Commit Graph

198 Commits

Author SHA1 Message Date
Rui Ueyama c487f7728e Revert "r214897 - Remove dead zero store to calloc initialized memory"
It broke msan.

llvm-svn: 214989
2014-08-06 19:30:38 +00:00
Philip Reames 00c9b6461f Remove dead zero store to calloc initialized memory
Optimize the following IR:

%1 = tail call noalias i8* @calloc(i64 1, i64 4)
%2 = bitcast i8* %1 to i32*
; This store is dead and should be removed
store i32 0, i32* %2, align 4

Memory returned by calloc is guaranteed to be zero initialized. If the value being stored is the constant zero (and the store is not otherwise observable across threads), we can delete the store.  If the store is to an out of bounds address, it is undefined and thus also removable.

Reviewed By: nicholas

Differential Revision: http://reviews.llvm.org/D3942

llvm-svn: 214897
2014-08-05 17:48:20 +00:00
Duncan P. N. Exon Smith 6c99015fe2 Revert "[C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges."
This reverts commit r213474 (and r213475), which causes a miscompile on
a stage2 LTO build.  I'll reply on the list in a moment.

llvm-svn: 213562
2014-07-21 17:06:51 +00:00
Manuel Jacob d11beffef4 [C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges.
Summary: This patch introduces two new iterator ranges and updates existing code to use it.  No functional change intended.

Test Plan: All tests (make check-all) still pass.

Reviewers: dblaikie

Reviewed By: dblaikie

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D4481

llvm-svn: 213474
2014-07-20 09:10:11 +00:00
Craig Topper f40110f4d8 [C++] Use 'nullptr'. Transforms edition.
llvm-svn: 207196
2014-04-25 05:29:35 +00:00
Chandler Carruth 964daaaf19 [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE
definition below all of the header #include lines, lib/Transforms/...
edition.

This one is tricky for two reasons. We again have a couple of passes
that define something else before the includes as well. I've sunk their
name macros with the DEBUG_TYPE.

Also, InstCombine contains headers that need DEBUG_TYPE, so now those
headers #define and #undef DEBUG_TYPE around their code, leaving them
well formed modular headers. Fixing these headers was a large motivation
for all of these changes, as "leaky" macros of this form are hard on the
modules implementation.

llvm-svn: 206844
2014-04-22 02:55:47 +00:00
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
Benjamin Kramer 9c794c7a7c [C++11] Remove a leftover std::function instance.
It's not needed anymore.

llvm-svn: 202748
2014-03-03 19:49:02 +00:00
Chandler Carruth d031fe9fcf [C++11] Remove the completely unnecessary requirement on SetVector's
remove_if that its predicate is adaptable. We don't actually need this,
we can write a generic adapter for any predicate.

This lets us remove some very wrong std::function usages. We should
never be using std::function for predicates to algorithms. This incurs
an *indirect* call overhead for every evaluation of the predicate, and
makes it very hard to inline through.

llvm-svn: 202742
2014-03-03 19:28:52 +00:00
Benjamin Kramer b6d0bd48bd [C++11] Replace llvm::next and llvm::prior with std::next and std::prev.
Remove the old functions.

llvm-svn: 202636
2014-03-02 12:27:27 +00:00
Benjamin Kramer 3a377bce4e Now that we have C++11, turn simple functors into lambdas and remove a ton of boilerplate.
No intended functionality change.

llvm-svn: 202588
2014-03-01 11:47:00 +00:00
Rafael Espindola 6d6e87be9f Factor out calls to AA.getDataLayout().
llvm-svn: 202157
2014-02-25 15:52:19 +00:00
Rafael Espindola 5f57f462a8 Rename a few more DataLayout variables from TD to DL.
llvm-svn: 201870
2014-02-21 18:34:28 +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
Reid Kleckner 26af2cae05 Update optimization passes to handle inalloca arguments
Summary:
I searched Transforms/ and Analysis/ for 'ByVal' and updated those call
sites to check for inalloca if appropriate.

I added tests for any change that would allow an optimization to fire on
inalloca.

Reviewers: nlewycky

Differential Revision: http://llvm-reviews.chandlerc.com/D2449

llvm-svn: 200281
2014-01-28 02:38:36 +00:00
Chandler Carruth 73523021d0 [PM] Split DominatorTree into a concrete analysis result object which
can be used by both the new pass manager and the old.

This removes it from any of the virtual mess of the pass interfaces and
lets it derive cleanly from the DominatorTreeBase<> template. In turn,
tons of boilerplate interface can be nuked and it turns into a very
straightforward extension of the base DominatorTree interface.

The old analysis pass is now a simple wrapper. The names and style of
this split should match the split between CallGraph and
CallGraphWrapperPass. All of the users of DominatorTree have been
updated to match using many of the same tricks as with CallGraph. The
goal is that the common type remains the resulting DominatorTree rather
than the pass. This will make subsequent work toward the new pass
manager significantly easier.

Also in numerous places things became cleaner because I switched from
re-running the pass (!!! mid way through some other passes run!!!) to
directly recomputing the domtree.

llvm-svn: 199104
2014-01-13 13:07:17 +00:00
Chandler Carruth 5ad5f15cff [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.

llvm-svn: 199082
2014-01-13 09:26:24 +00:00
Dan Gohman 20a2ae9df5 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.

llvm-svn: 174024
2013-01-31 02:00:45 +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
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
Benjamin Kramer 650b1dbd56 Unquadratize SetVector removal loops in DSE.
Erasing from the beginning or middle of the vector is expensive, remove_if can
do it in linear time even though it's a bit ugly without lambdas.

No functionality change.

llvm-svn: 165903
2012-10-14 10:21:31 +00:00
Micah Villmow cdfe20b97f Move TargetData to DataLayout.
llvm-svn: 165402
2012-10-08 16:38:25 +00:00
Nick Lewycky 42bca056e0 Don't forget that strcpy and friends return a pointer to the destination, so
it's not a dead store if that pointer is used. Whoops!

llvm-svn: 164583
2012-09-25 01:55:59 +00:00
Nick Lewycky 627d217727 Remove unused name of variable to quiet a warning. Also canonicalize a
declaration to use the same form as in the rest of the file. No functionality
change.

llvm-svn: 164576
2012-09-24 23:47:23 +00:00
Nick Lewycky 9f4729d331 Teach DSE that strcpy, strncpy, strcat and strncat are all stores which may be
dead.

llvm-svn: 164561
2012-09-24 22:09:10 +00:00
Nick Lewycky 135ac9ac89 Move all the calls to AA.getTargetLibraryInfo() to using a TLI member variable.
No functionality change.

llvm-svn: 164560
2012-09-24 22:07:09 +00:00
Benjamin Kramer 2b11eb0729 DSE: Poking holes into a SetVector is expensive, avoid it if possible.
llvm-svn: 163480
2012-09-09 16:44:05 +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
Craig Topper 2a40418a99 Change greater than to greater than or equal so that an identical sized store to the same offset is treated as completing overwriting.
llvm-svn: 161857
2012-08-14 07:32:05 +00:00
Eli Friedman 08ec0a8122 isAllocLikeFn is allowed to return true for functions which read memory; make
sure we account for that correctly in DeadStoreElimination.  Fixes a regression
from r158919.  PR13547.

llvm-svn: 161468
2012-08-08 02:17:32 +00:00
Nadav Rotem 465834c85f Clean whitespaces.
llvm-svn: 160668
2012-07-24 10:51:42 +00:00
Nuno Lopes 55fff83422 refactor the MemoryBuiltin analysis:
- provide more extensive set of functions to detect library allocation functions (e.g., malloc, calloc, strdup, etc)
 - provide an API to compute the size and offset of an object pointed by

Move a few clients (GVN, AA, instcombine, ...) to the new API.
This implementation is a lot more aggressive than each of the custom implementations being replaced.

Patch reviewed by Nick Lewycky and Chandler Carruth, thanks.

llvm-svn: 158919
2012-06-21 15:45:28 +00:00
Evan Cheng 773b2cd63c It's not deterministic to iterate over SmallPtrSet. Replace it with SmallSetVector. Patch by Daniel Reynaud. rdar://11671029
llvm-svn: 158594
2012-06-16 04:28:11 +00:00
Dan Gohman ed7c24e2d9 Teach DeadStoreElimination to eliminate exit-block stores with phi addresses.
llvm-svn: 156558
2012-05-10 18:57:38 +00:00
Nuno Lopes 300d629924 teach DSE and isInstructionTriviallyDead() about calloc
llvm-svn: 156553
2012-05-10 17:14:00 +00:00
Pete Cooper 39b5255df4 Reverted r152620 - DSE: Shorten memset when a later store overwrites the start of it. There were all sorts of buildbot issues
llvm-svn: 151621
2012-02-28 05:06:24 +00:00
Pete Cooper f3862f91de DSE: Shorten memset when a later store overwrites the start of it
llvm-svn: 151620
2012-02-28 04:27:10 +00:00
Craig Topper a2886c21d9 Convert assert(0) to llvm_unreachable
llvm-svn: 149967
2012-02-07 05:05:23 +00:00
Nick Lewycky fe970725cc Fix infinite loop in DSE when deleting a free in a reachable loop that's also
trivially infinite.

llvm-svn: 146197
2011-12-08 22:36:35 +00:00
Pete Cooper e03fe83d98 Fixed deadstoreelimination bug where negative indices were incorrectly causing the optimisation to occur
Turns out long long + unsigned long long is unsigned.  Doh!

Fixes http://llvm.org/bugs/show_bug.cgi?id=11455

llvm-svn: 145731
2011-12-03 00:04:30 +00:00
Nick Lewycky c7f1e7993c Merge isObjectPointerWithTrustworthySize with getPointerSize. Use it when
looking at the size of the pointee. Fixes PR11390!

llvm-svn: 144773
2011-11-16 03:49:48 +00:00
Pete Cooper a4237c380e Fixed bug in DeadStoreElimination commit r144239
Size of data being pointed to wasn't always being checked so some small writes were killing big writes

Fixes <rdar://problem/10426753>

llvm-svn: 144312
2011-11-10 20:22:08 +00:00
Pete Cooper 856977cb15 DeadStoreElimination can now trim the size of a store if the end of the store is dead.
Currently checks alignment and killing stores on a power of 2 boundary as this is likely
to trim the size of the earlier store without breaking large vector stores into scalar ones.

Fixes <rdar://problem/10140300>

llvm-svn: 144239
2011-11-09 23:07:35 +00:00
Nick Lewycky f2905afe62 Do simple cross-block DSE when we encounter a free statement. Fixes PR11240.
llvm-svn: 143808
2011-11-05 10:48:42 +00:00
Daniel Dunbar e6d40de414 Speculatively revert "DeadStoreElimination can now trim the size of a store if
the end of it is dead.", which appears to break bootstrapping LLVM.

llvm-svn: 143668
2011-11-04 00:48:26 +00:00
Pete Cooper 8a95aedb5d DeadStoreElimination can now trim the size of a store if the end of it is dead.
Only currently done if the later store is writing to a power of 2 address or 
has the same alignment as the earlier store as then its likely to not break up
large stores into smaller ones

Fixes <rdar://problem/10140300>

llvm-svn: 143630
2011-11-03 18:01:56 +00:00
Nick Lewycky 32f8051d66 A non-escaping malloc in the entry block is not unlike an alloca. Do dead-store
elimination on them too.

llvm-svn: 142735
2011-10-22 21:59:35 +00:00
Eli Friedman c1702c8f22 Enhance the memdep interface so that users can tell the difference between a dependency which cannot be calculated and a path reaching the entry point of the function. This patch introduces isNonFuncLocal, which replaces isUnknown in some cases.
Patch by Xiaoyi Guo.

llvm-svn: 141896
2011-10-13 22:14:57 +00:00
Eli Friedman 72a93e5e9b Add comment to clarify the behavior of a helper in DSE.
llvm-svn: 139571
2011-09-13 01:28:59 +00:00
Owen Anderson 58704ee442 Try again at r138809 (make DSE more aggressive in removing dead stores at the end of a function), now with less deleting stores before memcpy's.
llvm-svn: 139150
2011-09-06 18:14:09 +00:00