basic changes to the IR such as folding pointers through PHIs, Selects,
integer casts, store/load pairs, or outlining.
This leaves the feature available behind a flag. This flag's default
could be flipped if necessary, but the real-world performance impact of
this particular feature of GMR may not be sufficiently significant for
many folks to want to run the risk.
Currently, the risk here is somewhat mitigated by half-hearted attempts
to update GlobalsModRef when the rest of the optimizer changes
something. However, I am currently trying to remove that update
mechanism as it makes migrating the AA infrastructure to a form that can
be readily shared between new and old pass managers very challenging.
Without this update mechanism, it is possible that this still unlikely
failure mode will start to trip people, and so I wanted to try to
proactively avoid that.
There is a lengthy discussion on the mailing list about why the core
approach here is flawed, and likely would need to look totally different
to be both reasonably effective and resilient to basic IR changes
occuring. This patch is essentially the first of two which will enact
the result of that discussion. The next patch will remove the current
update mechanism.
Thanks to lots of folks that helped look at this from different angles.
Especial thanks to Michael Zolotukhin for doing some very prelimanary
benchmarking of LTO without GlobalsModRef to get a rough idea of the
impact we could be facing here. So far, it looks very small, but there
are some concerns lingering from other benchmarking. The default here
may get flipped if performance results end up pointing at this as a more
significant issue.
Also thanks to Pete and Gerolf for reviewing!
Differential Revision: http://reviews.llvm.org/D11213
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242512 91177308-0d34-0410-b5e6-96231b3b80d8
Since r230724 ("Skip promotable allocas to improve performance at -O0"), there is a regression in the generated debug info for those non-instrumented variables. When inspecting such a variable's value in LLDB, you often get garbage instead of the actual value. ASan instrumentation is inserted before the creation of the non-instrumented alloca. The only allocas that are considered standard stack variables are the ones declared in the first basic-block, but the initial instrumentation setup in the function breaks that invariant.
This patch makes sure uninstrumented allocas stay in the first BB.
Differential Revision: http://reviews.llvm.org/D11179
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242510 91177308-0d34-0410-b5e6-96231b3b80d8
This is mostly done to disable the PostRAScheduler which optimizes for
instruction latencies which isn't a good fit for out-of-order
architectures. This also allows to leave out the itinerary table in
swift in favor of the SchedModel ones.
This change leads to performance improvements/regressions by as much as
10% in some benchmarks, in fact we loose 0.4% performance over the
llvm-testsuite for reasons that appear to be unknown or out of the
compilers control. rdar://20803802 documents the investigation of
these effects.
While it is probably a good idea to perform the same switch for the
other ARM out-of-order CPUs, I limited this change to swift as I cannot
perform the benchmark verification on the other CPUs.
Differential Revision: http://reviews.llvm.org/D10513
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242500 91177308-0d34-0410-b5e6-96231b3b80d8
Those new constructors make it more natural to construct an object for a function. For example, previously to build a LoopInfo for a function, we need four statements:
DominatorTree DT;
LoopInfo LI;
DT.recalculate(F);
LI.analyze(DT);
Now we only need one statement:
LoopInfo LI(DominatorTree(F));
http://reviews.llvm.org/D11274
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242486 91177308-0d34-0410-b5e6-96231b3b80d8
Constructing a name based on the function name didn't give us a unique
symbol if we had more than one setjmp in a function. Using
MCContext::createTempSymbol() always gives us a unique name.
Differential Revision: http://reviews.llvm.org/D9314
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242482 91177308-0d34-0410-b5e6-96231b3b80d8
llvm.eh.sjlj.setjmp was used as part of the SjLj exception handling
style but is also used in clang to implement __builtin_setjmp. The ARM
backend needs to output additional dispatch tables for the SjLj
exception handling style, these tables however can't be emitted if
llvm.eh.sjlj.setjmp is simply used for __builtin_setjmp and no actual
landing pad blocks exist.
To solve this issue a new llvm.eh.sjlj.setup_dispatch intrinsic is
introduced which is used instead of llvm.eh.sjlj.setjmp in the SjLj
exception handling lowering, so we can differentiate between the case
where we actually need to setup a dispatch table and the case where we
just need the __builtin_setjmp semantic.
Differential Revision: http://reviews.llvm.org/D9313
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242481 91177308-0d34-0410-b5e6-96231b3b80d8
C11 leaves the choice on whether round-to-integer operations set the inexact
flag implementation-defined. Darwin does expect it to be set, but this seems to
be against the intent of the IEEE document and slower to implement anyway. So
it should be opt-in.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242446 91177308-0d34-0410-b5e6-96231b3b80d8
I was looking at some vector code generation and kept seeing
unnecessary vector copies into the Altivec half of the VSX registers.
I discovered that we overlooked v4i32 when adding the register classes
for VSX; we only added v4f32 and v2f64. This means that anything that
canonicalizes into v4i32 (which is a LOT of stuff) ends up being
forced into VRRC on its way to VSRC.
The fix is one line. The rest of the patch is fixing up some test
cases whose code generation has changed as a result.
This seems like it would be a good candidate for backport to 3.7.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242442 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
SpeculativeExecution enables a series straight line optimizations (such
as SLSR and NaryReassociate) on conditional code. For example,
if (...)
... b * s ...
if (...)
... (b + 1) * s ...
speculative execution can hoist b * s and (b + 1) * s from then-blocks,
so that we have
... b * s ...
if (...)
...
... (b + 1) * s ...
if (...)
...
Then, SLSR can rewrite (b + 1) * s to (b * s + s) because after
speculative execution b * s dominates (b + 1) * s.
The performance impact of this change is significant. It speeds up the
benchmarks running EigenFloatContractionKernelInternal16x16
(ba68f42fa6/unsupported/Eigen/CXX11/src/Tensor/TensorContractionCuda.h (cl-526))
by roughly 2%. Some internal benchmarks that have the above code pattern
are improved by up to 40%. No significant slowdowns are observed on
Eigen CUDA microbenchmarks.
Reviewers: jholewinski, broune, eliben
Subscribers: llvm-commits, jholewinski
Differential Revision: http://reviews.llvm.org/D11201
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242437 91177308-0d34-0410-b5e6-96231b3b80d8
This is a new iteration of the reverted r238793 /
http://reviews.llvm.org/D8232 which wrongly assumed that any and/or
trees can be represented by conditional compare sequences, however there
are some restrictions to that. This version fixes this and adds comments
that explain exactly what types of and/or trees can actually be
implemented as conditional compare sequences.
Related to http://llvm.org/PR20927, rdar://18326194
Differential Revision: http://reviews.llvm.org/D10579
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242436 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
We can safely assume that the high bit of scratch offsets will never
be set, because this would require at least 128 GB of GPU memory.
Reviewers: arsenm
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D11225
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242433 91177308-0d34-0410-b5e6-96231b3b80d8
Empty subranges are not allowed in a LiveInterval and must be removed
instead: Check this in the verifiers, put a reminder for this in the
comment of the shrinkToUses variant for a single lane and make it
automatic for the shrinkToUses variant for a LiveInterval.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242431 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r242300.
This is causing buildbot failures which we are investigating.
I'll reapply once we know whats going on, but for now want to
get the bots green.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242428 91177308-0d34-0410-b5e6-96231b3b80d8
Internalizing an individual comdat group member without also internalizing
the other members of the comdat can break comdat semantics. For example,
if a module contains a reference to an internalized comdat member, and the
linker chooses a comdat group from a different object file, this will break
the reference to the internalized member.
This change causes the internalizer to only internalize comdat members if all
other members of the comdat are not externally visible. Once a comdat group
has been fully internalized, there is no need to apply comdat rules to its
members; later optimization passes (e.g. globaldce) can legally drop individual
members of the comdat. So we drop the comdat attribute from all comdat members.
Differential Revision: http://reviews.llvm.org/D10679
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242423 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.
The ExecutionEngine will act as an exception and will be unsafe to
be reused across context. We don't enforce this rule but undefined
behavior can occurs if the user tries to do it.
Reviewers: lhames
Subscribers: echristo, llvm-commits, rafael, yaron.keren
Differential Revision: http://reviews.llvm.org/D11110
From: Mehdi Amini <mehdi.amini@apple.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242414 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This fixes an issue on MIPS where the infinite-loop-evergreen.ll test
was failing to terminate.
Fixes PR24147.
Reviewers: arsenm, dsanders
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D11260
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242410 91177308-0d34-0410-b5e6-96231b3b80d8
This adds new intrinsics "*absdiff" for absolute difference ops to facilitate efficient code generation for "sum of absolute differences" operation.
The patch also contains the introduction of corresponding SDNodes and basic legalization support.Sanity of the generated code is tested on X86.
This is 1st of the three patches.
Patch by Shahid Asghar-ahmad!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242409 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The checking pointer grouping algorithm assumes that the
starts/ends of the pointers are well formed (start <= end).
The runtime memory checking algorithm also assumes this by doing:
start0 < end1 && start1 < end0
to detect conflicts. This check only works if start0 <= end0 and
start1 <= end1.
This change correctly orders the interval ends by either checking
the stride (if it is constant) or by using min/max SCEV expressions.
Reviewers: anemet, rengolin
Subscribers: rengolin, llvm-commits
Differential Revision: http://reviews.llvm.org/D11149
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242400 91177308-0d34-0410-b5e6-96231b3b80d8
This allows more call sequences to use pushes instead of movs when optimizing for size.
In particular, calling conventions that pass some parameters in registers (e.g. thiscall) are now supported.
This should no longer cause miscompiles, now that a bug in emitPrologue was fixed in r242395.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242398 91177308-0d34-0410-b5e6-96231b3b80d8
When X86FrameLowering::emitPrologue() looks for where to insert the %esp subtraction
to allocate stack space for local allocations, it assumes that any sequence of push
instructions that starts at function entry consists purely of spills of callee-save
registers.
This may be false, since from some point forward, the pushes may pushing arguments
to a subsequent function call.
This caused a miscompile that was exposed by r240257, and is not easily testable
since r240257 was reverted. A test will be committed separately after r240257 is
reapplied.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242395 91177308-0d34-0410-b5e6-96231b3b80d8
This extension point allows passes to be executed right before the vectorizer
and other highly target specific optimizations are run.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242389 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.
The ExecutionEngine will act as an exception and will be unsafe to
be reused across context. We don't enforce this rule but undefined
behavior can occurs if the user tries to do it.
Reviewers: lhames
Subscribers: echristo, llvm-commits, rafael, yaron.keren
Differential Revision: http://reviews.llvm.org/D11110
From: Mehdi Amini <mehdi.amini@apple.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242387 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.
This patch is quite boring overall, except for some uglyness in
ASMPrinter which has a getDataLayout function but has some clients
that use it without a Module (llmv-dsymutil, llvm-dwarfdump), so
some methods are taking a DataLayout as parameter.
Reviewers: echristo
Subscribers: yaron.keren, rafael, llvm-commits, jholewinski
Differential Revision: http://reviews.llvm.org/D11090
From: Mehdi Amini <mehdi.amini@apple.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242386 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.
Reviewers: echristo
Subscribers: yaron.keren, rafael, llvm-commits, jholewinski
Differential Revision: http://reviews.llvm.org/D11079
From: Mehdi Amini <mehdi.amini@apple.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242385 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Because llvm-dsymutil is using ASMPrinter without any MachineFunction
of Module available.
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.
Reviewers: echristo
Subscribers: yaron.keren, rafael, llvm-commits
Differential Revision: http://reviews.llvm.org/D11078
From: Mehdi Amini <mehdi.amini@apple.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242384 91177308-0d34-0410-b5e6-96231b3b80d8
This is made a static public member function to allow the transition of
this logic from LAA to LoopDistribution. (Technically, it could be an
implementation-local static function but then it would not be accessible
from LoopDistribution.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242376 91177308-0d34-0410-b5e6-96231b3b80d8
It miscompiles some code and a reduced test case has been sent to the
author.
This reverts commit r240257.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242373 91177308-0d34-0410-b5e6-96231b3b80d8
Revert the changes to the C API LLVMBuildLandingPad that were part of
the personality function move. We now set the personality on the parent
function when the C API attempts to construct a landingpad with a
personality.
This reverts commit r240010.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242372 91177308-0d34-0410-b5e6-96231b3b80d8