If alignment was manifested but it is actually only as good as the
data-layout provided one we should not report it as a change.
For testing purposes we still manifest the information.
Summary:
Third part in series to support Safe Whole Program Devirtualization
Enablement, see RFC here:
http://lists.llvm.org/pipermail/llvm-dev/2019-December/137543.html
This patch adds type test metadata under -fwhole-program-vtables,
even for classes without hidden visibility. It then changes WPD to skip
devirtualization for a virtual function call when any of the compatible
vtables has public vcall visibility.
Additionally, internal LLVM options as well as lld and gold-plugin
options are added which enable upgrading all public vcall visibility
to linkage unit (hidden) visibility during LTO. This enables the more
aggressive WPD to kick in based on LTO time knowledge of the visibility
guarantees.
Support was added to all flavors of LTO WPD (regular, hybrid and
index-only), and to both the new and old LTO APIs.
Unfortunately it was not simple to split the first and second parts of
this part of the change (the unconditional emission of type tests and
the upgrading of the vcall visiblity) as I needed a way to upgrade the
public visibility on legacy WPD llvm assembly tests that don't include
linkage unit vcall visibility specifiers, to avoid a lot of test churn.
I also added a mechanism to LowerTypeTests that allows dropping type
test assume sequences we now aggressively insert when we invoke
distributed ThinLTO backends with null indexes, which is used in testing
mode, and which doesn't invoke the normal ThinLTO backend pipeline.
Depends on D71907 and D71911.
Reviewers: pcc, evgeny777, steven_wu, espindola
Subscribers: emaste, Prazek, inglorion, arichardson, hiraditya, MaskRay, dexonsmith, dang, davidxl, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D71913
The utility method RecursivelyDeleteTriviallyDeadInstructions receives
as input a vector of Instructions, where all inputs are valid
instructions. This same vector is used as a scratch storage (per the
header comment) to recursively delete instructions. If an instruction is
added as an operand of multiple other instructions, it may be added twice,
then deleted once, then the second reference in the vector is invalid.
Switch to using a Vector<WeakTrackingVH>.
This change facilitates a clean-up in LoopStrengthReduction.
MSVC 2013 would refuse to pass highly aligned things (typically vectors
and aggregates) by value. Users would receive this error:
t.cpp(11) : error C2719: 'w': formal parameter with __declspec(align('32')) won't be aligned
t.cpp(11) : error C2719: 'q': formal parameter with __declspec(align('32')) won't be aligned
However, in MSVC 2015, this behavior was changed, and highly aligned
things are now passed indirectly. To avoid breaking backwards
incompatibility, objects that do not have a *required* high alignment
(i.e. double) are still passed directly, even though they are not
naturally aligned. This change implements the new behavior of passing
things indirectly.
The new behavior is:
- up to three vector parameters can be passed in [XYZ]MM0-2
- remaining arguments with required alignment greater than 4 bytes are
passed indirectly
Previously, MSVC never passed things truly indirectly, meaning clang
would always apply the byval attribute to indirect arguments. We had to
go to the trouble of adding inalloca so that non-trivially copyable C++
types could be passed in place without copying the object
representation. When inalloca was added, we asserted that all arguments
passed indirectly must use byval. With this change, that assert no
longer holds, and I had to update inalloca to handle that case. The
implicit sret pointer parameter was already handled this way, and this
change generalizes some of that logic to arguments.
There are two cases that this change leaves unfixed:
1. objects that are non-trivially copyable *and* overaligned
2. vectorcall + inalloca + vectors
For case 1, I need to touch C++ ABI code in MicrosoftCXXABI.cpp, so I
want to do it in a follow-up.
For case 2, my fix is one line, but it will require updating IR tests to
use lots of inreg, so I wanted to separate it out.
Related to D71915 and D72110
Fixes most of PR44395
Reviewed By: rjmccall, craig.topper, erichkeane
Differential Revision: https://reviews.llvm.org/D72114
When I cached this a long time ago it seems I forgot to remove the locally
declared variable of the same name in select(), so the caching wasn't having
any compile time benefit. Doh.
Summary:
Rationale:
Some examples were using "offsets : [0, 2]" syntax which
should use a "=" instead. The same examples were referring
to the integer attribute array as k-dimensional, which is
a bit confusing (it is 1-dimensional, with k elements).
Changed to "k-sized".
Reviewers: nicolasvasilache, andydavis1, ftynse
Reviewed By: nicolasvasilache
Subscribers: merge_guards_bot, mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, arpith-jacob, mgester, lucyrfox, liufengdb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73293
Scope of changes:
1) Moved RecordedAssumptions vector to ScopBuilder. RecordedAssumptions are used only for Scop constructions.
2) Moved definition of RecordedAssumptionsTy to ScopHelper. It is required both by ScopBuilder and SCEVAffinator.
3) Add new function recordAssumption to ScopHelper. One of its argument is a reference to RecordedAssumption vector. This function is used by ScopBuilder and SCEVAffinator.
4) All RecordedAssumptions are created by ScopBuilder. isl::pw_aff
objects for corresponding SCEVs are created inside ScopBuilder. Scop
functions do not record any assumptions. Scop can use isl::pw_aff
objects which were created by ScopBuilder.
5) Removed functions for handling RecordedAssumptions from Scop class.
6) Removed constness from getScopArrayInfo functions.
7) Replaced SCEVVisitor struct from SCEVAffinator with taylored version, which allow to pass pointer to RecordedAssumptions as function argument.
Differential Revision: https://reviews.llvm.org/D68056
Summary:
This patch applies D60551 to an additional file. In particular, the test
is currently marked XFAIL for a number of big-endian targets; however,
the failure is actually dependent on the host endianness instead. The
test actually specifies a specific target triple.
Reviewers: rampitec, xingxue, daltenty
Reviewed By: rampitec
Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, fedor.sergeev, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73192
Now with concepts support merged and mostly complete, we do not need -fconcepts-ts
(which was also misleading as we were not implementing the TS) and can enable
concepts features under C++2a. A warning will be generated if users still attempt
to use -fconcepts-ts.
We ran into an assert when debugging clang and performing an expression on a class derived from DeclContext. The assert was indicating we were getting the offsets wrong for RecordDeclBitfields. We were getting both the size and offset of unnamed bit-field members wrong. We could fix this case with a quick change but as I extended the test suite to include more combinations we kept finding more cases that were being handled incorrectly. A fix that handled all the new cases as well as the cases already covered required a refactor of the existing technique.
Differential Revision: https://reviews.llvm.org/D72953
Explicitly disallow using lldb instead of %lldb in the shell tests. This
is a clever trick that is used by Swift to achieve the same results.
Differential revision: https://reviews.llvm.org/D73289
Using the same strategy as c38e42527b.
D69825 revealed (introduced?) a problem when building with ASan, and
some memory leaks somewhere. More details are available in the original
patch.
Looks like we missed one failing tests, this patch adds the workaround
to this test as well.
We currently use integer ranges to merge concrete function arguments.
We use the ParamState range for those, but we only look up concrete
values in the regular state. For concrete function arguments that are
themselves arguments of the containing function, we can use the param
state directly and improve the precision in some cases.
Besides improving the results in some cases, this is also a small step towards
switching to ValueLatticeElement, by allowing D60582 to be a NFC.
Reviewers: efriedma, davide
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D71836
Proper ExpressionEvaluationContext were not being entered when instantiating constraint
expressions, which caused assertion failures in certain cases, including bug #44614.
Summary:
Second patch in series to support Safe Whole Program Devirtualization
Enablement, see RFC here:
http://lists.llvm.org/pipermail/llvm-dev/2019-December/137543.html
Summarize vcall_visibility metadata in ThinLTO global variable summary.
Depends on D71907.
Reviewers: pcc, evgeny777, steven_wu
Subscribers: mehdi_amini, Prazek, inglorion, hiraditya, dexonsmith, arphaman, ostannard, llvm-commits, cfe-commits, davidxl
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D71911
Summary:
In order to do this `FUZZER_SUPPORTED_OS` had to be pulled out of
`lib/fuzzer/CMakeLists.txt` and into the main config so we can use it
from the `test/fuzzer/CMakeList.txt`. `FUZZER_SUPPORTED_OS` currently
has the same value of `SANITIZER_COMMON_SUPPORTED_OS` which preserves
the existing behaviour but this allows us in the future to adjust the
supported platforms independent of `SANITIZER_COMMON_SUPPORTED_OS`. This
mirrors the other sanitizers.
For non-Apple platforms `FUZZER_SUPPORTED_OS` is not defined and
surprisingly this was the behaviour before this patch because
`SANITIZER_COMMON_SUPPORTED_OS` was actually empty. This appears to
not matter right now because the functions that take an `OS` as an
argument seem to ignore it on non-Apple platforms.
While this change tries to be NFC it is technically not because we
now generate an iossim config whereas previously we didn't. This seems
like the right thing to do because the build system was configured to
compile LibFuzzer for iossim but previously we weren't generating a lit
test config for it. The device/simulator testing configs don't run by
default anyway so this shouldn't break testing.
This change relies on the get_capitalized_apple_platform() function
added in a previous commit.
rdar://problem/58798733
Reviewers: kubamracek, yln
Subscribers: mgorny, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D73243
Summary:
The previous code hard-coded platform names but compiler-rt's CMake
build system actually already knows which Apple platforms TSan supports.
This change uses this information to enumerate the different Apple
platforms.
This change relies on the `get_capitalized_apple_platform()` function
added in a previous commit.
rdar://problem/58798733
Reviewers: kubamracek, yln
Subscribers: mgorny, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D73238
Summary:
The previous code hard-coded platform names but compiler-rt's CMake
build system actually already knows which Apple platforms ASan supports.
This change uses this information to enumerate the different Apple
platforms.
rdar://problem/58798733
Reviewers: kubamracek, yln
Subscribers: mgorny, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D73232
calls to commonly un-overridden methods into a function that checks whether
the method is overridden anywhere and if not directly dispatches to the
NSObject implementation.
That means if you do override any of these methods, "step-in" will not step
into your code, since we hit the wrapper function, which has no debug info,
and immediately step out again.
Add code to recognize these functions as "trampolines" and a thread plan that
will get us from the function to the user code, if overridden.
<rdar://problem/54404114>
Differential Revision: https://reviews.llvm.org/D73225
We were incorrectly parsing the -C argument to breakpoint set as the
column breakpoint, even though according to the help this should be the
breakpoint command. This fixes that by renaming the option to -u, adding
it to help, and adding a test case.
Differential revision: https://reviews.llvm.org/D73284
I felt really sad to push this commit for my selfish purpose to make
glibc -static-pie build with lld. Some code constructs in glibc require
R_X86_64_GOTPCREL/R_X86_64_REX_GOTPCRELX referencing undefined weak to
be resolved to a GOT entry not relocated by R_X86_64_GLOB_DAT (GNU ld
behavior), e.g.
csu/libc-start.c
if (__pthread_initialize_minimal != NULL)
__pthread_initialize_minimal ();
elf/dl-object.c
void
_dl_add_to_namespace_list (struct link_map *new, Lmid_t nsid)
{
/* We modify the list of loaded objects. */
__rtld_lock_lock_recursive (GL(dl_load_write_lock));
Emitting a GLOB_DAT will make the address equal &__ehdr_start (true
value) and cause elf/ldconfig to segfault. glibc really should move away
from weak references, which do not have defined semantics.
Temporarily special case --no-dynamic-linker.
Since register classes go up to 1024, 32 elements, all masks bits are
needed and a 32-bit shift by 32 is illegal. We didn't have any
instructions theoretically using a 32 element VGPR before
d1dbb5e471
Summary:
I kind-of understand why it is restricted to integer-typed arguments,
for general enum's the value passed is not nessesairly the alignment implied,
although one might say that user would know best.
But we clearly should whitelist `std::align_val_t`,
which is just a thin wrapper over `std::size_t`,
and is the C++ standard way of specifying alignment.
Reviewers: erichkeane, rsmith, aaron.ballman, jdoerfert
Reviewed By: erichkeane
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D73019
Summary:
Much like with the previous patch (D73005) with `AssumeAlignedAttr`
handling, results in mildly more readable IR,
and will improve test coverage in upcoming patch.
Note that in `AllocAlignAttr`'s case, there is no requirement
for that alignment parameter to end up being an I-C-E.
Reviewers: erichkeane, jdoerfert, hfinkel, aaron.ballman, rsmith
Reviewed By: erichkeane
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D73006
Summary:
This should be mostly NFC - we still lower the same alignment
knowledge to the IR. The main reasoning here is that
this somewhat improves readability of IR like this,
and will improve test coverage in upcoming patch.
Even though the alignment is guaranteed to always be an I-C-E,
we don't always materialize it as llvm's Alignment Attribute because:
1. There may be a non-zero offset
2. We may be sanitizing for alignment
Note that if there already was an IR alignment attribute
on return value, we union them, and thus the alignment
only ever rises.
Also, there is a second relevant clang attribute `AllocAlignAttr`,
so that is why `AbstractAssumeAlignedAttrEmitter` is templated.
Reviewers: erichkeane, jdoerfert, hfinkel, aaron.ballman, rsmith
Reviewed By: erichkeane
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D73005
Summary:
I initially encountered those assertions when trying to create
this IR `alignment` attribute from clang's `__attribute__((assume_aligned(imm)))`,
because until D72994 there is no sanity checking for the value of `imm`.
But even then, we have `llvm::Value::MaximumAlignment` constant (which is `536870912`),
which is enforced for clang attributes, and then there are some other magical constant
(`0x40000000` i.e. `1073741824` i.e. `2 * 536870912`) in
`Attribute::getWithAlignment()`/`AttrBuilder::addAlignmentAttr()`.
I strongly suspect that `0x40000000` is incorrect,
and that also should be `llvm::Value::MaximumAlignment`.
Reviewers: erichkeane, hfinkel, jdoerfert, gchatelet, courbet
Reviewed By: erichkeane
Subscribers: hiraditya, cfe-commits, llvm-commits
Tags: #llvm, #clang
Differential Revision: https://reviews.llvm.org/D72998
Summary:
`alloc_align` attribute takes parameter number, not the alignment itself,
so given **just** the attribute/function declaration we can't do any
sanity checking for said alignment.
However, at call site, given the actual `Expr` that is passed
into that parameter, we //might// be able to evaluate said `Expr`
as Integer Constant Expression, and perform the sanity checks.
But since there is no requirement for that argument to be an immediate,
we may fail, and that's okay.
However if we did evaluate, we should enforce the same constraints
as with `__builtin_assume_aligned()`/`__attribute__((assume_aligned(imm)))`:
said alignment is a power of two, and is not greater than our magic threshold
Reviewers: erichkeane, aaron.ballman, hfinkel, rsmith, jdoerfert
Reviewed By: erichkeane
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D72996
Summary:
For `__builtin_assume_aligned()`, we do validate that the alignment
is not greater than `536870912` (D68824), but we don't do that for
`__attribute__((assume_aligned(N)))` attribute.
I suspect we should.
Reviewers: erichkeane, aaron.ballman, hfinkel, rsmith, jdoerfert
Reviewed By: erichkeane
Subscribers: cfe-commits, llvm-commits
Tags: #llvm, #clang
Differential Revision: https://reviews.llvm.org/D72994
conduit_uri was renamed to phabricator.uri and git-phab fails to load
.arcconfig without this field.
Differential Revision: https://reviews.llvm.org/D72960
Summary:
First patch to support Safe Whole Program Devirtualization Enablement,
see RFC here: http://lists.llvm.org/pipermail/llvm-dev/2019-December/137543.html
Always emit !vcall_visibility metadata under -fwhole-program-vtables,
and not just for -fvirtual-function-elimination. The vcall visibility
metadata will (in a subsequent patch) be used to communicate to WPD
which vtables are safe to devirtualize, and we will optionally convert
the metadata to hidden visibility at link time. Subsequent follow on
patches will help enable this by adding vcall_visibility metadata to the
ThinLTO summaries, and always emit type test intrinsics under
-fwhole-program-vtables (and not just for vtables with hidden
visibility).
In order to do this safely with VFE, since for VFE all vtable loads must
be type checked loads which will no longer be the case, this patch adds
a new "Virtual Function Elim" module flag to communicate to GlobalDCE
whether to perform VFE using the vcall_visibility metadata.
One additional advantage of using the vcall_visibility metadata to drive
more WPD at LTO link time is that we can use the same mechanism to
enable more aggressive VFE at LTO link time as well. The link time
option proposed in the RFC will convert vcall_visibility metadata to
hidden (aka linkage unit visibility), which combined with
-fvirtual-function-elimination will allow it to be done more
aggressively at LTO link time under the same conditions.
Reviewers: pcc, ostannard, evgeny777, steven_wu
Subscribers: mehdi_amini, Prazek, hiraditya, dexonsmith, davidxl, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D71907
Johannes Doerfert