Graph

393 Commits

Author SHA1 Message Date
Craig Topper
3e4c697ca1 [C++11] Add 'override' keyword to virtual methods that override their base class.
llvm-svn: 202953
2014-03-05 09:10:37 +00:00
Chandler Carruth
4220e9c154 [Modules] Move ValueHandle into the IR library where Value itself lives.
Move the test for this class into the IR unittests as well.

This uncovers that ValueMap too is in the IR library. Ironically, the
unittest for ValueMap is useless in the Support library (honestly, so
was the ValueHandle test) and so it already lives in the IR unittests.
Mmmm, tasty layering.

llvm-svn: 202821
2014-03-04 11:17:44 +00:00
Rafael Espindola
935125126c Make DataLayout a plain object, not a pass.
Instead, have a DataLayoutPass that holds one. This will allow parts of LLVM
don't don't handle passes to also use DataLayout.

llvm-svn: 202168
2014-02-25 17:30:31 +00:00
Rafael Espindola
aeff8a9c05 Make some DataLayout pointers const.
No functionality change. Just reduces the noise of an upcoming patch.

llvm-svn: 202087
2014-02-24 23:12:18 +00:00
Rafael Espindola
37dc9e19f5 Rename many DataLayout variables from TD to DL.
I am really sorry for the noise, but the current state where some parts of the
code use TD (from the old name: TargetData) and other parts use DL makes it
hard to write a patch that changes where those variables come from and how
they are passed along.

llvm-svn: 201827
2014-02-21 00:06:31 +00:00
Paul Robinson
af4e64d095 Disable most IR-level transform passes on functions marked 'optnone'.
Ideally only those transform passes that run at -O0 remain enabled,
in reality we get as close as we reasonably can.
Passes are responsible for disabling themselves, it's not the job of
the pass manager to do it for them.

llvm-svn: 200892
2014-02-06 00:07:05 +00:00
Bill Wendling
90dd90afcb Don't eliminate a partially redundant load if it's in a landing pad.
A landing pad can be jumped to only by the unwind edge of an invoke
instruction. If we eliminate a partially redundant load in a landing pad, it
will create a basic block that violates this constraint. It then leads to other
problems down the line if it tries to merge that basic block with the landing
pad. Avoid this by not eliminating the load in a landing pad.

PR17621

llvm-svn: 193064
2013-10-21 04:09:17 +00:00
Benjamin Kramer
6a4976d3e0 JumpThreading: Turn a select instruction into branching if it allows to thread one half of the select.
This is a common pattern coming out of simplifycfg generating gross code.

a:                                       ; preds = %entry
  %sel = select i1 %cmp1, double %add, double 0.000000e+00
  br label %b

b:
  %cond5 = phi double [ %sel, %a ], [ %sub, %entry ]
  %cmp6 = fcmp oeq double %cond5, 0.000000e+00
  br i1 %cmp6, label %if.then, label %if.end

becomes

a:
  br i1 %cmp1, label %b, label %if.then

b:
  %cond5 = phi double [ %sub, %entry ], [ %add, %a ]
  %cmp6 = fcmp oeq double %cond5, 0.000000e+00
  br i1 %cmp6, label %if.then, label %if.end

Skipping block b completely if possible.

llvm-svn: 187880
2013-08-07 10:29:38 +00:00
Nick Lewycky
0b68245ec8 Reimplement isPotentiallyReachable to make nocapture deduction much stronger.
Adds unit tests for it too.

Split BasicBlockUtils into an analysis-half and a transforms-half, and put the
analysis bits into a new Analysis/CFG.{h,cpp}. Promote isPotentiallyReachable
into llvm::isPotentiallyReachable and move it into Analysis/CFG.

llvm-svn: 187283
2013-07-27 01:24:00 +00:00
Chandler Carruth
9fb823bbd4 Move all of the header files which are involved in modelling the LLVM IR
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.

There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.

The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.

I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).

I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.

llvm-svn: 171366
2013-01-02 11:36:10 +00:00
James Molloy
4f6fb953a7 Add a new attribute, 'noduplicate'. If a function contains a noduplicate call, the call cannot be duplicated - Jump threading, loop unrolling, loop unswitching, and loop rotation are inhibited if they would duplicate the call.
Similarly inlining of the function is inhibited, if that would duplicate the call (in particular inlining is still allowed when there is only one callsite and the function has internal linkage).

llvm-svn: 170704
2012-12-20 16:04:27 +00:00
Nadav Rotem
2349531def Teach the jump threading optimization to stop scanning the basic block when calculating the cost after passing the threshold.
llvm-svn: 169135
2012-12-03 17:34:44 +00:00
Chandler Carruth
ed0881b2a6 Use the new script to sort the includes of every file under lib.
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.

Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]

llvm-svn: 169131
2012-12-03 16:50:05 +00:00
Micah Villmow
cdfe20b97f Move TargetData to DataLayout.
llvm-svn: 165402
2012-10-08 16:38:25 +00:00
Benjamin Kramer
8bcc971174 Make MemoryBuiltins aware of TargetLibraryInfo.
This disables malloc-specific optimization when -fno-builtin (or -ffreestanding)
is specified. This has been a problem for a long time but became more severe
with the recent memory builtin improvements.

Since the memory builtin functions are used everywhere, this required passing
TLI in many places. This means that functions that now have an optional TLI
argument, like RecursivelyDeleteTriviallyDeadFunctions, won't remove dead
mallocs anymore if the TLI argument is missing. I've updated most passes to do
the right thing.

Fixes PR13694 and probably others.

llvm-svn: 162841
2012-08-29 15:32:21 +00:00
Nadav Rotem
465834c85f Clean whitespaces.
llvm-svn: 160668
2012-07-24 10:51:42 +00:00
Richard Osborne
0ab2b0df82 Fix assertion in jump threading (PR13405).
GetBestDestForJumpOnUndef() assumes there is at least 1 successor, which isn't
true if the block ends in an indirect branch with no successors. Fix this by
bailing out earlier in this case.

llvm-svn: 160546
2012-07-20 10:36:17 +00:00
Chris Lattner
87fa77bd8a enhance jump threading to preserve TBAA information when PRE'ing loads,
fixing rdar://11039258, an issue that came up when inspecting clang's 
bootstrapped codegen.

llvm-svn: 152635
2012-03-13 18:07:41 +00:00
Stepan Dyatkovskiy
5b648afb4d Taken into account Duncan's comments for r149481 dated by 2nd Feb 2012:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20120130/136146.html

Implemented CaseIterator and it solves almost all described issues: we don't need to mix operand/case/successor indexing anymore. Base iterator class is implemented as a template since it may be initialized either from "const SwitchInst*" or from "SwitchInst*".

ConstCaseIt is just a read-only iterator.
CaseIt is read-write iterator; it allows to change case successor and case value.

Usage of iterator allows totally remove resolveXXXX methods. All indexing convertions done automatically inside the iterator's getters.

Main way of iterator usage looks like this:
SwitchInst *SI = ... // intialize it somehow

for (SwitchInst::CaseIt i = SI->caseBegin(), e = SI->caseEnd(); i != e; ++i) {
  BasicBlock *BB = i.getCaseSuccessor();
  ConstantInt *V = i.getCaseValue();
  // Do something.
}

If you want to convert case number to TerminatorInst successor index, just use getSuccessorIndex iterator's method.
If you want initialize iterator from TerminatorInst successor index, use CaseIt::fromSuccessorIndex(...) method.

There are also related changes in llvm-clients: klee and clang.

llvm-svn: 152297
2012-03-08 07:06:20 +00:00
Stepan Dyatkovskiy
513aaa5691 SwitchInst refactoring.
The purpose of refactoring is to hide operand roles from SwitchInst user (programmer). If you want to play with operands directly, probably you will need lower level methods than SwitchInst ones (TerminatorInst or may be User). After this patch we can reorganize SwitchInst operands and successors as we want.

What was done:

1. Changed semantics of index inside the getCaseValue method:
getCaseValue(0) means "get first case", not a condition. Use getCondition() if you want to resolve the condition. I propose don't mix SwitchInst case indexing with low level indexing (TI successors indexing, User's operands indexing), since it may be dangerous.
2. By the same reason findCaseValue(ConstantInt*) returns actual number of case value. 0 means first case, not default. If there is no case with given value, ErrorIndex will returned.
3. Added getCaseSuccessor method. I propose to avoid usage of TerminatorInst::getSuccessor if you want to resolve case successor BB. Use getCaseSuccessor instead, since internal SwitchInst organization of operands/successors is hidden and may be changed in any moment.
4. Added resolveSuccessorIndex and resolveCaseIndex. The main purpose of these methods is to see how case successors are really mapped in TerminatorInst.
4.1 "resolveSuccessorIndex" was created if you need to level down from SwitchInst to TerminatorInst. It returns TerminatorInst's successor index for given case successor.
4.2 "resolveCaseIndex" converts low level successors index to case index that curresponds to the given successor.

Note: There are also related compatability fix patches for dragonegg, klee, llvm-gcc-4.0, llvm-gcc-4.2, safecode, clang.
llvm-svn: 149481
2012-02-01 07:49:51 +00:00
Jakub Staszak
f5b32e52db SplitBlockPredecessors uses ArrayRef instead of Data and Size.
llvm-svn: 146277
2011-12-09 21:19:53 +00:00
Chad Rosier
43a33066b4 Fix a few more places where TargetData/TargetLibraryInfo is not being passed.
Add FIXMEs to places that are non-trivial to fix.

llvm-svn: 145661
2011-12-02 01:26:24 +00:00
Eli Friedman
7c5dc122a0 Change a bunch of isVolatile() checks to check for atomic load/store as well.
No tests; these changes aren't really interesting in the sense that the logic is the same for volatile and atomic.

I believe this completes all of the changes necessary for the optimizer to handle loads and stores correctly.  I'm going to try and come up with some additional testing, though.

llvm-svn: 139533
2011-09-12 20:23:13 +00:00
Jakub Staszak
423651e46a Calculate GetBestDestForJumpOnUndef correctly.
llvm-svn: 133946
2011-06-27 21:51:12 +00:00
Frits van Bommel
ad964559ef Add a parameter to ConstantFoldTerminator() that callers can use to ask it to also clean up the condition of any conditional terminator it folds to be unconditional, if that turns the condition into dead code. This just means it calls RecursivelyDeleteTriviallyDeadInstructions() in strategic spots. It defaults to the old behavior.
I also changed -simplifycfg, -jump-threading and -codegenprepare to use this to produce slightly better code without any extra cleanup passes (AFAICT this was the only place in -simplifycfg where now-dead conditions of replaced terminators weren't being cleaned up). The only other user of this function is -sccp, but I didn't read that thoroughly enough to figure out whether it might be holding pointers to instructions that could be deleted by this.

llvm-svn: 131855
2011-05-22 16:24:18 +00:00
Devang Patel
306f8db721 Preserve line number information while threading jumps.
llvm-svn: 130880
2011-05-04 22:48:19 +00:00
Owen Anderson
92651ec374 Fix an infinite alternation in JumpThreading where two transforms would repeatedly undo each other. The solution is to perform more aggressive constant folding to make one of the edges just folded away rather than trying to thread it.
Fixes <rdar://problem/9284786>.

Discovered with CSmith.

llvm-svn: 129538
2011-04-14 21:35:50 +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
Chris Lattner
1a924e770a prevent jump threading from merging blocks when their address is
taken (and used!).  This prevents merging the blocks (invalidating
the block addresses) in a case like this:

#define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })

void foo() {
  printf("%p\n", _THIS_IP_);
  printf("%p\n", _THIS_IP_);
  printf("%p\n", _THIS_IP_);
}

which fixes PR4151.

llvm-svn: 125829
2011-02-18 04:43:06 +00:00
Frits van Bommel
9bbe849fc3 Fix a bug in the loop in JumpThreading::ProcessThreadableEdges() where it could falsely produce a MultipleDestSentinel value if the first predecessor ended with an 'indirectbr'. If that happened, it caused an unnecessary FindMostPopularDest() call.
This wasn't a correctness problem, but it broke the fast path for single-predecessor blocks.

llvm-svn: 121966
2010-12-16 12:16:00 +00:00
Frits van Bommel
3d1803495e Teach jump threading to "look through" a select when the branch direction of a terminator depends on it.
When it sees a promising select it now tries to figure out whether the condition of the select is known in any of the predecessors and if so it maps the operands appropriately.

llvm-svn: 121859
2010-12-15 09:51:20 +00:00
Chris Lattner
73a58627c3 simplify code and reduce indentation
llvm-svn: 121670
2010-12-13 02:38:13 +00:00
Frits van Bommel
d2f4b09e10 Remove some dead code from the jump threading pass.
The last uses of these functions were removed in r113852 when LazyValueInfo was permanently enabled and removed the need for them.

llvm-svn: 121133
2010-12-07 13:08:07 +00:00
Frits van Bommel
d9df6eaa9c Implement jump threading of 'indirectbr' by keeping track of whether we're looking for ConstantInt*s or BlockAddress*s.
llvm-svn: 121066
2010-12-06 23:36:56 +00:00
Frits van Bommel
76244867cf Refactor jump threading.
Should have no functional change other than the order of two transformations that are mutually-exclusive and the exact formatting of debug output.
Internally, it now stores the ConstantInt*s as Constant*s, and actual undef values instead of nulls.

llvm-svn: 120946
2010-12-05 19:06:41 +00:00
Frits van Bommel
5e75ef4a8e Remove trailing whitespace.
llvm-svn: 120945
2010-12-05 19:02:47 +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
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
99c985c37d Fix PR8247: JumpThreading can cause a block to become unreachable while still having predecessor, if it is part of a self-loop.
Because of this, we cannot use the Simplify* APIs, as they can assert-fail on unreachable code.  Since it's not easy to determine
if a given threading will cause a block to become unreachable, simply defer simplifying simplification to later InstCombine and/or
DCE passes.

llvm-svn: 115082
2010-09-29 20:34:41 +00:00
Owen Anderson
d361aac3d0 Remove the option to disable LazyValueInfo in JumpThreading, as it is now
on by default and has received significant testing.

llvm-svn: 113852
2010-09-14 20:57:41 +00:00
Chris Lattner
e6214557e7 Change lower atomic pass to use IntrinsicInst to simplify it a bit.
llvm-svn: 113114
2010-09-05 20:10:47 +00:00
Chris Lattner
05ef361b5e eliminate some non-obvious casts. UndefValue isa Constant.
llvm-svn: 113113
2010-09-05 20:03:09 +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
Owen Anderson
73f988cafa JumpThreading keeps LazyValueInfo up to date, so we don't need to rerun it
if we schedule another LVI-using pass afterwards.

llvm-svn: 112722
2010-09-01 18:27:22 +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
Owen Anderson
3c84ecb067 More cleanups of my JumpThreading transforms, including extracting some duplicated code into a helper function.
llvm-svn: 112634
2010-08-31 20:26:04 +00:00
Owen Anderson
6fdcb172a9 Add an RAII helper to make cleanup of the RecursionSet more fool-proof.
llvm-svn: 112628
2010-08-31 19:24:27 +00:00
Owen Anderson
cd4de7f399 Refactor my fix for PR5652 to terminate the predecessor lookups after the first failure.
llvm-svn: 112620
2010-08-31 18:48:48 +00:00
Owen Anderson
3997a07fb9 More Chris-inspired JumpThreading fixes: use ConstantExpr to correctly constant-fold undef, and be more careful with its return value.
This actually exposed an infinite recursion bug in ComputeValueKnownInPredecessors which theoretically already existed (in JumpThreading's
handling of and/or of i1's), but never manifested before.  This patch adds a tracking set to prevent this case.

llvm-svn: 112589
2010-08-31 07:36:34 +00:00
Owen Anderson
c910acb54a Re-apply r112539, being more careful to respect the return values of the constant folding methods. Additionally,
use the ConstantExpr::get*() methods to simplify some constant folding.

llvm-svn: 112550
2010-08-30 23:22:36 +00:00
Owen Anderson
1ddcbbe49c Revert r112539. It accidentally introduced a miscompilation.
llvm-svn: 112543
2010-08-30 22:33:41 +00:00
Owen Anderson
75f6037c7c Fixes and cleanups pointed out by Chris. In general, be careful to handle 0 results from ComputeValueKnownInPredecessors
(indicating undef), and re-use existing constant folding APIs.

llvm-svn: 112539
2010-08-30 22:07:52 +00:00
Owen Anderson
99d4cb861b Fix typos in comments.
llvm-svn: 112286
2010-08-27 20:32:56 +00:00
Owen Anderson
6ebbd92380 Use LVI to eliminate conditional branches where we've tested a related condition previously. Update tests for this change.
This fixes PR5652.

llvm-svn: 112270
2010-08-27 17:12:29 +00:00
Owen Anderson
bd2ecc7e68 Make JumpThreading smart enough to properly thread StrSwitch when it's compiled with clang++.
llvm-svn: 112198
2010-08-26 17:40:24 +00:00
Owen Anderson
7c853e877e Turn LVI on, previously detected failures should be fixed now.
llvm-svn: 111923
2010-08-24 17:21:18 +00:00
Owen Anderson
6ffa3f2aea Turn LVI back off, I have a testcase now.
llvm-svn: 111834
2010-08-23 19:59:27 +00:00
Owen Anderson
630add39a6 Re-enable LazyValueInfo. Monitoring for failures.
llvm-svn: 111816
2010-08-23 18:12:23 +00:00
Owen Anderson
aac8cbb261 Disable LVI while I evaluate a failure.
llvm-svn: 111551
2010-08-19 19:47:08 +00:00
Owen Anderson
5c87dd55d3 Tentatively enabled LVI by default. I'll be monitoring for any failures.
llvm-svn: 111543
2010-08-19 19:04:40 +00:00
Owen Anderson
208636fa33 Inform LazyValueInfo whenever a block is deleted, to avoid dangling pointer issues.
llvm-svn: 111382
2010-08-18 18:39:01 +00:00
Chris Lattner
3c603024bb Fix PR7755: knowing something about an inval for a pred
from the LHS should disable reconsidering that pred on the
RHS.  However, knowing something about the pred on the RHS
shouldn't disable subsequent additions on the RHS from
happening.

llvm-svn: 111349
2010-08-18 03:14:36 +00:00
Owen Anderson
a7aed18624 Reapply r110396, with fixes to appease the Linux buildbot gods.
llvm-svn: 110460
2010-08-06 18:33:48 +00:00
Owen Anderson
bda59bd247 Revert r110396 to fix buildbots.
llvm-svn: 110410
2010-08-06 00:23:35 +00:00
Owen Anderson
755aceb5d0 Don't use PassInfo* as a type identifier for passes. Instead, use the address of the static
ID member as the sole unique type identifier.  Clean up APIs related to this change.

llvm-svn: 110396
2010-08-05 23:42:04 +00:00
Owen Anderson
4674dd6cf5 Give JumpThreading+LVI a long-form cl::opt so that it's easier to toggle the default.
llvm-svn: 110384
2010-08-05 22:11:31 +00:00
Owen Anderson
aa7f66ba67 Add an initial implementation of LazyValueInfo updating for JumpThreading. Disabled for now.
llvm-svn: 109424
2010-07-26 18:48:03 +00:00
Owen Anderson
a57b97e7e7 Fix batch of converting RegisterPass<> to INTIALIZE_PASS().
llvm-svn: 109045
2010-07-21 22:09:45 +00:00
Gabor Greif
a5fa885d47 cache results of operator*
llvm-svn: 108142
2010-07-12 14:10:24 +00:00
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
use it instead of duplicating its functionality.

llvm-svn: 51499
2008-05-23 21:05:58 +00:00
Matthijs Kooijman
5148a4ba66 Fix typo.
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
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.
llvm-svn: 50881
2008-05-09 04:43:13 +00:00
Gordon Henriksen
829046b0b4 Improve pass documentation and comments.
Patch by Matthijs Kooijman!

llvm-svn: 50861
2008-05-08 17:46:35 +00:00
Chris Lattner
de68fabb35 fix typo Duncan noticed
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.
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
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
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.
llvm-svn: 50106
2008-04-22 20:46:09 +00:00
Chris Lattner
3df4c15dc7 Teach jump threading to thread through blocks like:
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.
llvm-svn: 50094
2008-04-22 06:36:15 +00:00
Chris Lattner
bab7bec9c8 fix grammar-o, thanks to Duncan for noticing.
llvm-svn: 50047
2008-04-21 18:25:01 +00:00
Chris Lattner
f6236cc2e9 Use the new SplitBlockPredecessors to implement a todo.
llvm-svn: 50022
2008-04-21 02:57:57 +00:00
Chris Lattner
ff1c6e388c finish the first cut of a jump threading pass implementation.
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.
llvm-svn: 50003
2008-04-20 21:18:09 +00:00
Chris Lattner
2115722ffa improve comments, infrastructure, and add some validity checks for threading.
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
such as those in PR2235.  Right now the pass is not very
effective. :)

llvm-svn: 50000
2008-04-20 20:35:01 +00:00