Commit Graph

214 Commits

Author SHA1 Message Date
Dinesh Dwivedi
c2b11baf5f This patch removed duplicate code for matching patterns
which are now handled in SimplifyUsingDistributiveLaws() 
(after r211261)

Differential Revision: http://reviews.llvm.org/D4253



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211768 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-26 08:57:33 +00:00
Nick Lewycky
fe3a219355 Move optimization of some cases of (A & C1)|(B & C2) from instcombine to instsimplify. Patch by Rahul Jain, plus some last minute changes by me -- you can blame me for any bugs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211252 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-19 03:51:46 +00:00
Nick Lewycky
650b6ea893 Make instsimplify's analysis of icmp eq/ne use computeKnownBits to determine whether the icmp is always true or false. Patch by Suyog Sarda!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211251 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-19 03:35:49 +00:00
David Majnemer
3258443195 InstSimplify: Improve handling of ashr/lshr
Summary:
Analyze the range of values produced by ashr/lshr cst, %V when it is
being used in an icmp.

Reviewers: nicholas

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D3774

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209000 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-16 17:14:03 +00:00
David Majnemer
7a2ed26563 InstSimplify: Optimize using dividend in sdiv
Summary:
The dividend in an sdiv tells us the largest and smallest possible
results.  Use this fact to optimize comparisons against an sdiv with a
constant dividend.

Reviewers: nicholas

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D3795

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208999 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-16 16:57:04 +00:00
David Majnemer
cd237ed585 InstSimplify: Optimize signed icmp of -(zext V)
Summary:
We know that -(zext V) will always be <= zero, simplify signed icmps
that have these.

Uncovered using http://www.cs.utah.edu/~regehr/souper/

Reviewers: nicholas

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D3754

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208809 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-14 20:16:28 +00:00
Chandler Carruth
4da253756d [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE
definition below all the header #include lines, lib/Analysis/...
edition.

This one has a bit extra as there were *other* #define's before #include
lines in addition to DEBUG_TYPE. I've sunk all of them as a block.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206843 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-22 02:48:03 +00:00
Craig Topper
570e52c6f1 [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@206243 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-15 04:59:12 +00:00
Chandler Carruth
36b699f2b1 [C++11] Add range based accessors for the Use-Def chain of a Value.
This requires a number of steps.
1) Move value_use_iterator into the Value class as an implementation
   detail
2) Change it to actually be a *Use* iterator rather than a *User*
   iterator.
3) Add an adaptor which is a User iterator that always looks through the
   Use to the User.
4) Wrap these in Value::use_iterator and Value::user_iterator typedefs.
5) Add the range adaptors as Value::uses() and Value::users().
6) Update *all* of the callers to correctly distinguish between whether
   they wanted a use_iterator (and to explicitly dig out the User when
   needed), or a user_iterator which makes the Use itself totally
   opaque.

Because #6 requires churning essentially everything that walked the
Use-Def chains, I went ahead and added all of the range adaptors and
switched them to range-based loops where appropriate. Also because the
renaming requires at least churning every line of code, it didn't make
any sense to split these up into multiple commits -- all of which would
touch all of the same lies of code.

The result is still not quite optimal. The Value::use_iterator is a nice
regular iterator, but Value::user_iterator is an iterator over User*s
rather than over the User objects themselves. As a consequence, it fits
a bit awkwardly into the range-based world and it has the weird
extra-dereferencing 'operator->' that so many of our iterators have.
I think this could be fixed by providing something which transforms
a range of T&s into a range of T*s, but that *can* be separated into
another patch, and it isn't yet 100% clear whether this is the right
move.

However, this change gets us most of the benefit and cleans up
a substantial amount of code around Use and User. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203364 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-09 03:16:01 +00:00
Chandler Carruth
19d764fb05 [Modules] Move the ConstantRange class into the IR library. This is
a bit surprising, as the class is almost entirely abstracted away from
any particular IR, however it encodes the comparsion predicates which
mutate ranges as ICmp predicate codes. This is reasonable as they're
used for both instructions and constants. Thus, it belongs in the IR
library with instructions and constants.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202838 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-04 12:24:34 +00:00
Chandler Carruth
eb3d76da81 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202821 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-04 11:17:44 +00:00
Chandler Carruth
df3d8e8b4d [Modules] Move the LLVM IR pattern match header into the IR library, it
obviously is coupled to the IR.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202818 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-04 11:08:18 +00:00
Chandler Carruth
bd7cba0d81 [Modules] Move GetElementPtrTypeIterator into the IR library. As its
name might indicate, it is an iterator over the types in an instruction
in the IR.... You see where this is going.

Another step of modularizing the support library.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202815 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-04 10:40:04 +00:00
Rafael Espindola
f116e5308d 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201827 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-21 00:06:31 +00:00
Benjamin Kramer
c166623dcd InstSimplify: Make shift, select and GEP simplifications vector-aware.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200016 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 17:09:53 +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
974a445bd9 Re-sort all of the includes with ./utils/sort_includes.py so that
subsequent changes are easier to review. About to fix some layering
issues, and wanted to separate out the necessary churn.

Also comment and sink the include of "Windows.h" in three .inc files to
match the usage in Memory.inc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198685 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-07 11:48:04 +00:00
Benjamin Kramer
6629210aaf Teach MemoryBuiltins and InstructionSimplify that operator new never returns NULL.
This is safe per C++11 18.6.1.1p3: [operator new returns] a non-null pointer to
suitably aligned storage (3.7.4), or else throw a bad_alloc exception. This
requirement is binding on a replacement version of this function.

Brings us a tiny bit closer to eliminating more vector push_backs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191310 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-24 16:37:51 +00:00
Benjamin Kramer
baca5334db InstSimplify: Fold equality comparisons between non-inbounds GEPs.
Overflow doesn't affect the correctness of equalities. Computing this is cheap,
we just reuse the computation for the inbounds case and try to peel of more
non-inbounds GEPs. This pattern is unlikely to ever appear in code generated by
Clang, but SCEV occasionally produces it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191200 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-23 14:16:38 +00:00
Hal Finkel
41418d17cc Add ISD::FROUND for libm round()
All libm floating-point rounding functions, except for round(), had their own
ISD nodes. Recent PowerPC cores have an instruction for round(), and so here I'm
adding ISD::FROUND so that round() can be custom lowered as well.

For the most part, this is straightforward. I've added an intrinsic
and a matching ISD node just like those for nearbyint() and friends. The
SelectionDAG pattern I've named frnd (because ISD::FP_ROUND has already claimed
fround).

This will be used by the PowerPC backend in a follow-up commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187926 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-07 22:49:12 +00:00
Matt Arsenault
6b4dde71cf Minor address space code simplification.
Remove assertion that the verifier should catch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187692 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-03 01:03:12 +00:00
Matt Arsenault
7eef3bdd7b Teach InstructionSimplify about pointer address spaces
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187635 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-02 00:10:44 +00:00
Nick Lewycky
8a23270ce6 Fix logic error optimizing "icmp pred (urem X, Y), Y" where pred is signed.
Fixes PR16605.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186229 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-12 23:42:57 +00:00
David Majnemer
8c5c6f0e09 InstSimplify: X >> X -> 0
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185973 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-09 22:01:22 +00:00
NAKAMURA Takumi
92c3742319 InstructionSimplify.cpp: Fix a ligature, "fi", to get rid of utf8 in comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179066 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-08 23:05:21 +00:00
Michael Ilseman
f89de816ae Identify and simplify idempotent intrinsics. Test case included.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174650 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-07 19:26:05 +00:00
Benjamin Kramer
d9f32c20da InstSimplify: stripAndComputeConstantOffsets can be called with vectors of pointers too.
Prepare it for vectors of pointers and handle simple cases. We don't handle
complicated cases because accumulateConstantOffset bails on pointer vectors.
Fixes selfhost on i386.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174179 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-01 15:21:10 +00:00
Dan Gohman
901261d558 Add a comment explaining an unavailable optimization.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174131 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-01 00:49:06 +00:00
Dan Gohman
fdd1eafe86 Rewrite instsimplify's handling if icmp on pointer values to remove the
remaining use of AliasAnalysis concepts such as isIdentifiedObject to
prove pointer inequality.

@external_compare in test/Transforms/InstSimplify/compare.ll shows a simple
case where a noalias argument can be equal to a global variable address, and
while AliasAnalysis can get away with saying that these pointers don't alias,
instsimplify cannot say that they are not equal.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174122 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-01 00:11:13 +00:00
Dan Gohman
ac08785eda An alloca can be equal to an argument. It can't *alias* an alloca, but it could
be equal, since there's nothing preventing a caller from correctly predicting
the stack location of an alloca.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174119 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-31 23:49:33 +00:00
Dan Gohman
3e3de565e9 Change stripAndComputeConstantOffsets to accept a NULL DataLayout pointer
as well.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174030 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-31 02:50:36 +00:00
Dan Gohman
819f9d6bf9 Add a comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174028 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-31 02:45:26 +00:00
Dan Gohman
5f1686f0b0 Minor code simplification.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174005 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-31 00:32:11 +00:00
Dan Gohman
f2335dcb17 stripAndComputeConstantOffsets is only called on pointers; check this
with an assert instead of failing and requiring callers to check for failure.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173998 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-31 00:12:20 +00:00
Chandler Carruth
0b8c9a80f2 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171366 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-02 11:36:10 +00:00
Chandler Carruth
a84e7508eb Nuke some dead code that snuck in some how. I thought I had already
deleted this, but apparantly not. Charmingly, Clang didn't warn on it
but GCC did.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171197 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-28 14:50:51 +00:00
Chandler Carruth
e949aa1c91 Teach instsimplify to use the constant folder where appropriate for
constant folding calls. Add the initial tests for this which show that
now instsimplify can simplify blindingly obvious code patterns expressed
with both intrinsics and library calls.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171194 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-28 14:23:29 +00:00
Chandler Carruth
c98bd9f1a7 Add entry points to instsimplify for simplifying calls. The entry points
are nice and decomposed so that we can simplify synthesized calls as
easily as actually call instructions. The internal utility still has the
same behavior, it just now operates on a more generic interface so that
I can extend the set of call simplifications that instsimplify knows
about.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171189 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-28 11:30:55 +00:00
Rafael Espindola
dbaa2376f7 Rename isPowerOfTwo to isKnownToBeAPowerOfTwo.
In a previous thread it was pointed out that isPowerOfTwo is not a very precise
name since it can return false for powers of two if it is unable to show that
they are powers of two.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170093 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-13 03:37:24 +00:00
Rafael Espindola
b09c146b11 The TargetData is not used for the isPowerOfTwo determination. It has never
been used in the first place.  It simply was passed to the function and to the
recursive invocations.  Simply drop the parameter and update the callers for the
new signature.

Patch by Saleem Abdulrasool!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169988 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-12 16:52:40 +00:00
Michael Ilseman
d0a0d221da Have SimplifyBinOp call the new FAdd/FSub/FMul helpers, with fast-math flags off
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169943 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-12 00:29:16 +00:00
Michael Ilseman
09ee250e72 Added a slew of SimplifyInstruction floating-point optimizations, many of which take advantage of fast-math flags. Test cases included.
fsub X, +0 ==> X
  fsub X, -0 ==> X, when we know X is not -0
  fsub +/-0.0, (fsub -0.0, X) ==> X
  fsub nsz +/-0.0, (fsub +/-0.0, X) ==> X
  fsub nnan ninf X, X ==> 0.0
  fadd nsz X, 0 ==> X
  fadd [nnan ninf] X, (fsub [nnan ninf] 0, X) ==> 0
    where nnan and ninf have to occur at least once somewhere in this expression
  fmul X, 1.0 ==> X



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169940 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-12 00:27:46 +00:00
Chandler Carruth
7550f96b2f Holding my nose and moving the accumulation routine to GEPOperator
instead of the instruction. I've left a forwarding wrapper for the
instruction so users with the instruction don't need to create
a GEPOperator themselves.

This lets us remove the copy of this code in instsimplify.

I've looked at most of the other copies of similar code, and this is the
only one I've found that is actually exactly the same. The one in
InlineCost is very close, but it requires re-mapping non-constant
indices through the cost analysis value simplification map. I could add
direct support for this to the generic routine, but it seems overly
specific.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169853 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-11 11:05:15 +00:00
Michael Ilseman
1638b83909 Reorganize FastMathFlags to be a wrapper around unsigned, and streamline some interfaces.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169712 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-09 21:12:04 +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
Michael Ilseman
eb61c920f1 Fast-math optimization: fold multiply by zero
Added in first optimization using fast-math flags to serve as an example for following optimizations. SimplifyInstruction will now try to optimize an fmul observing its FastMathFlags to see if it can fold multiply by zero when 'nnan' and 'nsz' flags are set.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168648 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-27 00:46:26 +00:00
Duncan Sands
4f0dfbb454 Make this easier to understand, as suggested by Chandler.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168196 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-16 20:53:08 +00:00
Duncan Sands
aceb03eb58 InstructionSimplify should be able to simplify A+B==B+A to 'true'
but wasn't due to the same logic bug that caused PR14361.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168186 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-16 19:41:26 +00:00
Chandler Carruth
426c2bf5cd Revert the majority of the next patch in the address space series:
r165941: Resubmit the changes to llvm core to update the functions to
         support different pointer sizes on a per address space basis.

Despite this commit log, this change primarily changed stuff outside of
VMCore, and those changes do not carry any tests for correctness (or
even plausibility), and we have consistently found questionable or flat
out incorrect cases in these changes. Most of them are probably correct,
but we need to devise a system that makes it more clear when we have
handled the address space concerns correctly, and ideally each pass that
gets updated would receive an accompanying test case that exercises that
pass specificaly w.r.t. alternate address spaces.

However, from this commit, I have retained the new C API entry points.
Those were an orthogonal change that probably should have been split
apart, but they seem entirely good.

In several places the changes were very obvious cleanups with no actual
multiple address space code added; these I have not reverted when
I spotted them.

In a few other places there were merge conflicts due to a cleaner
solution being implemented later, often not using address spaces at all.
In those cases, I've preserved the new code which isn't address space
dependent.

This is part of my ongoing effort to clean out the partial address space
code which carries high risk and low test coverage, and not likely to be
finished before the 3.2 release looms closer. Duncan and I would both
like to see the above issues addressed before we return to these
changes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167222 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-01 09:14:31 +00:00
Chandler Carruth
ece6c6bb63 Revert the series of commits starting with r166578 which introduced the
getIntPtrType support for multiple address spaces via a pointer type,
and also introduced a crasher bug in the constant folder reported in
PR14233.

These commits also contained several problems that should really be
addressed before they are re-committed. I have avoided reverting various
cleanups to the DataLayout APIs that are reasonable to have moving
forward in order to reduce the amount of churn, and minimize the number
of commits that were reverted. I've also manually updated merge
conflicts and manually arranged for the getIntPtrType function to stay
in DataLayout and to be defined in a plausible way after this revert.

Thanks to Duncan for working through this exact strategy with me, and
Nick Lewycky for tracking down the really annoying crasher this
triggered. (Test case to follow in its own commit.)

After discussing with Duncan extensively, and based on a note from
Micah, I'm going to continue to back out some more of the more
problematic patches in this series in order to ensure we go into the
LLVM 3.2 branch with a reasonable story here. I'll send a note to
llvmdev explaining what's going on and why.

Summary of reverted revisions:

r166634: Fix a compiler warning with an unused variable.
r166607: Add some cleanup to the DataLayout changes requested by
         Chandler.
r166596: Revert "Back out r166591, not sure why this made it through
         since I cancelled the command. Bleh, sorry about this!
r166591: Delete a directory that wasn't supposed to be checked in yet.
r166578: Add in support for getIntPtrType to get the pointer type based
         on the address space.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167221 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-01 08:07:29 +00:00