Commit Graph

566 Commits

Author SHA1 Message Date
Sanjay Patel
473e5d658e don't repeat function names in comments; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240591 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-24 20:40:57 +00:00
Sanjay Patel
8e5b874f17 fix typos; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240585 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-24 20:07:50 +00:00
Alexander Kornienko
cd52a7a381 Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)
Apparently, the style needs to be agreed upon first.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240390 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 09:49:53 +00:00
Alexander Kornienko
cf0db29df2 Fixed/added namespace ending comments using clang-tidy. NFC
The patch is generated using this command:

tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
  -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
  llvm/lib/


Thanks to Eugene Kosov for the original patch!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240137 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-19 15:57:42 +00:00
Eric Christopher
933d2bd391 Fix "the the" in comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240112 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-19 01:53:21 +00:00
Hans Wennborg
7a301c1b8c SimplifyCFG: Correctly handle switch lookup tables which fully cover the input type and use bit tests to check for holes
When using bit tests for hole checks, we call AddPredecessorToBlock to give the
phi node a value from the bit test block. This would break if we've
previously called removePredecessor on the default destination because the
switch is fully covered.

Test case by Mark Lacey.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235771 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-24 20:57:56 +00:00
Mark Lacey
e0a6f13a5d Fix typo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234706 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-12 18:18:51 +00:00
David Blaikie
4a86b381a3 [opaque pointer type] More GEP IRBuilder API migrations...
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234058 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-03 21:33:42 +00:00
Philip Reames
6bde9f6994 Merge empty landing pads in SimplifyCFG
This patch tries to merge duplicate landing pads when they branch to a common shared target.

Given IR that looks like this:
lpad1:
  %exn = landingpad {i8*, i32} personality i32 (...)* @__gxx_personality_v0
         cleanup
  br label %shared_resume
lpad2:
  %exn2 = landingpad {i8*, i32} personality i32 (...)* @__gxx_personality_v0
          cleanup
  br label %shared_resume
shared_resume:
  call void @fn()
  ret void
}

We can rewrite the users of both landing pad blocks to use one of them. This will generally allow the shared_resume block to be merged with the common landing pad as well.

Without this change, tail duplication would likely kick in - creating N (2 in this case) copies of the shared_resume basic block.

Differential Revision: http://reviews.llvm.org/D8297



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233125 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-24 22:28:45 +00:00
Sanjoy Das
da5f3a3ca5 [ConstantRange] Split makeICmpRegion in two.
Summary:
This change splits `makeICmpRegion` into `makeAllowedICmpRegion` and
`makeSatisfyingICmpRegion` with slightly different contracts.  The first
one is useful for determining what values some expression //may// take,
given that a certain `icmp` evaluates to true.  The second one is useful
for determining what values are guaranteed to //satisfy// a given
`icmp`.

Reviewers: nlewycky

Reviewed By: nlewycky

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8345

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232575 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-18 00:41:24 +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
Chad Rosier
6229219f7e Prevent hoisting fmul from THEN/ELSE to IF if there is fmsub/fmadd opportunity.
This patch adds the isProfitableToHoist API.  For AArch64, we want to prevent a
fmul from being hoisted in cases where it is more profitable to form a
fmsub/fmadd.

Phabricator Review: http://reviews.llvm.org/D7299
Patch by Lawrence Hu <lawrence@codeaurora.org>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230241 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-23 19:15:16 +00:00
Benjamin Kramer
1ce666d86c Demote vectors to arrays. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229861 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-19 15:26:17 +00:00
Aaron Ballman
66981fe208 Removing LLVM_DELETED_FUNCTION, as MSVC 2012 was the last reason for requiring the macro. NFC; LLVM edition.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229340 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-15 22:54:22 +00:00
James Molloy
c76bff0715 [SimplifyCFG] Be more aggressive
Up the phi node folding threshold from a cheap "1" to a meagre "2".

Update tests for extra added selects and slight code churn.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229099 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 10:48:30 +00:00
James Molloy
4de471dd0a [SimplifyCFG] Swap to using TargetTransformInfo for cost
analysis.

We're already using TTI in SimplifyCFG, so remove the hard-baked "cheapness"
heuristic and use TTI directly. Generally NFC intended, but we're using a slightly
different heuristic now so there is a slight test churn.

Test changes:
  * combine-comparisons-by-cse.ll: Removed unneeded branch check.
  * 2014-08-04-muls-it.ll: Test now doesn't branch but emits muleq.
  * coalesce-subregs.ll: Superfluous block check.
  * 2008-01-02-hoist-fp-add.ll: fadd is safe to speculate. Change to udiv.
  * PhiBlockMerge.ll: Superfluous CFG checking code. Main checks still present.
  * select-gep.ll: A variable GEP is not expensive, just TCC_Basic, according to the TTI.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228826 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-11 12:15:41 +00:00
Hans Wennborg
325385a37f SimplifyCFG: Omit range checks for switch lookup tables when default is unreachable
The range check would get optimized away later, but we might as well not emit
them in the first place.

http://reviews.llvm.org/D6471

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227126 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-26 19:52:34 +00:00
Hans Wennborg
d5c2318adc SimplifyCFG: don't remove unreachable default switch destinations
An unreachable default destination can be exploited by other optimizations and
allows for more efficient lowering. Both the SDag switch lowering and
LowerSwitch can exploit unreachable defaults.

Also make TurnSwitchRangeICmp handle switches with unreachable default.
This is kind of separate change, but it cannot be tested without the change
above, and I don't want to land the change above without this since that would
regress other tests.

Differential Revision: http://reviews.llvm.org/D6471

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227125 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-26 19:52:32 +00:00
Reid Kleckner
7ed0364cee Revert "Don't remove a landing pad if the invoke requires a table entry."
This reverts commit r176827.

Björn Steinbrink pointed out that this didn't actually fix the bug
(PR15555) it was attempting to fix.

With this reverted, we can now remove landingpad cleanups that
immediately resume unwinding, converting the invoke to a call.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226850 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-22 19:29:46 +00:00
Ramkumar Ramachandra
65535d3842 fix {typo, build failure} in r225760
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225762 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 04:17:47 +00:00
Ramkumar Ramachandra
2bcc808cf9 Standardize {pred,succ,use,user}_empty()
The functions {pred,succ,use,user}_{begin,end} exist, but many users
have to check *_begin() with *_end() by hand to determine if the
BasicBlock or User is empty. Fix this with a standard *_empty(),
demonstrating a few usecases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225760 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 03:46:47 +00:00
Hans Wennborg
ca71be6415 SimplifyCFG: check uses of constant-foldable instrs in switch destinations (PR20210)
The previous code assumed that such instructions could not have any uses
outside CaseDest, with the motivation that the instruction could not
dominate CommonDest because CommonDest has phi nodes in it. That simply
isn't true; e.g., CommonDest could have an edge back to itself.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225552 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-09 22:13:31 +00:00
Chandler Carruth
5a9cd4d44e [PM] Split the AssumptionTracker immutable pass into two separate APIs:
a cache of assumptions for a single function, and an immutable pass that
manages those caches.

The motivation for this change is two fold. Immutable analyses are
really hacks around the current pass manager design and don't exist in
the new design. This is usually OK, but it requires that the core logic
of an immutable pass be reasonably partitioned off from the pass logic.
This change does precisely that. As a consequence it also paves the way
for the *many* utility functions that deal in the assumptions to live in
both pass manager worlds by creating an separate non-pass object with
its own independent API that they all rely on. Now, the only bits of the
system that deal with the actual pass mechanics are those that actually
need to deal with the pass mechanics.

Once this separation is made, several simplifications become pretty
obvious in the assumption cache itself. Rather than using a set and
callback value handles, it can just be a vector of weak value handles.
The callers can easily skip the handles that are null, and eventually we
can wrap all of this up behind a filter iterator.

For now, this adds boiler plate to the various passes, but this kind of
boiler plate will end up making it possible to port these passes to the
new pass manager, and so it will end up factored away pretty reasonably.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225131 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-04 12:03:27 +00:00
Michael Liao
b9e302f3ca [SimplifyCFG] Revise common code sinking
- Fix the case where more than 1 common instructions derived from the same
  operand cannot be sunk. When a pair of value has more than 1 derived values
  in both branches, only 1 derived value could be sunk.
- Replace BB1 -> (BB2, PN) map with joint value map, i.e.
  map of (BB1, BB2) -> PN, which is more accurate to track common ops.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224757 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-23 08:26:55 +00:00
Duncan P. N. Exon Smith
dad20b2ae2 IR: Split Metadata from Value
Split `Metadata` away from the `Value` class hierarchy, as part of
PR21532.  Assembly and bitcode changes are in the wings, but this is the
bulk of the change for the IR C++ API.

I have a follow-up patch prepared for `clang`.  If this breaks other
sub-projects, I apologize in advance :(.  Help me compile it on Darwin
I'll try to fix it.  FWIW, the errors should be easy to fix, so it may
be simpler to just fix it yourself.

This breaks the build for all metadata-related code that's out-of-tree.
Rest assured the transition is mechanical and the compiler should catch
almost all of the problems.

Here's a quick guide for updating your code:

  - `Metadata` is the root of a class hierarchy with three main classes:
    `MDNode`, `MDString`, and `ValueAsMetadata`.  It is distinct from
    the `Value` class hierarchy.  It is typeless -- i.e., instances do
    *not* have a `Type`.

  - `MDNode`'s operands are all `Metadata *` (instead of `Value *`).

  - `TrackingVH<MDNode>` and `WeakVH` referring to metadata can be
    replaced with `TrackingMDNodeRef` and `TrackingMDRef`, respectively.

    If you're referring solely to resolved `MDNode`s -- post graph
    construction -- just use `MDNode*`.

  - `MDNode` (and the rest of `Metadata`) have only limited support for
    `replaceAllUsesWith()`.

    As long as an `MDNode` is pointing at a forward declaration -- the
    result of `MDNode::getTemporary()` -- it maintains a side map of its
    uses and can RAUW itself.  Once the forward declarations are fully
    resolved RAUW support is dropped on the ground.  This means that
    uniquing collisions on changing operands cause nodes to become
    "distinct".  (This already happened fairly commonly, whenever an
    operand went to null.)

    If you're constructing complex (non self-reference) `MDNode` cycles,
    you need to call `MDNode::resolveCycles()` on each node (or on a
    top-level node that somehow references all of the nodes).  Also,
    don't do that.  Metadata cycles (and the RAUW machinery needed to
    construct them) are expensive.

  - An `MDNode` can only refer to a `Constant` through a bridge called
    `ConstantAsMetadata` (one of the subclasses of `ValueAsMetadata`).

    As a side effect, accessing an operand of an `MDNode` that is known
    to be, e.g., `ConstantInt`, takes three steps: first, cast from
    `Metadata` to `ConstantAsMetadata`; second, extract the `Constant`;
    third, cast down to `ConstantInt`.

    The eventual goal is to introduce `MDInt`/`MDFloat`/etc. and have
    metadata schema owners transition away from using `Constant`s when
    the type isn't important (and they don't care about referring to
    `GlobalValue`s).

    In the meantime, I've added transitional API to the `mdconst`
    namespace that matches semantics with the old code, in order to
    avoid adding the error-prone three-step equivalent to every call
    site.  If your old code was:

        MDNode *N = foo();
        bar(isa             <ConstantInt>(N->getOperand(0)));
        baz(cast            <ConstantInt>(N->getOperand(1)));
        bak(cast_or_null    <ConstantInt>(N->getOperand(2)));
        bat(dyn_cast        <ConstantInt>(N->getOperand(3)));
        bay(dyn_cast_or_null<ConstantInt>(N->getOperand(4)));

    you can trivially match its semantics with:

        MDNode *N = foo();
        bar(mdconst::hasa               <ConstantInt>(N->getOperand(0)));
        baz(mdconst::extract            <ConstantInt>(N->getOperand(1)));
        bak(mdconst::extract_or_null    <ConstantInt>(N->getOperand(2)));
        bat(mdconst::dyn_extract        <ConstantInt>(N->getOperand(3)));
        bay(mdconst::dyn_extract_or_null<ConstantInt>(N->getOperand(4)));

    and when you transition your metadata schema to `MDInt`:

        MDNode *N = foo();
        bar(isa             <MDInt>(N->getOperand(0)));
        baz(cast            <MDInt>(N->getOperand(1)));
        bak(cast_or_null    <MDInt>(N->getOperand(2)));
        bat(dyn_cast        <MDInt>(N->getOperand(3)));
        bay(dyn_cast_or_null<MDInt>(N->getOperand(4)));

  - A `CallInst` -- specifically, intrinsic instructions -- can refer to
    metadata through a bridge called `MetadataAsValue`.  This is a
    subclass of `Value` where `getType()->isMetadataTy()`.

    `MetadataAsValue` is the *only* class that can legally refer to a
    `LocalAsMetadata`, which is a bridged form of non-`Constant` values
    like `Argument` and `Instruction`.  It can also refer to any other
    `Metadata` subclass.

(I'll break all your testcases in a follow-up commit, when I propagate
this change to assembly.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223802 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-09 18:38:53 +00:00
Juergen Ributzka
f3ac16dcb4 Revert "Move function to obtain branch weights into the BranchInst class. NFC."
This reverts commit r223784 and copies the 'ExtractBranchMetadata' to CodeGenPrepare.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223795 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-09 17:32:12 +00:00
Juergen Ributzka
50f10eb432 Move function to obtain branch weights into the BranchInst class. NFC.
Make this function available to other parts of LLVM.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223784 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-09 16:36:06 +00:00
Hans Wennborg
c9605b6067 Revert r223049, r223050 and r223051 while investigating test failures.
I didn't foresee affecting the Clang test suite :/

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223054 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-01 17:36:43 +00:00
Hans Wennborg
07c6024f48 SimplifyCFG: Omit range checks for switch lookup tables when default is unreachable
They would get optimized away later, but we might as well not emit them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223051 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-01 17:08:38 +00:00
Hans Wennborg
b2fd944378 SimplifyCFG: don't remove unreachable default switch destinations
An unreachable default destination can be exploited by other optimizations, and
SDag lowering is now prepared to handle them efficiently.

For example, branches to the unreachable destination will be optimized away,
such as in the case of range checks for switch lookup tables.

On 64-bit Linux, this reduces the size of a clang bootstrap by 80 kB (and
Chromium by 30 kB).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223050 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-01 17:08:35 +00:00
Erik Eckstein
6cfbf12d77 reinstate r222872: Peephole optimization in switch table lookup: reuse the guarding table comparison if possible.
Fixed missing dominance check.
Original commit message:

This optimization tries to reuse the generated compare instruction, if there is a comparison against the default value after the switch.
Example:
   if (idx < tablesize)
      r = table[idx]; // table does not contain default_value
   else
      r = default_value;
   if (r != default_value)
      ...
Is optimized to:
   cond = idx < tablesize;
   if (cond)
      r = table[idx];
   else
      r = default_value;
   if (cond)
      ...
Jump threading will then eliminate the second if(cond).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222891 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-27 15:13:14 +00:00
Erik Eckstein
4646580bc8 Revert "Peephole optimization in switch table lookup: reuse the guarding table comparison if possible."
It is breaking the clang bootstrag.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222877 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-27 10:59:08 +00:00
Erik Eckstein
c394c42d6d Peephole optimization in switch table lookup: reuse the guarding table comparison if possible.
This optimization tries to reuse the generated compare instruction, if there is a comparison against the default value after the switch.
Example:
    if (idx < tablesize)
       r = table[idx]; // table does not contain default_value
    else
       r = default_value;
    if (r != default_value)
       ...
Is optimized to:
    cond = idx < tablesize;
    if (cond)
       r = table[idx];
    else
       r = default_value;
    if (cond)
       ...
\endcode
Jump threading will then eliminate the second if(cond).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222872 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-27 08:33:51 +00:00
Mehdi Amini
517842e6fd SimplifyCFG: Refactor GatherConstantCompares() result in a struct
Code seems cleaner and easier to understand this way

This is basically r222416, after fixes for MSVC lack of standard 
support, and a few cleaning (got rid of a warning).
Thanks Nakamura Takumi and Nico Weber for the MSVC fixes.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222472 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-20 22:40:25 +00:00
Timur Iskhodzhanov
4b8337efd9 Revert r222416, r222422, r222426: the former revision had problems and fixing them introduced bugs
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222428 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-20 12:36:43 +00:00
Timur Iskhodzhanov
6a490ac188 Fix a typo
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222426 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-20 11:48:58 +00:00
NAKAMURA Takumi
f9f464d44b SimplifyCFG.cpp: Tweak to let msc17 compliant.
- Use LLVM_DELETED_FUNCTION.
  - Don't use member initializers.
  - Don't use initializer list.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222422 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-20 08:59:02 +00:00
Mehdi Amini
b3e705ed1d SimplifyCFG: Refactor GatherConstantCompares() result in a struct
Code seems cleaner and easier to understand this way




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222416 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-20 06:51:02 +00:00
Nico Weber
660bac6a57 Try to fix MSVS build after r222384. No intended behavior change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222386 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-19 21:16:11 +00:00
Mehdi Amini
30bd0c753e SimplifyCFG: turn recursive GatherConstantCompares into iterative
A long sequence of || or && could lead to a stack explosion.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222384 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-19 20:09:11 +00:00
David Blaikie
5401ba7099 Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool>
This is to be consistent with StringSet and ultimately with the standard
library's associative container insert function.

This lead to updating SmallSet::insert to return pair<iterator, bool>,
and then to update SmallPtrSet::insert to return pair<iterator, bool>,
and then to update all the existing users of those functions...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222334 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-19 07:49:26 +00:00
Hans Wennborg
9ba744b089 SimplifyCFG: Range'ify some for-loops. No functional change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222215 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-18 02:37:11 +00:00
Juergen Ributzka
18db81a0ec [SimplifyCFG] Make the value type of the hole check bitmask a power-of-2.
When converting a switch to a lookup table we might have to generate a bitmaks
to encode and check for holes in the original switch statement.

The type of this mask depends on the number of switch statements, which can
result in illegal types for pretty much all architectures.

To avoid unnecessary type legalization and help FastISel this commit increases
the size of the bitmask to next power-of-2 value when necessary.

This fixes rdar://problem/18984639.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222168 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-17 19:39:56 +00:00
Erik Eckstein
72a1394991 Optimize switch lookup tables with linear mapping.
This is a simple optimization for switch table lookup:
It computes the output value directly with an (optional) mul and add if there is a linear mapping between index and output.
Example:

int f1(int x) {
  switch (x) {
    case 0: return 10;
    case 1: return 11;
    case 2: return 12;
    case 3: return 13;
  }
  return 0;
}

generates:

define i32 @f1(i32 %x) #0 {
entry:
  %0 = icmp ult i32 %x, 4
  br i1 %0, label %switch.lookup, label %return

switch.lookup:
  %switch.offset = add i32 %x, 10
  ret i32 %switch.offset

return:
  ret i32 0
}



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222121 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-17 09:13:57 +00:00
Duncan P. N. Exon Smith
5bf8ade9d0 Revert "IR: MDNode => Value"
Instead, we're going to separate metadata from the Value hierarchy.  See
PR21532.

This reverts commit r221375.
This reverts commit r221373.
This reverts commit r221359.
This reverts commit r221167.
This reverts commit r221027.
This reverts commit r221024.
This reverts commit r221023.
This reverts commit r220995.
This reverts commit r220994.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221711 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 21:30:22 +00:00
Duncan P. N. Exon Smith
3a84a6377c IR: MDNode => Value: Instruction::getMetadata()
Change `Instruction::getMetadata()` to return `Value` as part of
PR21433.

Update most callers to use `Instruction::getMDNode()`, which wraps the
result in a `cast_or_null<MDNode>`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221024 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-01 00:10:31 +00:00
Philip Reames
1b8af6a8f0 Preserving 'nonnull' metadata in SimplifyCFG
When we hoist two loads above an if, we can preserve the nonnull metadata.  We could also do the same for sinking them, but we appear to not handle metadata at all in that case.

Thanks to Hal for the review.

Differential Revision: http://reviews.llvm.org/D5910



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220392 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-22 16:37:13 +00:00
Marcello Maggioni
db9fed93fa Switch to select optimization for two-case switches
This is the same optimization of r219233 with modifications to support PHIs with multiple incoming edges from the same block
and a test to check that this condition is handled.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219656 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 01:58:26 +00:00
Joerg Sonnenberger
c6133c17e0 Revert r219223, it creates invalid PHI nodes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219587 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-12 17:16:04 +00:00
Arnold Schwaighofer
dd8c386432 SimplifyCFG: Don't convert phis into selects if we could remove undef behavior
instead

We used to transform this:

  define void @test6(i1 %cond, i8* %ptr) {
  entry:
    br i1 %cond, label %bb1, label %bb2

  bb1:
    br label %bb2

  bb2:
    %ptr.2 = phi i8* [ %ptr, %entry ], [ null, %bb1 ]
    store i8 2, i8* %ptr.2, align 8
    ret void
  }

into this:

  define void @test6(i1 %cond, i8* %ptr) {
    %ptr.2 = select i1 %cond, i8* null, i8* %ptr
    store i8 2, i8* %ptr.2, align 8
    ret void
  }

because the simplifycfg transformation into selects would happen to happen
before the simplifycfg transformation that removes unreachable control flow
(We have 'unreachable control flow' due to the store to null which is undefined
behavior).

The existing transformation that removes unreachable control flow in simplifycfg
is:

  /// If BB has an incoming value that will always trigger undefined behavior
  /// (eg. null pointer dereference), remove the branch leading here.
  static bool removeUndefIntroducingPredecessor(BasicBlock *BB)

Now we generate:

  define void @test6(i1 %cond, i8* %ptr) {
    store i8 2, i8* %ptr.2, align 8
    ret void
  }

I did not see any impact on the test-suite + externals.

rdar://18596215

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219462 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-10 01:27:02 +00:00