Commit Graph

31 Commits

Author SHA1 Message Date
Artur Pilipenko
f2e7bb5d2f Take alignment into account in isSafeToLoadUnconditionally
Reviewed By: hfinkel

Differential Revision: http://reviews.llvm.org/D10475


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240636 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-25 12:18:43 +00:00
Mehdi Amini
529919ff31 DataLayout is mandatory, update the API to reflect it with references.
Summary:
Now that the DataLayout is a mandatory part of the module, let's start
cleaning the codebase. This patch is a first attempt at doing that.

This patch is not exactly NFC as for instance some places were passing
a nullptr instead of the DataLayout, possibly just because there was a
default value on the DataLayout argument to many functions in the API.
Even though it is not purely NFC, there is no change in the
validation.

I turned as many pointer to DataLayout to references, this helped
figuring out all the places where a nullptr could come up.

I had initially a local version of this patch broken into over 30
independant, commits but some later commit were cleaning the API and
touching part of the code modified in the previous commits, so it
seemed cleaner without the intermediate state.

Test Plan:

Reviewers: echristo

Subscribers: llvm-commits

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231740 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 02:37:25 +00:00
Mehdi Amini
c94da20917 Make DataLayout Non-Optional in the Module
Summary:
DataLayout keeps the string used for its creation.

As a side effect it is no longer needed in the Module.
This is "almost" NFC, the string is no longer
canonicalized, you can't rely on two "equals" DataLayout
having the same string returned by getStringRepresentation().

Get rid of DataLayoutPass: the DataLayout is in the Module

The DataLayout is "per-module", let's enforce this by not
duplicating it more than necessary.
One more step toward non-optionality of the DataLayout in the
module.

Make DataLayout Non-Optional in the Module

Module->getDataLayout() will never returns nullptr anymore.

Reviewers: echristo

Subscribers: resistor, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D7992

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231270 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-04 18:43:29 +00:00
Mehdi Amini
a716c07147 Remove getDataLayout() from Instruction/GlobalValue/BasicBlock/Function
Summary:
This does not conceptually belongs here. Instead provide a shortcut
getModule() that provides access to the DataLayout.

Reviewers: chandlerc, echristo

Reviewed By: echristo

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8027

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231147 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-03 22:01:13 +00:00
Chandler Carruth
a87c35420b Revert r220349 to re-instate r220277 with a fix for PR21330 -- quite
clearly only exactly equal width ptrtoint and inttoptr casts are no-op
casts, it says so right there in the langref. Make the code agree.

Original log from r220277:
Teach the load analysis to allow finding available values which require
inttoptr or ptrtoint cast provided there is datalayout available.
Eventually, the datalayout can just be required but in practice it will
always be there today.

To go with the ability to expose available values requiring a ptrtoint
or inttoptr cast, helpers are added to perform one of these three casts.

These smarts are necessary to finish canonicalizing loads and stores to
the operational type requirements without regressing fundamental
combines.

I've added some test cases. These should actually improve as the load
combining and store combining improves, but they may fundamentally be
highlighting some missing combines for select in addition to exercising
the specific added logic to load analysis.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222739 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-25 08:20:27 +00:00
Hans Wennborg
ec4e924836 Revert "Teach the load analysis to allow finding available values which require" (r220277)
This seems to have caused PR21330.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220349 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-21 23:49:52 +00:00
Chandler Carruth
9156c5e3ba Teach the load analysis to allow finding available values which require
inttoptr or ptrtoint cast provided there is datalayout available.
Eventually, the datalayout can just be required but in practice it will
always be there today.

To go with the ability to expose available values requiring a ptrtoint
or inttoptr cast, helpers are added to perform one of these three casts.

These smarts are necessary to finish canonicalizing loads and stores to
the operational type requirements without regressing fundamental
combines.

I've added some test cases. These should actually improve as the load
combining and store combining improves, but they may fundamentally be
highlighting some missing combines for select in addition to exercising
the specific added logic to load analysis.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220277 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-21 09:00:40 +00:00
Chandler Carruth
3ac929c473 Fix a miscompile introduced in r220178.
The original code had an implicit assumption that if the test for
allocas or globals was reached, the two pointers were not equal. With my
changes to make the pointer analysis more powerful here, I also had to
guard against circumstances where the results weren't useful. That in
turn violated the assumption and gave rise to a circumstance in which we
could have a store with both the queried pointer and stored pointer
rooted at *the same* alloca. Clearly, we cannot ignore such a store.
There are other things we might do in this code to better handle the
case of both pointers ending up at the same alloca or global, but it
seems best to at least make the test explicit in what it intends to
check.

I've added tests for both the alloca and global case here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220190 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-20 10:03:01 +00:00
Chandler Carruth
35c4e071be Teach the load analysis driving core instcombine logic and other bits of
logic to look through pointer casts, making them trivially stronger in
the face of loads and stores with intervening pointer casts.

I've included a few test cases that demonstrate the kind of folding
instcombine can do without pointer casts and then variations which
obfuscate the logic through bitcasts. Without this patch, the variations
all fail to optimize fully.

This is more important now than it has been in the past as I've started
moving the load canonicialization to more closely follow the value type
requirements rather than the pointer type requirements and thus this
needs to be prepared for more pointer casts. When I made the same change
to stores several test cases regressed without logic along these lines
so I wanted to systematically improve matters first.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220178 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-20 00:24:14 +00:00
Chandler Carruth
908d4514f6 Fix a long-standing miscompile in the load analysis that was uncovered
by my refactoring of this code.

The method isSafeToLoadUnconditionally assumes that the load will
proceed with the preferred type alignment. Given that, it has to ensure
that the alloca or global is at least that aligned. It has always done
this historically when a datalayout is present, but has never checked it
when the datalayout is absent. When I refactored the code in r220156,
I exposed this path when datalayout was present and that turned the
latent bug into a patent bug.

This fixes the issue by just removing the special case which allows
folding things without datalayout. This isn't worth the complexity of
trying to tease apart when it is or isn't safe without actually knowing
the preferred alignment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220161 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-19 08:17:50 +00:00
Chandler Carruth
f84407be32 Switch how the datalayout availability test is handled in this code to
make much more sense and in theory be more correct.

If you trace the code alllll the way back to when it was first
introduced, the comments make it slightly more clear what was going on
here. At that time, the only way Base != V was if DL (then TD) was
non-null. As a consequence, if DL *was* null, that meant we were loading
directly from the alloca or global found above the test. After
refactoring, this has become at least terribly subtle and potentially
incorrect. There are many forms of pointer manipulation that can be
traversed without DataLayout, and some of them would in fact change the
size of object being loaded vs. allocated.

Rather than this subtlety, I've hoisted the actual 'return true' bits
into the code which actually found an alloca or global and based them on
the loaded pointer being that alloca or global. This is both more clear
and safer. I've also added comments about exactly why this set of
predicates is used.

I've also corrected a misleading comment about globals -- if overridden
they may not just have a different size, they may be null and completely
unsafe to load from!

Hopefully this confuses the next reader a bit less. I don't have any
test cases or anything, the patch is motivated strictly to improve the
readability of the code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220156 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-19 00:42:16 +00:00
Chandler Carruth
652627d301 Rename 'TD' to 'DL' in this function as the argument is now a DataLayout
argument.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220151 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-18 23:47:22 +00:00
Chandler Carruth
dacb8a615d Fix the other comment to use modern doxygen style and be a bit more
direct. Notably, comment on the fact that the loaded type is significant
in that it determines how wide of an access must be safe.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220150 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-18 23:46:17 +00:00
Chandler Carruth
28502a895a More formatting cleanup brought to you by clang-format.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220149 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-18 23:41:25 +00:00
Chandler Carruth
e99ca835bc Clean up doxygen syntax and reword comments to flow better, have a brief
section, and not have unfinished sentence fragments.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220147 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-18 23:31:55 +00:00
Chandler Carruth
01dc911c73 Clean up the formatting and trailing whitespace of a routine before
editting it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220146 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-18 23:19:03 +00:00
Hal Finkel
2c7c54c86c AA metadata refactoring (introduce AAMDNodes)
In order to enable the preservation of noalias function parameter information
after inlining, and the representation of block-level __restrict__ pointer
information (etc.), additional kinds of aliasing metadata will be introduced.
This metadata needs to be carried around in AliasAnalysis::Location objects
(and MMOs at the SDAG level), and so we need to generalize the current scheme
(which is hard-coded to just one TBAA MDNode*).

This commit introduces only the necessary refactoring to allow for the
introduction of other aliasing metadata types, but does not actually introduce
any (that will come in a follow-up commit). What it does introduce is a new
AAMDNodes structure to hold all of the aliasing metadata nodes associated with
a particular memory-accessing instruction, and uses that structure instead of
the raw MDNode* in AliasAnalysis::Location, etc.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213859 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-24 12:16:19 +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
Dan Gohman
a070d2a035 Change GetPointerBaseWithConstantOffset's DataLayout argument from a
reference to a pointer, so that it can handle the case where DataLayout
is not available and behave conservatively.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174024 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-31 02:00:45 +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
Nuno Lopes
1ef05b1a2a use ValueTracking's GetPointerBaseWithConstantOffset() function instead of a local implementation
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171307 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-31 17:42:11 +00:00
Micah Villmow
3574eca1b0 Move TargetData to DataLayout.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165402 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-08 16:38:25 +00:00
Chris Lattner
5161de6ebb 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152635 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-13 18:07:41 +00:00
Eli Friedman
c869b4397a Add some comments here because the lack of a check for volatile/atomic here is a bit unusual.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137662 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-15 21:56:39 +00:00
Jay Foad
8fbbb39807 Convert TargetData::getIndexedOffset to use ArrayRef.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135478 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-19 14:01:37 +00:00
Chris Lattner
db125cfaf5 land David Blaikie's patch to de-constify Type, with a few tweaks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135375 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-18 04:54:35 +00:00
Hans Wennborg
68df608fd1 Test commit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132558 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-03 17:15:37 +00:00
Jay Foad
562b84b3ae Don't include Operator.h from InstrTypes.h.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129271 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-11 09:35:34 +00:00
Dan Gohman
5034dd318a Move Value::getUnderlyingObject to be a standalone
function so that it can live in Analysis instead of
VMCore.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121885 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-15 20:02:24 +00:00
Dan Gohman
3da848bbda Reapply r116831 and r116839, converting AliasAnalysis to use
uint64_t, plus fixes for places I missed before.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116875 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-19 22:54:46 +00:00
Dan Gohman
dd9344f3fa Move FindAvailableLoadedValue isSafeToLoadUnconditionally out of
lib/Transforms/Utils and into lib/Analysis so that Analysis passes
can use them.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104949 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-28 16:19:17 +00:00