Commit Graph

2083 Commits

Author SHA1 Message Date
Duncan P. N. Exon Smith
5d801364e2 DebugInfo: Remove DIDescriptor from the DebugInfo API
Stop using `DIDescriptor` and its subclasses in the `DebugInfoFinder`
API, as well as the rest of the API hanging around in `DebugInfo.h`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235240 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-17 23:20:10 +00:00
Duncan P. N. Exon Smith
ed0e117ff3 DebugInfo: Gut DICompileUnit and DIFile
Continuing gutting `DIDescriptor` subclasses; this edition,
`DICompileUnit` and `DIFile`.  In the name of PR23080.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235055 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-15 23:19:27 +00:00
Duncan P. N. Exon Smith
35adce33f1 DebugInfo: Update signature of DICompileUnit::replace*()
Change `DICompileUnit::replaceSubprograms()` and
`DICompileUnit::replaceGlobalVariables()` to match the `MDCompileUnit`
equivalents that they're wrapping.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234852 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-14 03:51:36 +00:00
Duncan P. N. Exon Smith
125e3d3959 DebugInfo: Gut DISubprogram and DILexicalBlock*
Gut the `DIDescriptor` wrappers around `MDLocalScope` subclasses.  Note
that `DILexicalBlock` wraps `MDLexicalBlockBase`, not `MDLexicalBlock`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234850 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-14 03:40:37 +00:00
Duncan P. N. Exon Smith
355ec009e5 DebugInfo: Gut DIVariable and DIGlobalVariable
Gut all the non-pointer API from the variable wrappers, except an
implicit conversion from `DIGlobalVariable` to `DIDescriptor`.  Note
that if you're updating out-of-tree code, `DIVariable` wraps
`MDLocalVariable` (`MDVariable` is a common base class shared with
`MDGlobalVariable`).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234840 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-14 02:22:36 +00:00
Duncan P. N. Exon Smith
afb02d5d0d StripSymbols: Use DIGlobalVariable::getConstant() instead of getGlobal()
The only difference between the two is a `dyn_cast<>` to
`GlobalVariable`.  If optimizations have left anything behind when a
global gets replaced, then it doesn't seem like the debug info is dead.

I can't seem to find an optimization that would leave behind a
non-`GlobalVariable` without nulling the reference entirely, so I
haven't added a testcase (but I'll be deleting `getGlobal()` in a future
commit).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234792 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-13 20:13:30 +00:00
Benjamin Kramer
e749325463 [CallSite] Make construction from Value* (or Instruction*) explicit.
CallSite roughly behaves as a common base CallInst and InvokeInst. Bring
the behavior closer to that model by making upcasts explicit. Downcasts
remain implicit and work as before.

Following dyn_cast as a mental model checking whether a Value *V isa
CallSite now looks like this: 
  if (auto CS = CallSite(V)) // think dyn_cast
instead of:
  if (CallSite CS = V)

This is an extra token but I think it is slightly clearer. Making the
ctor explicit has the advantage of not accidentally creating nullptr
CallSites, e.g. when you pass a Value * to a function taking a CallSite
argument.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234601 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-10 14:50:08 +00:00
Duncan P. N. Exon Smith
573ca050d2 Transforms: Stop using DIDescriptor::is*() and auto-casting
Same as r234255, but for lib/Analysis and lib/Transforms.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234257 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-06 23:27:00 +00:00
David Blaikie
4f67d9167d ArgPromo: Bail out earlier for varargs functions
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234224 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-06 21:27:31 +00:00
Duncan P. N. Exon Smith
1ea24954c6 DebugInfo: Remove DIDescriptor::Verify()
Remove `DIDescriptor::Verify()` and the `Verify()`s from subclasses.
They had already been gutted, and just did an `isa<>` check.

In a couple of cases I've temporarily dropped the check entirely, but
subsequent commits are going to disallow conversions to the
`DIDescriptor`s directly from `MDNode`, so the checks will come back in
another form soon enough.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234201 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-06 19:49:39 +00:00
David Blaikie
cf57d81b6e [opaque pointer type] More GEP API migrations in IRBuilder uses
The plan here is to push the API changes out from the common components
(like Constant::getGetElementPtr and IRBuilder::CreateGEP related
functions) and just update callers to either pass the type if it's
obvious, or pass null.

Do this with LoadInst as well and anything else that comes up, then to
start porting specific uses to not pass null anymore - this may require
some refactoring in each case.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234042 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-03 19:41:44 +00:00
David Blaikie
19443c1bcb [opaque pointer type] API migration for GEP constant factories
Require the pointee type to be passed explicitly and assert that it is
correct. For now it's possible to pass nullptr here (and I've done so in
a few places in this patch) but eventually that will be disallowed once
all clients have been updated or removed. It'll be a long road to get
all the way there... but if you have the cahnce to update your callers
to pass the type explicitly without depending on a pointer's element
type, that would be a good thing to do soon and a necessary thing to do
eventually.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233938 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-02 18:55:32 +00:00
David Blaikie
25e3d2d6d3 [opaque pointer type] Change GetElementPtrInst::getIndexedType to take the pointee type
This pushes the use of PointerType::getElementType up into several
callers - I'll essentially just have to keep pushing that up the stack
until I can eliminate every call to it...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233604 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-30 21:41:43 +00:00
Yaron Keren
2a9bbcbbad Remove superfluous .str() and replace std::string concatenation with Twine.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233392 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-27 17:51:30 +00:00
James Molloy
fb45b9fafc Reapply r233175 and r233183: float2int.
This re-adds float2int to the tree, after fixing PR23038. It turns
out the argument to APSInt() is true-if-unsigned, rather than
true-if-signed :(. Added testcase and explanatory comment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233370 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-27 10:36:57 +00:00
Nick Lewycky
b3ad90eacc Revert r233175 and r233183 with it. This pulls float2int back out of the tree, due to PR23038.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233350 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-27 02:00:11 +00:00
James Molloy
09f1b672cb Reapply r233062: "float2int": Add a new pass to demote from float to int where possible.
Now with a fix for PR23008 and extra regression test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233175 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-25 10:03:42 +00:00
Hans Wennborg
f61cd8b368 Revert r233062 ""float2int": Add a new pass to demote from float to int where possible."
This caused PR23008, compiles failing with: "Use still stuck around after Def is
destroyed: %.sroa.speculated"

Also reverting follow-up r233064.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233105 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-24 20:07:08 +00:00
James Molloy
a54c5b4489 "float2int": Add a new pass to demote from float to int where possible.
It is possible to have code that converts from integer to float, performs operations then converts back, and the result is provably the same as if integers were used.

This can come from different sources, but the most obvious is a helper function that uses floats but the arguments given at an inlined callsites are integers.

This pass considers all integers requiring a bitwidth less than or equal to the bitwidth of the mantissa of a floating point type (23 for floats, 52 for doubles) as exactly representable in floating point.

To reduce the risk of harming efficient code, the pass only attempts to perform complete removal of inttofp/fptoint operations, not just move them around.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233062 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-24 11:15:23 +00:00
Benjamin Kramer
1bfcd1f675 Re-sort includes with sort-includes.py and insert raw_ostream.h where it's used.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232998 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-23 19:32:43 +00:00
Duncan P. N. Exon Smith
a60d430e31 Verifier: Remove the separate -verify-di pass
Remove `DebugInfoVerifierLegacyPass` and the `-verify-di` pass.
Instead, call into the `DebugInfoVerifier` from inside
`VerifierLegacyPass::finalizeModule()`.  This better matches the logic
in `verifyModule()` (used by the new PassManager), avoids requiring two
separate passes to verify the IR, and makes the API for "add a pass to
verify the IR" simple.

Note: the `-verify-debug-info` flag still works (for now, at least;
eventually it might make sense to just remove it).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232772 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-19 22:24:17 +00:00
Peter Collingbourne
58e8e3505d LowerBitSets: Avoid reusing byte set addresses.
Each use of the byte array uses a different alias. This makes the
backend less likely to reuse previously computed byte array addresses,
improving the security of the CFI mechanism based on this pass.

Differential Revision: http://reviews.llvm.org/D8455

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232770 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-19 22:02:10 +00:00
Peter Collingbourne
416d8ecf80 libLTO, llvm-lto, gold: Introduce flag for controlling optimization level.
This change also introduces a link-time optimization level of 1. This
optimization level runs only the globaldce pass as well as cleanup passes for
passes that run at -O0, specifically simplifycfg which cleans up lowerbitsets.

http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20150316/266951.html

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232769 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-19 22:01:00 +00:00
Duncan P. N. Exon Smith
0dda07ad4d PassManagerBuilder: Remove effectively dead 'StripDebug' option
`StripDebug` was only used by tools/opt/opt.cpp in
`AddStandardLinkPasses()`, but opt.cpp adds the same pass based on its
command-line flag before it calls `AddStandardLinkPasses()`.  Stripping
debug info twice isn't very useful.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232765 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-19 21:37:17 +00:00
Peter Collingbourne
c226d9f334 GlobalDCE: Improve performance for large modules containing comdats.
When we encounter a global with a comdat, rather than iterating over
every global in the module to find globals in the same comdat, store the
members in a multimap. This effectively lowers the complexity to O(N log N),
improving performance significantly for large modules such as might be
encountered during LTO.

It looks like we used to do something like this until r219191.

No functional change.

Differential Revision: http://reviews.llvm.org/D8431

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232743 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-19 18:23:29 +00:00
Peter Collingbourne
4556b1fe22 LowerBitSets: do not use private aliases at all on Darwin.
LLVM currently turns these into linker-private symbols, which can be dead
stripped by the Darwin linker.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232435 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-16 23:36:24 +00:00
David Blaikie
cf4419f88b Add some missed formatting
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232281 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-14 21:40:12 +00:00
David Blaikie
2f69477cfd [opaque pointer type] gep API migration, ArgPromo
This involved threading the type-to-gep through a data structure, since
the code was relying on the pointer type to carry this information. I
imagine there will be a lot of this work across the project... slow
work chasing each use case, but the assertions will help keep me honest.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232277 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-14 21:11:26 +00:00
David Blaikie
f508adde2e [opaque pointer type] more gep API migration
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232274 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-14 19:53:33 +00:00
David Blaikie
99b7898c29 [opaque pointer type] more gep API migrations
Adding nullptr to all the IRBuilder stuff because it's the first thing
that fails to build when testing without the back-compat functions, so
I'll keep having to re-add these locally for each chunk of migration I
do. Might as well check them in to save me the churn. Eventually I'll
have to migrate these too, but I'm going breadth-first.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232270 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-14 19:24:04 +00:00
David Blaikie
fb5115d02a [opaque pointer type] Start migrating GEP creation to explicitly specify the pointee type
I'm just going to migrate these in a pretty ad-hoc & incremental way -
providing the backwards compatible API for now, then locally removing
it, fixing a few callers, adding it back in and commiting those callers.
Rinse, repeat.

The assertions should ensure that if I get this wrong we'll find out
about it and not just have one giant patch to revert, recommit, revert,
recommit, etc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232240 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-14 01:53:18 +00:00
Peter Collingbourne
99e2c354a8 LowerBitSets: Do not export symbols for bit set referenced globals on Darwin.
The linker on that platform may re-order symbols or strip dead symbols, which
will break bit set checks. Avoid this by hiding the symbols from the linker.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232235 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-14 00:00:49 +00:00
Kevin Qin
a56999c5de Reapply 'Run LICM pass after loop unrolling pass.'
It's firstly committed at r231630, and reverted at r231635.

Function pass InstructionSimplifier is inserted as barrier to
make sure loop unroll pass won't affect on LICM pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232011 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-12 05:36:01 +00:00
Michael Zolotukhin
7212f8bb52 Enable loop-rotate before loop-vectorize by default
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231820 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 19:07:41 +00:00
Sanjay Patel
f681b3f13f remove function names from comments; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231801 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 16:42:24 +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
Kevin Qin
1428f080a8 Revert r231630 - Run LICM pass after loop unrolling pass.
As it broke llvm bootstrap.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231635 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-09 07:26:37 +00:00
Kevin Qin
3836dd0315 Run LICM pass after loop unrolling pass.
Runtime unrollng will introduce a runtime check in loop prologue.
If the unrolled loop is a inner loop, then the proglogue will be inside
the outer loop. LICM pass can help to promote the runtime check out if
the checked value is loop invariant.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231630 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-09 06:14:07 +00:00
Karthik Bhat
52610d84ad Add a new pass "Loop Interchange"
This pass interchanges loops to provide a more cache-friendly memory access.

For e.g. given a loop like -
  for(int i=0;i<N;i++)
    for(int j=0;j<N;j++)
      A[j][i] = A[j][i]+B[j][i];

is interchanged to -
  for(int j=0;j<N;j++)
    for(int i=0;i<N;i++)
      A[j][i] = A[j][i]+B[j][i];

This pass is currently disabled by default.

To give a brief introduction it consists of 3 stages-

LoopInterchangeLegality : Checks the legality of loop interchange based on Dependency matrix.
LoopInterchangeProfitability: A very basic heuristic has been added to check for profitibility. This will evolve over time.
LoopInterchangeTransform : Which does the actual transform.

LNT Performance tests shows improvement in Polybench/linear-algebra/kernels/mvt and Polybench/linear-algebra/kernels/gemver becnmarks.

TODO:
1) Add support for reductions and lcssa phi.
2) Improve profitability model.
3) Improve loop selection algorithm to select best loop for interchange. Currently the innermost loop is selected for interchange.
4) Improve compile time regression found in llvm lnt due to this pass.
5) Fix issues in Dependency Analysis module.

A special thanks to Hal for reviewing this code.
Review: http://reviews.llvm.org/D7499




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231458 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-06 10:11:25 +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
Peter Collingbourne
27821d7200 LowerBitSets: Use byte arrays instead of bit sets to represent in-memory bit sets.
By loading from indexed offsets into a byte array and applying a mask, a
program can test bits from the bit set with a relatively short instruction
sequence. For example, suppose we have 15 bit sets to lay out:

A (16 bits), B (15 bits), C (14 bits), D (13 bits), E (12 bits),
F (11 bits), G (10 bits), H (9 bits), I (7 bits), J (6 bits), K (5 bits),
L (4 bits), M (3 bits), N (2 bits), O (1 bit)

These bits can be laid out in a 16-byte array like this:

      Byte Offset
    0123456789ABCDEF
Bit
  7 HHHHHHHHHIIIIIII
  6 GGGGGGGGGGJJJJJJ
  5 FFFFFFFFFFFKKKKK
  4 EEEEEEEEEEEELLLL
  3 DDDDDDDDDDDDDMMM
  2 CCCCCCCCCCCCCCNN
  1 BBBBBBBBBBBBBBBO
  0 AAAAAAAAAAAAAAAA

For example, to test bit X of A, we evaluate ((bits[X] & 1) != 0), or to
test bit X of I, we evaluate ((bits[9 + X] & 0x80) != 0). This can be done
in 1-2 machine instructions on x86, or 4-6 instructions on ARM.

This uses the LPT multiprocessor scheduling algorithm to lay out the bits
efficiently.

Saves ~450KB of instructions in a recent build of Chromium.

Differential Revision: http://reviews.llvm.org/D7954

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231043 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-03 00:49:28 +00:00
Benjamin Kramer
bac8d0ec70 Convert push_back loops into append calls.
No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230849 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-28 13:20:15 +00:00
Peter Collingbourne
d63e5ad9c5 LowerBitSets: Align referenced globals.
This change aligns globals to the next highest power of 2 bytes, up to a
maximum of 128. This makes it more likely that we will be able to compress
bit sets with a greater alignment. In many more cases, we can now take
advantage of a new optimization also introduced in this patch that removes
bit set checks if the bit set is all ones.

The 128 byte maximum was found to provide the best tradeoff between instruction
overhead and data overhead in a recent build of Chromium. It allows us to
remove ~2.4MB of instructions at the cost of ~250KB of data.

Differential Revision: http://reviews.llvm.org/D7873

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230540 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-25 20:42:41 +00:00
Peter Collingbourne
0bf03cb473 LowerBitSets: Introduce global layout builder.
The builder is based on a layout algorithm that tries to keep members of
small bit sets together. The new layout compresses Chromium's bit sets to
around 15% of their original size.

Differential Revision: http://reviews.llvm.org/D7796

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230394 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-24 23:17:02 +00:00
NAKAMURA Takumi
9c2a703d7c LowerBitSets.cpp: Prune incorrect \param(s). [-Wdocumentation]
\param should be used as itemized.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230167 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-22 09:51:42 +00:00
Peter Collingbourne
5a81e14385 Introduce bitset metadata format and bitset lowering pass.
This patch introduces a new mechanism that allows IR modules to co-operatively
build pointer sets corresponding to addresses within a given set of
globals. One particular use case for this is to allow a C++ program to
efficiently verify (at each call site) that a vtable pointer is in the set
of valid vtable pointers for the class or its derived classes. One way of
doing this is for a toolchain component to build, for each class, a bit set
that maps to the memory region allocated for the vtables, such that each 1
bit in the bit set maps to a valid vtable for that class, and lay out the
vtables next to each other, to minimize the total size of the bit sets.

The patch introduces a metadata format for representing pointer sets, an
'@llvm.bitset.test' intrinsic and an LTO lowering pass that lays out the globals
and builds the bitsets, and documents the new feature.

Differential Revision: http://reviews.llvm.org/D7288

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230054 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-20 20:30:47 +00:00
Hal Finkel
5b43c8551e [BDCE] Add a bit-tracking DCE pass
BDCE is a bit-tracking dead code elimination pass. It is based on ADCE (the
"aggressive DCE" pass), with the added capability to track dead bits of integer
valued instructions and remove those instructions when all of the bits are
dead.

Currently, it does not actually do this all-bits-dead removal, but rather
replaces the instruction's uses with a constant zero, and lets instcombine (and
the later run of ADCE) do the rest. Because we essentially get a run of ADCE
"for free" while tracking the dead bits, we also do what ADCE does and removes
actually-dead instructions as well (this includes instructions newly trivially
dead because all bits were dead, but not all such instructions can be removed).

The motivation for this is a case like:

int __attribute__((const)) foo(int i);
int bar(int x) {
  x |= (4 & foo(5));
  x |= (8 & foo(3));
  x |= (16 & foo(2));
  x |= (32 & foo(1));
  x |= (64 & foo(0));
  x |= (128& foo(4));
  return x >> 4;
}

As it turns out, if you order the bit-field insertions so that all of the dead
ones come last, then instcombine will remove them. However, if you pick some
other order (such as the one above), the fact that some of the calls to foo()
are useless is not locally obvious, and we don't remove them (without this
pass).

I did a quick compile-time overhead check using sqlite from the test suite
(Release+Asserts). BDCE took ~0.4% of the compilation time (making it about
twice as expensive as ADCE).

I've not looked at why yet, but we eliminate instructions due to having
all-dead bits in:
External/SPEC/CFP2006/447.dealII/447.dealII
External/SPEC/CINT2006/400.perlbench/400.perlbench
External/SPEC/CINT2006/403.gcc/403.gcc
MultiSource/Applications/ClamAV/clamscan
MultiSource/Benchmarks/7zip/7zip-benchmark

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229462 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-17 01:36:59 +00:00
James Molloy
25a35b5639 Run LICM as part of the cleanup phase from the scalar optimizer.
Things like LoopUnrolling can produce loop invariant values - make sure
we pick them up.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229419 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-16 18:59:54 +00:00
Duncan P. N. Exon Smith
7520a90c75 Transforms: Canonicalize access to function attributes, NFC
Canonicalize access to function attributes to use the simpler API.

getAttributes().getAttribute(AttributeSet::FunctionIndex, Kind)
  => getFnAttribute(Kind)

getAttributes().hasAttribute(AttributeSet::FunctionIndex, Kind)
  => hasFnAttribute(Kind)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229202 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-14 01:11:29 +00:00
Chandler Carruth
417c5c172c [PM] Remove the old 'PassManager.h' header file at the top level of
LLVM's include tree and the use of using declarations to hide the
'legacy' namespace for the old pass manager.

This undoes the primary modules-hostile change I made to keep
out-of-tree targets building. I sent an email inquiring about whether
this would be reasonable to do at this phase and people seemed fine with
it, so making it a reality. This should allow us to start bootstrapping
with modules to a certain extent along with making it easier to mix and
match headers in general.

The updates to any code for users of LLVM are very mechanical. Switch
from including "llvm/PassManager.h" to "llvm/IR/LegacyPassManager.h".
Qualify the types which now produce compile errors with "legacy::". The
most common ones are "PassManager", "PassManagerBase", and
"FunctionPassManager".

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229094 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 10:01:29 +00:00