Commit Graph

121 Commits

Author SHA1 Message Date
Duncan P. N. Exon Smith
32791b02fa verify-di: Implement DebugInfoVerifier
Implement DebugInfoVerifier, which steals verification relying on
DebugInfoFinder from Verifier.

  - Adds LegacyDebugInfoVerifierPassPass, a ModulePass which wraps
    DebugInfoVerifier.  Uses -verify-di command-line flag.

  - Change verifyModule() to invoke DebugInfoVerifier as well as
    Verifier.

  - Add a call to createDebugInfoVerifierPass() wherever there was a
    call to createVerifierPass().

This implementation as a module pass should sidestep efficiency issues,
allowing us to turn debug info verification back on.

<rdar://problem/15500563>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206300 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-15 16:27:38 +00:00
Craig Topper
4ba844388c [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206142 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-14 00:51:57 +00:00
Mark Seaborn
9bb9615e1f Remove LowerInvoke's obsolete "-enable-correct-eh-support" option
This option caused LowerInvoke to generate code using SJLJ-based
exception handling, but there is no code left that interprets the
jmp_buf stack that the resulting code maintained (llvm.sjljeh.jblist).
This option has been obsolete for a while, and replaced by
SjLjEHPrepare.

This leaves the default behaviour of LowerInvoke, which is to convert
invokes to calls.

Differential Revision: http://llvm-reviews.chandlerc.com/D3136

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204388 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-20 19:54:47 +00:00
Juergen Ributzka
943ce55f39 Revert "Revert "Add Constant Hoisting Pass" (r200034)"
This reverts commit r200058 and adds the using directive for
ARMTargetTransformInfo to silence two g++ overload warnings.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200062 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 02:02:55 +00:00
Hans Wennborg
503793e834 Revert "Add Constant Hoisting Pass" (r200034)
This commit caused -Woverloaded-virtual warnings. The two new
TargetTransformInfo::getIntImmCost functions were only added to the superclass,
and to the X86 subclass. The other targets were not updated, and the
warning highlighted this by pointing out that e.g. ARMTTI::getIntImmCost was
hiding the two new getIntImmCost variants.

We could pacify the warning by adding "using TargetTransformInfo::getIntImmCost"
to the various subclasses, or turning it off, but I suspect that it's wrong to
leave the functions unimplemnted in those targets. The default implementations
return TCC_Free, which I don't think is right e.g. for ARM.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200058 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-25 01:18:18 +00:00
Juergen Ributzka
96172cb4a4 Add Constant Hoisting Pass
Retry commit r200022 with a fix for the build bot errors. Constant expressions
have (unlike instructions) module scope use lists and therefore may have users
in different functions. The fix is to simply ignore these out-of-function uses.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200034 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 20:18:00 +00:00
Juergen Ributzka
dc6f9b9a4f Revert "Add Constant Hoisting Pass"
This reverts commit r200022 to unbreak the build bots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200024 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 18:40:30 +00:00
Juergen Ributzka
fb282c68b7 Add Constant Hoisting Pass
This pass identifies expensive constants to hoist and coalesces them to
better prepare it for SelectionDAG-based code generation. This works around the
limitations of the basic-block-at-a-time approach.

First it scans all instructions for integer constants and calculates its
cost. If the constant can be folded into the instruction (the cost is
TCC_Free) or the cost is just a simple operation (TCC_BASIC), then we don't
consider it expensive and leave it alone. This is the default behavior and
the default implementation of getIntImmCost will always return TCC_Free.

If the cost is more than TCC_BASIC, then the integer constant can't be folded
into the instruction and it might be beneficial to hoist the constant.
Similar constants are coalesced to reduce register pressure and
materialization code.

When a constant is hoisted, it is also hidden behind a bitcast to force it to
be live-out of the basic block. Otherwise the constant would be just
duplicated and each basic block would have its own copy in the SelectionDAG.
The SelectionDAG recognizes such constants as opaque and doesn't perform
certain transformations on them, which would create a new expensive constant.

This optimization is only applied to integer constants in instructions and
simple (this means not nested) constant cast experessions. For example:
%0 = load i64* inttoptr (i64 big_constant to i64*)

Reviewed by Eric

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200022 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 18:23:08 +00:00
Andrew Trick
de0847d6a5 Hide the pre-RA-sched= option.
This is a very confusing option for a feature that will go away.

-enable-misched is exposed instead to help triage issues with the new
scheduler.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199133 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-13 20:08:27 +00:00
Chandler Carruth
56e1394c88 [cleanup] Move the Dominators.h and Verifier.h headers into the IR
directory. These passes are already defined in the IR library, and it
doesn't make any sense to have the headers in Analysis.

Long term, I think there is going to be a much better way to divide
these matters. The dominators code should be fully separated into the
abstract graph algorithm and have that put in Support where it becomes
obvious that evn Clang's CFGBlock's can use it. Then the verifier can
manually construct dominance information from the Support-driven
interface while the Analysis library can provide a pass which both
caches, reconstructs, and supports a nice update API.

But those are very long term, and so I don't want to leave the really
confusing structure until that day arrives.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199082 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-13 09:26:24 +00:00
Chandler Carruth
a5ced5ed37 [PM] Simplify the interface exposed for IR printing passes.
Nothing was using the ability of the pass to delete the raw_ostream it
printed to, and nothing was trying to pass it a pointer to the
raw_ostream. Also, the function variant had a different order of
arguments from all of the others which was just really confusing. Now
the interface accepts a reference, doesn't offer to delete it, and uses
a consistent order. The implementation of the printing passes haven't
been updated with this simplification, this is just the API switch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199044 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-12 11:30:46 +00:00
Chandler Carruth
8a5351f0f5 [PM] Rename the IR printing pass header to a more generic and correct
name to match the source file which I got earlier. Update the include
sites. Also modernize the comments in the header to use the more
recommended doxygen style.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199041 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-12 11:10:32 +00:00
Chandler Carruth
bc65a8d518 Move the LLVM IR asm writer header files into the IR directory, as they
are part of the core IR library in order to support dumping and other
basic functionality.

Rename the 'Assembly' include directory to 'AsmParser' to match the
library name and the only functionality left their -- printing has been
in the core IR library for quite some time.

Update all of the #includes to match.

All of this started because I wanted to have the layering in good shape
before I started adding support for printing LLVM IR using the new pass
infrastructure, and commandline support for the new pass infrastructure.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198688 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-07 12:34:26 +00:00
Andrew Trick
c5443a90d8 Stub out a PostMachineScheduler pass.
Placeholder and boilerplate for a PostRA MachineScheduler pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198120 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-28 21:56:51 +00:00
Josh Magee
5b6af7163d [stackprotector] Use analysis from the StackProtector pass for stack layout in PEI a nd LocalStackSlot passes.
This changes the MachineFrameInfo API to use the new SSPLayoutKind information
produced by the StackProtector pass (instead of a boolean flag) and updates a
few pass dependencies (to preserve the SSP analysis).

The stack layout follows the same approach used prior to this change - i.e.,
only LargeArray stack objects will be placed near the canary and everything
else will be laid out normally.  After this change, structures containing large
arrays will also be placed near the canary - a case previously missed by the
old implementation.

Out of tree targets will need to update their usage of
MachineFrameInfo::CreateStackObject to remove the MayNeedSP argument. 

The next patch will implement the rules for sspstrong and sspreq.  The end goal
is to support ssp-strong stack layout rules.

WIP.

Differential Revision: http://llvm-reviews.chandlerc.com/D2158


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197653 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-19 03:17:11 +00:00
Juergen Ributzka
aaecc0fc08 [Stackmap] Liveness Analysis Pass
This optional register liveness analysis pass can be enabled with either
-enable-stackmap-liveness, -enable-patchpoint-liveness, or both. The pass
traverses each basic block in a machine function. For each basic block the
instructions are processed in reversed order and if a patchpoint or stackmap
instruction is encountered the current live-out register set is encoded as a
register mask and attached to the instruction.

Later on during stackmap generation the live-out register mask is processed and
also emitted as part of the stackmap.

This information is optional and intended for optimization purposes only. This
will enable a client of the stackmap to reason about the registers it can use
and which registers need to be preserved.

Reviewed by Andy

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197317 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-14 06:53:06 +00:00
Andrew Trick
38c9ecda9b Revert "Liveness Analysis Pass"
This reverts commit r197254.

This was an accidental merge of Juergen's patch. It will be checked in
shortly, but wasn't meant to go in quite yet.

Conflicts:
	include/llvm/CodeGen/StackMaps.h
	lib/CodeGen/StackMaps.cpp
	test/CodeGen/X86/stackmap-liveness.ll

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197260 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-13 18:57:20 +00:00
Andrew Trick
539e93120c Liveness Analysis Pass
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197254 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-13 18:37:03 +00:00
Vincent Lejeune
d254d3111e Add a RequireStructuredCFG Field to TargetMachine.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196634 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-07 01:49:19 +00:00
Rafael Espindola
67b28826cd Remove the now unused strong phi elimination pass.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192604 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-14 16:39:04 +00:00
Andrew Trick
b6ac11cd03 Added temp flag -misched-bench for staging in default changes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191423 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-26 05:53:35 +00:00
Benjamin Kramer
f8e16c6f5a Don't leak passes if added outside of the area determined by Started/Stopped flags.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187722 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-05 11:11:11 +00:00
Craig Topper
f22fd3f7b5 Use SmallVectorImpl instead of SmallVector for iterators and references to avoid specifying the vector size unnecessarily.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185512 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-03 05:11:49 +00:00
Bill Wendling
f9fd58a44b Access the TargetLoweringInfo from the TargetMachine object instead of caching it. The TLI may change between functions. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184352 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-19 21:07:11 +00:00
Bill Wendling
ea44281d5d Access the TargetLoweringInfo from the TargetMachine object instead of caching it. The TLI may change between functions. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184349 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-19 20:51:24 +00:00
Bill Wendling
3b1040c703 The DWARF EH pass doesn't need the TargetMachine, only the TargetLoweringBase like the other EH passes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182321 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-20 21:54:18 +00:00
Benjamin Kramer
fdca221290 Add braces around || in && to pacify GCC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179275 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-11 11:57:01 +00:00
Andrew Trick
5ed028385c Generalize the PassConfig API and remove addFinalizeRegAlloc().
The target hooks are getting out of hand. What does it mean to run
before or after regalloc anyway? Allowing either Pass* or AnalysisID
pass identification should make it much easier for targets to use the
substitutePass and insertPass APIs, and create less need for badly
named target hooks.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179140 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-10 01:06:56 +00:00
Benjamin Kramer
74a4533a42 Remove the old CodePlacementOpt pass.
It was superseded by MachineBlockPlacement and disabled by default since LLVM 3.1.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178349 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-29 17:14:24 +00:00
Bill Wendling
69d37fa635 Remove unused #includes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176467 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-05 01:00:45 +00:00
Cameron Zwarich
d7c7a686ac Fix a typo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174830 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-10 06:42:34 +00:00
Jakob Stoklund Olesen
02c6325a45 Provide a place for targets to insert ILP optimization passes.
Move the early if-conversion pass into this group.

ILP optimizations usually need to find the right balance between
register pressure and ILP using the MachineTraceMetrics analysis to
identify critical paths and estimate other costs. Such passes should run
together so they can share dominator tree and loop info analyses.

Besides if-conversion, future passes to run here here could include
expression height reduction and ARM's MLxExpansion pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172687 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-17 00:58:38 +00:00
Chandler Carruth
e4ba75f43e Switch the SCEV expander and LoopStrengthReduce to use
TargetTransformInfo rather than TargetLowering, removing one of the
primary instances of the layering violation of Transforms depending
directly on Target.

This is a really big deal because LSR used to be a "special" pass that
could only be tested fully using llc and by looking at the full output
of it. It also couldn't run with any other loop passes because it had to
be created by the backend. No longer is this true. LSR is now just
a normal pass and we should probably lift the creation of LSR out of
lib/CodeGen/Passes.cpp and into the PassManagerBuilder. =] I've not done
this, or updated all of the tests to use opt and a triple, because
I suspect someone more familiar with LSR would do a better job. This
change should be essentially without functional impact for normal
compilations, and only change behvaior of targetless compilations.

The conversion required changing all of the LSR code to refer to the TTI
interfaces, which fortunately are very similar to TargetLowering's
interfaces. However, it also allowed us to *always* expect to have some
implementation around. I've pushed that simplification through the pass,
and leveraged it to simplify code somewhat. It required some test
updates for one of two things: either we used to skip some checks
altogether but now we get the default "no" answer for them, or we used
to have no information about the target and now we do have some.

I've also started the process of removing AddrMode, as the TTI interface
doesn't use it any longer. In some cases this simplifies code, and in
others it adds some complexity, but I think it's not a bad tradeoff even
there. Subsequent patches will try to clean this up even further and use
other (more appropriate) abstractions.

Yet again, almost all of the formatting changes brought to you by
clang-format. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171735 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-07 14:41:08 +00:00
Evan Cheng
ab37b2c4bb Add targets to skip running the GC passes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170836 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-21 02:57:04 +00:00
Chandler Carruth
d04a8d4b33 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. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169131 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-03 16:50:05 +00:00
Bill Wendling
08510b14d4 Replace r168930 with a more reasonable patch.
The original patch removed a bunch of code that the SjLjEHPrepare pass placed
into the entry block if all of the landing pads were removed during the
CodeGenPrepare class. The more natural way of doing things is to run the CGP
*before* we run the SjLjEHPrepare pass.

Make it so!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169044 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-30 22:08:55 +00:00
Craig Topper
8f54a53f0e Move else onto line with preceding closing brace.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168294 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-19 00:11:50 +00:00
Andrew Trick
ad1cc1d1bf misched: Allow subtargets to enable misched and dependent options.
This allows me to begin enabling (or backing out) misched by default
for one subtarget at a time. To run misched we typically want to:
- Disable SelectionDAG scheduling (use the source order scheduler)
- Enable more aggressive coalescing (until we decide to always run the coalescer this way)
- Enable MachineScheduler pass itself.

Disabling PostRA sched may follow for some subtargets.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167826 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-13 08:47:29 +00:00
Nadav Rotem
a04a4a79ea revert r166264 because the LTO build is still failing
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166340 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-19 21:28:43 +00:00
Nadav Rotem
725f1d1280 recommit the patch that makes LSR and LowerInvoke use the TargetTransform interface.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166264 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-19 04:27:49 +00:00
Bob Wilson
3b9a911efc Temporarily revert the TargetTransform changes.
The TargetTransform changes are breaking LTO bootstraps of clang.  I am
working with Nadav to figure out the problem, but I am reverting it for now
to get our buildbots working.

This reverts svn commits: 165665 165669 165670 165786 165787 165997
and I have also reverted clang svn 165741

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166168 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-18 05:43:52 +00:00
Nadav Rotem
e3d0e86919 Add a new interface to allow IR-level passes to access codegen-specific information.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165665 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-10 22:04:55 +00:00
Jakob Stoklund Olesen
0d141f867d The early if conversion pass is ready to be used as an opt-in.
Enable the pass by default for targets that request it, and change the
-enable-early-ifcvt to the opposite -disable-early-ifcvt.

There are still some x86 regressions when enabling early if-conversion
because of the missing machine models. Disable the pass for x86 until
machine models are added.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165075 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-03 00:51:32 +00:00
Nadav Rotem
c05d30601c Add a new optimization pass: Stack Coloring, that merges disjoint static allocations (allocas). Allocas are known to be
disjoint if they are marked by disjoint lifetime markers (@llvm.lifetime.XXX intrinsics).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163299 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-06 09:17:37 +00:00
Roman Divacky
5932429765 Stop casting away const qualifier needlessly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163258 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-05 22:26:57 +00:00
Jakob Stoklund Olesen
228e3f5fac Add a verification pass after ExpandISelPseudos.
This pass often has weird CFG hacks and hand-written MI building code
that can go wrong in many ways.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162224 91177308-0d34-0410-b5e6-96231b3b80d8
2012-08-20 20:52:08 +00:00
Jakob Stoklund Olesen
dcc4436cdd Add an experimental -early-live-intervals option.
This option runs LiveIntervals before TwoAddressInstructionPass which
will eventually learn to exploit and update the analysis.

Eventually, LiveIntervals will run before PHIElimination, and we can get
rid of LiveVariables.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161270 91177308-0d34-0410-b5e6-96231b3b80d8
2012-08-03 22:12:54 +00:00
Jakob Stoklund Olesen
f86c00f1f8 Make sure -print-machineinstrs applies to the first pass as well.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159720 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-04 19:28:27 +00:00
Jakob Stoklund Olesen
33242fd3ed Add an experimental early if-conversion pass, off by default.
This pass performs if-conversion on SSA form machine code by
speculatively executing both sides of the branch and using a cmov
instruction to select the result. This can help lower the number of
branch mispredictions on architectures like x86 that don't have
predicable instructions.

The current implementation is very aggressive, and causes regressions on
mosts tests. It needs good heuristics that have yet to be implemented.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159694 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-04 00:09:54 +00:00
Chandler Carruth
6068c48498 All glory to address sanitizer. ;]
It appears to have caught a use-after-free introduced as by r159567
and/or friends which call 'addPass' from many more places. The bug in
'addPass' doesn't appear to be new, and was spotted by inspection when
ASan shown a bright light of a stacktrace at these functions.

Hopefully this will fix the ASan failure -- I have no test case other
than running an ASan-built clang over the test suite.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159614 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-02 22:56:41 +00:00