Lifting from Bob Wilson's notes: The hash value that we compute and
store in PGO profile data to detect out-of-date profiles does not
include enough information. This means that many significant changes to
the source will not cause compiler warnings about the profile being out
of date, and worse, we may continue to use the outdated profile data to
make bad optimization decisions. There is some tension here because
some source changes won't affect PGO and we don't want to invalidate the
profile unnecessarily.
This patch adds a new hashing scheme which is more sensitive to loop
nesting, conditions, and out-of-order control flow. Here are examples
which show snippets which get the same hash under the current scheme,
and different hashes under the new scheme:
Loop Nesting Example
--------------------
// Snippet 1
while (foo()) {
while (bar()) {}
}
// Snippet 2
while (foo()) {}
while (bar()) {}
Condition Example
-----------------
// Snippet 1
if (foo())
bar();
baz();
// Snippet 2
if (foo())
bar();
else
baz();
Out-of-order Control Flow Example
---------------------------------
// Snippet 1
while (foo()) {
if (bar()) {}
baz();
}
// Snippet 2
while (foo()) {
if (bar())
continue;
baz();
}
In each of these cases, it's useful to differentiate between the
snippets because swapping their profiles gives bad optimization hints.
The new hashing scheme considers some logical operators in an effort to
detect more changes in conditions. This isn't a perfect scheme. E.g, it
does not produce the same hash for these equivalent snippets:
// Snippet 1
bool c = !a || b;
if (d && e) {}
// Snippet 2
bool f = d && e;
bool c = !a || b;
if (f) {}
This would require an expensive data flow analysis. Short of that, the
new hashing scheme looks reasonably complete, based on a scan over the
statements we place counters on.
Profiles which use the old version of the PGO hash remain valid and can
be used without issue (there are tests in tree which check this).
rdar://17068282
Differential Revision: https://reviews.llvm.org/D39446
llvm-svn: 318229
This updates -mcount to use the new attribute names (LLVM r318195), and
switches over -finstrument-functions to also use these attributes rather
than inserting instrumentation in the frontend.
It also adds a new flag, -finstrument-functions-after-inlining, which
makes the cygprofile instrumentation get inserted after inlining rather
than before.
Differential Revision: https://reviews.llvm.org/D39331
llvm-svn: 318199
This is a recommit of r312781; in some build configurations
variable names are omitted, so changed the new regression
test accordingly.
llvm-svn: 312794
This adds _Float16 as a source language type, which is a 16-bit floating point
type defined in C11 extension ISO/IEC TS 18661-3.
In follow up patches documentation and more tests will be added.
Differential Revision: https://reviews.llvm.org/D33719
llvm-svn: 312781
This patch adds a flag -fclang-abi-compat that can be used to request that
Clang attempts to be ABI-compatible with some older version of itself.
This is provided on a best-effort basis; right now, this can be used to undo
the ABI change in r310401, reverting Clang to its prior C++ ABI for pass/return
by value of class types affected by that change, and to undo the ABI change in
r262688, reverting Clang to using integer registers rather than SSE registers
for passing <1 x long long> vectors. The intent is that we will maintain this
backwards compatibility path as we make ABI-breaking fixes in future.
The reversion to the old behavior for r310401 is also applied to the PS4 target
since that change is not part of its platform ABI (which is essentially to do
whatever Clang 3.2 did).
llvm-svn: 311823
Discovered due to a goofy git setup, the test system-headerline-directive.c
(and a few others) failed because the token-consumption will consume only the
'\r' in CRLF, making the preprocessor's printed value give the wrong line number
when returning from an include. For example:
(line 1):#include <noline.h>\r\n
The "file exit" code causes the printer to try to print the 'returned to the
main file' line. It looks up what the current line number is. However, since the
current 'token' is the '\n' (since only the \r was consumed), it will give the
line number as '1", not '2'. This results in a few failed tests, but more
importantly, results in error messages being incorrect when compiling a
previously preprocessed file.
Differential Revision: https://reviews.llvm.org/D37079
llvm-svn: 311683
The original patch was an improvement to IR ValueTracking on non-negative
integers. It has been checked in to trunk (D18777, r284022). But was disabled by
default due to performance regressions.
Perf impact has improved. The patch would be enabled by default.
Reviewers: reames, hfinkel
Differential Revision: https://reviews.llvm.org/D34101
Patch by: Olga Chupina <olga.chupina@intel.com>
llvm-svn: 310582
Summary:
Tools like clang that use RemoveFileOnSignal on their output files
weren't actually able to clean up their outputs before this change. Now
the call to llvm::sys::fs::remove succeeds and the temporary file is
deleted. This is a stop-gap to fix clang before implementing the
solution outlined in PR34070.
Reviewers: davide
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D36337
llvm-svn: 310137
Summary:
Un-revert https://reviews.llvm.org/D34868, but with a slight tweak to the
documentation to fix an error -- I had used the wrong syntax for a link.
llvm-svn: 306948
Summary:
Depends on https://reviews.llvm.org/D34867.
Add a Clang frontend option to enable optimization remark hotness
thresholds, which were added to LLVM in https://reviews.llvm.org/D34867.
This prevents diagnostics that do not meet a minimum hotness
threshold from being output. When generating optimization remarks for large
codebases with a ton of cold code paths, this option can be used
to limit the optimization remark output at a reasonable size.
Discussion of this change can be read here:
http://lists.llvm.org/pipermail/llvm-dev/2017-June/114377.html
Reviewers: anemet, davidxl, hfinkel
Reviewed By: anemet
Subscribers: fhahn, cfe-commits
Differential Revision: https://reviews.llvm.org/D34868
llvm-svn: 306945
Summary:
Prior to this change, using `-fdiagnostics-show-hotness` with a sampling
profile specified via `-fprofile-sample-use=` would result in the Clang
frontend emitting a warning: "argument '-fdiagnostics-show-hotness' requires
profile-guided optimization information". Of course, a sampling profile
*is* profile-guided optimization information, so the warning is misleading.
Furthermore, despite the warning, hotness was displayed based on the data in
the sampling profile.
Prevent the warning from being emitted when a sampling profile is used, and
add a test that verifies this.
Reviewers: anemet, davidxl
Reviewed By: davidxl
Subscribers: danielcdh, cfe-commits
Differential Revision: https://reviews.llvm.org/D34082
llvm-svn: 306079
for preprocessing
r300667 added support for editor placeholder to Clang. That commit didn’t take
into account that users who use Clang for preprocessing only (-E) will get the
"editor placeholder in source file" error when preprocessing their source
(PR33394). This commit ensures that Clang doesn't lex editor placeholders when
running a preprocessor only action.
rdar://32718000
Differential Revision: https://reviews.llvm.org/D34256
llvm-svn: 305576
Also comes with a cmake cache for building the runtime bits:
$ cmake <normal cmake flags> \
-DBAREMETAL_ARMV6M_SYSROOT=/path/to/sysroot \
-DBAREMETAL_ARMV7M_SYSROOT=/path/to/sysroot \
-DBAREMETAL_ARMV7EM_SYSROOT=/path/to/sysroot \
-C /path/to/clang/cmake/caches/BaremetalARM.cmake \
/path/to/llvm
https://reviews.llvm.org/D33259
llvm-svn: 303873
This allows #line directives to appear in system headers that have code
that clang would normally warn on. This is compatible with GCC, which is
easy to test by running `gcc -E`.
Fixes PR30752
llvm-svn: 303582
Many of our supported configurations support modules but do not have any
first-class syntax to perform a module import. This leaves us with a problem:
there is no way to represent the expansion of a #include that imports a module
in the -E output for such languages. (We don't want to just leave it as a
#include because that requires the consumer of the preprocessed source to have
the same file system layout and include paths as the creator.)
This patch adds a new pragma:
#pragma clang module import MODULE.NAME.HERE
that imports a module, and changes -E and -frewrite-includes to use it when
rewriting a #include that maps to a module import. We don't make any attempt
to use a native language syntax import if one exists, to get more consistent
output. (If in the future, @import and #include have different semantics in
some way, the pragma will track the #include semantics.)
llvm-svn: 301725
We already prohibited this in most cases (in r130710), but had some bugs in our
enforcement of this rule. Specifically, this prevents the following
combinations:
* -x c -std=clN.M, which would previously effectively act as if -x cl were
used, despite the input being a C source file. (-x cl -std=cNN continues
to be disallowed.)
* -x c++ -std=cuda, which would previously select C++98 + CUDA, despite that
not being a C++ standard. (-x cuda -std=c++NN is still permitted, and
selects CUDA with the given C++ standard as its base language.
-x cuda -std=cuda is still supported with the meaning of CUDA + C++98.)
* -x renderscript -std=c++NN, which would previously form a hybrid "C++ with
RenderScript extensions" language. We could support such a thing, but
shouldn't do so by accident.
llvm-svn: 301497
This commit adds support for a new -iframeworkwithsysroot compiler option which
allows the user to specify a framework path that can be prefixed with the
sysroot. This option is similar to the -iwithsysroot option that exists to
supplement -isystem.
rdar://21316352
Differential Revision: https://reviews.llvm.org/D30183
llvm-svn: 297614
Summary:
This is a revised version of D28796. Included test is changed to
resolve the target compatibility issue reported (rL293032).
Reviewers: inglorion, dblaikie, echristo, aprantl, probinson
Reviewed By: inglorion
Subscribers: mehdi_amini, cfe-commits
Differential Revision: https://reviews.llvm.org/D30663
llvm-svn: 297194
This reverts commit r293004 because it broke the buildbots with "unknown CPU"
errors. I tried to fix it in r293026, but that broke on Green Dragon with this
kind of error:
error: expected string not found in input
// CHECK: l{{ +}}df{{ +}}*ABS*{{ +}}{{0+}}{{.+}}preprocessed-input.c{{$}}
^
<stdin>:2:1: note: scanning from here
/Users/buildslave/jenkins/sharedspace/incremental@2/clang-build/tools/clang/test/Frontend/Output/preprocessed-input.c.tmp.o: file format Mach-O 64-bit x86-64
^
<stdin>:2:67: note: possible intended match here
/Users/buildslave/jenkins/sharedspace/incremental@2/clang-build/tools/clang/test/Frontend/Output/preprocessed-input.c.tmp.o: file format Mach-O 64-bit x86-64
I suppose this means that llvm-objdump doesn't support Mach-O, so the test
should indeed check for linux (but not for x86). I'll leave it to someone that
knows better.
llvm-svn: 293032
This test broke on a lot of non-x86 buildbots with "unknowm CPU" errors. I don't
see anything platform-specific about this test, and it seems to work fine on ARM
if we just remove the -triple i686 flags from the run line.
llvm-svn: 293026
Summary:
Clang appears to always use name as specified on the command
line, whereas gcc uses the name as specified in the linemarker at the
first line when compiling a preprocessed source. This results mismatch
between two compilers in FILE symbol table entry. This patch makes clang
to resemble gcc's behavior in finding the original source file name and
use it as an input file name.
Even with this patch, values of FILE symbol table entry may still be
different because clang uses dirname+basename for the entry whlie gcc
uses basename only. I'll write a patch for that once this patch is
committed.
Reviewers: dblaikie, inglorion
Reviewed By: inglorion
Subscribers: inglorion, aprantl, bruno
Differential Revision: https://reviews.llvm.org/D28796
llvm-svn: 293004
Summary:
This patch enables the following
1. AMD family 17h architecture using "znver1" tune flag (-march, -mcpu).
2. ISAs that are enabled for "znver1" architecture.
3. Checks ADX isa from cpuid to identify "znver1" flag when -march=native is used.
4. ISAs FMA4, XOP are disabled as they are dropped from amdfam17.
5. For the time being, it uses the btver2 scheduler model.
6. Test file is updated to check this flag.
This is linked to llvm review item https://reviews.llvm.org/D28017
Patch by Ganesh Gopalasubramanian. Additional test cases added by Craig Topper.
Reviewers: RKSimon, craig.topper
Subscribers: cfe-commits, RKSimon, ashutosh.nema, llvm-commits
Differential Revision: https://reviews.llvm.org/D28018
llvm-svn: 291544
removed as a duplicate header search path
The commit r126167 started passing the First index into RemoveDuplicates, but
forgot to update 0 to First in the loop that looks for the duplicate. This
resulted in a bug where an -iquoted search path was incorrectly removed if you
passed in the same path into -iquote and more than one time into -isystem.
rdar://23991350
Differential Revision: https://reviews.llvm.org/D27298
llvm-svn: 288491
Other AST consumers can deserialize interesting decls that we might
codegen, but they won't make it to the final object file and can trigger
assertions in debug information generation after finalization.
llvm-svn: 288221
This commit adds a new predefined macro named __OBJC_BOOL_IS_BOOL that describes
the Objective-C boolean type: its value is zero if the Objective-C boolean uses
the signed character type, otherwise its value is one as the Objective-C boolean
uses the builtin boolean type.
rdar://21170440
Differential Revision: https://reviews.llvm.org/D26234
llvm-svn: 287529
This option behaves in a similar spirit as -save-temps and writes
internal llvm statistics in json format to a file.
Differential Revision: https://reviews.llvm.org/D24820
llvm-svn: 282426
Original commit message:
Add -fdiagnostics-show-hotness
Summary:
I've recently added the ability for optimization remarks to include the
hotness of the corresponding code region. This uses PGO and allows
filtering of the optimization remarks by relevance. The idea was first
discussed here:
http://thread.gmane.org/gmane.comp.compilers.llvm.devel/98334
The general goal is to produce a YAML file with the remarks. Then, an
external tool could dynamically filter these by hotness and perhaps by
other things.
That said it makes sense to also expose this at the more basic level
where we just include the hotness info with each optimization remark.
For example, in D22694, the clang flag was pretty useful to measure the
overhead of the additional analyses required to include hotness.
(Without the flag we don't even run the analyses.)
For the record, Hal has already expressed support for the idea of this
patch on IRC.
Differential Revision: https://reviews.llvm.org/D23284
llvm-svn: 281293
Summary:
I've recently added the ability for optimization remarks to include the
hotness of the corresponding code region. This uses PGO and allows
filtering of the optimization remarks by relevance. The idea was first
discussed here:
http://thread.gmane.org/gmane.comp.compilers.llvm.devel/98334
The general goal is to produce a YAML file with the remarks. Then, an
external tool could dynamically filter these by hotness and perhaps by
other things.
That said it makes sense to also expose this at the more basic level
where we just include the hotness info with each optimization remark.
For example, in D22694, the clang flag was pretty useful to measure the
overhead of the additional analyses required to include hotness.
(Without the flag we don't even run the analyses.)
For the record, Hal has already expressed support for the idea of this
patch on IRC.
Differential Revision: https://reviews.llvm.org/D23284
llvm-svn: 281276
Since some profiling tools, such as gprof, ftrace, and uftrace, use
-pg option to generate a mcount function call at the entry of each
function. Function invocation can be detected by this hook function.
But mcount insertion is done before function inlining phase in clang,
sometime a function that already has a mcount call can be inlined in the
middle of another function.
This patch adds an attribute "counting-function" to each function
rather than emitting the mcount call directly in frontend so that this
attribute can be processed in backend. Then the mcount calls can be
properly inserted in backend after all the other optimizations are
completed.
Link: https://llvm.org/bugs/show_bug.cgi?id=28660
Reviewers: hans, rjmccall, hfinkel, rengolin, compnerd
Subscribers: shenhan, cfe-commits
Differential Revision: https://reviews.llvm.org/D22666
llvm-svn: 280355
Vedant Kumar