The original fix (commit 23ec5782c3) of
https://github.com/llvm/llvm-project/issues/52787 only adds `Function`s
that have `Instruction`s that directly use `BlockAddress`es into the
bitcode (`FUNC_CODE_BLOCKADDR_USERS`).
However, in either @rickyz's original reproducing code:
```
void f(long);
__attribute__((noinline)) static void fun(long x) {
f(x + 1);
}
void repro(void) {
fun(({
label:
(long)&&label;
}));
}
```
```
...
define dso_local void @repro() #0 {
entry:
br label %label
label: ; preds = %entry
tail call fastcc void @fun()
ret void
}
define internal fastcc void @fun() unnamed_addr #1 {
entry:
tail call void @f(i64 add (i64 ptrtoint (i8* blockaddress(@repro, %label) to i64), i64 1)) #3
ret void
}
...
```
or the xfs and overlayfs in the Linux kernel, `BlockAddress`es (e.g.,
`i8* blockaddress(@repro, %label)`) may first compose `ConstantExpr`s
(e.g., `i64 ptrtoint (i8* blockaddress(@repro, %label) to i64)`) and
then used by `Instruction`s. This case is not handled by the original
fix.
This patch adds *indirect* users of `BlockAddress`es, i.e., the
`Instruction`s using some `Constant`s which further use the
`BlockAddress`es, into the bitcode as well, by doing depth-first
searches.
Fixes: https://github.com/llvm/llvm-project/issues/52787
Fixes: 23ec5782c3 ("[Bitcode] materialize Functions early when BlockAddress taken")
Reviewed By: nickdesaulniers
Differential Revision: https://reviews.llvm.org/D124878
This continues the push away from hard-coded knowledge about functions
towards attributes. We'll use this to annotate free(), realloc() and
cousins and obviate the hard-coded list of free functions.
Differential Revision: https://reviews.llvm.org/D123083
As implemented this patch assumes that Typed pointer support remains in
the llvm::PointerType class, however this could be modified to use a
different subclass of llvm::Type that could be disallowed from use in
other contexts.
This does not rely on inserting typed pointers into the Module, it just
uses the llvm::PointerType class to track and unique types.
Fixes#54918
Reviewed By: kuhar
Differential Revision: https://reviews.llvm.org/D122268
The patch adds SPIRV-specific MC layer implementation, SPIRV object
file support and SPIRVInstPrinter.
Differential Revision: https://reviews.llvm.org/D116462
Authors: Aleksandr Bezzubikov, Lewis Crawford, Ilia Diachkov,
Michal Paszkowski, Andrey Tretyakov, Konrad Trifunovic
Co-authored-by: Aleksandr Bezzubikov <zuban32s@gmail.com>
Co-authored-by: Ilia Diachkov <iliya.diyachkov@intel.com>
Co-authored-by: Michal Paszkowski <michal.paszkowski@outlook.com>
Co-authored-by: Andrey Tretyakov <andrey1.tretyakov@intel.com>
Co-authored-by: Konrad Trifunovic <konrad.trifunovic@intel.com>
specifying DW_AT_trampoline as a string. Also update the signature
of DIBuilder::createFunction to reflect this addition.
Differential Revision: https://reviews.llvm.org/D123697
IRLinker builds a work list of functions to materialize, then moves them
from a source module to a destination module one at a time.
This is a problem for blockaddress Constants, since they need not refer
to the function they are used in; IPSCCP is quite good at sinking these
constants deep into other functions when passed as arguments.
This would lead to curious errors during LTO:
ld.lld: error: Never resolved function from blockaddress ...
based on the ordering of function definitions in IR.
The problem was that IRLinker would basically do:
for function f in worklist:
materialize f
splice f from source module to destination module
in one pass, with Functions being lazily added to the running worklist.
This confuses BitcodeReader, which cannot disambiguate whether a
blockaddress is referring to a function which has not yet been parsed
("materialized") or is simply empty because its body was spliced out.
This causes BitcodeReader to insert Functions into its BasicBlockFwdRefs
list incorrectly, as it will never re-materialize an already
materialized (but spliced out) function.
Because of the possibility that blockaddress Constants may appear in
Functions other than the ones they reference, this patch adds a new
bitcode function code FUNC_CODE_BLOCKADDR_USERS that is a simple list of
Functions that contain BlockAddress Constants that refer back to this
Function, rather then the Function they are scoped in. We then
materialize those functions when materializing `f` from the example loop
above. This might over-materialize Functions should the user of
BitcodeReader ultimately decide not to link those Functions, but we can
at least now we can avoid this ordering related issue with blockaddresses.
Fixes: https://github.com/llvm/llvm-project/issues/52787
Fixes: https://github.com/ClangBuiltLinux/linux/issues/1215
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D120781
Returning `std::array<uint8_t, N>` is better ergonomics for the hashing functions usage, instead of a `StringRef`:
* When returning `StringRef`, client code is "jumping through hoops" to do string manipulations instead of dealing with fixed array of bytes directly, which is more natural
* Returning `std::array<uint8_t, N>` avoids the need for the hasher classes to keep a field just for the purpose of wrapping it and returning it as a `StringRef`
As part of this patch also:
* Introduce `TruncatedBLAKE3` which is useful for using BLAKE3 as the hasher type for `HashBuilder` with non-default hash sizes.
* Make `MD5Result` inherit from `std::array<uint8_t, 16>` which improves & simplifies its API.
Differential Revision: https://reviews.llvm.org/D123100
DXIL is wrapped in a container format defined by the DirectX 11
specification. Codebases differ in calling this format either DXBC or
DXILContainer.
Since eventually we want to add support for DXBC as a target
architecture and the format is used by DXBC and DXIL, I've termed it
DXContainer here.
Most of the changes in this patch are just adding cases to switch
statements to address warnings.
Reviewed By: pete
Differential Revision: https://reviews.llvm.org/D122062
The one use check here is very misleading: At this point we should
actually have no uses, because the only possible use in llvm.used
was already dropped. But because the use in llvm.used is generally
bitcasted, we end up still having one dead use here.
What we actually want to check is that there are no live uses, for
which a helper has recently been added.
The constexpr source element type was enumerated if the GEP was
used as part of an instruction. However, things like global
initializers go through a different code path, and we need to
enumerate the type there as well.
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.
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
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
D116542 adds EmbedBufferInModule which introduces a layer violation
(https://llvm.org/docs/CodingStandards.html#library-layering).
See 2d5f857a1e for detail.
EmbedBufferInModule does not use BitcodeWriter functionality and should be moved
LLVMTransformsUtils. While here, change the function case to the prevailing
convention.
It seems that EmbedBufferInModule just follows the steps of
EmbedBitcodeInModule. EmbedBitcodeInModule calls WriteBitcodeToFile but has IR
update operations which ideally should be refactored to another library.
Reviewed By: jhuber6
Differential Revision: https://reviews.llvm.org/D118666
Summary:
The changes introduced in D116542 added a dependency on TransformUtils
to use the `appendToCompilerUsed` method. This created a circular
dependency. This patch simply copies the needed function locally to
remove the dependency.
This patch adds support for a flag `-fembed-offload-binary` to embed a
file as an ELF section in the output by placing it in a global variable.
This can be used to bundle offloading files with the host binary so it
can be accessed by the linker. The section is named using the
`-fembed-offload-section` option.
Depends on D116541
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D116542
DIStringType is used to encode the debug info of a character object
in Fortran. A Fortran deferred-length character object is typically
implemented as a pair of the following two pieces of info: An address
of the raw storage of the characters, and the length of the object.
The stringLocationExp field contains the DIExpression to get to the
raw storage.
This patch also enables the emission of DW_AT_data_location attribute
in a DW_TAG_string_type debug info entry based on stringLocationExp
in DIStringType.
A test is also added to ensure that the bitcode reader is backward
compatible with the old DIStringType format.
Differential Revision: https://reviews.llvm.org/D117586
Instead use either Type::getPointerElementType() or
Type::getNonOpaquePointerElementType().
This is part of D117885, in preparation for deprecating the API.
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
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
Add UNIQUED and DISTINCT properties in Metadata.def and use them to
implement restrictions on the `distinct` property of MDNodes:
* DIExpression can currently be parsed from IR or read from bitcode
as `distinct`, but this property is silently dropped when printing
to IR. This causes accepted IR to fail to round-trip. As DIExpression
appears inline at each use in the canonical form of IR, it cannot
actually be `distinct` anyway, as there is no syntax to describe it.
* Similarly, DIArgList is conceptually always uniqued. It is currently
restricted to only appearing in contexts where there is no syntax for
`distinct`, but for consistency it is treated equivalently to
DIExpression in this patch.
* DICompileUnit is already restricted to always being `distinct`, but
along with adding general support for the inverse restriction I went
ahead and described this in Metadata.def and updated the parser to be
general. Future nodes which have this restriction can share this
support.
The new UNIQUED property applies to DIExpression and DIArgList, and
forbids them to be `distinct`. It also implies they are canonically
printed inline at each use, rather than via MDNode ID.
The new DISTINCT property applies to DICompileUnit, and requires it to
be `distinct`.
A potential alternative change is to forbid the non-inline syntax for
DIExpression entirely, as is done with DIArgList implicitly by requiring
it appear in the context of a function. For example, we would forbid:
!named = !{!0}
!0 = !DIExpression()
Instead we would only accept the equivalent inlined version:
!named = !{!DIExpression()}
This essentially removes the ability to create a `distinct` DIExpression
by construction, as there is no syntax for `distinct` inline. If this
patch is accepted as-is, the result would be that the non-canonical
version is accepted, but the following would be an error and produce a diagnostic:
!named = !{!0}
; error: 'distinct' not allowed for !DIExpression()
!0 = distinct !DIExpression()
Also update some documentation to consistently use the inline syntax for
DIExpression, and to describe the restrictions on `distinct` for nodes
where applicable.
Reviewed By: StephenTozer, t-tye
Differential Revision: https://reviews.llvm.org/D104827
This moves the registry higher in the LLVM library dependency stack.
Every client of the target registry needs to link against MC anyway to
actually use the target, so we might as well move this out of Support.
This allows us to ensure that Support doesn't have includes from MC/*.
Differential Revision: https://reviews.llvm.org/D111454
To better reflect the meaning of the now-disambiguated {GlobalValue,
GlobalAlias}::getBaseObject after breaking off GlobalIFunc::getResolverFunction
(D109792), the function is renamed to getAliaseeObject.
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
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
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
We expose the fact that we rely on unsigned wrapping to iterate through
all indexes. This can be confusing. Rather, keeping it as an
implementation detail through an iterator is less confusing and is less
code.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D110885
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
In ThinLTO for locals we normally compute the GUID from the name after
prepending the source path to get a unique global id. SamplePGO indirect
call profiles contain the target GUID without this uniquification,
however (unless compiling with -funique-internal-linkage-names).
In order to correctly handle the call edges added to the combined index
for these indirect calls, during importing and bitcode writing we
consult a map of original to full GUID to identify the actual callee.
However, for a large application this was consuming a lot of compile
time as we need to do this repeatedly (especially during importing where
we may traverse call edges multiple times).
To fix this implement a suggestion in one of the FIXME comments, and
actually modify the call edges during a single traversal after the index
is built to perform the fixups once. I combined this fixup with the dead
code analysis performed on the index in order to avoid adding an
additional walk of the index. The dead code analysis is the first
analysis performed on the index.
This reduced the time required for a large thin link with SamplePGO by
about 20%.
No new test added, but I confirmed that there are existing tests that
will fail when no fixup is performed.
Differential Revision: https://reviews.llvm.org/D110374
In ThinLTO for locals we normally compute the GUID from the name after
prepending the source path to get a unique global id. SamplePGO indirect
call profiles contain the target GUID without this uniquification,
however (unless compiling with -funique-internal-linkage-names).
Therefore, the index contains the original GUID of the local symbols
(without module path prepended to uniquify), in order to correctly
handle the call edges added for these indirect call profile targets
with SamplePGO.
We were emitting these to the combined index when writing it out as
bitcode, which is unnecessary and causes overhead when writing out the
indexes for distributed backends. The only use of the original GUID name
is in the thin link. Suppress it in that case. This reduced the thin
link time for a large distributed build by about 7%, and the aggregate
size of the serialized indexes by over 2%.
Continue to print it when writing out the full index, since that is just
used for debugging and testing.
Update a distributed thinlto index test to contain a local and ensure
that we don't get a COMBINED_ORIGINAL_NAME record.
Differential Revision: https://reviews.llvm.org/D110296
New field `elements` is added to '!DIImportedEntity', representing
list of aliased entities.
This is needed to dump optimized debugging information where all names
in a module are imported, but a few names are imported with overriding
aliases.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D109343
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
Generate btf_tag annotations for function parameters.
A field "annotations" is introduced to DILocalVariable, and
annotations are represented as an DINodeArray, similar to
DIComposite elements. The following example illustrates how
annotations are encoded in IR:
distinct !DILocalVariable(name: "info",, arg: 1, ..., annotations: !10)
!10 = !{!11, !12}
!11 = !{!"btf_tag", !"a"}
!12 = !{!"btf_tag", !"b"}
Differential Revision: https://reviews.llvm.org/D106620
Generate btf_tag annotations for DIGlobalVariable.
A field "annotations" is introduced to DIGlobalVariable, and
annotations are represented as an DINodeArray, similar to
DIComposite elements. The following example illustrates how
annotations are encoded in IR:
distinct !DIGlobalVariable(..., annotations: !10)
!10 = !{!11, !12}
!11 = !{!"btf_tag", !"a"}
!12 = !{!"btf_tag", !"b"}
Differential Revision: https://reviews.llvm.org/D106619
Generate btf_tag annotations for DISubprogram types.
A field "annotations" is introduced to DISubprogram, and
annotations are represented as an DINodeArray, similar to
DIComposite elements. The following example illustrates how
annotations are encoded in IR:
distinct !DISubprogram(..., annotations: !10)
!10 = !{!11, !12}
!11 = !{!"btf_tag", !"a"}
!12 = !{!"btf_tag", !"b"}
Differential Revision: https://reviews.llvm.org/D106618
Fangrui Song