Over the past day or so, i've took a large swing at our tests,
and reduced the number of tests that were still using the old syntax
from ~1800 to just 200.
Left to handle: (as it is seen in this patch)
* Transforms/LSR
* Transforms/CGP
* Transforms/TypePromotion
* Transforms/HardwareLoops
* Analysis/*
* some misc.
I think this is the right point to start actively refusing
to honor the old syntax, except for the old tests,
to prevent the old syntax from creeping back in.
Thus, let's add temporary default-off flag,
and if it is not passed refuse to accept old syntax.
The tests that still need porting are annotated with this flag.
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D139647
This switches everything to use the memory attribute proposed in
https://discourse.llvm.org/t/rfc-unify-memory-effect-attributes/65579.
The old argmemonly, inaccessiblememonly and inaccessiblemem_or_argmemonly
attributes are dropped. The readnone, readonly and writeonly attributes
are restricted to parameters only.
The old attributes are auto-upgraded both in bitcode and IR.
The bitcode upgrade is a policy requirement that has to be retained
indefinitely. The IR upgrade is mainly there so it's not necessary
to update all tests using memory attributes in this patch, which
is already large enough. We could drop that part after migrating
tests, or retain it longer term, to make it easier to import IR
from older LLVM versions.
High-level Function/CallBase APIs like doesNotAccessMemory() or
setDoesNotAccessMemory() are mapped transparently to the memory
attribute. Code that directly manipulates attributes (e.g. via
AttributeList) on the other hand needs to switch to working with
the memory attribute instead.
Differential Revision: https://reviews.llvm.org/D135780
Based on D130896, we can model operand bundles more precisely. In
addition to the baseline ModRefBehavior, a reading/clobbering operand
bundle may also read/write all locations. For example, a memcpy with
deopt bundle can read any memory, but only write argument memory.
This means that getModRefInfo() for memcpy with a pointer that does
not alias the arguments results in Ref, rather than ModRef, without
the need to implement any special handling.
Differential Revision: https://reviews.llvm.org/D130980
WinEHPrepare marks any function call from EH funclets as unreachable, if it's not a nounwind intrinsic or has no proper funclet bundle operand. This
affects ARC intrinsics on Windows, because they are lowered to regular function calls in the PreISelIntrinsicLowering pass. It caused silent binary truncations and crashes during unwinding with the GNUstep ObjC runtime: https://github.com/gnustep/libobjc2/issues/222
This patch adds a new function `llvm::IntrinsicInst::mayLowerToFunctionCall()` that aims to collect all affected intrinsic IDs.
* Clang CodeGen uses it to determine whether or not it must emit a funclet bundle operand.
* PreISelIntrinsicLowering asserts that the function returns true for all ObjC runtime calls it lowers.
* LLVM uses it to determine whether or not a funclet bundle operand must be propagated to inlined call sites.
Reviewed By: theraven
Differential Revision: https://reviews.llvm.org/D128190
If we have a writeonly function called from a callsite with a potentially reading operand bundle, we can not conclude the callsite is writeonly.
The changed test is the only one I've been able to demonstrate a current miscompile on, but an incorrect result here could show up in a bunch of subtle ways. For instance, this issue caused several spurious test changes when combined with D117591.
This fixes a bug in 740057d. There's two ways to describe the issue:
* One caller hasn't yet proven nocapture on the argument. Given that, the inference routine is responsible for bailing out on a potential capture.
* Even if we know the argument is nocapture, the access inference needs to traverse the exact set of users the capture tracking would (or exit conservatively). Even if capture tracking can prove a store is non-capturing (e.g. to a local alloc which doesn't escape), we still need to track the copy of the pointer to see if it's later reloaded and accessed again.
Note that all the test changes except the newly added ones appear to be false negatives. That is, cases where we could prove writeonly, but the current code isn't strong enough. That's why I didn't spot this originally.
This change extends the current logic for inferring readonly and readnone argument attributes to also infer writeonly.
This change is deliberately minimal; there's a couple of areas for follow up.
* I left out all call handling and thus any benefit from the SCC walk. When examining the test changes, I realized the existing code is imprecise, and am going to fix that in it's own revision before adding in the writeonly handling. (Mostly because updating the tests is hard when I, the human, can't figure out whether the result is correct.)
* I left out handling for storing a value (as opposed to storing to a pointer). This should benefit readonly/readnone as well, and applies to a bunch of other instructions. Seemed worth having as a separate review.
Differential Revision: https://reviews.llvm.org/D114963
Simply use the new PM syntax instead of the deprecated legacy PM
syntax when specifying the opt pipeline in some regression tests.
Differential Revision: https://reviews.llvm.org/D114518
In both ADCE and BDCE (via DemandedBits) we should not remove
instructions that are not guaranteed to return. This issue was
pointed out by fhahn in the recent llvm-dev thread.
Differential Revision: https://reviews.llvm.org/D96993
With the addition of the `willreturn` attribute, functions that may
not return (e.g. due to an infinite loop) are well defined, if they are
not marked as `willreturn`.
This patch updates `wouldInstructionBeTriviallyDead` to not consider
calls that may not return as dead.
This patch still provides an escape hatch for intrinsics, which are
still assumed as willreturn unconditionally. It will be removed once
all intrinsics definitions have been reviewed and updated.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D94106
As discussed in D86843, -earlycse-debug-hash should be used in more regression
tests to catch inconsistency between the hashing and the equivalence check.
Differential Revision: https://reviews.llvm.org/D86863
To match NewPM pass name, and also for readability.
Also rename rpo-functionattrs -> rpo-function-attrs while we're here.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D84694
This patch adds a function attribute, nofree, to indicate that a function does
not, directly or indirectly, call a memory-deallocation function (e.g., free,
C++'s operator delete).
Reviewers: jdoerfert
Differential Revision: https://reviews.llvm.org/D49165
llvm-svn: 365336
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
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
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
Summary:
This change teaches the LLVM inliner to not inline through callsites
with unknown operand bundles. Currently all operand bundles are
"unknown" operand bundles but in the near future we will add support for
inlining through some select kinds of operand bundles.
Reviewers: reames, chandlerc, majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D14001
llvm-svn: 251141
Summary:
If a `CallSite` has operand bundles, then do not peek into the called
function to get a more precise `ModRef` answer.
This is tested using `argmemonly`, `-basicaa` and `-gvn`; but the
functionality is not specific to any of these.
Depends on D13961
Reviewers: reames, chandlerc
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D13962
llvm-svn: 250974
Summary:
This makes attribute accessors on `CallInst` and `InvokeInst` do the
(conservatively) right thing. This essentially involves, in some
cases, *not* falling back querying the attributes on the called
`llvm::Function` when operand bundles are present.
Attributes locally present on the `CallInst` or `InvokeInst` will still
override operand bundle semantics. The LangRef has been amended to
reflect this. Note: this change does not do anything prevent
`-function-attrs` from inferring `CallSite` local attributes after
inspecting the called function -- that will be done as a separate
change.
I've used `-adce` and `-early-cse` to test these changes. There is
nothing special about these passes (and they did not require any
changes) except that they seemed be the easiest way to write the tests.
This change does not add deal with `argmemonly`. That's a later change
because alias analysis requires a related fix before `argmemonly` can be
tested.
Reviewers: reames, chandlerc
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D13961
llvm-svn: 250973
