12514 Commits

Author SHA1 Message Date
Stanislav Mekhanoshin
a8d9d50762 [AMDGPU] gfx90a support
Differential Revision: https://reviews.llvm.org/D96906
2021-02-17 16:01:32 -08:00
Rahman Lavaee
0252e6ead1 [obj2yaml,yaml2obj] Add NumBlocks to the BBAddrMapEntry yaml field.
As discussed in D95511, this allows us to encode invalid BBAddrMap
sections to be used in more rigorous testing.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D96831
2021-02-17 15:45:13 -08:00
Teresa Johnson
50ac3b1d78 [gold] Match lld WPD behavior for shared library symbols and add test
lld already marks shared library defs as ExportDynamic, which prevents
potentially unsafe devirtualization of symbols defined in shared
libraries. Match that behavior in the gold plugin, and add the same
test.

Depends on D96721.

Differential Revision: https://reviews.llvm.org/D96722
2021-02-17 15:28:49 -08:00
Alexander Shaposhnikov
cdcb60a820 [llvm-libtool] Emit warnings for files without symbols
1. Emit warnings for files without symbols.
2. Add -no_warning_for_no_symbols.

Test plan: make check-all

Differential revision: https://reviews.llvm.org/D95843
2021-02-16 17:52:12 -08:00
Simonas Kazlauskas
6ffcb2937c [llvm-dwp] Join dwo paths correctly when DWOPath is absolute
When the `DWOPath` is absolute, we want to use `DWOPath` as is, without prepending any other
components to the path. The `sys::path::append` does not join, but rather unconditionally appends
the paths, so something like `sys::path::append("/tmp", "/tmp/banana")` will result in
`/tmp/tmp/banana` rather than the desired `/tmp/banana`.

This then causes `llvm-dwp` to fail in a following situation:

```
$ clang -gsplit-dwarf /tmp/banana/test.c -c -o /tmp/outdir/foo.o
$ clang outdir/foo.o -o outdir/hm
$ llvm-dwarfdump outdir/hm | grep -C2 foo.dwo
                  DW_AT_comp_dir    ("/tmp")
                  DW_AT_GNU_pubnames  (true)
                  DW_AT_GNU_dwo_name    ("/tmp/outdir/foo.dwo")
                                DW_AT_GNU_dwo_id    (0xde4d396f3bf0e257)
                  DW_AT_low_pc  (0x0000000000401100)
$ strace -o trace llvm-dwp -e outdir/hm -o outdir/hm.dwp
error: No such file or directory
$ cat trace | grep foo.dwo
openat(AT_FDCWD, "/tmp/tmp/outdir/foo.dwo", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
```

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D96678
2021-02-16 13:38:35 -08:00
Sameer Sahasrabuddhe
11bf7da64a [NewPM] Introduce (GPU)DivergenceAnalysis in the new pass manager
The GPUDivergenceAnalysis is now renamed to just "DivergenceAnalysis"
since there is no conflict with LegacyDivergenceAnalysis. In the
legacy PM, this analysis can only be used through the legacy DA
serving as a wrapper. It is now made available as a pass in the new
PM, and has no relation with the legacy DA.

The new DA currently cannot handle irreducible control flow; its
presence can cause the analysis to run indefinitely. The analysis is
now modified to detect this and report all instructions in the
function as divergent. This is super conservative, but allows the
analysis to be used without hanging the compiler.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D96615
2021-02-16 10:26:45 +05:30
Fangrui Song
c465429f28 [llvm-objcopy] Delete --build-id-link-{dir,input,output}
The few options are niche. They solved a problem which was traditionally solved
with more shell commands (`llvm-readelf -n` fetches the Build ID. Then
`ln` is used to hard link the file to a directory derived from the Build ID.)

Due to limitation, they are no longer used by Fuchsia and they don't appear to
be used elsewhere (checked with Google Search and Debian Code Search). So delete
them without a transition period.

Announcement: https://lists.llvm.org/pipermail/llvm-dev/2021-February/148446.html

Differential Revision: https://reviews.llvm.org/D96310
2021-02-15 11:17:32 -08:00
James Henderson
94828afd0a [llvm-nm] Tidy up error messages
This adds colons to separate the file name from the message, removes a
duplicate space, and removes a trailing full stop from some messages.
These help bring the error messages into line with other tools, as well
as making all llvm-nm message more self-consistent.

Differential Revision: https://reviews.llvm.org/D96601

Reviewed by: Higuoxing, rupprecht, MaskRay
2021-02-15 13:54:08 +00:00
Kirill Bobyrev
eefd620a25
[llvm] NFC: Cleanup llvm-yaml-numeric-parser-fuzzer
* Use static variables instead of non-trivially destructible global ones.
* Remove unused header.

Differential Revision: https://reviews.llvm.org/D91600
2021-02-15 14:52:53 +01:00
Florian Hahn
c70737ba1d Recommit "[LTO] Use lto::backend for code generation."
This version of the patch includes a fix for the cfi failures.

(undoes the revert commit 7db390cc7738a9ba0ed7d4ca59ab6ea2e69c47e9)

It also undoes reverts of follow-up patches that also needed reverting
originally:

  * [LTO] Add option enable NewPM with LTOCodeGenerator.
    (undoes revert commit 0a17664b47c153aa26a0d31b4835f26375440ec6)

  * [LTOCodeGenerator] Use lto::Config for options (NFC)."
    (undoes revert commit b0a8e41cfff717ff067bf63412d6edb0280608cd)
2021-02-15 10:05:42 +00:00
Kazu Hirata
910e2d1e57 [llvm] Use llvm::is_contained (NFC) 2021-02-14 08:36:20 -08:00
Jian Cai
c2a84771bb [llvm-objcopy] preserve file ownership when overwritten by root
As of binutils 2.36, GNU strip calls chown(2) for "sudo strip foo" and
"sudo strip foo -o foo", but no "sudo strip foo -o bar" or "sudo strip
foo -o ./foo". In other words, while "sudo strip foo -o bar" creates a
new file bar with root access, "sudo strip foo" will keep the owner and
group of foo unchanged. Currently llvm-objcopy and llvm-strip behave
differently, always changing the owner and gropu to root. The
discrepancy prevents Chrome OS from migrating to llvm-objcopy and
llvm-strip as they change file ownership and cause intended users/groups
to lose access when invoked by sudo with the following sequence
(recommended in man page of GNU strip).

1.<Link the executable as normal.>
1.<Copy "foo" to "foo.full">
1.<Run "strip --strip-debug foo">
1.<Run "objcopy --add-gnu-debuglink=foo.full foo">

This patch makes llvm-objcopy and llvm-strip follow GNU's behavior.

Link: crbug.com/1108880
2021-02-12 18:01:43 -08:00
wlei
afd8bd601e [CSSPGO][llvm-profgen] Filter out the instructions without location info for symbolizer
It appears some instructions doesn't have the debug location info and the symbolizer will return an empty call stack for them which will cause some crash later in profile unwinding. Actually we do not record the sample info for them, so this change just filter out those instruction.

As those instruction would appears at the begin and end of the instruction list, without them we need to add the boundary check for IP `advance` and `backward`.

Also for pseudo probe based profile, we actually don't need the symbolized location info, so here just change to use an empty stack for it. This could save half of the binary loading time.

Differential Revision: https://reviews.llvm.org/D96434
2021-02-12 16:47:49 -08:00
James Y Knight
8bd8534aa3 LLVM-C: Allow LLVM{Get/Set}Alignment on an atomicrmw/cmpxchg instruction.
(Now that these can have alignment specified.)
2021-02-12 18:31:18 -05:00
wlei
426e326a19 [CSSPGO][llvm-profgen] Renovate perfscript check and command line input validation
This include some changes related with PerfReader's the input check and command line change:

1) It appears there might be thousands of leading MMAP-Event line in the perfscript for large workload. For this case, the 4k threshold is not eligible to determine it's a hybrid sample. This change renovated the `isHybridPerfScript` by going through the script without threshold limitation checking whether there is a non-empty call stack immediately followed by a LBR sample. It will stop once it find a valid one.

2) Added several input validations for the command line switches in PerfReader.

3) Changed the command line `show-disassembly` to `show-disassembly-only`, it will print to stdout and exit early which leave an empty output profile.

Reviewed By: hoy, wenlei

Differential Revision: https://reviews.llvm.org/D96387
2021-02-12 15:18:50 -08:00
Lukas Sommer
6577cef9b0 [CodeGen] New pass: Replace vector intrinsics with call to vector library
This patch adds a pass to replace calls to vector intrinsics (i.e., LLVM
intrinsics operating on vector operands) with calls to a vector library.

Currently, calls to LLVM intrinsics are only replaced with calls to vector
libraries when scalar calls to intrinsics are vectorized by the Loop- or
SLP-Vectorizer.

With this pass, it is now possible to replace calls to LLVM intrinsics
already operating on vector operands, e.g., if such code was generated
by MLIR. For the replacement, information from the TargetLibraryInfo,
e.g., as specified via -vector-library is used.

This is a re-try of the original commit 2303e93e66 that was reverted
due to pass manager problems. Other minor changes have also been made.

Differential Revision: https://reviews.llvm.org/D95373
2021-02-12 12:53:27 -05:00
Hongtao Yu
0b1914e83a [ThinLTO][gold] Fix filenaming scheme for tasks.
The gold LTO plugin uses a set of hooks to implements emit-llvm and capture intermediate file generated during LTO. The hooks are called by each lto backend thread with a taskID as argument to differentiate between threads and tasks. Currently, all threads are overwriting the same file which results into only the intermediate output of the last backend thread to be preserved. This diff encodes the taskID into the filename.

Reviewed By: tejohnson, wenlei

Differential Revision: https://reviews.llvm.org/D96173
2021-02-12 09:40:08 -08:00
Abhina Sreeskantharajan
fdb640ea30 Mark output as text if it is really text
This is a continuation of https://reviews.llvm.org/D67696. The following places need to set the OF_Text flag correctly.

Reviewed By: JDevlieghere

Differential Revision: https://reviews.llvm.org/D96363
2021-02-12 07:14:21 -05:00
Maxim Kuvyrkov
06f53f2f09 Fix exegesis build on aarch64-windows-msvc host
Include x86 intrinsics only when compiling for x86_64
or i386.  _MSC_VER no longer implies x86.

Reviewed By: gchatelet

Differential Revision: https://reviews.llvm.org/D96498
2021-02-12 09:50:22 +00:00
wlei
c3aeabaea1 [CSSPGO][llvm-profgen] Add brackets for context id to support extended binary format
To align with https://reviews.llvm.org/D95547, we need to add brackets for context id before initializing the `SampleContext`.

Also added test cases for extended binary format from llvm-profgen side.

Differential Revision: https://reviews.llvm.org/D95929
2021-02-12 01:14:53 -08:00
Arthur Eubanks
cee9869c4e [opt] Add helpful alternatives for -analyze under new PM
Reviewed By: reames

Differential Revision: https://reviews.llvm.org/D96449
2021-02-10 14:09:17 -08:00
Jameson Nash
a7db680183 Renovate CMake files in the llvm-exegesis tool.
This attempts to move all tools over to using `add_llvm_library` for
better consistency. After doing this, I noticed it ended up as nearly a
reimplementation of https://reviews.llvm.org/rL342148, which later got
reverted in r342336 (b09a8c9bd9b819741b38071a7ccd95042ef2643a).

With ccache and ninja on a large core machine (40), I haven't run into
build errors, so I'm hopeful it's better now, though it doesn't seem to
be any different / new.

Reviewed By: stephenneuendorffer

Differential Revision: https://reviews.llvm.org/D90970
2021-02-10 14:22:55 -05:00
Arthur Eubanks
5d960cba34 [opt][NewPM] Add a --print-passes flag to print all available passes
It seems nicer to list passes given a flag rather than displaying all
passes in opt --help.

This is awkwardly structured because a PassBuilder is required, but
reusing the PassBuilder in runPassPipeline() doesn't work because we
read the input IR before getting to runPassPipeline(). So printing the
list of passes needs to happen before reading the input IR. If we remove
the legacy PM code in main() and move everything from NewPMDriver.cpp
into opt.cpp, we can create the PassBuilder before reading IR and check
if we should print the list of passes and exit. But until then this hack
seems fine.

Compared to the legacy PM, the new PM passes are lacking descriptions.
We'll need to figure out a way to add descriptions if we think this is
important.

Also, this only works for passes specified in PassRegistry.def. If we
want to print other custom registered passes, we'll need a different
mechanism.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D96101
2021-02-10 11:22:12 -08:00
Arthur Eubanks
c2c977ce50 Specify that some flags are legacy PM-specific
Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D96100
2021-02-10 10:53:04 -08:00
Fangrui Song
4f30a3d3d2 [llvm-cfi-verify] Set UseSymbolTable to false
parseSectionContents expects to skip regions not described by DWARF.  With my
pending DebugInfo/Symbolize change, the filename can be recovered and there
will be more IndirectInstructions entries.
2021-02-10 09:44:13 -08:00
Todd Lipcon
747c450e6f
Fix JSON formatting when converting to trace event format
Reviewed By: dberris

Differential Revision: https://reviews.llvm.org/D96384
2021-02-10 13:00:28 +11:00
Alex Richardson
7dc3136033 [llvm-readobj] Add support for decoding FreeBSD ELF notes
The current support only printed coredump notes, but most binaries also
contain notes. This change adds names for four FreeBSD-specific notes and
pretty-prints three of them:

NT_FREEBSD_ABI_TAG:
This note holds a 32-bit (decimal) integer containing the value of the
__FreeBSD_version macro, which is defined in crt1.o and will hold a value
such as 1300076 for a binary build on a FreeBSD 13 system.

NT_FREEBSD_ARCH_TAG:
A string containing the value of the build-time MACHINE_ARCH

NT_FREEBSD_FEATURE_CTL: A 32-bit flag that indicates to the kernel that
the binary wants certain bevahiour. Examples include setting
NT_FREEBSD_FCTL_ASLR_DISABLE which tells the kernel to disable ASLR.

After this change llvm-readobj also no longer decodes coredump-only
FreeBSD notes in non-coredump files. I've also converted the
note-freebsd.s test to use yaml2obj instead of llvm-mc.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D74393
2021-02-09 16:59:22 +00:00
Alex Richardson
135df21248 [llvm-readelf] Print raw ELF note contents if we can't parse it
Currently, if the note name is known, but the value isn't we don't print
the contents.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D74367
2021-02-09 16:59:22 +00:00
Alex Richardson
d613d8eb0e [yaml2obj] Handle NT_* string values in for ELF note types
This is required for D74393.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D95953
2021-02-09 16:59:22 +00:00
Alex Richardson
f4670fbfff [llvm-readobj] Print empty line between note sections in GNU mode
This matches GNU binutils.

Reviewed By: rupprecht, jhenderson, MaskRay

Differential Revision: https://reviews.llvm.org/D96010
2021-02-09 16:59:21 +00:00
Jameson Nash
10c1d290d9 Revert "Renovate CMake files in the llvm-exegesis tool."
This reverts commit 549a1e2e59508d4aeaf9a93912b479798954bd5e.

I see some buildbot failures, so reverting while I look into them.
2021-02-08 19:12:08 -05:00
Jameson Nash
16e7973c5d Renovate CMake file for the llvm-cfi-verify tool
Hopefully this is the non-problematic part from https://reviews.llvm.org/rL342148, which later got reverted in r342336 (b09a8c9bd9b819741b38071a7ccd95042ef2643a) due to problems with the llvm-exegesis part of the change. That part would also still be desirable, but currently appears not to be possible (https://reviews.llvm.org/D81922).

I think this should replace https://reviews.llvm.org/D44650, per Keno's comment there.

Reviewed By: hctim

Differential Revision: https://reviews.llvm.org/D90969
2021-02-08 18:20:38 -05:00
Jameson Nash
549a1e2e59 Renovate CMake files in the llvm-exegesis tool.
This attempts to move all tools over to using `add_llvm_library` for
better consistency. After doing this, I noticed it ended up as nearly a
reimplementation of https://reviews.llvm.org/rL342148, which later got
reverted in r342336 (b09a8c9bd9b819741b38071a7ccd95042ef2643a).

With ccache and ninja on a large core machine (40), I haven't run into
build errors, so I'm hopeful it's better now, though it doesn't seem to
be any different / new.

Reviewed By: stephenneuendorffer

Differential Revision: https://reviews.llvm.org/D90970
2021-02-08 18:06:07 -05:00
Sanjay Patel
c981f6f8e1 Revert "[Codegen][ReplaceWithVecLib] add pass to replace vector intrinsics with calls to vector library"
This reverts commit 2303e93e666e13ebf6d24323729c28f520ecca37.
Investigating bot failures.
2021-02-05 15:10:11 -05:00
Lukas Sommer
2303e93e66 [Codegen][ReplaceWithVecLib] add pass to replace vector intrinsics with calls to vector library
This patch adds a pass to replace calls to vector intrinsics
(i.e., LLVM intrinsics operating on vector operands) with
calls to a vector library.

Currently, calls to LLVM intrinsics are only replaced with
calls to vector libraries when scalar calls to intrinsics are
vectorized by the Loop- or SLP-Vectorizer.

With this pass, it is now possible to replace calls to LLVM
intrinsics already operating on vector operands, e.g., if
such code was generated by MLIR. For the replacement,
information from the TargetLibraryInfo, e.g., as specified
via -vector-library is used.

Differential Revision: https://reviews.llvm.org/D95373
2021-02-05 14:25:19 -05:00
James Henderson
b0f4ffbfaa [llvm-objdump] Fix missing first line of license in header file 2021-02-05 08:45:50 +00:00
Dan Gohman
698c6b0a09 [WebAssembly] Support single-floating-point immediate value
As mentioned in TODO comment, casting double to float causes NaNs to change bits.
To avoid the change, this patch adds support for single-floating-point immediate value on MachineCode.

Patch by Yuta Saito.

Differential Revision: https://reviews.llvm.org/D77384
2021-02-04 18:05:06 -08:00
wlei
dd9e219014 [CSSPGO][llvm-profgen] Fix bug with parsing hybrid sample trace line
when we skip the call stack starting with an external address, we should also skip the bottom LBR entry, otherwise it will cause a truncated context issue.

Reviewed By: hoy, wenlei

Differential Revision: https://reviews.llvm.org/D95480
2021-02-04 16:15:05 -08:00
wlei
e10b73f646 [CSSPGO][llvm-profgen] Merge and trim profile for cold context to reduce profile size
This change allows merging and trimming cold context profile in llvm-profgen to solve profile size bloat problem. Currently when the profile's total sample is below threshold(supported by a switch), it will be considered cold and merged into a base context-less profile, which will at least keep the profile quality as good as the baseline(non-cs).

For example, two input profiles:
 [main @ foo @ bar]:60
 [main @ bar]:50
Under threshold = 100, the two profiles will be merge into one with the base context, get result:
 [bar]:110

Added two switches:
`--csprof-cold-thres=<value>`: Specified the total samples threshold for a context profile to be considered cold, with 100 being the default. Any cold context profiles will be merged into context-less base profile by default.
`--csprof-keep-cold`: Force profile generation to keep cold context profiles instead of dropping them. By default, any cold context will not be written to output profile.

Results:
Though not yet evaluating it with the latest CSSPGO, our internal branch shows neutral on performance but significantly reduce the profile size. Detailed evaluation on llvm-profgen with CSSPGO will come later.

Differential Revision: https://reviews.llvm.org/D94111
2021-02-04 11:05:03 -08:00
Peng Guo
91e7a17133 [NFC][llvm-mca] Fix compiler warning
Fix clang compiler warning from `-Wrange-loop-analysis`.

Reviewed By: andreadb

Differential Revision: https://reviews.llvm.org/D95997
2021-02-04 09:44:36 -08:00
Fangrui Song
eecbb1c776 [llvm-objdump] --source: drop the warning when there is no debug info
Warnings have been added for three cases (PR41905): (1) missing debug info, (2)
the source file cannot be found, (3) the debug info points at a line beyond the
end of the file.

(1) is probably less useful. This was brought up once on
http://lists.llvm.org/pipermail/llvm-dev/2020-April/141264.html and two
internal users mentioned it to me that it was annoying. (I personally
find the warning confusing, too.)

Users specify --source to get additional information if sources happen to be
available.  If sources are not available, it should be obvious as the output
will have no interleaved source lines. The warning can be especially annoying
when using llvm-objdump -S on a bunch of files.

This patch drops the warning when there is no debug info.
(If LLVMSymbolizer::symbolizeCode returns an `Error`, there will still be
an error. There is currently no test for an `Error` return value.
The only code path is probably a broken symbol table, but we probably already emit a warning
in that case)

`source-interleave-prefix.test` has an inappropriate "malformed" test - the test simply has no
.debug_* because new llc does not produce debug info when the filename is empty (invalid).
I have tried tampering the header of .debug_info/.debug_line but llvm-symbolizer does not warn.
This patch does not intend to add the missing test coverage.

Differential Revision: https://reviews.llvm.org/D88715
2021-02-04 09:07:44 -08:00
wlei
3869309a0c [CSSPGO][llvm-profgen] Aggregate samples on call frame trie to speed up profile generation
For CS profile generation, the process of call stack unwinding is time-consuming since for each LBR entry we need linear time to generate the context( hash, compression, string concatenation). This change speeds up this by grouping all the call frame within one LBR sample into a trie and aggregating the result(sample counter) on it, deferring the context compression and string generation to the end of unwinding.

Specifically, it uses `StackLeaf` as the top frame on the stack and manipulates(pop or push a trie node) it dynamically during virtual unwinding so that the raw sample can just be recoded on the leaf node, the path(root to leaf) will represent its calling context. In the end, it traverses the trie and generates the context on the fly.

Results:
Our internal branch shows about 5X speed-up on some large workloads in SPEC06 benchmark.

Differential Revision: https://reviews.llvm.org/D94110
2021-02-04 08:43:21 -08:00
wlei
ac14bb14e7 [CSSPGO][llvm-profgen] Compress recursive cycles in calling context
This change compresses the context string by removing cycles due to recursive function for CS profile generation. Removing recursion cycles is a way to normalize the calling context which will be better for the sample aggregation and also make the context promoting deterministic.
Specifically for implementation, we recognize adjacent repeated frames as cycles and deduplicated them through multiple round of iteration.
For example:
Considering a input context string stack:
[“a”, “a”, “b”, “c”, “a”, “b”, “c”, “b”, “c”, “d”]
For first iteration,, it removed all adjacent repeated frames of size 1:
[“a”, “b”, “c”, “a”, “b”, “c”, “b”, “c”, “d”]
For second iteration, it removed all adjacent repeated frames of size 2:
[“a”, “b”, “c”, “a”, “b”, “c”, “d”]
So in the end, we get compressed output:
[“a”, “b”, “c”, “d”]

Compression will be called in two place: one for sample's context key right after unwinding, one is for the eventual context string id in the ProfileGenerator.
Added a switch `compress-recursion` to control the size of duplicated frames, default -1 means no size limit.
Added unit tests and regression test for this.

Differential Revision: https://reviews.llvm.org/D93556
2021-02-03 22:16:07 -08:00
wlei
6bccdcdb35 Revert "[CSSPGO][llvm-profgen] Compress recursive cycles in calling context"
This reverts commit 0609f257dc2e2c3e4c7cd30fe2ffd520117e706b.
2021-02-03 22:16:05 -08:00
wlei
08e8bb60cf Revert "[CSSPGO][llvm-profgen] Aggregate samples on call frame trie to speed up profile generation"
This reverts commit 1714ad2336293f351b15dd4b518f9e8618ec38f2.
2021-02-03 22:16:05 -08:00
wlei
1714ad2336 [CSSPGO][llvm-profgen] Aggregate samples on call frame trie to speed up profile generation
For CS profile generation, the process of call stack unwinding is time-consuming since for each LBR entry we need linear time to generate the context( hash, compression, string concatenation). This change speeds up this by grouping all the call frame within one LBR sample into a trie and aggregating the result(sample counter) on it, deferring the context compression and string generation to the end of unwinding.

Specifically, it uses `StackLeaf` as the top frame on the stack and manipulates(pop or push a trie node) it dynamically during virtual unwinding so that the raw sample can just be recoded on the leaf node, the path(root to leaf) will represent its calling context. In the end, it traverses the trie and generates the context on the fly.

Results:
Our internal branch shows about 5X speed-up on some large workloads in SPEC06 benchmark.

Differential Revision: https://reviews.llvm.org/D94110
2021-02-03 18:50:14 -08:00
wlei
0609f257dc [CSSPGO][llvm-profgen] Compress recursive cycles in calling context
This change compresses the context string by removing cycles due to recursive function for CS profile generation. Removing recursion cycles is a way to normalize the calling context which will be better for the sample aggregation and also make the context promoting deterministic.
Specifically for implementation, we recognize adjacent repeated frames as cycles and deduplicated them through multiple round of iteration.
For example:
Considering a input context string stack:
[“a”, “a”, “b”, “c”, “a”, “b”, “c”, “b”, “c”, “d”]
For first iteration,, it removed all adjacent repeated frames of size 1:
[“a”, “b”, “c”, “a”, “b”, “c”, “b”, “c”, “d”]
For second iteration, it removed all adjacent repeated frames of size 2:
[“a”, “b”, “c”, “a”, “b”, “c”, “d”]
So in the end, we get compressed output:
[“a”, “b”, “c”, “d”]

Compression will be called in two place: one for sample's context key right after unwinding, one is for the eventual context string id in the ProfileGenerator.
Added a switch `compress-recursion` to control the size of duplicated frames, default -1 means no size limit.
Added unit tests and regression test for this.

Differential Revision: https://reviews.llvm.org/D93556
2021-02-03 18:50:14 -08:00
wlei
c82b24f475 [CSSPGO][llvm-profgen] Pseudo probe based CS profile generation
This change implements profile generation infra for pseudo probe in llvm-profgen. During virtual unwinding, the raw profile is extracted into range counter and branch counter and aggregated to sample counter map indexed by the call stack context. This change introduces the last step and produces the eventual profile. Specifically, the body of function sample is recorded by going through each probe among the range and callsite target sample is recorded by extracting the callsite probe from branch's source.

Please refer https://groups.google.com/g/llvm-dev/c/1p1rdYbL93s and https://reviews.llvm.org/D89707 for more context about CSSPGO and llvm-profgen.

**Implementation**

- Extended `PseudoProbeProfileGenerator` for pseudo probe based profile generation.
- `populateBodySamplesWithProbes` reading range counter is responsible for recording function body samples and inferring caller's body samples.
- `populateBoundarySamplesWithProbes` reading branch counter is responsible for recording call site target samples.
- Each sample is recorded with its calling context(named `ContextId`). Remind that the probe based context key doesn't include the leaf frame probe info, so the `ContextId` string is created from two part: one from the probe stack strings' concatenation and other one from the leaf frame probe.
- Added regression test

Test Plan:

ninja & ninja check-llvm

Differential Revision: https://reviews.llvm.org/D92998
2021-02-03 16:21:53 -08:00
Florian Hahn
7db390cc77
Revert "[LTO] Use lto::backend for code generation."
This reverts commit 6a59f0560648b43324b5aed51b9ef996404a25e0, because
it is causing failures on green dragon.
2021-02-03 22:49:30 +00:00
Florian Hahn
0a17664b47
Revert "[LTO] Add option enable NewPM with LTOCodeGenerator."
This reverts commit 7a6a2cc81aaf064e6f5bc9a9a16973f552d2bdc2 because
it is causing failures on green dragon.
2021-02-03 22:49:20 +00:00