LLVM now has the ability to record information from optimization remarks in a
machine-consumable YAML file for later analysis. This can be enabled in opt
(see r282539), and D25225 adds a Clang flag to do the same. This patch adds
llvm-opt-report, a tool to generate basic optimization "listing" files
(annotated sources with information about what optimizations were performed)
from one of these YAML inputs.
D19678 proposed to add this capability directly to Clang, but this more-general
YAML-based infrastructure was the direction we decided upon in that review
thread.
For this optimization report, I focused on making the output as succinct as
possible while providing information on inlining and loop transformations. The
goal here is that the source code should still be easily readable in the
report. My primary inspiration here is the reports generated by Cray's tools
(http://docs.cray.com/books/S-2496-4101/html-S-2496-4101/z1112823641oswald.html).
These reports are highly regarded within the HPC community. Intel's compiler,
for example, also has an optimization-report capability
(https://software.intel.com/sites/default/files/managed/55/b1/new-compiler-optimization-reports.pdf).
$ cat /tmp/v.c
void bar();
void foo() { bar(); }
void Test(int *res, int *c, int *d, int *p, int n) {
int i;
#pragma clang loop vectorize(assume_safety)
for (i = 0; i < 1600; i++) {
res[i] = (p[i] == 0) ? res[i] : res[i] + d[i];
}
for (i = 0; i < 16; i++) {
res[i] = (p[i] == 0) ? res[i] : res[i] + d[i];
}
foo();
foo(); bar(); foo();
}
D25225 adds -fsave-optimization-record (and
-fsave-optimization-record=filename), and this would be used as follows:
$ clang -O3 -o /tmp/v.o -c /tmp/v.c -fsave-optimization-record
$ llvm-opt-report /tmp/v.yaml > /tmp/v.lst
$ cat /tmp/v.lst
< /tmp/v.c
2 | void bar();
3 | void foo() { bar(); }
4 |
5 | void Test(int *res, int *c, int *d, int *p, int n) {
6 | int i;
7 |
8 | #pragma clang loop vectorize(assume_safety)
9 V4,2 | for (i = 0; i < 1600; i++) {
10 | res[i] = (p[i] == 0) ? res[i] : res[i] + d[i];
11 | }
12 |
13 U16 | for (i = 0; i < 16; i++) {
14 | res[i] = (p[i] == 0) ? res[i] : res[i] + d[i];
15 | }
16 |
17 I | foo();
18 |
19 | foo(); bar(); foo();
I | ^
I | ^
20 | }
Each source line gets a prefix giving the line number, and a few columns for
important optimizations: inlining, loop unrolling and loop vectorization. An
'I' is printed next to a line where a function was inlined, a 'U' next to an
unrolled loop, and 'V' next to a vectorized loop. These are printed on the
relevant code line when that seems unambiguous, or on subsequent lines when
multiple potential options exist (messages, both positive and negative, from
the same optimization with different column numbers are taken to indicate
potential ambiguity). When on subsequent lines, a '^' is output in the relevant
column.
Annotated source for all relevant input files are put into the listing file
(each starting with '<' and then the file name).
You can disable having the unrolling/vectorization factors appear by using the
-s flag.
Differential Revision: https://reviews.llvm.org/D25262
llvm-svn: 283398
This adds a copy of the demangler in libcxxabi.
The code also has no dependencies on anything else in LLVM. To enforce
that I added it as another library. That way a BUILD_SHARED_LIBS will
fail if anyone adds an use of StringRef for example.
The no llvm dependency combined with the fact that this has to build
on linux, OS X and Windows required a few changes to the code. In
particular:
No constexpr.
No alignas
On OS X at least this library has only one global symbol:
__ZN4llvm16itanium_demangleEPKcPcPmPi
My current plan is:
Commit something like this
Change lld to use it
Change lldb to use it as the fallback
Add a few #ifdefs so that exactly the same file can be used in
libcxxabi to export abi::__cxa_demangle.
Once the fast demangler in lldb can handle any names this
implementation can be replaced with it and we will have the one true
demangler.
llvm-svn: 280732
This restores commit r278330, with fixes for a few bot failures:
- Fix a late change I had made to the save temps output file that I
missed due to existing files sitting on my disk
- Fix a bunch of Windows bot failures with "ambiguous call to overloaded
function" due to confusion between llvm::make_unique vs
std::make_unique (preface the new make_unique calls with "llvm::")
- Attempt to fix a modules bot failure by adding a missing include
to LTO/Config.h.
Original change:
Resolution-based LTO API.
Summary:
This introduces a resolution-based LTO API. The main advantage of this API over
existing APIs is that it allows the linker to supply a resolution for each
symbol in each object, rather than the combined object as a whole. This will
become increasingly important for use cases such as ThinLTO which require us
to process symbol resolutions in a more complicated way than just adjusting
linkage.
Patch by Peter Collingbourne.
Reviewers: rafael, tejohnson, mehdi_amini
Subscribers: lhames, tejohnson, mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D20268
llvm-svn: 278338
This reverts commit r278330.
I made a change to the save temps output that is causing issues with the
bots. Didn't realize this because I had older output files sitting on
disk in my test output directory.
llvm-svn: 278331
Summary:
This introduces a resolution-based LTO API. The main advantage of this API over
existing APIs is that it allows the linker to supply a resolution for each
symbol in each object, rather than the combined object as a whole. This will
become increasingly important for use cases such as ThinLTO which require us
to process symbol resolutions in a more complicated way than just adjusting
linkage.
Patch by Peter Collingbourne.
Reviewers: rafael, tejohnson, mehdi_amini
Subscribers: lhames, tejohnson, mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D20268
Address review comments
llvm-svn: 278330
Summary:
When this flag is specified, the target llvm-lto is not built, but is still
used as a dependency of the test targets. cmake 2.8 silently ignored this
situation, but with cmake_minimum_required(3.4) it becomes an error. Fix this
by avoiding the inclusion of the target as a dependency.
Reviewers: beanz
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D20882
llvm-svn: 271530
This is part of a new statistics gathering feature for the sanitizers.
See clang/docs/SanitizerStats.rst for further info and docs.
Differential Revision: http://reviews.llvm.org/D16174
llvm-svn: 257970
The module splitter splits a module into linkable partitions. It will
be used to implement parallel LTO code generation.
This initial version of the splitter does not attempt to deal with the
somewhat subtle symbol visibility issues around module splitting. These
will be dealt with in a future change.
Differential Revision: http://reviews.llvm.org/D12132
llvm-svn: 245662
llvm-lib is intended to be a lib.exe compatible utility that also
understands bitcode. The implementation lives in a library so that
lld can use it to implement /lib.
Differential Revision: http://reviews.llvm.org/D10297
llvm-svn: 239434
In r233009 we gained specific check-llvm-* build targets for invoking
specific parts of the test suite, but they were copying the
dependencies for check-all, rather than just listing the dependencies
for check-llvm.
This moves the creation of these targets next to the check-llvm
target, and uses that target's configuration rather than the check-all
config.
llvm-svn: 233174
This works in a similar way to the gold plugin tests. We search for a compatible
linker on $PATH and use it to run tests against our just-built libLTO. To start
with, test the just added opt level functionality.
Differential Revision: http://reviews.llvm.org/D8472
llvm-svn: 232785
I saw a failure on an internal bot, opened this file, saw it was missing,
thought "aha!", tried to land, got an "file is out of date", synced, didn't see
the file listed right above the line I added (cause I didn't add it in the
right place) and landed. Apologies!
llvm-svn: 224152
The goal of this tool is to replicate Darwin's dsymutil functionality
based on LLVM. dsymutil is a DWARF linker. Darwin's linker (ld64) does
not link the debug information, it leaves it in the object files in
relocatable form, but embbeds a `debug map` into the executable that
describes where to find the debug information and how to relocate it.
When releasing/archiving a binary, dsymutil is called to link all the DWARF
information into a `dsym bundle` that can distributed/stored along with
the binary.
With this commit, the LLVM based dsymutil is just able to parse the STABS
debug maps embedded by ld64 in linked binaries (and not all of them, for
example archives aren't supported yet).
Note that the tool directory is called dsymutil, but the executable is
currently called llvm-dsymutil. This discrepancy will disappear once the
tool will be feature complete. At this point the executable will be renamed
to dsymutil, but until then you do not want it to override the system one.
Differential Revision: http://reviews.llvm.org/D6242
llvm-svn: 224134
This tool lets us build LLVM components within the tree by setting up a
$GOPATH that resembles a tree fetched in the normal way with "go get".
It is intended that components such as the Go frontend will be built in-tree
using this tool.
Differential Revision: http://reviews.llvm.org/D5902
llvm-svn: 220462
Ugh. Turns out not even transformation passes link in how to read IR.
I sincerely believe the buildbots will finally agree with my system
after this though. (I don't really understand why all of this has been
working on my system, but not on all the buildbots.)
Create a new tool called llvm-uselistorder to use for verifying use-list
order. For now, just dump everything from the (now defunct)
-verify-use-list-order pass into the tool.
This might be a better way to test use-list order anyway.
Part of PR5680.
llvm-svn: 213957
Introducing llvm-profdata, a tool for merging profile data generated by
PGO instrumentation in clang.
- The name indicates a file extension of <name>.profdata. Eventually
profile data output by clang should be changed to that extension.
- llvm-profdata merges two profiles. However, the name is more general,
since it will likely pick up more tasks (such as summarizing a single
profile).
- llvm-profdata parses the current text-based format, but will be
updated once we settle on a binary format.
<rdar://problem/15949645>
llvm-svn: 201535
Hal Finkel