A call to @llvm.trap can be expected to be cold (i.e. unlikely to be
reached in a normal program execution).
Outlining paths which unconditionally trap is an important memory
saving. As the hot/cold splitting pass (imho) should not treat all
noreturn calls as cold, explicitly mark @llvm.trap cold so that it can
be outlined.
Split out of https://reviews.llvm.org/D54244.
Differential Revision: https://reviews.llvm.org/D54329
llvm-svn: 346885
The plan had always been to move towards using this rather than so much
in-pass simplification within the loop pipeline, but we never got around
to it.... until only a couple months after it was removed due to disuse.
=/
This commit is just a pure revert of the removal. I will add tests and
do some basic cleanup in follow-up commits. Then I'll wire it into the
loop pass pipeline.
Differential Revision: https://reviews.llvm.org/D47353
llvm-svn: 333250
LoopInstSimplify is unused and untested. Reading through the commit
history the pass also seems to have a high maintenance burden.
It would be best to retire the pass for now. It should be easy to
recover if we need something similar in the future.
Differential Revision: https://reviews.llvm.org/D44053
llvm-svn: 327329
These were introduced in r323783 and use an X86 triple. I'll follow up
on the list to check if it would make more sense to remove the triple
and mark them REQUIRES: default_triple instead.
llvm-svn: 323847
Introduce an extension to support passing linker options to the linker.
These would be ignored by older linkers, but newer linkers which support
this feature would be able to process the linker.
Emit a special discarded section `.linker-option`. The content of this
section is a pair of strings (key, value). The key is a type identifier for
the parameter. This allows for an argument free parameter that will be
processed by the linker with the value being the parameter. As an example,
`lib` identifies a library to be linked against, traditionally the `-l`
argument for Unix-based linkers with the parameter being the library name.
Thanks to James Henderson, Cary Coutant, Rafael Espinolda, Sean Silva
for the valuable discussion on the design of this feature.
llvm-svn: 323783
The lowering isn't really an optimization, so optnone shouldn't make a
difference. ARM relies on the pass running when using "-mthread-model
single", because in that mode, it doesn't run AtomicExpand. See bug for
more details.
Differential Revision: https://reviews.llvm.org/D37040
llvm-svn: 311565
It served us well, helped kick-start much of the vectorization efforts
in LLVM, etc. Its time has come and past. Back in 2014:
http://lists.llvm.org/pipermail/llvm-dev/2014-November/079091.html
Time to actually let go and move forward. =]
I've updated the release notes both about the removal and the
deprecation of the corresponding C API.
llvm-svn: 306797
also a discussion about exactly what we should do prior to re-enabling
it.
The current bug is http://llvm.org/PR32821 and the discussion about this
is in the review thread for r300200.
llvm-svn: 301505
This commit introduces a set of experimental intrinsics intended to prevent
optimizations that make assumptions about the rounding mode and floating point
exception behavior. These intrinsics will later be extended to specify
flush-to-zero behavior. More work is also required to model instruction
dependencies in machine code and to generate these instructions from clang
(when required by pragmas and/or command line options that are not currently
supported).
Differential Revision: https://reviews.llvm.org/D27028
llvm-svn: 293226
GVN-Hoist appears to miscompile llvm-testsuite
SingleSource/Benchmarks/Misc/fbench.c at the moment.
I filed http://llvm.org/PR28880
This reverts commit r277786.
llvm-svn: 277909
Summary:
Adding a flag to diable GVN Hoisting by default.
Note: The GVN Hoist Pass causes some Halide tests to hang. Halide will disable the pass while investigating.
Reviewers: llvm-commits, chandlerc, spop, dberlin
Subscribers: mehdi_amini
Differential Revision: https://reviews.llvm.org/D22639
llvm-svn: 276479
Summary:
The llvm.invariant.start and llvm.invariant.end intrinsics currently
support specifying invariant memory objects only in the default address
space.
With this change, these intrinsics are overloaded for any adddress space
for memory objects
and we can use these llvm invariant intrinsics in non-default address
spaces.
Example: llvm.invariant.start.p1i8(i64 4, i8 addrspace(1)* %ptr)
This overloaded intrinsic is needed for representing final or invariant
memory in managed languages.
Reviewers: apilipenko, reames
Subscribers: llvm-commits
llvm-svn: 276447
Summary:
The llvm.invariant.start and llvm.invariant.end intrinsics currently
support specifying invariant memory objects only in the default address space.
With this change, these intrinsics are overloaded for any adddress space for memory objects
and we can use these llvm invariant intrinsics in non-default address spaces.
Example: llvm.invariant.start.p1i8(i64 4, i8 addrspace(1)* %ptr)
This overloaded intrinsic is needed for representing final or invariant memory in managed languages.
Reviewers: tstellarAMD, reames, apilipenko
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D22519
llvm-svn: 276316
If a local_unnamed_addr attribute is attached to a global, the address
is known to be insignificant within the module. It is distinct from the
existing unnamed_addr attribute in that it only describes a local property
of the module rather than a global property of the symbol.
This attribute is intended to be used by the code generator and LTO to allow
the linker to decide whether the global needs to be in the symbol table. It is
possible to exclude a global from the symbol table if three things are true:
- This attribute is present on every instance of the global (which means that
the normal rule that the global must have a unique address can be broken without
being observable by the program by performing comparisons against the global's
address)
- The global has linkonce_odr linkage (which means that each linkage unit must have
its own copy of the global if it requires one, and the copy in each linkage unit
must be the same)
- It is a constant or a function (which means that the program cannot observe that
the unique-address rule has been broken by writing to the global)
Although this attribute could in principle be computed from the module
contents, LTO clients (i.e. linkers) will normally need to be able to compute
this property as part of symbol resolution, and it would be inefficient to
materialize every module just to compute it.
See:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160509/356401.htmlhttp://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160516/356738.html
for earlier discussion.
Part of the fix for PR27553.
Differential Revision: http://reviews.llvm.org/D20348
llvm-svn: 272709
An oddity of the .ll syntax is that the "@var = " in
@var = global i32 42
is optional. Writing just
global i32 42
is equivalent to
@0 = global i32 42
This means that there is a pretty big First set at the top level. The
current implementation maintains it manually. I was trying to refactor
it, but then started wondering why keep it a all. I personally find the
above syntax confusing. It looks like something is missing.
This patch removes the feature and simplifies the parser.
llvm-svn: 269096
Summary:
I've completed my audit of all the code that looks at noduplicate and
added handling of convergent where appropriate, so we no longer need
noduplicate on these intrinsics.
Reviewers: jholewinski
Subscribers: llvm-commits, jholewinski
Differential Revision: http://reviews.llvm.org/D18168
llvm-svn: 264107
Summary:
This is intended to be a performance flag, on the same level as clang
cc1 option "--disable-free". LLVM will never initialize it by default,
it will be up to the client creating the LLVMContext to request this
behavior. Clang will do it by default in Release build (just like
--disable-free).
"opt" and "llc" can opt-in using -disable-named-value command line
option.
When performing LTO on llvm-tblgen, the initial merging of IR peaks
at 92MB without this patch, and 86MB after this patch,setNameImpl()
drops from 6.5MB to 0.5MB.
The total link time goes from ~29.5s to ~27.8s.
Compared to a compile-time flag (like the IRBuilder one), it performs
very close. I profiled on SROA and obtain these results:
420ms with IRBuilder that preserve name
372ms with IRBuilder that strip name
375ms with IRBuilder that preserve name, and a runtime flag to strip
Reviewers: chandlerc, dexonsmith, bogner
Subscribers: joker.eph, llvm-commits
Differential Revision: http://reviews.llvm.org/D17946
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 263086
In general, memory restrictions on a called function (e.g. readnone)
cannot be transferred to a CallSite that has operand bundles. It is
possible to make this inference smarter, but lets fix the behavior to be
correct first.
llvm-svn: 260193
Summary:
This is the attribute purpose-made for e.g. __syncthreads. It appears
that NoDuplicate may not be sufficient to prevent Sink from touching a
call to __syncthreads.
Reviewers: jingyue, hfinkel
Subscribers: llvm-commits, jholewinski, jhen, rnk, tra, majnemer
Differential Revision: http://reviews.llvm.org/D16941
llvm-svn: 260005
Summary:
Funclet EH personalities require a tree-like nesting among funclets
(enforced by the ParentPad linkage in the IR), and also require that
unwind edges conform to certain rules with respect to the tree:
- An unwind edge may exit 0 or more ancestor pads
- An unwind edge must enter exactly one EH pad, which must be distinct
from any exited pads
- A cleanupret's edge must exit its cleanuppad
Describe these rules in the LangRef, and enforce them in the verifier.
Reviewers: rnk, majnemer, andrew.w.kaylor
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D15961
llvm-svn: 257272
It turns out that terminatepad gives little benefit over a cleanuppad
which calls the termination function. This is not sufficient to
implement fully generic filters but MSVC doesn't support them which
makes terminatepad a little over-designed.
Depends on D15478.
Differential Revision: http://reviews.llvm.org/D15479
llvm-svn: 255522
While we have successfully implemented a funclet-oriented EH scheme on
top of LLVM IR, our scheme has some notable deficiencies:
- catchendpad and cleanupendpad are necessary in the current design
but they are difficult to explain to others, even to seasoned LLVM
experts.
- catchendpad and cleanupendpad are optimization barriers. They cannot
be split and force all potentially throwing call-sites to be invokes.
This has a noticable effect on the quality of our code generation.
- catchpad, while similar in some aspects to invoke, is fairly awkward.
It is unsplittable, starts a funclet, and has control flow to other
funclets.
- The nesting relationship between funclets is currently a property of
control flow edges. Because of this, we are forced to carefully
analyze the flow graph to see if there might potentially exist illegal
nesting among funclets. While we have logic to clone funclets when
they are illegally nested, it would be nicer if we had a
representation which forbade them upfront.
Let's clean this up a bit by doing the following:
- Instead, make catchpad more like cleanuppad and landingpad: no control
flow, just a bunch of simple operands; catchpad would be splittable.
- Introduce catchswitch, a control flow instruction designed to model
the constraints of funclet oriented EH.
- Make funclet scoping explicit by having funclet instructions consume
the token produced by the funclet which contains them.
- Remove catchendpad and cleanupendpad. Their presence can be inferred
implicitly using coloring information.
N.B. The state numbering code for the CLR has been updated but the
veracity of it's output cannot be spoken for. An expert should take a
look to make sure the results are reasonable.
Reviewers: rnk, JosephTremoulet, andrew.w.kaylor
Differential Revision: http://reviews.llvm.org/D15139
llvm-svn: 255422
Teach LLVM optimize to more precisely in the presence of "deopt" operand
bundles. "deopt" operand bundles imply that the call they're attached
to is at least `readonly` (i.e. they don't imply clobber semantics), and
they don't capture their bundle operands.
llvm-svn: 254118
Summary:
Teach the FunctionAttrs to do the right thing for IR with operand
bundles.
Reviewers: reames, chandlerc
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D14408
llvm-svn: 252387
Summary:
Earlier CaptureTracking would assume all "interesting" operands to a
call or invoke were its arguments. With operand bundles this is no
longer true.
Note: an earlier change got `doesNotCapture` working correctly with
operand bundles.
This change uses DSE to test the changes to CaptureTracking. DSE is a
vehicle for testing only, and is not directly involved in this change.
Reviewers: reames, majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D14306
llvm-svn: 252095
Vedant Kumar