Commit Graph

1201 Commits

Author SHA1 Message Date
Nikita Popov b190108693 [Bitcode] Encode alloca address space
Since D101045, allocas are no longer required to be part of the
default alloca address space. There may be allocas in multiple
different address spaces. However, the bitcode reader would
simply assume the default alloca address space, resulting in
either an error or incorrect IR.

Add an optional record for allocas which encodes the address
space.
2022-03-11 16:08:38 +01:00
Nikita Popov cda82d39f3 [Bitcode] Check for type mismatch when assigning value
If the value is forward-declared, then the type must match,
otherwise we can't RAUW.
2022-03-11 12:12:54 +01:00
Nikita Popov 36be8fabb0 [Bitcode] Delete phi node on error
These error conditions are checked after the phi node has been
created, so we also need to delete it.
2022-03-11 11:37:29 +01:00
Nikita Popov ba3380026a [Bitcode] Improve some error messages
It's not particularly helpful if 95% of our errors just say
"Invalid record". This at least adds the record type to a subset
of errors.
2022-03-11 11:37:29 +01:00
Nikita Popov d7645f4ef8 [Bitcode] Delete instruction on error
As these errors are detected after the instruction has already been
created (but before it has been inserted into the function), we
also need to delete it.
2022-03-11 10:56:43 +01:00
Nikita Popov e732f69ea1 [Bitcode] Report error for missing element type for attr upgrade
Otherwise this is going to crash either the TypeFinder or the
Verifier.
2022-03-11 10:18:42 +01:00
Nikita Popov 22f9159bed [BitcodeReader] Support GEP without indices
LLVM considers these to be legal, so make sure the bitcode reader
can read them. I broke this when implementing opaque pointer
auto upgrade support.
2022-03-10 15:48:47 +01:00
Augie Fackler d664c4b73c Attributes: add a new allocalign attribute
This will let us start moving away from hard-coded attributes in
MemoryBuiltins.cpp and put the knowledge about various attribute
functions in the compilers that emit those calls where it probably
belongs.

Differential Revision: https://reviews.llvm.org/D117921
2022-03-04 15:57:53 -05:00
Nikita Popov 7a258c6a37 [Bitcode] Move x86_intrcc upgrade to bitcode reader
This upgrade requires access the legacy pointer element type, so
it needs to happen inside the bitcode reader.
2022-03-04 10:30:50 +01:00
Nikita Popov e3a9f68e2c [Bitcode] Fully support opaque pointer auto upgrade
This completes the propagation of type IDs through bitcode reading,
and switches remaining uses of getPointerElementType() to use
contained type IDs.

The main new thing here is that sometimes we need to create a type
ID for a type that was not explicitly encoded in bitcode (or we
don't know its ID at the current point). For such types we create a
"virtual" type ID, which is cached based on the type and the
contained type IDs. Luckily, we generally only need zero or one
contained type IDs, and in the one case where we need two, we can
get away with not including it in the cache key.

With this change, we pass the entirety of llvm-test-suite at O3
with opaque pointers.

Differential Revision: https://reviews.llvm.org/D120471
2022-03-04 10:23:06 +01:00
Tong Zhang 17ce89fa80 [SanitizerBounds] Add support for NoSanitizeBounds function
Currently adding attribute no_sanitize("bounds") isn't disabling
-fsanitize=local-bounds (also enabled in -fsanitize=bounds). The Clang
frontend handles fsanitize=array-bounds which can already be disabled by
no_sanitize("bounds"). However, instrumentation added by the
BoundsChecking pass in the middle-end cannot be disabled by the
attribute.

The fix is very similar to D102772 that added the ability to selectively
disable sanitizer pass on certain functions.

In this patch, if no_sanitize("bounds") is provided, an additional
function attribute (NoSanitizeBounds) is attached to IR to let the
BoundsChecking pass know we want to disable local-bounds checking. In
order to support this feature, the IR is extended (similar to D102772)
to make Clang able to preserve the information and let BoundsChecking
pass know bounds checking is disabled for certain function.

Reviewed By: melver

Differential Revision: https://reviews.llvm.org/D119816
2022-03-01 18:47:02 +01:00
Nikita Popov 87ebd9a36f [IR] Use CallBase::getParamElementType() (NFC)
As this method now exists on CallBase, use it rather than the
one on AttributeList.
2022-02-25 10:01:58 +01:00
Nikita Popov 4d37bbc429 [Bitcode] Store function type IDs rather than function types
This resolves one of the type ID propagation TODOs.
2022-02-23 16:36:20 +01:00
Nikita Popov b6eafba296 [Bitcode] Store type IDs for values
This is the next step towards supporting bitcode auto upgrade with
opaque pointers. The ValueList now stores the Value* together with
its associated type ID, which allows inspecting the original pointer
element type of arbitrary values.

This is a largely mechanical change threading the type ID through
various places. I've left TODOTypeID placeholders in a number of
places where determining the type ID is either non-trivial or
requires allocating a new type ID not present in the original
bitcode. For this reason, the new type IDs are also not used for
anything yet (apart from propagation). They will get used once the
TODOs are resolved.

Differential Revision: https://reviews.llvm.org/D119821
2022-02-22 17:27:06 +01:00
Nikita Popov 093e9489d5 [BitcodeReader] Change order of assignValue() arguments (NFC)
Other methods in ValueList generally pass Idx first, and it is
more convention for assignment methods to have the target on the
LHS rather than RHS.
2022-02-15 10:11:01 +01:00
Nikita Popov 1c456a8220 [Bitcode] Improve support for opaque-pointer bitcode upgrade
This is step two of supporting autoupgrade of old bitcode to opaque
pointers. Rather than tracking the element type ID of pointers in
particular, track all type IDs that a type contains. This allows us
to recover the element type in more complex situations, e.g. when
we need to determine the pointer element type of a vector element
or function type parameter.

Differential Revision: https://reviews.llvm.org/D119339
2022-02-15 09:39:48 +01:00
Fangrui Song edf4780ad1 [BitcodeReader] Fix use-after-move 2022-02-14 10:54:37 -08:00
Momchil Velikov 6398903ac8 Extend the `uwtable` attribute with unwind table kind
We have the `clang -cc1` command-line option `-funwind-tables=1|2` and
the codegen option `VALUE_CODEGENOPT(UnwindTables, 2, 0) ///< Unwind
tables (1) or asynchronous unwind tables (2)`. However, this is
encoded in LLVM IR by the presence or the absence of the `uwtable`
attribute, i.e.  we lose the information whether to generate want just
some unwind tables or asynchronous unwind tables.

Asynchronous unwind tables take more space in the runtime image, I'd
estimate something like 80-90% more, as the difference is adding
roughly the same number of CFI directives as for prologues, only a bit
simpler (e.g. `.cfi_offset reg, off` vs. `.cfi_restore reg`). Or even
more, if you consider tail duplication of epilogue blocks.
Asynchronous unwind tables could also restrict code generation to
having only a finite number of frame pointer adjustments (an example
of *not* having a finite number of `SP` adjustments is on AArch64 when
untagging the stack (MTE) in some cases the compiler can modify `SP`
in a loop).
Having the CFI precise up to an instruction generally also means one
cannot bundle together CFI instructions once the prologue is done,
they need to be interspersed with ordinary instructions, which means
extra `DW_CFA_advance_loc` commands, further increasing the unwind
tables size.

That is to say, async unwind tables impose a non-negligible overhead,
yet for the most common use cases (like C++ exceptions), they are not
even needed.

This patch extends the `uwtable` attribute with an optional
value:
      -  `uwtable` (default to `async`)
      -  `uwtable(sync)`, synchronous unwind tables
      -  `uwtable(async)`, asynchronous (instruction precise) unwind tables

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D114543
2022-02-14 14:35:02 +00:00
Nikita Popov 4d477ba50f [BitcodeReader] Rename method for element type by ID (NFC)
Make it clearer that this method is specifically for pointer
element types, and not other element types. This distinction will
be relevant in the future.

The somewhat unusual spelling is to make sure this does not show
up when grepping for getPointerElementType.
2022-02-14 11:15:43 +01:00
Nikita Popov c28b0b9d18 [Bitcode] Add partial support for opaque pointer auto-upgrade
Auto-upgrades that rely on the pointer element type do not work in
opaque pointer mode. The idea behind this patch is that we can
instead work with type IDs, for which we can retain the pointer
element type. For typed pointer bitcode, we will have a distinct
type ID for pointers with distinct element type, even if there will
only be a single corresponding opaque pointer type.

The disclaimer here is that this is only the first step of the change,
and there are still more getPointerElementType() calls to remove.
I expect that two more patches will be needed:
1. Track all "contained" type IDs, which will allow us to handle
function params (which are contained in the function type) and GEPs
(which may use vectors of pointers)
2. Track type IDs for values, which is e.g. necessary to handle loads.

Differential Revision: https://reviews.llvm.org/D118694
2022-02-11 09:32:46 +01:00
Nikita Popov 72248712e5 [Bitcode] Check minimum size of constant GEP record
Checking this early, because we may end up reading up to two
records before the operands.
2022-02-09 14:23:30 +01:00
Nikita Popov 6d52ea885f [Bitcode] Prevent OOB read for invalid name size 2022-02-08 09:49:39 +01:00
Nikita Popov f4fca0fbb0 [Bitcode] Replace assertion with check 2022-02-07 12:39:35 +01:00
Nikita Popov fdf8cb978f [Bitcode] Handle invalid data layout gracefully 2022-02-07 12:28:15 +01:00
Nikita Popov 0c553bff8e [Bitcode] Guard against out of bounds value reference
We should make sure that the value ID is in bounds, otherwise
we will assert / read out of bounds.
2022-02-07 12:16:13 +01:00
Nikita Popov 89017772d9 [Bitcode] Don't assert on invalid attribute group record
Report an error instead.
2022-02-07 12:16:12 +01:00
Nikita Popov f392e9d264 [BitcodeReader] Resolve error handling todo
If possible, forward the inner error instead of creating a new
one.
2022-02-04 17:14:45 +01:00
Nikita Popov aa97bc116d [NFC] Remove uses of PointerType::getElementType()
Instead use either Type::getPointerElementType() or
Type::getNonOpaquePointerElementType().

This is part of D117885, in preparation for deprecating the API.
2022-01-25 09:44:52 +01:00
minglotus-6 e95ad93e6e [llvm-dis] Add an option `dump-thinlto-index-only` in llvm-dis to read ThinLTO minimized code only. 2022-01-19 18:07:50 -08:00
Serge Guelton d2cc6c2d0c Use a sorted array instead of a map to store AttrBuilder string attributes
Using and std::map<SmallString, SmallString> for target dependent attributes is
inefficient: it makes its constructor slightly heavier, and involves extra
allocation for each new string attribute. Storing the attribute key/value as
strings implies extra allocation/copy step.

Use a sorted vector instead. Given the low number of attributes generally
involved, this is cheaper, as showcased by

https://llvm-compile-time-tracker.com/compare.php?from=5de322295f4ade692dc4f1823ae4450ad3c48af2&to=05bc480bf641a9e3b466619af43a2d123ee3f71d&stat=instructions

Differential Revision: https://reviews.llvm.org/D116599
2022-01-10 14:49:53 +01:00
Nikita Popov e4d1779990 [IR] Add ConstraintInfo::hasArg() helper (NFC)
Checking whether a constraint corresponds to an argument is a
recurring pattern.
2022-01-07 10:44:38 +01:00
Nikita Popov eddd5be1df [BitCode] Autoupgrade inline asm elementtype attribute
This is the autoupgrade part of D116531. If old bitcode is missing
the elementtype attribute for indirect inline asm constraints,
automatically add it. As usual, this only works when upgrading
in typed mode, we haven't figured out upgrade in opaque mode yet.
2022-01-06 15:13:01 +01:00
Roman Lebedev 62b1682570
[Opaqueptrs][IR Serialization] Improve inlineasm [de]serialization
The bitcode reader expected that the pointers are typed,
so that it can extract the function type for the assembly
so `bitc::CST_CODE_INLINEASM` did not explicitly store said function type.

I'm not really sure how the upgrade path will look for existing bitcode,
but i think we can easily support opaque pointers going forward,
by simply storing the function type.

Reviewed By: #opaque-pointers, nikic

Differential Revision: https://reviews.llvm.org/D116341
2021-12-30 13:54:37 +03:00
Roman Lebedev a5337d6a1c
[BitcodeReader] `bitc::CST_CODE_INLINEASM`: un-hardcode offsets 2021-12-30 13:50:02 +03:00
Roman Lebedev d5a4d6a497
[BitcodeReader] propagateAttributeTypes(): fix opaque pointer handling
Can't get the pointee type of an opaque pointer,
but in that case said attributes must already be typed,
so just don't try to rewrite them if they already are.
2021-12-28 22:06:51 +03:00
Sami Tolvanen 5dc8aaac39 [llvm][IR] Add no_cfi constant
With Control-Flow Integrity (CFI), the LowerTypeTests pass replaces
function references with CFI jump table references, which is a problem
for low-level code that needs the address of the actual function body.

For example, in the Linux kernel, the code that sets up interrupt
handlers needs to take the address of the interrupt handler function
instead of the CFI jump table, as the jump table may not even be mapped
into memory when an interrupt is triggered.

This change adds the no_cfi constant type, which wraps function
references in a value that LowerTypeTestsModule::replaceCfiUses does not
replace.

Link: https://github.com/ClangBuiltLinux/linux/issues/1353

Reviewed By: nickdesaulniers, pcc

Differential Revision: https://reviews.llvm.org/D108478
2021-12-20 12:55:32 -08:00
Nikita Popov 18ab892ff7 [Bitcode] Avoid setting invalid comdat pointer (NFC)
Instead track global objects with implicit comdat in a separate
set. The current approach of temporarily assigning an invalid
comdat pointer is incompatible with D115864.
2021-12-17 20:27:37 +01:00
Mingming Liu 09a704c5ef [LTO] Ignore unreachable virtual functions in WPD in hybrid LTO.
Differential Revision: https://reviews.llvm.org/D115492
2021-12-14 20:18:04 +00:00
Kazu Hirata 7787a8f1b7 [llvm] Use llvm::reverse (NFC) 2021-12-13 21:54:51 -08:00
Kazu Hirata f6bce30cf9 [llvm] Use range-based for loops (NFC) 2021-11-20 18:42:10 -08:00
Kazu Hirata 3c06920cd1 [llvm] Use make_early_inc_range (NFC) 2021-11-08 09:09:39 -08:00
Itay Bookstein 848812a55e [Verifier] Add verification logic for GlobalIFuncs
Verify that the resolver exists, that it is a defined
Function, and that its return type matches the ifunc's
type. Add corresponding check to BitcodeReader, change
clang to emit the correct type, and fix tests to comply.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D112349
2021-10-31 20:00:57 -07:00
Duncan P. N. Exon Smith b12a864c29 Bitcode: Use Expected<T>::takeError() and moveInto() more, NFC
Avoid naming some Expected<T> values in the Bitcode reader by using
takeError() and moveInto() more often. This follows the smaller set of
changes included in 2410fb4616.
2021-10-25 16:03:40 -07:00
Duncan P. N. Exon Smith 2410fb4616 Support: Use Expected<T>::moveInto() in a few places
These are some usage examples for `Expected<T>::moveInto()`.

Differential Revision: https://reviews.llvm.org/D112280
2021-10-22 12:40:10 -07:00
Itay Bookstein 08ed216000 [IR] Refactor GlobalIFunc to inherit from GlobalObject, Remove GlobalIndirectSymbol
As discussed in:
* https://reviews.llvm.org/D94166
* https://lists.llvm.org/pipermail/llvm-dev/2020-September/145031.html

The GlobalIndirectSymbol class lost most of its meaning in
https://reviews.llvm.org/D109792, which disambiguated getBaseObject
(now getAliaseeObject) between GlobalIFunc and everything else.
In addition, as long as GlobalIFunc is not a GlobalObject and
getAliaseeObject returns GlobalObjects, a GlobalAlias whose aliasee
is a GlobalIFunc cannot currently be modeled properly. Creating
aliases for GlobalIFuncs does happen in the wild (e.g. glibc). In addition,
calling getAliaseeObject on a GlobalIFunc will currently return nullptr,
which is undesirable because it should return the object itself for
non-aliases.

This patch refactors the GlobalIFunc class to inherit directly from
GlobalObject, and removes GlobalIndirectSymbol (while inlining the
relevant parts into GlobalAlias and GlobalIFunc). This allows for
calling getAliaseeObject() on a GlobalIFunc to return the GlobalIFunc
itself, making getAliaseeObject() more consistent and enabling
alias-to-ifunc to be properly modeled in the IR.

I exercised some judgement in the API clients of GlobalIndirectSymbol:
some were 'monomorphized' for GlobalAlias and GlobalIFunc, and
some remained shared (with the type adapted to become GlobalValue).

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D108872
2021-10-20 10:29:47 -07:00
william woodruff 778bf73d7b [BitcodeReader] fix a logic error in vector type element validation
The current code checks whether the vector's element type is a valid structure element type, rather than a valid vector element type. The two have separate implementations and but only accept very slightly different sets of types, which is probably why this wasn't caught before.

Differential Revision: https://reviews.llvm.org/D109655
2021-10-09 09:42:02 +05:30
Arthur Eubanks 05392466f0 Reland [IR] Increase max alignment to 4GB
Currently the max alignment representable is 1GB, see D108661.
Setting the align of an object to 4GB is desirable in some cases to make sure the lower 32 bits are clear which can be used for some optimizations, e.g. https://crbug.com/1016945.

This uses an extra bit in instructions that carry an alignment. We can store 15 bits of "free" information, and with this change some instructions (e.g. AtomicCmpXchgInst) use 14 bits.
We can increase the max alignment representable above 4GB (up to 2^62) since we're only using 33 of the 64 values, but I've just limited it to 4GB for now.

The one place we have to update the bitcode format is for the alloca instruction. It stores its alignment into 5 bits of a 32 bit bitfield. I've added another field which is 8 bits and should be future proof for a while. For backward compatibility, we check if the old field has a value and use that, otherwise use the new field.

Updating clang's max allowed alignment will come in a future patch.

Reviewed By: hans

Differential Revision: https://reviews.llvm.org/D110451
2021-10-06 13:29:23 -07:00
Arthur Eubanks 569346f274 Revert "Reland [IR] Increase max alignment to 4GB"
This reverts commit 8d64314ffe.
2021-10-06 11:38:11 -07:00
Arthur Eubanks 8d64314ffe Reland [IR] Increase max alignment to 4GB
Currently the max alignment representable is 1GB, see D108661.
Setting the align of an object to 4GB is desirable in some cases to make sure the lower 32 bits are clear which can be used for some optimizations, e.g. https://crbug.com/1016945.

This uses an extra bit in instructions that carry an alignment. We can store 15 bits of "free" information, and with this change some instructions (e.g. AtomicCmpXchgInst) use 14 bits.
We can increase the max alignment representable above 4GB (up to 2^62) since we're only using 33 of the 64 values, but I've just limited it to 4GB for now.

The one place we have to update the bitcode format is for the alloca instruction. It stores its alignment into 5 bits of a 32 bit bitfield. I've added another field which is 8 bits and should be future proof for a while. For backward compatibility, we check if the old field has a value and use that, otherwise use the new field.

Updating clang's max allowed alignment will come in a future patch.

Reviewed By: hans

Differential Revision: https://reviews.llvm.org/D110451
2021-10-06 11:03:51 -07:00
Arthur Eubanks 72cf8b6044 Revert "[IR] Increase max alignment to 4GB"
This reverts commit df84c1fe78.

Breaks some bots
2021-10-06 10:21:35 -07:00
Arthur Eubanks df84c1fe78 [IR] Increase max alignment to 4GB
Currently the max alignment representable is 1GB, see D108661.
Setting the align of an object to 4GB is desirable in some cases to make sure the lower 32 bits are clear which can be used for some optimizations, e.g. https://crbug.com/1016945.

This uses an extra bit in instructions that carry an alignment. We can store 15 bits of "free" information, and with this change some instructions (e.g. AtomicCmpXchgInst) use 14 bits.
We can increase the max alignment representable above 4GB (up to 2^62) since we're only using 33 of the 64 values, but I've just limited it to 4GB for now.

The one place we have to update the bitcode format is for the alloca instruction. It stores its alignment into 5 bits of a 32 bit bitfield. I've added another field which is 8 bits and should be future proof for a while. For backward compatibility, we check if the old field has a value and use that, otherwise use the new field.

Updating clang's max allowed alignment will come in a future patch.

Reviewed By: hans

Differential Revision: https://reviews.llvm.org/D110451
2021-10-06 09:54:14 -07:00
modimo 20faf78919 [ThinLTO] Add noRecurse and noUnwind thinlink function attribute propagation
Thinlink provides an opportunity to propagate function attributes across modules, enabling additional propagation opportunities.

This change propagates (currently default off, turn on with `disable-thinlto-funcattrs=1`) noRecurse and noUnwind based off of function summaries of the prevailing functions in bottom-up call-graph order. Testing on clang self-build:
1. There's a 35-40% increase in noUnwind functions due to the additional propagation opportunities.
2. Throughput is measured at 10-15% increase in thinlink time which itself is 1.5% of E2E link time.

Implementation-wise this adds the following summary function attributes:
1. noUnwind: function is noUnwind
2. mayThrow: function contains a non-call instruction that `Instruction::mayThrow` returns true on (e.g. windows SEH instructions)
3. hasUnknownCall: function contains calls that don't make it into the summary call-graph thus should not be propagated from (e.g. indirect for now, could add no-opt functions as well)

Testing:
Clang self-build passes and 2nd stage build passes check-all
ninja check-all with newly added tests passing

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D36850
2021-09-27 12:28:07 -07:00
guopeilin 749ddd25e9 [BitcodeReader] Delay select until all constants resolved
Like the shuffle, we should treat the select delayed so that
all constants can be resolved.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D109053
2021-09-11 18:51:35 +08:00
Nikita Popov 90ec6dff86 [OpaquePtr] Forbid mixing typed and opaque pointers
Currently, opaque pointers are supported in two forms: The
-force-opaque-pointers mode, where all pointers are opaque and
typed pointers do not exist. And as a simple ptr type that can
coexist with typed pointers.

This patch removes support for the mixed mode. You either get
typed pointers, or you get opaque pointers, but not both. In the
(current) default mode, using ptr is forbidden. In -opaque-pointers
mode, all pointers are opaque.

The motivation here is that the mixed mode introduces additional
issues that don't exist in fully opaque mode. D105155 is an example
of a design problem. Looking at D109259, it would probably need
additional work to support mixed mode (e.g. to generate GEPs for
typed base but opaque result). Mixed mode will also end up
inserting many casts between i8* and ptr, which would require
significant additional work to consistently avoid.

I don't think the mixed mode is particularly valuable, as it
doesn't align with our end goal. The only thing I've found it to
be moderately useful for is adding some opaque pointer tests in
between typed pointer tests, but I think we can live without that.

Differential Revision: https://reviews.llvm.org/D109290
2021-09-10 15:18:23 +02:00
Nikita Popov f5832eaaad [UseListOrder] Fix use list order for function operands
Functions can have a personality function, as well as prefix and
prologue data as additional operands. Unused operands are assigned
a dummy value of i1* null. This patch addresses multiple issues in
use-list order preservation for these:

 * Fix verify-uselistorder to also enumerate the dummy values.
   This means that now use-list order values of these values are
   shuffled even if there is no other mention of i1* null in the
   module. This results in failures of Assembler/call-arg-is-callee.ll,
   Assembler/opaque-ptr.ll and Bitcode/use-list-order2.ll.
 * The use-list order prediction in ValueEnumerator does not take
   into account the fact that a global may use a value more than
   once and leaves uses in the same global effectively unordered.
   We should be comparing the operand number here, as we do for
   the more general case.
 * While we enumerate all operands of a function together (which
   seems sensible to me), the bitcode reader would first resolve
   prefix data for all function, then prologue data for all
   functions, then personality functions for all functions. Change
   this to resolve all operands for a given function together
   instead.

Differential Revision: https://reviews.llvm.org/D109282
2021-09-07 20:59:12 +02:00
Alexander Potapenko b0391dfc73 [clang][Codegen] Introduce the disable_sanitizer_instrumentation attribute
The purpose of __attribute__((disable_sanitizer_instrumentation)) is to
prevent all kinds of sanitizer instrumentation applied to a certain
function, Objective-C method, or global variable.

The no_sanitize(...) attribute drops instrumentation checks, but may
still insert code preventing false positive reports. In some cases
though (e.g. when building Linux kernel with -fsanitize=kernel-memory
or -fsanitize=thread) the users may want to avoid any kind of
instrumentation.

Differential Revision: https://reviews.llvm.org/D108029
2021-08-20 14:01:06 +02:00
Arthur Eubanks 3f4d00bc3b [NFC] More get/removeAttribute() cleanup 2021-08-17 21:05:41 -07:00
Arthur Eubanks 80ea2bb574 [NFC] Rename AttributeList::getParam/Ret/FnAttributes() -> get*Attributes()
This is more consistent with similar methods.
2021-08-13 11:16:52 -07:00
Fangrui Song 3924877932 [IR] Rename `comdat noduplicates` to `comdat nodeduplicate`
In the textual format, `noduplicates` means no COMDAT/section group
deduplication is performed. Therefore, if both sets of sections are retained, and
they happen to define strong external symbols with the same names,
there will be a duplicate definition linker error.

In PE/COFF, the selection kind lowers to `IMAGE_COMDAT_SELECT_NODUPLICATES`.
The name describes the corollary instead of the immediate semantics.  The name
can cause confusion to other binary formats (ELF, wasm) which have implemented/
want to implement the "no deduplication" selection kind. Rename it to be clearer.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D106319
2021-07-20 12:47:10 -07:00
Nikita Popov 6312a75dba [BitcodeReader] Handle type attributes more explicitly (NFCI)
For attributes in legacy bitcode that are now typed, explicitly
create a type attribute with nullptr type, the same as we do
for the attribute group representation. This is so we can assert
use of the correct constructor in the future.
2021-07-20 21:08:06 +02:00
Nikita Popov be5af50e7d [BPF] Use elementtype attribute for preserve.array/struct.index intrinsics
Use the elementtype attribute introduced in D105407 for the
llvm.preserve.array/struct.index intrinsics. It carries the
element type of the GEP these intrinsics effectively encode.

This patch:

 * Adds a verifier check that the attribute is required.
 * Adds it in the IRBuilder methods for these intrinsics.
 * Autoupgrades old bitcode without the attribute.
 * Updates the lowering code to use the attribute rather than
   the pointer element type.
 * Updates lots of tests to specify the attribute.
 * Adds -force-opaque-pointers to the intrinsic-array.ll test
   to demonstrate they work now.

https://reviews.llvm.org/D106184
2021-07-17 11:09:18 +02:00
Nikita Popov c191035f42 [IR] Add elementtype attribute
This implements the elementtype attribute specified in D105407. It
just adds the attribute and the specified verifier rules, but
doesn't yet make use of it anywhere.

Differential Revision: https://reviews.llvm.org/D106008
2021-07-15 18:04:26 +02:00
Nikita Popov 3fb0621faf [Attributes] Assert correct attribute constructor is used (NFCI)
Assert that enum/int/type attributes go through the constructor
they are supposed to use.

To make sure this can't happen via invalid bitcode, explicitly
verify that the attribute kind if correct there.
2021-07-12 21:11:59 +02:00
Nikita Popov 5d1464cbfe [Attributes] Make type attribute handling more generic (NFCI)
Followup to D105658 to make AttrBuilder automatically work with
new type attributes. TableGen is tweaked to emit First/LastTypeAttr
markers, based on which we can handle type attributes
programmatically.

Differential Revision: https://reviews.llvm.org/D105763
2021-07-12 20:49:38 +02:00
Arthur Eubanks cb3580e7ad [OpaquePtr][BitcodeWriter] Handle attributes with types
For example, byval.

Skip the type attribute auto-upgrade if we already have the type.

I've actually seen this error of the ValueEnumerator missing a type
attribute's type in a non-opaque pointer context.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D105138
2021-06-29 14:47:29 -07:00
Nathan Chancellor 4ae0ab095b
[BitCode] Add noprofile to getAttrFromCode()
After D104475 / D104658, building the Linux kernel with ThinLTO is
broken:

ld.lld: error: Unknown attribute kind (73) (Producer: 'LLVM13.0.0git'
Reader: 'LLVM 13.0.0git')

getAttrFromCode() has never handled this attribute so it is written
during the ThinLTO phase but it cannot be handled during the linking
phase.

Add noprofile to getAttrFromCode() so that disassembly works properly.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D104995
2021-06-27 11:59:57 -07:00
Nikita Popov e5f2b035dd [OpaquePtr] Support invoke instruction
With call support in place, this is only a matter of relaxing a
bitcode reader assertion.
2021-06-23 20:24:33 +02:00
Nikita Popov f660af46e3 [OpaquePtr] Support call instruction
Add support for call of opaque pointer, currently only possible for
indirect calls.

This requires a bit of special casing in LLParser, as calls do not
specify the callee operand type explicitly.

Differential Revision: https://reviews.llvm.org/D104740
2021-06-23 20:17:26 +02:00
Florian Hahn 34cccdaed7
[BitcodeReader] Validate Strtab before accessing.
This fixes a crash with invalid bitcode files that have records
referencing names in Strtab, but Strtab is not present or the index is
out-of-bounds.

This fixes the following clusterfuzz issue:
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=29895

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D95554
2021-06-22 14:52:16 +01:00
Nikita Popov d9fe96fe26 [OpaquePtr] Support opaque constant expression GEP
Adjust assertions to use isOpaqueOrPointeeTypeMatches() and make
it return an opaque pointer result for an opaque base pointer. We
also need to enumerate the element type, as it is no longer
implicitly enumerated through the pointer type.

Differential Revision: https://reviews.llvm.org/D104655
2021-06-21 20:06:25 +02:00
Arthur Eubanks cc8d32ae7d Move some code under NDEBUG from D103135 2021-06-14 11:39:12 -07:00
Arthur Eubanks 8c5a44901c [OpaquePtr] Remove existing support for forward compatibility
It assumes that PointerType will keep having an optional pointee type,
but we'd like to remove the pointee type in PointerType at some point.

I feel like the current implementation could be simplified anyway,
although perhaps I'm underestimating the amount of work needed
throughout BitcodeReader.

We will still need a side table to keep track of pointee types. This
will be reimplemented at some point.

This is essentially a revert of a4771e9d (which doesn't look like it was
reviewed anyway).

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D103135
2021-06-14 10:52:56 -07:00
Arthur Eubanks 1202f559bd [OpaquePtr] Make atomicrmw work with opaque pointers
FullTy is only necessary when we need to figure out what type an
instruction works with given a pointer's pointee type. However, we just
end up using the value operand's type, so FullTy isn't necessary.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D102788
2021-05-25 20:16:21 -07:00
Arthur Eubanks ad90a6be21 [OpaquePtr] Create new bitcode encoding for atomicrmw
Since the opaque pointer type won't contain the pointee type, we need to
separately encode the value type for an atomicrmw.

Emit this new code for atomicrmw.

Handle this new code and the old one in the bitcode reader.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D103123
2021-05-25 16:30:34 -07:00
Arthur Eubanks 0bbb502daa Revert "[OpaquePtr] Make atomicrmw work with opaque pointers"
This reverts commit 0bebda17be.

Causing "Invalid record" errors.
2021-05-25 10:14:58 -07:00
Marco Elver 280333021e [SanitizeCoverage] Add support for NoSanitizeCoverage function attribute
We really ought to support no_sanitize("coverage") in line with other
sanitizers. This came up again in discussions on the Linux-kernel
mailing lists, because we currently do workarounds using objtool to
remove coverage instrumentation. Since that support is only on x86, to
continue support coverage instrumentation on other architectures, we
must support selectively disabling coverage instrumentation via function
attributes.

Unfortunately, for SanitizeCoverage, it has not been implemented as a
sanitizer via fsanitize= and associated options in Sanitizers.def, but
rolls its own option fsanitize-coverage. This meant that we never got
"automatic" no_sanitize attribute support.

Implement no_sanitize attribute support by special-casing the string
"coverage" in the NoSanitizeAttr implementation. To keep the feature as
unintrusive to existing IR generation as possible, define a new negative
function attribute NoSanitizeCoverage to propagate the information
through to the instrumentation pass.

Fixes: https://bugs.llvm.org/show_bug.cgi?id=49035

Reviewed By: vitalybuka, morehouse

Differential Revision: https://reviews.llvm.org/D102772
2021-05-25 12:57:14 +02:00
Arthur Eubanks 7a29a12301 [Verifier] Move some atomicrmw/cmpxchg checks to instruction creation
These checks already exist as asserts when creating the corresponding
instruction. Anybody creating these instructions already need to take
care to not break these checks.

Move the checks for success/failure ordering in cmpxchg from the
verifier to the LLParser and BitcodeReader plus an assert.

Add some tests for cmpxchg ordering. The .bc files are created from the
.ll files with an llvm-as with these checks disabled.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D102803
2021-05-21 13:41:17 -07:00
Steven Wu 5b6cae5524 [IR][AutoUpgrade] Drop alignment from non-pointer parameters and returns
This is a follow-up of D102201. After some discussion, it is a better idea
to upgrade all invalid uses of alignment attributes on function return
values and parameters, not just limited to void function return types.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D102726
2021-05-20 09:54:38 -07:00
Arthur Eubanks 0bebda17be [OpaquePtr] Make atomicrmw work with opaque pointers
FullTy is only necessary when we need to figure out what type an
instruction works with given a pointer's pointee type. However, we just
end up using the value operand's type, so FullTy isn't necessary.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D102788
2021-05-19 12:49:28 -07:00
Arthur Eubanks 28b9771472 [OpaquePtr] Make GEPs work with opaque pointers
No verifier changes needed, the verifier currently doesn't check that
the pointer operand's pointee type matches the GEP type. There is a
similar check in GetElementPtrInst::Create() though.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D102744
2021-05-19 12:39:37 -07:00
Arthur Eubanks 6013d84392 [OpaquePtr] Make loads and stores work with opaque pointers
Don't check that types match when the pointer operand is an opaque
pointer.

I would separate the Assembler and Verifier changes, but
verify-uselistorder in the Assembler test ends up running the verifier.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D102450
2021-05-18 13:43:50 -07:00
Tim Northover ea0eec69f1 IR+AArch64: add a "swiftasync" argument attribute.
This extends any frame record created in the function to include that
parameter, passed in X22.

The new record looks like [X22, FP, LR] in memory, and FP is stored with 0b0001
in bits 63:60 (CodeGen assumes they are 0b0000 in normal operation). The effect
of this is that tools walking the stack should expect to see one of three
values there:

  * 0b0000 => a normal, non-extended record with just [FP, LR]
  * 0b0001 => the extended record [X22, FP, LR]
  * 0b1111 => kernel space, and a non-extended record.

All other values are currently reserved.

If compiling for arm64e this context pointer is address-discriminated with the
discriminator 0xc31a and the DB (process-specific) key.

There is also an "i8** @llvm.swift.async.context.addr()" intrinsic providing
front-ends access to this slot (and forcing its creation initialized to nullptr
if necessary).
2021-05-14 11:43:58 +01:00
Arthur Eubanks 2155dc51d7 [IR] Introduce the opaque pointer type
The opaque pointer type is essentially just a normal pointer type with a
null pointee type.

This also adds support for the opaque pointer type to the bitcode
reader/writer, as well as to textual IR.

To avoid confusion with existing pointer types, we disallow creating a
pointer to an opaque pointer.

Opaque pointer types should not be widely used at this point since many
parts of LLVM still do not support them. The next steps are to add some
very simple use cases of opaque pointers to make sure they work, then
start pretending that all pointers are opaque pointers and see what
breaks.

https://lists.llvm.org/pipermail/llvm-dev/2021-May/150359.html

Reviewed By: dblaikie, dexonsmith, pcc

Differential Revision: https://reviews.llvm.org/D101704
2021-05-13 15:22:27 -07:00
cynecx 8ec9fd4839 Support unwinding from inline assembly
I've taken the following steps to add unwinding support from inline assembly:

1) Add a new `unwind` "attribute" (like `sideeffect`) to the asm syntax:

```
invoke void asm sideeffect unwind "call thrower", "~{dirflag},~{fpsr},~{flags}"()
    to label %exit unwind label %uexit
```

2.) Add Bitcode writing/reading support + LLVM-IR parsing.

3.) Emit EHLabels around inline assembly lowering (SelectionDAGBuilder + GlobalISel) when `InlineAsm::canThrow` is enabled.

4.) Tweak InstCombineCalls/InlineFunction pass to not mark inline assembly "calls" as nounwind.

5.) Add clang support by introducing a new clobber: "unwind", which lower to the `canThrow` being enabled.

6.) Don't allow unwinding callbr.

Reviewed By: Amanieu

Differential Revision: https://reviews.llvm.org/D95745
2021-05-13 19:13:03 +01:00
Steven Wu 4eff946947 [IR][AutoUpgrade] Drop align attribute from void return types
Since D87304, `align` become an invalid attribute on none pointer types and
verifier will reject bitcode that has invalid `align` attribute.

The problem is before the change, DeadArgumentElimination can easily
turn a pointer return type into a void return type without removing
`align` attribute. Teach Autograde to remove invalid `align` attribute
from return types to maintain bitcode compatibility.

rdar://77022993

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D102201
2021-05-11 08:23:55 -07:00
Matt Arsenault 9a0c9402fa Reapply "OpaquePtr: Turn inalloca into a type attribute"
This reverts commit 07e46367ba.
2021-03-29 08:55:30 -04:00
Oliver Stannard 07e46367ba Revert "Reapply "OpaquePtr: Turn inalloca into a type attribute""
Reverting because test 'Bindings/Go/go.test' is failing on most
buildbots.

This reverts commit fc9df30991.
2021-03-29 11:32:22 +01:00
Matt Arsenault fc9df30991 Reapply "OpaquePtr: Turn inalloca into a type attribute"
This reverts commit 20d5c42e0e.
2021-03-28 13:35:21 -04:00
Nico Weber 20d5c42e0e Revert "OpaquePtr: Turn inalloca into a type attribute"
This reverts commit 4fefed6563.
Broke check-clang everywhere.
2021-03-28 13:02:52 -04:00
Matt Arsenault 4fefed6563 OpaquePtr: Turn inalloca into a type attribute
I think byval/sret and the others are close to being able to rip out
the code to support the missing type case. A lot of this code is
shared with inalloca, so catch this up to the others so that can
happen.
2021-03-28 11:12:23 -04:00
Bradley Smith 48f5a392cb [IR] Add vscale_range IR function attribute
This attribute represents the minimum and maximum values vscale can
take. For now this attribute is not hooked up to anything during
codegen, this will be added in the future when such codegen is
considered stable.

Additionally hook up the -msve-vector-bits=<x> clang option to emit this
attribute.

Differential Revision: https://reviews.llvm.org/D98030
2021-03-22 12:05:06 +00:00
Leonard Chan 1c932baeaa [llvm][Bitcode] Add bitcode reader/writer for DSOLocalEquivalent
This is necessary for compilation with [thin]lto.

Differential Revision: https://reviews.llvm.org/D96170
2021-02-22 10:37:57 -08:00
Wei Wang 80dc0661bd [LTO] Perform DSOLocal propagation in combined index
Perform DSOLocal propagation within summary list of every GV. This
avoids the repeated query of this information during function
importing.

Differential Revision: https://reviews.llvm.org/D96398
2021-02-12 22:58:26 -08:00
James Y Knight db00953ff3 Fix bitcode decoder error in "Encode alignment attribute for `atomicrmw`"
The wrong record field number was being used in bitcode decoding,
which broke a self-hosted LTO build. (Yet, somehow, this _doesn't_
seem to have broken simple bitcode encode/decode roundtrip tests, and
I'm not sure why...)

Fixes commit d06ab79816
2021-02-11 22:29:03 -05:00
Guillaume Chatelet 17517f3178 Encode alignment attribute for `cmpxchg`
This is a follow up patch to D83136 adding the align attribute to `cmpxchg`.
See also D83465 for `atomicrmw`.

Differential Revision: https://reviews.llvm.org/D87443
2021-02-11 15:17:50 -05:00
Guillaume Chatelet d06ab79816 Encode alignment attribute for `atomicrmw`
This is a follow up patch to D83136 adding the align attribute to `atomicwmw`.

Differential Revision: https://reviews.llvm.org/D83465
2021-02-11 15:17:37 -05:00
Fangrui Song 54fb3ca96e [ThinLTO] Add Visibility bits to GlobalValueSummary::GVFlags
Imported functions and variable get the visibility from the module supplying the
definition.  However, non-imported definitions do not get the visibility from
(ELF) the most constraining visibility among all modules (Mach-O) the visibility
of the prevailing definition.

This patch

* adds visibility bits to GlobalValueSummary::GVFlags
* computes the result visibility and propagates it to all definitions

Protected/hidden can imply dso_local which can enable some optimizations (this
is stronger than GVFlags::DSOLocal because the implied dso_local can be
leveraged for ELF -shared while default visibility dso_local has to be cleared
for ELF -shared).

Note: we don't have summaries for declarations, so for ELF if a declaration has
the most constraining visibility, the result visibility may not be that one.

Differential Revision: https://reviews.llvm.org/D92900
2021-01-27 10:43:51 -08:00
Kazu Hirata 16baad8f4e [llvm] Use pop_back_val (NFC) 2021-01-24 12:18:57 -08:00
Kazu Hirata 1d0bc05551 [llvm] Use llvm::append_range (NFC) 2021-01-06 18:27:33 -08:00
Luo, Yuanke 981a0bd858 [X86] Add x86_amx type for intel AMX.
The x86_amx is used for AMX intrisics. <256 x i32> is bitcast to x86_amx when
it is used by AMX intrinsics, and x86_amx is bitcast to <256 x i32> when it
is used by load/store instruction. So amx intrinsics only operate on type x86_amx.
It can help to separate amx intrinsics from llvm IR instructions (+-*/).
Thank Craig for the idea. This patch depend on https://reviews.llvm.org/D87981.

Differential Revision: https://reviews.llvm.org/D91927
2020-12-30 13:52:13 +08:00