7166 Commits

Author SHA1 Message Date
Jacek Caban
c41966161f
[llvm-ar] Be explicit about archive format in coff-symtab.test tests. (#85112)
Fixes test failures on AIX after #82898.
2024-03-13 18:56:46 +01:00
Craig Topper
ab9564c315
[RISCV] Add SMLoc to expanded vector pseudoinstructions in AsmParser. (#84875)
This is needed for llvm-mca to correctly apply vsetvli instruments to
these instructions.

Fixes #84799.
2024-03-13 10:51:48 -07:00
Fangrui Song
122d368b2b
[llvm-objcopy] --[de]compress-debug-sections: don't compress SHF_ALLOC sections, only decompress .debug sections
Simplify --[de]compress-debug-sections to make it easier to add custom section [de]compression.
Change the following two behaviors to match GNU objcopy.

* --compress-debug-sections compresses SHF_ALLOC sections while GNU
  doesn't.
* --decompress-debug-sections decompresses non-debug sections while GNU
  doesn't.

Pull Request: https://github.com/llvm/llvm-project/pull/84885
2024-03-13 10:13:21 -07:00
Jacek Caban
2037577768
[llvm-ar] Use COFF archive format for COFF targets. (#82898)
Detect COFF files by default and allow specifying it with --format
argument.

This is important for ARM64EC, which uses a separated symbol map for EC
symbols. Since K_COFF is mostly compatible with K_GNU, this shouldn't
really make a difference for other targets.

This originally landed as #82642, but was reverted due to test failures
in tests using no symbol table. Since COFF symbol can't express it,
fallback to GNU format in that case.
2024-03-13 13:27:20 +01:00
Daniel Paoliello
1a6ec906fb
[Arm64EC] Copy import descriptors to the EC Map (#84834)
As noted in <https://github.com/llvm/llvm-project/pull/78537>, MSVC
places import descriptors in both the EC and regular map - that PR moved
the descriptors to ONLY the regular map, however this causes linking
errors when linking as Arm64EC:

```
bcryptprimitives.lib(bcryptprimitives.dll) : error LNK2001: unresolved external symbol __IMPORT_DESCRIPTOR_bcryptprimitives (EC Symbol)
```

This change copies import descriptors from the regular map to the EC
map, which fixes this linking error.
2024-03-12 14:10:49 -07:00
Simon Pilgrim
ad8c828136 [X86] (V)MPSADBW instructions can run on Port1 or Port5 for one uop stage
When we copied the IceLake model from the SkylakeServer model we missed this diff

Confirmed with uops.info and Agner
2024-03-11 15:48:08 +00:00
Teresa Johnson
08ddd2ce40
[PGO] Add support for writing previous indexed format (#84505)
Enable temporary support to ease use of new llvm-profdata with slightly
older indexed profiles after 16e74fd48988ac95551d0f64e1b36f78a82a89a2,
which bumped the indexed format for type profiling.
2024-03-08 12:27:46 -08:00
Simon Pilgrim
ce683273aa [X86] PBLENDW instructions can run on Port1 or Port5
When we copied the SkylakeServer model we missed this diff

Confirmed with uops.info and Agner
2024-03-08 15:10:47 +00:00
Nicolai Hähnle
3846019d8f update_test_checks: keep meta variables stable by default
Resubmitting this after previous revert with the following changes:

- Split table into table_rhs_idx and table_candidate_idx so that
  bisect.bisect_left can be used without the `key` argument, which
  was introduced in Python 3.10
- Remove a re.Pattern type annotation

Original commit message:

Prior to this change, running UTC on larger tests, especially tests
with unnamed IR values, often resulted in a spuriously large diff
because e.g. TMPnn variables in the CHECK lines were renumbered. This
change attempts to reduce the diff by keeping those variable names the
same.

There are cases in which this "drift" of variable names can end up being
more confusing. The old behavior can be re-enabled with the
--reset-variable-names command line argument.

The improvement may not be immediately apparent in the diff of this change.
The point is that the diff of stable_ir_values.ll against
stable_ir_values.ll.expected after this change is smaller.

Ideally, we'd also keep meta variables for "global" objects stable, e.g.
for attributes (#nn) and metadata (!nn). However, that would require a
much more substantial refactoring of how we generate check lines, so I
left it for future work.
2024-03-08 04:33:38 +01:00
Nicolai Hähnle
b565126b4d Revert "update_test_checks: keep meta variables stable by default"
This reverts commit fb02f9ac84a6151e41aba8f7391edd132a9aaf14.

Looks like some Python version incompatibility, will investigate.
2024-03-08 04:25:07 +01:00
Nicolai Hähnle
fb02f9ac84 update_test_checks: keep meta variables stable by default
Prior to this change, running UTC on larger tests, especially tests
with unnamed IR values, often resulted in a spuriously large diff
because e.g. TMPnn variables in the CHECK lines were renumbered. This
change attempts to reduce the diff by keeping those variable names the
same.

There are cases in which this "drift" of variable names can end up being
more confusing. The old behavior can be re-enabled with the
--reset-variable-names command line argument.

The improvement may not be immediately apparent in the diff of this change.
The point is that the diff of stable_ir_values.ll against
stable_ir_values.ll.expected after this change is smaller.

Ideally, we'd also keep meta variables for "global" objects stable, e.g.
for attributes (#nn) and metadata (!nn). However, that would require a
much more substantial refactoring of how we generate check lines, so I
left it for future work.
2024-03-08 03:58:12 +01:00
Nicolai Hähnle
448419007e update_test_checks: precommit a test case
The test case demonstrates how meta variables are needlessly renamed,
making diffs harder to read.
2024-03-08 03:58:11 +01:00
Igor Kudrin
fe84764724
[DWARF] Dump an updated location for DW_CFA_advance_loc* (#84274)
When dumping FDEs, `readelf` prints new location values after
`DW_CFA_advance_loc(*)` instructions, which looks quite convenient:

```
> readelf -wf test.o
...
... FDE ... pc=0000000000000030..0000000000000064
  DW_CFA_advance_loc: 4 to 0000000000000034
  ...
  DW_CFA_advance_loc: 4 to 0000000000000038
...
```

This patch makes `llvm-dwarfdump` and `llvm-readobj` do the same.
2024-03-08 07:34:36 +07:00
Emma Pilkington
4490003a22
[AMDGPU] Rename COV module flag to amdhsa_code_object_version (#79905)
The previous name 'amdgpu_code_object_version', was misleading since
this is really a property of the HSA OS. The new spelling also matches
the asm directive I added in bc82cfb.
2024-03-06 09:51:48 -05:00
Michael Maitland
a6ee0adb72
[llvm-mca][AMDGPU] Retire instructions that have issue carry over correctly (#83881)
https://github.com/llvm/llvm-project/issues/83775 shows llvm-mca hits
sanitizer error in cycleEnd. There was an instruction that takes
multiple cycles to issue and is finished executing directly after issue.
Prior to this patch, the instruction is retired on the first issue
cycle, despite taking multiple cycles to issue.

To fix this, if an instruction takes multiple cycles to issue and is
done executing after issue, let updateCarriedOver retire the instruction
when it is fully issued.
2024-03-06 07:59:29 -05:00
Matt Arsenault
0f3628a937
AMDGPU: Correct cycle counts for f64 mfma on gfx940 (#83782) 2024-03-06 09:36:01 +05:30
Paul Walker
341d674b6f
[LLVM][AArch64][CodeGen] Mark FFR as a reserved register. (#83437)
This allows the removal of FFR related psuedo nodes that only existed to
work round machine verifier failures.
2024-03-05 12:34:15 +00:00
wanglei
a5c90e48b6
[LoongArch] Switch to the Machine Scheduler (#83759)
The SelectionDAG scheduling preference now becomes source order
scheduling (machine scheduler generates better code -- even without
there being a machine model defined for LoongArch yet).

Most of the test changes are trivial instruction reorderings and
differing register allocations, without any obvious performance impact.

This is similar to commit: 3d0fbafd0bce43bb9106230a45d1130f7a40e5ec
2024-03-05 09:15:44 +08:00
Alan Zhao
922a431e10
[profdata][nfc] Disable several tests on Windows (#83907)
Several profdata tests pass the byte 012 to printf. This causes these
tests to fail when using GnuWin32's version of printf because printf
will detect that 012 is the LF character and will prepend the byte 015
(CR) in front of LF.

This change is required after
https://github.com/llvm/llvm-project/pull/82711 which bumped the version
number.
2024-03-04 13:15:50 -08:00
Matt Arsenault
f407f2df2c AMDGPU: Test a few more cycle counts for mfma ops 2024-03-04 20:30:01 +05:30
Matt Arsenault
3a146d5720 AMDGPU: Partially re-add scheduling test for gfx940
31295bbe83c3ea9d8a3372efe34342a299d1018a reverted the original patch.
Submit part of the test that happens to not hit the sanitizer error,
which covers the instructions I more need test coverage for.
2024-03-04 12:32:30 +05:30
zhijian lin
3034632a27
[llvm-readobj] enable demangle option for the xcoff object file (#78455)
enable `--demangle` option for the xcoff object file for llvm-readobj
2024-03-01 09:21:11 -05:00
Mitch Phillips
31295bbe83 Revert "AMDGPU: Add scheduling test for gfx940 (#83220)"
This reverts commit f0484e08bdcf64106592808e3ca80404937b4657.

Reason: Broke the sanitizer build bots. See the github comments on
f0484e08bd
for more information
2024-02-29 12:48:22 +01:00
Matt Arsenault
f0484e08bd
AMDGPU: Add scheduling test for gfx940 (#83220)
I'm not sure the f64 fma cases are correct.
2024-02-29 09:13:34 +05:30
Henrik G. Olsson
6a65b44322
[UTC] Don't leave dangling CHECK-SAME when removing CHECK lines (#82569)
When removing only lines that are global value CHECK lines, a related
CHECK-SAME line could be left dangling without a previous line to belong
to.

Resolves #78517
2024-02-28 17:08:36 -08:00
Ilia Kuklin
07d8a457ad
[llvm-objcopy] Add --set-symbol-visibility and --set-symbols-visibility options (#80872)
Add options --set-symbol-visibility and --set-symbols-visibility to
manually change the visibility of symbols.

There is already an option to set the visibility of newly added symbols
via --add-symbol and --new-symbol-visibility. This option will allow to
change the visibility of already existing symbols.
2024-02-28 17:38:26 +05:00
Aiden Grossman
1d1186de34
[llvm-exegesis] Add loop-register snippet annotation (#82873)
This patch adds a LLVM-EXEGESIS-LOOP-REGISTER snippet annotation which
allows a user to specify the register to use for the loop counter in the
loop repetition mode. This allows for executing snippets that don't work
with the default value (currently R8 on X86).
2024-02-27 12:28:25 -08:00
Micah Weston
9ca8db352d
[SHT_LLVM_BB_ADDR_MAP] Adds pretty printing of BFI and BPI for PGO Analysis Map in tools. (#82292)
Primary change is to add a flag `--pretty-pgo-analysis-map` to
llvm-readobj and llvm-objdump that prints block frequencies and branch
probabilities in the same manner as BFI and BPI respectively. This can
be helpful if you are manually inspecting the outputs from the tools.

In order to print, I moved the `printBlockFreqImpl` function from
Analysis to Support and renamed it to `printRelativeBlockFreq`.
2024-02-27 14:13:00 -05:00
Mingming Liu
16e74fd489
Reland "[TypeProf][InstrPGO] Introduce raw and instr profile format change for type profiling." (#82711)
New change on top of [reviewed
patch](https://github.com/llvm/llvm-project/pull/81691) are [in commits
after this
one](d0757f46b3).
Previous commits are restored from the remote branch with timestamps.

1. Fix build breakage for non-ELF platforms, by defining the missing
functions {`__llvm_profile_begin_vtables`, `__llvm_profile_end_vtables`,
`__llvm_profile_begin_vtabnames `, `__llvm_profile_end_vtabnames`}
everywhere.
* Tested on mac laptop (for darwins) and Windows. Specifically,
functions in `InstrProfilingPlatformWindows.c` returns `NULL` to make it
more explicit that type prof isn't supported; see comments for the
reason.
* For the rest (AIX, other), mostly follow existing examples (like this
[one](f95b2f1acf))
   
2. Rename `__llvm_prf_vtabnames` -> `__llvm_prf_vns` for shorter section
name, and make returned pointers
[const](a825d2a4ec (diff-4de780ce726d76b7abc9d3353aef95013e7b21e7bda01be8940cc6574fb0b5ffR120-R121))

**Original Description**

* Raw profile format
- Header: records the byte size of compressed vtable names, and the
number of profiled vtable entries (call it `VTableProfData`). Header
also records padded bytes of each section.
- Payload: adds a section for compressed vtable names, and a section to
store `VTableProfData`. Both sections are padded so the size is a
multiple of 8.
* Indexed profile format
  - Header: records the byte offset of compressed vtable names.
- Payload: adds a section to store compressed vtable names. This section
is used by `llvm-profdata` to show the list of vtables profiled for an
instrumented site.
  
[The originally reviewed
patch](https://github.com/llvm/llvm-project/pull/66825) will have
profile reader/write change and llvm-profdata change.
- To ensure this PR has all the necessary profile format change along
with profile version bump, created a copy of the originally reviewed
patch in https://github.com/llvm/llvm-project/pull/80761. The copy
doesn't have profile format change, but it has the set of tests which
covers type profile generation, profile read and profile merge. Tests
pass there.
  
rfc in
https://discourse.llvm.org/t/rfc-dynamic-type-profiling-and-optimizations-in-llvm/74600

---------

Co-authored-by: modiking <modiking213@gmail.com>
2024-02-27 11:07:40 -08:00
Visoiu Mistrih Francis
b791a51730
[CodeGenSchedule] Don't allow invalid ReadAdvances to be formed (#82685)
Forming a `ReadAdvance` with an entry in the `ValidWrites` list that is
not used by any instruction results in the entire `ReadAdvance` to be
ignored by the scheduler due to an invalid entry.

The `SchedRW` collection code only picks up `SchedWrites` that are
reachable from `Instructions`, `InstRW`, `ItinRW` and `SchedAlias`,
leaving the unreachable ones with an invalid entry (0) in
`SubtargetEmitter::GenSchedClassTables` when going through the list of
`ReadAdvances`
2024-02-26 18:25:21 -08:00
NAKAMURA Takumi
3b27cc2cee Regenerate llvm-cov tests 2024-02-25 18:33:53 +09:00
Jacek Caban
8a5aa103c5
Revert "[llvm-ar] Use COFF archive format for COFF targets." (#82889)
Reverts llvm/llvm-project#82642 for
lld/test/ELF/invalid/Output/data-encoding.test.tmp.a failures on
Windows.
2024-02-24 17:43:59 +01:00
Jacek Caban
cf9201cfdb
[llvm-ar] Use COFF archive format for COFF targets. (#82642)
Detect COFF files by default and allow specifying it with --format
argument.

This is important for ARM64EC, which uses a separated symbol map for EC
symbols. Since K_COFF is mostly compatible with K_GNU, this shouldn't
really make a difference for other targets.
2024-02-24 17:01:54 +01:00
Artem Tyurin
1901f442ca
[InstCombine] Handle more even/odd math functions (#81324)
At the moment this PR adds support only for `erf` function.

Fixes #77220.
2024-02-24 21:35:35 +08:00
Derek Schuff
ca09e08239
[Symbolizer][WebAssembly] Use wasm-specific getSymbolSize (#82083)
getSymbolSize was recently added to WasmObjectFile and has correct sizes 
for most symbol types. This makes llvm-symbolizer correctly symbolize
addresses in the middle of the symbol.

When reworking the test I also noticed that the DWARF info seems to be
wrong for the first instruction in each function. I noted that in the test
comments but didn't attempt to fix here.
2024-02-22 19:41:15 -08:00
Arthur Eubanks
91e9e31752
[NewPM/CodeGen] Rewrite pass manager nesting (#81068)
Currently the new PM infra for codegen puts everything into a
MachineFunctionPassManager. The MachineFunctionPassManager owns both
Module passes and MachineFunction passes, and batches adjacent
MachineFunction passes like a typical PassManager.

The current MachineFunctionAnalysisManager also directly references a
module and function analysis manager to get results.

The initial argument was that the codegen pipeline is relatively "flat",
meaning it's mostly machine function passes with a couple of module
passes here and there. However, there are a couple of issues with this
as compared to a more structured nesting more like the optimization
pipeline. For example, it doesn't allow running function passes then
machine function passes on a function and its machine function all at
once. It also currently requires the caller to split out the IR passes
into one pass manager and the MIR passes into another pass manager.

This patch rewrites the new pass manager infra for the codegen pipeline
to be more similar to the nesting in the optimization pipeline.
Basically, a Function contains a MachineFunction. So we can have Module
-> Function -> MachineFunction adaptors. It also rewrites the analysis
managers to have inner/outer proxies like the ones in the optimization
pipeline. The new pass managers/adaptors/analysis managers can be seen
in use in PassManagerTest.cpp.

This allows us to consolidate to just having to add to one
ModulePassManager when using the codegen pipeline.

I haven't added the Function -> MachineFunction adaptor in this patch,
but it should be added when we merge AddIRPass/AddMachinePass so that we
can run IR and MIR passes on a function before proceeding to the next
function.

The MachineFunctionProperties infra for MIR verification is still WIP.
2024-02-22 12:47:36 -08:00
Fangrui Song
26d71d9ed5
[llvm-readobj,ELF] Support --decompress/-z (#82594)
When a section has the SHF_COMPRESSED flag, -p/-x dump the compressed
content by default. In GNU readelf, if --decompress/-z is specified,
-p/-x will dump the decompressed content. This patch implements the
option.

Close #82507
2024-02-22 09:24:21 -08:00
Yury Gribov
6193233540
[AArch64] Fix sched model for TSV110 core. (#82343)
Accumulator operand of MADD instruction can be bypassed from another
MUL-like operation. Before this fix bypassing was incorrectly applied to
multiplier operand.

Co-authored-by: Yury Gribov <gribov.yuri@huawei.com>
2024-02-22 13:01:37 +03:00
Mingming Liu
0e8d1877cd
Revert type profiling change as compiler-rt test break on Windows. (#82583)
Examples
https://lab.llvm.org/buildbot/#/builders/127/builds/62532/steps/8/logs/stdio
2024-02-21 21:41:33 -08:00
Mingming Liu
db7e9e6841
[TypeProf][InstrPGO] Introduce raw and instr profile format change for type profiling. (#81691)
* Raw profile format
- Header: records the byte size of compressed vtable names, and the
number of profiled vtable entries (call it `VTableProfData`). Header
also records padded bytes of each section.
- Payload: adds a section for compressed vtable names, and a section to
store `VTableProfData`. Both sections are padded so the size is a
multiple of 8.
* Indexed profile format
  - Header: records the byte offset of compressed vtable names.
- Payload: adds a section to store compressed vtable names. This section
is used by `llvm-profdata` to show the list of vtables profiled for an
instrumented site.
  
[The originally reviewed
patch](https://github.com/llvm/llvm-project/pull/66825) will have
profile reader/write change and llvm-profdata change.
- To ensure this PR has all the necessary profile format change along
with profile version bump, created a copy of the originally reviewed
patch in https://github.com/llvm/llvm-project/pull/80761. The copy
doesn't have profile format change, but it has the set of tests which
covers type profile generation, profile read and profile merge. Tests
pass there.
  
rfc in
https://discourse.llvm.org/t/rfc-dynamic-type-profiling-and-optimizations-in-llvm/74600

---------

Co-authored-by: modiking <modiking213@gmail.com>
2024-02-21 20:59:42 -08:00
Fangrui Song
2167881f51 [ARM,MC] Support FDPIC relocations
Linux kernel fs/binfmt_elf_fdpic.c supports FDPIC for MMU-less systems.
GCC/binutils/qemu support FDPIC ABI for ARM
(https://github.com/mickael-guene/fdpic_doc).
_ARM FDPIC Toolchain and ABI_ provides a summary.

This patch implements FDPIC relocations to the integrated assembler.
There are 6 static relocations and 2 dynamic relocations, with
R_ARM_FUNCDESC as both static and dynamic.

gas requires `--fdpic` to assemble data relocations like `.word f(FUNCDESC)`.
This patch adds `MCTargetOptions::FDPIC` and reports an error if FDPIC
is not set.

Pull Request: https://github.com/llvm/llvm-project/pull/82187
2024-02-21 10:13:26 -08:00
Fangrui Song
ef28379022
[llvm-objcopy] Fix file offsets when PT_INTERP/PT_LOAD offsets are equal (#80562)
(#79887) When the offset of a PT_INTERP segment equals the offset of a
PT_LOAD segment, we consider that the parent of the PT_LOAD segment is
the PT_INTERP segment. In `layoutSegments`, we place both segments to be
after the current `Offset`, ignoring the PT_LOAD alignment.

This scenario is possible with fixed section addresses, but doesn't
happen with default linker layouts (.interp precedes other sections and
is part of a PT_LOAD segment containing the ELF header and program
headers).

```
% cat a.s
.globl _start; _start: ret
.rodata; .byte 0
.tdata; .balign 4096; .byte 0
% clang -fuse-ld=lld a.s -o a -nostdlib -no-pie -z separate-loadable-segments -Wl,-Ttext=0x201000,--section-start=.interp=0x202000,--section-start=.rodata=0x202020,-z,nognustack
% llvm-objcopy a a2
% llvm-readelf -l a2   # incorrect offset(PT_LOAD)
  Type           Offset   VirtAddr           PhysAddr           FileSiz  MemSiz   Flg Align
  PHDR           0x000040 0x0000000000200040 0x0000000000200040 0x0001c0 0x0001c0 R   0x8
  INTERP         0x001001 0x0000000000202000 0x0000000000202000 0x00001c 0x00001c R   0x1
      [Requesting program interpreter: /lib64/ld-linux-x86-64.so.2]
  LOAD           0x000000 0x0000000000200000 0x0000000000200000 0x000200 0x000200 R   0x1000
  LOAD           0x001000 0x0000000000201000 0x0000000000201000 0x000001 0x000001 R E 0x1000
//// incorrect offset
  LOAD           0x001001 0x0000000000202000 0x0000000000202000 0x000021 0x000021 R   0x1000
  LOAD           0x002000 0x0000000000203000 0x0000000000203000 0x000001 0x001000 RW  0x1000
  TLS            0x002000 0x0000000000203000 0x0000000000203000 0x000001 0x000001 R   0x1000
  GNU_RELRO      0x002000 0x0000000000203000 0x0000000000203000 0x000001 0x001000 R   0x1000
```

The same issue occurs for PT_TLS/PT_GNU_RELRO if we PT_TLS's alignment
is smaller and we place the PT_LOAD after PT_TLS/PT_GNU_RELRO segments
(not linker default, but possible with a `PHDRS` linker script command).

Fix #79887: when two segments have the same offset, order the one with a
larger alignment first. In the previous case, the PT_LOAD segment will
go before the PT_INTERP segment. In case of equal alignments, it doesn't
matter which segment is treated as the parent segment.
2024-02-20 09:26:04 -08:00
stephenpeckham
26db845536
[XCOFF] Support the subtype flag in DWARF section headers (#81667)
The section headers for XCOFF files have a subtype flag for Dwarf
sections. This PR updates obj2yaml, yaml2obj, and llvm-readobj so that
they recognize the subtype.
2024-02-20 08:42:12 -06:00
Frederic Cambus
a8d7511811
[llvm-readobj] Add support for the PT_OPENBSD_SYSCALLS segment type. (#82122)
Reference: https://github.com/openbsd/src/blob/master/sys/sys/exec_elf.h
2024-02-20 09:12:58 +01:00
Frederic Cambus
1b89486486
[llvm-objdump] Add support for the PT_OPENBSD_SYSCALLS segment type. (#82121)
Reference: https://github.com/openbsd/src/blob/master/sys/sys/exec_elf.h
2024-02-20 09:11:54 +01:00
Jonas Devlieghere
513d9f2395
[ptrauth] Teach LLVM & LLDB about LLVM_ptrauth_authentication_mode (#82272)
Teach LLVM & LLDB about `DW_AT_LLVM_ptrauth_authentication_mode`
2024-02-19 15:29:00 -08:00
Fangrui Song
cd20a7ff9a
[llvm-readelf] Print ARM specific OSABI values in GNU mode (#82186)
Similar to #75661. Currently, there is only ELFOSABI_ARM, but I plan to
add ELFOSABI_ARM_FDPIC in a subsequent patch #82187
2024-02-19 11:45:54 -08:00
Wentao Zhang
0bf4f82f66
[llvm-cov][CoverageView] minor fix/improvement to HTML and text coverage output (#80952)
1. add the missing condition for MC/DC in hasSubViews()
2. add style for selected line
3. remove name="Ln" attribute in the link within MC/DC views
4. remove color for \n
2024-02-16 23:24:31 -06:00
Lei Wang
24f025175d
[llvm-profgen] Filter out ambiguous cold profiles during profile generation (#81803)
For the built-in local initialization function(`__cxx_global_var_init`,
`__tls_init` prefix), there could be multiple versions of the functions
in the final binary, e.g. `__cxx_global_var_init`, which is a wrapper of
global variable ctors, the compiler could assign suffixes like
`__cxx_global_var_init.N` for different ctors.
However, in the profile generation, we call `getCanonicalFnName` to
canonicalize the names which strip the suffixes. Therefore, samples from
different functions queries the same profile(only
`__cxx_global_var_init`) and the counts are merged. As the functions are
essentially different, entries of the merged profile are ambiguous. In
sample loading, for each version of this function, the IR from one
version would be attributed towards a merged entries, which is
inaccurate, especially for fuzzy profile matching, it gets multiple
callsites(from different function) but using to match one callsite,
which mislead the matching and report a lot of false positives.
Hence, we want to filter them out from the profile map during the
profile generation time. The profiles are all cold functions, it won't
have perf impact.
2024-02-16 14:29:24 -08:00
Ulrich Weigand
3c02cb7492
[llvm-objcopy] Add SystemZ support (#81841)
This is also necessary for enabling ClangBuiltLinux:
https://github.com/ClangBuiltLinux/linux/issues/1530
2024-02-16 11:58:05 +01:00