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
Given that large parts of inst combine is restricted to instructions which have one use, getting rid of a use on the condition can help the effectiveness of the optimizer. Also, it allows the condition to potentially be deleted by instcombine rather than waiting for another pass.
I noticed this completely by accident in another test case. It's not anything that actually came from a real workload.
p.s. We should probably do the same thing for switch instructions.
Differential Revision: http://reviews.llvm.org/D8220
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231881 91177308-0d34-0410-b5e6-96231b3b80d8
Now the analysis won't "fail" if the memchecks exceed the threshold. It
is the transform pass' responsibility to perform the check.
This allows the transform pass to further analyze/eliminate the
memchecks. E.g. in Loop distribution we only need to check pointers
that end up in different partitions.
Note that there is a slight change of functionality here. The logic in
analyzeLoop is that if dependence checking fails due to non-constant
distance between the pointers, another attempt is made to prove safety
of the dependences purely using run-time checks.
Before this patch we could fail the loop due to exceeding the memcheck
threshold after the first step, now we only check the threshold in the
client after the full analysis. There is no measurable compile-time
effect but I wanted to record this here.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231817 91177308-0d34-0410-b5e6-96231b3b80d8
ReplaceInstUsesWith needs to return nullptr when the input has no users,
because in that case it does not mutate the program. Otherwise, we can
get stuck in an infinite loop of repeatedly attempting to constant fold
and instruction with no users.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231755 91177308-0d34-0410-b5e6-96231b3b80d8
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
Runtime unrolling is an expensive optimization which can bring benefit
only if the loop is hot and iteration number is relatively large enough.
For some loops, we know they are not worth to be runtime unrolled.
The scalar loop from vectorization is one of the cases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231631 91177308-0d34-0410-b5e6-96231b3b80d8
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
Specifically this:
* Prevents an "unused" warning in non-assert builds.
* In that error case return with out removing a child loop instead of
looping forever.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231459 91177308-0d34-0410-b5e6-96231b3b80d8
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
These refactored computations check whether or not we are at a stage
of the sequence where we can perform a match. This patch moves the
computation out of the main dataflow and into
{BottomUp,TopDown}PtrState.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231439 91177308-0d34-0410-b5e6-96231b3b80d8
This initialization occurs when we see a new retain or release. Before
we performed the actual initialization inline in the dataflow. That is
just messy.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231438 91177308-0d34-0410-b5e6-96231b3b80d8
This will enable the main ObjCARCOpts dataflow to work with higher
level concepts such as "can this ptr state be modified by this ref
count" and not need to understand the nitty gritty details of how that
is determined. This makes the dataflow cleaner.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231437 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
rL225282 introduced an ad-hoc way to promote some additions to nuw or
nsw. Since then SCEV has become smarter in directly proving no-wrap;
and using the canonical "ext(A op B) == ext(A) op ext(B)" method of
proving no-wrap is just as powerful now. Rip out the existing
complexity in favor of getting SCEV to do all the heaving lifting
internally.
This change does not add any unit tests because it is supposed to be a
non-functional change. Tests added in rL225282 and rL226075 are valid
tests for this change.
Reviewers: atrick, majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D7981
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231306 91177308-0d34-0410-b5e6-96231b3b80d8
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
Do not instrument direct accesses to stack variables that can be
proven to be inbounds, e.g. accesses to fields of structs on stack.
But it eliminates 33% of instrumentation on webrtc/modules_unittests
(number of memory accesses goes down from 290152 to 193998) and
reduces binary size by 15% (from 74M to 64M) and improved compilation time by 6-12%.
The optimization is guarded by asan-opt-stack flag that is off by default.
http://reviews.llvm.org/D7583
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231241 91177308-0d34-0410-b5e6-96231b3b80d8
RewriteStatepointsForGC pass emits an alloca for each GC pointer which will be relocated. It then inserts stores after def and all relocations, and inserts loads before each use as well. In the end, mem2reg is used to update IR with relocations in SSA form.
However, there is a problem with inserting stores for values defined by invoke instructions. The code didn't expect a def was a terminator instruction, and inserting instructions after these terminators resulted in malformed IR.
This patch fixes this problem by handling invoke instructions as a special case. If the def is an invoke instruction, the store will be inserted at the beginning of the normal destination block. Since return value from invoke instruction does not dominate the unwind destination block, no action is needed there.
Patch by: Chen Li
Differential Revision: http://reviews.llvm.org/D7923
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231183 91177308-0d34-0410-b5e6-96231b3b80d8
Introduce -mllvm -sanitizer-coverage-8bit-counters=1
which adds imprecise thread-unfriendly 8-bit coverage counters.
The run-time library maps these 8-bit counters to 8-bit bitsets in the same way
AFL (http://lcamtuf.coredump.cx/afl/technical_details.txt) does:
counter values are divided into 8 ranges and based on the counter
value one of the bits in the bitset is set.
The AFL ranges are used here: 1, 2, 3, 4-7, 8-15, 16-31, 32-127, 128+.
These counters provide a search heuristic for single-threaded
coverage-guided fuzzers, we do not expect them to be useful for other purposes.
Depending on the value of -fsanitize-coverage=[123] flag,
these counters will be added to the function entry blocks (=1),
every basic block (=2), or every edge (=3).
Use these counters as an optional search heuristic in the Fuzzer library.
Add a test where this heuristic is critical.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231166 91177308-0d34-0410-b5e6-96231b3b80d8
Selection conditions may be vectors or scalars. Make sure InstCombine
doesn't indiscriminately assume that a select which is value dependent
on another select have identical select condition types.
This fixes PR22773.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231156 91177308-0d34-0410-b5e6-96231b3b80d8
