Implements the ThinLTO summary support for memprof related metadata.
This includes support for the assembly format, and for building the
summary from IR during ModuleSummaryAnalysis.
To reduce space in both the bitcode format and the in memory index,
we do 2 things:
1. We keep a single vector of all uniq stack id hashes, and record the
index into this vector in the callsite and allocation memprof
summaries.
2. When building the combined index during the LTO link, the callsite
and allocation memprof summaries are only kept on the FunctionSummary
of the prevailing copy.
Differential Revision: https://reviews.llvm.org/D135714
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
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
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.
This adds the `--dump-blockinfo` flag to `llvm-bcanalyzer`, allowing a sufficiently motivated user to dump (parts of) the `BLOCKINFO_BLOCK` block. The default behavior is unchanged, and `--dump-blockinfo` only takes effect in the same context as other flags that control dump behavior (i.e., requires that `--dump` is also passed).
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D107536
This patch adds a new metadata node, DIArgList, which contains a list of SSA
values. This node is in many ways similar in function to the existing
ValueAsMetadata node, with the difference being that it tracks a list instead of
a single value. Internally, it uses ValueAsMetadata to track the individual
values, but there is also a reasonable amount of DIArgList-specific
value-tracking logic on top of that. Similar to ValueAsMetadata, it is a special
case in parsing and printing due to the fact that it requires a function state
(as it may reference function-local values).
This patch should not result in any immediate functional change; it allows for
DIArgLists to be parsed and printed, but debug variable intrinsics do not yet
recognize them as a valid argument (outside of parsing).
Differential Revision: https://reviews.llvm.org/D88175
Happened to notice some of these printing as UnknownCode while running llvm-bcanalyzer on a bc file I had.
Differential Revision: https://reviews.llvm.org/D86900
This is cleaning up comments (mostly in the bitcode handling) about
removing some backward compatibility aspect in the 4.0 release.
Historically, "4.0" was used during the development of the 3.x
versions as "this future major breaking change version". At the time
the major number was used to indicate the compatibility. When we
reached 3.9 we decided to change the numbering, instead of going to
3.10 we went to 4.0 but after changing the meaning of the major
number to not mean anything anymore with respect to bitcode backward
compatibility.
The current policy
(https://llvm.org/docs/DeveloperPolicy.html#ir-backwards-compatibility)
indicates only now:
The current LLVM version supports loading any bitcode since version 3.0.
Differential Revision: https://reviews.llvm.org/D82514
Summary:
This patch adds optional field into function summary,
implements asm and bitcode serialization. YAML
serialization is omitted and can be added later if
needed.
This patch includes this information into summary only
if module contains at least one sanitize_memtag function.
In a near future MTE is the user of the analysis.
Later if needed we can provede more direct control
on when information is included into summary.
Reviewers: eugenis
Subscribers: hiraditya, steven_wu, dexonsmith, arphaman, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80908
Summary:
Count the per-module number of basic blocks when the module summary is computed
and sum them up during Thin LTO indexing.
This is used to estimate the working set size under the partial sample PGO.
This is split off of D79831.
Reviewers: davidxl, espindola
Subscribers: emaste, inglorion, hiraditya, MaskRay, steven_wu, dexonsmith, arphaman, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80403
Add a new serializer, using a binary format based on the LLVM bitstream
format.
This format provides a way to serialize the remarks in two modes:
1) Separate mode: the metadata is separate from the remark entries.
2) Standalone mode: the metadata and the remark entries are in the same
file.
The format contains:
* a meta block: container version, container type, string table,
external file path, remark version
* a remark block: type, remark name, pass name, function name, debug
file, debug line, debug column, hotness, arguments (key, value, debug
file, debug line, debug column)
A string table is required for this format, which will be dumped in the
meta block to be consumed before parsing the remark blocks.
On clang itself, we noticed a size reduction of 13.4x compared to YAML,
and a compile-time reduction of between 1.7% and 3.5% on CTMark.
Differential Revision: https://reviews.llvm.org/D63466
Original llvm-svn: 367364
Revert llvm-svn: 367370
llvm-svn: 367372
Add a new serializer, using a binary format based on the LLVM bitstream
format.
This format provides a way to serialize the remarks in two modes:
1) Separate mode: the metadata is separate from the remark entries.
2) Standalone mode: the metadata and the remark entries are in the same
file.
The format contains:
* a meta block: container version, container type, string table,
external file path, remark version
* a remark block: type, remark name, pass name, function name, debug
file, debug line, debug column, hotness, arguments (key, value, debug
file, debug line, debug column)
A string table is required for this format, which will be dumped in the
meta block to be consumed before parsing the remark blocks.
On clang itself, we noticed a size reduction of 13.4x compared to YAML,
and a compile-time reduction of between 1.7% and 3.5% on CTMark.
Differential Revision: https://reviews.llvm.org/D63466
llvm-svn: 367364
After rL365286 I had failing test:
LLVM :: tools/gold/X86/v1.12/thinlto_emit_linked_objects.ll
It was failing with the output:
$ llvm-bcanalyzer --dump llvm/test/tools/gold/X86/v1.12/Output/thinlto_emit_linked_objects.ll.tmp3.o.thinlto.bc
Expected<T> must be checked before access or destruction.
Unchecked Expected<T> contained error:
Unexpected end of file reading 0 of 0 bytesStack dump:
Change-Id: I07e03262074ea5e0aae7a8d787d5487c87f914a2
llvm-svn: 366387
This allows us to use the analyzer from unit tests.
* Refactor the interface to use proper error handling for most functions
after JF's work.
* Move everything into a BitstreamAnalyzer class.
* Move that to Bitcode/BitcodeAnalyzer.h.
Differential Revision: https://reviews.llvm.org/D64116
llvm-svn: 365286
Teresa Johnson