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!
llvm-svn: 240137
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.
llvm-svn: 235771
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
llvm-svn: 233125
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
llvm-svn: 232575
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>
llvm-svn: 231740
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>
llvm-svn: 230241
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.
llvm-svn: 228826
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
llvm-svn: 227125
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.
llvm-svn: 226850
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.
llvm-svn: 225760
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.
llvm-svn: 225552
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.
llvm-svn: 225131
- 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.
llvm-svn: 224757
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.)
llvm-svn: 223802
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).
llvm-svn: 223050
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).
llvm-svn: 222891
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).
llvm-svn: 222872
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.
llvm-svn: 222472
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...
llvm-svn: 222334
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.
llvm-svn: 222168
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
}
llvm-svn: 222121
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.
llvm-svn: 221711
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>`.
llvm-svn: 221024
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
llvm-svn: 220392
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.
llvm-svn: 219656
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
llvm-svn: 219462
This optimization tries to convert switch instructions that are used to select a value with only 2 unique cases + default block
to a select or a couple of selects (depending if the default block is reachable or not).
The typical case this optimization wants to be able to optimize is this one:
Example:
switch (a) {
case 10: %0 = icmp eq i32 %a, 10
return 10; %1 = select i1 %0, i32 10, i32 4
case 20: ----> %2 = icmp eq i32 %a, 20
return 2; %3 = select i1 %2, i32 2, i32 %1
default:
return 4;
}
It also sets the base for further optimizations that are planned and being reviewed.
llvm-svn: 219223
Sanjay Patel