Convert "denormal-fp-math" and "denormal-fp-math-f32" into a first
class denormal_fpenv attribute. Previously the query for the effective
denormal mode involved two string attribute queries with parsing. I'm
introducing more uses of this, so it makes sense to convert this
to a more efficient encoding. The old representation was also awkward
since it was split across two separate attributes. The new encoding
just stores the default and float modes as bitfields, largely avoiding
the need to consider if the other mode is set.
The syntax in the common cases looks like this:
`denormal_fpenv(preservesign,preservesign)`
`denormal_fpenv(float: preservesign,preservesign)`
`denormal_fpenv(dynamic,dynamic float: preservesign,preservesign)`
I wasn't sure about reusing the float type name instead of adding a
new keyword. It's parsed as a type but only accepts float. I'm also
debating switching the name to subnormal to match the current
preferred IEEE terminology (also used by nofpclass and other
contexts).
This has a behavior change when using the command flag debug
options to set the denormal mode. The behavior of the flag
ignored functions with an explicit attribute set, per
the default and f32 version. Now that these are one attribute,
the flag logic can't distinguish which of the two components
were explicitly set on the function. Only one test appeared to
rely on this behavior, so I just avoided using the flags in it.
This also does not perform all the code cleanups this enables.
In particular the attributor handling could be cleaned up.
I also guessed at how to support this in MLIR. I followed
MemoryEffects as a reference; it appears bitfields are expanded
into arguments to attributes, so the representation there is
a bit uglier with the 2 2-element fields flattened into 4 arguments.
This removes most of the handling of the relative block frequency
support added in 2018 in c73cec84c99e5a63dca961fef67998a677c53a3c, which
was disabled by default and never utilized in the thin link as expected.
Support for reading old Bitcode containing the record is maintained as
required for backwards compatibility requirements, as is the support for
parsing old LLVM assembly containing that information. Tests ensure that
this backwards compatibility is maintained.
This came up in the context of redundant BFI/DT computations which
existed largely for the purpose of computing this information
and are being addressed in PR176646.
Deactivation symbol operands are supported in the code generator by
building on the previously added support for IRELATIVE relocations.
Reviewers: ojhunt, fmayer, ahmedbougacha, nikic, efriedma-quic
Reviewed By: fmayer
Pull Request: https://github.com/llvm/llvm-project/pull/133537
For swift async code, we need to use a debug intrinsic that behaves like
an llvm.dbg.declare but can take any location type rather than just a
pointer or integer.
To solve this, a new debug instrinsic called llvm.dbg.declare_value has
been created, which behaves exactly like an llvm.dbg.declare but can
take non pointer and integer location types.
More information here:
https://discourse.llvm.org/t/rfc-introduce-new-llvm-dbg-coroframe-entry-intrinsic/88269
This is the first patch as part of a stack of patches, with the one
succeeding it being: https://github.com/llvm/llvm-project/pull/168134
Also add a corresponding intrinsic property that can be used to mark
intrinsics that do not introduce poison, for example simple arithmetic
intrinsics that propagate poison just like a simple arithmetic
instruction.
As a smoke test this patch adds the new property to
llvm.amdgcn.fmul.legacy.
DW_TAG_base_type DIEs are permitted to have both byte_size and bit_size
attributes "If the value of an object of the given type does not fully
occupy the storage described by a byte size attribute"
* Add DataSizeInBits to DIBasicType (`DIBasicType(... dataSize: n ...)` in IR).
* Change Clang to add DataSizeInBits to _BitInt type metadata.
* Change LLVM to add DW_AT_bit_size to base_type DIEs that have non-zero
DataSizeInBits.
TODO: Do we need to emit DW_AT_data_bit_offset for big endian targets?
See discussion on the PR.
Fixes [#61952](https://github.com/llvm/llvm-project/issues/61952)
---------
Co-authored-by: David Stenberg <david.stenberg@ericsson.com>
In preparation for a follow on change that will require checking every
time a new summary is added to the SummaryList for a GUID, make the
SummaryList private and require all accesses to go through one of two
new interfaces. Most changes are to access the list via the read only
getSummaryList() method, and the few that add new summaries (e.g. while
building the combined summary) use the new addSummary() method.
This patch moves the `preserve-bc-uselistorder` and
`preserve-ll-uselistorder` options out of individual tools(opt, llvm-as,
llvm-dis, llvm-link, llvm-extract) and make them global defaults for
AsmWriter and BitcodeWriter.
These options are useful when we use `-print-*` options to dump LLVM IR.
This patch sets up `DICompileUnit` to support the DWARFv6
`DW_AT_language_name` and `DW_AT_language_version` attributes (which are
set to replace `DW_AT_language`). This patch changes the
`DICompileUnit::SourceLanguage` field type to a `DISourceLanguageName`
that encapsulates the notion of "versioned vs. unversioned name". A
"versioned" name is one that has an associated version stored separately
in `DISourceLanguageName::Version`.
This patch just changes all the clients of the `getSourceLanguage` API
to the expect a `DISourceLanguageName`. Currently they all just `assert`
(via `DISourceLanguageName::getUnversionedName`) that we're dealing with
"unversioned names" (i.e., the pre-DWARFv6 language codes). In follow-up
patches (e.g., draft is at
https://github.com/llvm/llvm-project/pull/162261), when we start
emitting versioned language codes, the `getUnversionedName` calls can
then be adjusted to `getName`.
**Implementation considerations**
* We could have added a new member to `DICompileUnit` alongside the
existing `SourceLanguage` field. I don't think this would have made the
transition any simpler (clients would still need to be aware of
"versioned" vs. "unversioned" language names). I felt that encapsulating
this inside a `DISourceLanguageName` was easier to reason about for
maintainers.
* Currently DISourceLanguageName is a `12` byte structure. We could
probably pack all the info inside a `uint64_t` (16-bits for the name,
32-bits for the version, 1-bit for answering the `hasVersionedName`).
Just to keep the prototype simple I used a `std::optional`. But since
the guts of the structure are hidden, we can always change the layout to
a more compact representation instead.
**How to review**
* The new `DISourceLanguageName` structure is defined in
`DebugInfoMetadata.h`. All the other changes fall out from changing the
`DICompileUnit::SourceLanguage` from `unsigned` to
`DISourceLanguageName`.
Teach the IR parser and writer to support metadata on ifuncs, and update
documentation.
In PR #153049, we have a use case of attaching the `!associated`
metadata to an ifunc.
Since an ifunc is similar to a function declaration, it seems natural to
allow metadata on ifuncs.
Currently, the metadata API allows adding Metadata to
llvm::GlobalObject, so the in-memory IR allows for metadata on ifuncs,
but the IR reader/writer is not aware of that.
---------
Co-authored-by: Wael Yehia <wyehia@ca.ibm.com>
MaxAlignment is used to produce the abbreviation for MODULE_CODE_GLOBALVAR
and is not used for anything related to function alignments, so stop
combining function alignments and rename it to make its purpose clearer.
Reviewers: teresajohnson
Reviewed By: teresajohnson
Pull Request: https://github.com/llvm/llvm-project/pull/155341
This introduces a new `ptrtoaddr` instruction which is similar to
`ptrtoint` but has two differences:
1) Unlike `ptrtoint`, `ptrtoaddr` does not capture provenance
2) `ptrtoaddr` only extracts (and then extends/truncates) the low
index-width bits of the pointer
For most architectures, difference 2) does not matter since index (address)
width and pointer representation width are the same, but this does make a
difference for architectures that have pointers that aren't just plain
integer addresses such as AMDGPU fat pointers or CHERI capabilities.
This commit introduces textual and bitcode IR support as well as basic code
generation, but optimization passes do not handle the new instruction yet
so it may result in worse code than using ptrtoint. Follow-up changes will
update capture tracking, etc. for the new instruction.
RFC: https://discourse.llvm.org/t/clarifiying-the-semantics-of-ptrtoint/83987/54
Reviewed By: nikic
Pull Request: https://github.com/llvm/llvm-project/pull/139357
Serialise key-instruction fields of DILocations and DISubprograms into
and outof bitcode, add tests. debug-info bitcode sizes grow, but it
balances out given an earlier size optimisation in 51f4e2c.
Co-authored-by: Orlando Cazalet-Hyams <orlando.hyams@sony.com>
DILocations that are not attached to instructions are encoded using
METADATA_LOCATION records which have an abbrev. DILocations attached to
instructions are interleaved with instruction records as FUNC_CODE_DEBUG_LOC
records, which do not have an abbrev (and FUNC_CODE_DEBUG_LOC_AGAIN
which have no operands).
Add a new FUNCTION_BLOCK abbrev FUNCTION_DEBUG_LOC_ABBREV for
FUNC_CODE_DEBUG_LOC records.
This reduces the bc file size by up to 7% in CTMark, with many between 2-4%
smaller.
[per-file file size
compile-time-tracker](https://llvm-compile-time-tracker.com/compare.php?from=75cf826849713c00829cdf657e330e24c1a2fd03&to=1e268ebd0a581016660d9d7e942495c1be041f7d&stat=size-file&details=on)
(go to stage1-ReleaseLTO-g).
This optimisation is motivated by #144102, which adds the new Key Instructions
fields to bitcode records. The combined patches still overall look to be a
slight improvement over the base.
(Originally reviewed in PR #146497)
Co-authored-by: Orlando Cazalet-Hyams <orlando.hyams@sony.com>
RFC on discourse:
https://discourse.llvm.org/t/rfc-debug-info-for-coroutine-suspension-locations-take-2/86606
With this commit, we add `DILabel` debug infos to the resume points of a
coroutine. Those labels can be used by debugging scripts to figure out
the exact line and column at which a coroutine was suspended by looking
up current `__coro_index` value inside the coroutines frame, and then
searching for the corresponding label inside the coroutine's resume
function.
The DWARF information generated for such a label looks like:
```
0x00000f71: DW_TAG_label
DW_AT_name ("__coro_resume_1")
DW_AT_decl_file ("generator-example.cpp")
DW_AT_decl_line (5)
DW_AT_decl_column (3)
DW_AT_artificial (true)
DW_AT_LLVM_coro_suspend_idx (0x01)
DW_AT_low_pc (0x00000000000019be)
```
The labels can be mapped to their corresponding `__coro_idx` values
either via their naming convention `__coro_resume_<N>` or using the new
`DW_AT_LLVM_coro_suspend_idx` attribute. In gdb, those line numebrs can
be looked up using `info line -function my_coroutine -label
__coro_resume_1`. LLDB unfortunately does not understand DW_TAG_label
debug information, yet.
Given this is an artificial compiler-generated label, I did apply the
DW_AT_artificial tag to it. The DWARFv5 standard only allows that tag on
type and variable definitions, but this is a natural extension and was
also blessed in the RFC on discourse.
Also, this commit adds `DW_AT_decl_column` to labels, not only for
coroutines but also for normal C and C++ labels. While not strictly
necessary, I am doing so now because it would be harder to do so later
without breaking the binary LLVM-IR format
Drive-by fixes: While reading the existing test cases to understand how
to write my own test case, I did a couple of small typo fixes and
comment improvements
Add abbreviations for icmp/fcmp, store and br, which are the most common
instructions that don't have abbreviations yet. This requires increasing
the abbreviation size to 5 bits.
This gives about 3-5% bitcode size reductions for the clang build.
Add `dead_on_return` attribute, which is meant to be taken advantage
by the frontend, and states that the memory pointed to by the argument
is dead upon function return. As with `byval`, it is supposed to be
used for passing aggregates by value. The difference lies in the ABI:
`byval` implies that the pointer is explicitly passed as argument to
the callee (during codegen the copy is emitted as per byval contract),
whereas a `dead_on_return`-marked argument implies that the copy
already exists in the IR, is located at a specific stack offset within
the caller, and this memory will not be read further by the caller upon
callee return – or otherwise poison, if read before being written.
RFC: https://discourse.llvm.org/t/rfc-add-dead-on-return-attribute/86871.
In Ada, a record type can have a non-constant size, and a field can
appear at a non-constant bit offset in a record.
To support this, this patch changes DIType to record the size and offset
using metadata, rather than plain integers. In addition to a constant
offset, both DIVariable and DIExpression are now supported here.
One thing of note in this patch is the choice of how exactly to
represent a non-constant bit offset, with the difficulty being that
DWARF 5 does not support this. DWARF 3 did have a way to support a
non-constant byte offset, combined with a constant bit offset within the
byte, but this was deprecated in DWARF 4 and removed from DWARF 5.
This patch takes a simple approach: a DWARF extension allowing the use
of an expression with DW_AT_data_bit_offset. There is a corresponding
DWARF issue, see https://dwarfstd.org/issues/250501.1.html. The main
reason for this approach is that it keeps API simplicity: just a single
value is needed, rather than having separate data describing the byte
offset and the bit within the byte.
Start removing debug intrinsics support -- starting with the flag that
controls production of their replacement, debug records. This patch
removes the command-line-flag and with it the ability to switch back to
intrinsics. The module / function / block level "IsNewDbgInfoFormat"
flags get hardcoded to true, I'll to incrementally remove things that
depend on those flags.
Reapply PR142507 with fix for test: add in the same x86_64-linux
requirement as other tests as the stack ids are currently computed
differently on big endian systems. This will be investigated separately.
In order to allow selective reporting of context hinting during the LTO
link, and in the future to allow selective more aggressive cloning, add
an option to specify a minimum percent of the max cold size in the
profile summary. Contexts that meet that threshold will get context size
info metadata (and ThinLTO summary information) on the associated
allocations.
Specifying -memprof-report-hinted-sizes during the pre-LTO compile step
will continue to cause all contexts to receive this metadata. But
specifying -memprof-report-hinted-sizes only during the LTO link will
cause only those that meet the new threshold and have the metadata to
get reported.
To support this, because the alloc info summary and associated bitcode
requires the context size information to be in the same order as the
other context information, 0s are inserted for contexts without this
metadata. The bitcode writer uses a more compact format for the context
ids to allow better compression of the 0s.
As part of this change several helper methods are added to query whether
metadata contains context size info on any or all contexts.
In order to allow selective reporting of context hinting during the LTO
link, and in the future to allow selective more aggressive cloning, add
an option to specify a minimum percent of the max cold size in the
profile summary. Contexts that meet that threshold will get context size
info metadata (and ThinLTO summary information) on the associated
allocations.
Specifying -memprof-report-hinted-sizes during the pre-LTO compile step
will continue to cause all contexts to receive this metadata. But
specifying -memprof-report-hinted-sizes only during the LTO link will
cause only those that meet the new threshold and have the metadata to
get reported.
To support this, because the alloc info summary and associated bitcode
requires the context size information to be in the same order as the
other context information, 0s are inserted for contexts without this
metadata. The bitcode writer uses a more compact format for the context
ids to allow better compression of the 0s.
As part of this change several helper methods are added to query whether
metadata contains context size info on any or all contexts.
## Purpose
This patch is one in a series of code-mods that annotate LLVM’s public
interface for export. This patch annotates the `llvm/AsmParser`,
`llvm/BinaryFormat`, `llvm/Bitcode` and `llvm/Bitstream libraries. These
annotations currently have no meaningful impact on the LLVM build;
however, they are a prerequisite to support an LLVM Windows DLL (shared
library) build.
## Background
This effort is tracked in #109483. Additional context is provided in
[this
discourse](https://discourse.llvm.org/t/psa-annotating-llvm-public-interface/85307),
and documentation for `LLVM_ABI` and related annotations is found in the
LLVM repo
[here](https://github.com/llvm/llvm-project/blob/main/llvm/docs/InterfaceExportAnnotations.rst).
The bulk of these changes were generated automatically using the
[Interface Definition Scanner (IDS)](https://github.com/compnerd/ids)
tool, followed formatting with `git clang-format`.
The following manual adjustments were also applied after running IDS on
Linux:
- Add `LLVM_ABI_FRIEND` to friend member functions declared with
`LLVM_ABI`
- Add `LLVM_ABI` symbols that require export but are not declared in
headers
## Validation
Local builds and tests to validate cross-platform compatibility. This
included llvm, clang, and lldb on the following configurations:
- Windows with MSVC
- Windows with Clang
- Linux with GCC
- Linux with Clang
- Darwin with Clang
These are identified by misc-include-cleaner. I've filtered out those
that break builds. Also, I'm staying away from llvm-config.h,
config.h, and Compiler.h, which likely cause platform- or
compiler-specific build failures.
With this change, some callers get to use StringRef::starts_with.
I'm planning to teach getAsmString to return StringRef also, but
I'ld like to keep that separate from this patch.
Since we currently only use the context information in the alloc info
summary in the LTO backend for assertion checking, there is no need to
write this into the combined summary index for distributed ThinLTO for
NDEBUG builds. Put this under a new -combined-index-memprof-context
option which is off by default for NDEBUG.
The advantage is that we save time (not having to sort in preparation
for building the radix trees), and space in the generated bitcode files.
We could also do so for the callsite info records, but those are smaller
and less expensive to prepare.
This patch adds support for LLVM IR atomicrmw `fmaximum` and `fminimum`
instructions.
These mirror the `llvm.maximum.*` and `llvm.minimum.*` instructions, but
are atomic and use IEEE754 2019 handling for NaNs, which is different to
`fmax` and `fmin`. See:
https://llvm.org/docs/LangRef.html#llvm-minimum-intrinsic
for more details.
Future changes will allow this LLVM IR to be lowered to specialised
assembler instructions on suitable targets, such as AArch64.
We currently accept label arguments to inline asm calls. This support
predates both blockaddresses and callbr and is only covered by one X86
test. Remove it in favor of callbr (or at least blockaddress, though
that cannot guarantee correct codegen, just like using block labels
directly can't).
I didn't bother implementing bitcode upgrade support for this, but I can
add it if desired.
This patch adds support for LLVM IR atomicrmw `fmaximum` and `fminimum`
instructions.
These mirror the `llvm.maximum.*` and `llvm.minimum.*` instructions, but
are atomic and use IEEE754 2019 handling for NaNs, which is different to
`fmax` and `fmin`. See:
https://llvm.org/docs/LangRef.html#llvm-minimum-intrinsic
for more details.
Future changes will allow this LLVM IR to be lowered to specialised
assembler instructions on suitable targets, such as AArch64.
During the transition from debug intrinsics to debug records, we used
several different command line options to customise handling: the
printing of debug records to bitcode and textual could be independent of
how the debug-info was represented inside a module, whether the
autoupgrader ran could be customised. This was all valuable during
development, but now that totally removing debug intrinsics is coming
up, this patch removes those options in favour of a single flag
(experimental-debuginfo-iterators), which enables autoupgrade, in-memory
debug records, and debug record printing to bitcode and textual IR.
We need to do this ahead of removing the
experimental-debuginfo-iterators flag, to reduce the amount of
test-juggling that happens at that time.
There are quite a number of weird test behaviours related to this --
some of which I simply delete in this commit. Things like
print-non-instruction-debug-info.ll , the test suite now checks for
debug records in all tests, and we don't want to check we can print as
intrinsics. Or the update_test_checks tests -- these are duplicated with
write-experimental-debuginfo=false to ensure file writing for intrinsics
is correct, but that's something we're imminently going to delete.
A short survey of curious test changes:
* free-intrinsics.ll: we don't need to test that debug-info is a zero
cost intrinsic, because we won't be using intrinsics in the future.
* undef-dbg-val.ll: apparently we pinned this to non-RemoveDIs in-memory
mode while we sorted something out; it works now either way.
* salvage-cast-debug-info.ll: was testing intrinsics-in-memory get
salvaged, isn't necessary now
* localize-constexpr-debuginfo.ll: was producing "dead metadata"
intrinsics for optimised-out variable values, dbg-records takes the
(correct) representation of poison/undef as an operand. Looks like we
didn't update this in the past to avoid spurious test differences.
* Transforms/Scalarizer/dbginfo.ll: this test was explicitly testing
that debug-info affected codegen, and we deferred updating the tests
until now. This is just one of those silent gnochange issues that get
fixed by RemoveDIs.
Finally: I've added a bitcode test, dbg-intrinsics-autoupgrade.ll.bc,
that checks we can autoupgrade debug intrinsics that are in bitcode into
the new debug records.
This adds DWARF generation for fixed-point types. This feature is needed
by Ada.
Note that a pre-existing GNU extension is used in one case. This has
been emitted by GCC for years, and is needed because standard DWARF is
otherwise incapable of representing these types.
In Ada, an array can be packed and the elements can take less space than
their natural object size. For example, for this type:
type Packed_Array is array (4 .. 8) of Boolean;
pragma pack (Packed_Array);
... each element of the array occupies a single bit, even though the
"natural" size for a Boolean in memory is a byte.
In DWARF, this is represented by putting a DW_AT_bit_stride onto the
array type itself.
This patch adds a bit stride to DICompositeType so that gnat-llvm can
emit DWARF for these sorts of arrays.
Before the patch,
`writeCombinedGlobalValueSummary` traversed entire
`cfiFunction*` for each module, just to pick a few
symbols from `DefOrUseGUIDs`.
Now we change internals of `cfiFunctionDefs` and
`cfiFunctionDecls` to maintain a map from GUID to StringSet.
So now we iterate `DefOrUseGUIDs`, usually small,
and pick exact subset of symbols.
Sorting is not strictly necessary, but it
preserves the order of emitted values.
The module currently stores the target triple as a string. This means
that any code that wants to actually use the triple first has to
instantiate a Triple, which is somewhat expensive. The change in #121652
caused a moderate compile-time regression due to this. While it would be
easy enough to work around, I think that architecturally, it makes more
sense to store the parsed Triple in the module, so that it can always be
directly queried.
For this change, I've opted not to add any magic conversions between
std::string and Triple for backwards-compatibilty purses, and instead
write out needed Triple()s or str()s explicitly. This is because I think
a decent number of them should be changed to work on Triple as well, to
avoid unnecessary conversions back and forth.
The only interesting part in this patch is that the default triple is
Triple("") instead of Triple() to preserve existing behavior. The former
defaults to using the ELF object format instead of unknown object
format. We should fix that as well.
