These command line options are not intended for public use, and often
don't even make sense in the context of a particular tool anyway. About
90% of them are already hidden, but when people add new options they
forget to hide them, so if you were to make a brand new tool today, link
against one of LLVM's libraries, and run tool -help you would get a
bunch of junk that doesn't make sense for the tool you're writing.
This patch hides these options. The real solution is to not have
libraries defining command line options, but that's a much larger effort
and not something I'm prepared to take on.
Differential Revision: https://reviews.llvm.org/D40674
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@319505 91177308-0d34-0410-b5e6-96231b3b80d8
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store in PGO profile data to detect out-of-date profiles does not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the source will not cause compiler warnings about the profile being out
of date, and worse, we may continue to use the outdated profile data to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
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@318229 91177308-0d34-0410-b5e6-96231b3b80d8
The root cause of the issues reported in D32406 and D34680 is that clang
instruments functions without bodies. Make it stop doing that, and also
teach it how to use old (incorrectly generated) profiles without
crashing.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@306883 91177308-0d34-0410-b5e6-96231b3b80d8
In doing so, clean up the MD5 interface a little. Most
existing users only care about the lower 8 bytes of an MD5,
but for some users that care about the upper and lower,
there wasn't a good interface. Furthermore, consumers
of the MD5 checksum were required to handle endianness
details on their own, so it seems reasonable to abstract
this into a nicer interface that just gives you the right
value.
Differential Revision: https://reviews.llvm.org/D31105
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@298322 91177308-0d34-0410-b5e6-96231b3b80d8
2nd attempt: the first was in r296231, but it had a use after lifetime
bug.
Clang has logic to lower certain conditional expressions directly into llvm
select instructions. However, it does not emit the correct profile counter
increment as it does this: it emits an unconditional increment of the counter
for the 'then branch', even if the value selected is from the 'else branch'
(this is PR32019).
That means, given the following snippet, we would report that "0" is selected
twice, and that "1" is never selected:
int f1(int x) {
return x ? 0 : 1;
^2 ^0
}
f1(0);
f1(1);
Fix the problem by using the instrprof_increment_step intrinsic to do the
proper increment.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@296245 91177308-0d34-0410-b5e6-96231b3b80d8
Clang has logic to lower certain conditional expressions directly into
llvm select instructions. However, it does not emit the correct profile
counter increment as it does this: it emits an unconditional increment
of the counter for the 'then branch', even if the value selected is from
the 'else branch' (this is PR32019).
That means, given the following snippet, we would report that "0" is
selected twice, and that "1" is never selected:
int f1(int x) {
return x ? 0 : 1;
^2 ^0
}
f1(0);
f1(1);
Fix the problem by using the instrprof_increment_step intrinsic to do
the proper increment.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@296231 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r269492 as the corresponding LLVM commit was
reverted due to lots of warnings. See the review thread for the original
LLVM commit (r269491) for details.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@269549 91177308-0d34-0410-b5e6-96231b3b80d8
Write out the PGOFuncName meta data if PGOFuncName is different from function's
raw name. This should only apply to internal linkage functions. This is to be
consumed by indirect-call promotion when called in LTO optimization pass.
Differential Revision: http://reviews.llvm.org/D18624
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@267224 91177308-0d34-0410-b5e6-96231b3b80d8
Value profiling should not profile constants and/or constant
expressions when they appear as callees in call instructions.
Constant expressions form when a direct callee has bitcasts or
inttoptr(ptrtint (callee)) nests surrounding it. Value profiling
should avoid instrumenting such cases. Mostly NFC.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@265037 91177308-0d34-0410-b5e6-96231b3b80d8
For terminator instructions, the value profiling instrumentation
happens in a basic block other than where the value site resides.
This CR moves the instrumentation point prior to the value site.
Mostly NFC.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@264783 91177308-0d34-0410-b5e6-96231b3b80d8
This patch changes cc1 option -fprofile-instr-generate to an enum option
-fprofile-instrument={clang|none}. It also changes cc1 options
-fprofile-instr-generate= to -fprofile-instrument-path=.
The driver level option -fprofile-instr-generate and -fprofile-instr-generate=
remain intact. This change will pave the way to integrate new PGO
instrumentation in IR level.
Review: http://reviews.llvm.org/D16730
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@259811 91177308-0d34-0410-b5e6-96231b3b80d8
Coverage mapping data may reference names of functions
that are skipped by FE (e.g, unused inline functions). Since
those functions are skipped, normal instr-prof function lowering
pass won't put those names in the right section, so special
handling is needed to walk through coverage mapping structure
and recollect the references.
With this patch, only names that are skipped are processed. This
simplifies the lowering code and it no longer needs to make
assumptions coverage mapping data layout. It should also be
more efficient.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@257092 91177308-0d34-0410-b5e6-96231b3b80d8
NFC. These hints are only used for inlining and the inliner now uses
the same criteria to identify hot and cold callees and set appropriate
thresholds without relying on these hints. Hence this removed code is
superfluous.
Differential Revision: http://reviews.llvm.org/D15726
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@256793 91177308-0d34-0410-b5e6-96231b3b80d8
Constructors and destructors may be represented by several functions
in IR. Only base structors correspond to source code, others are
small pieces of code and eventually call the base variant. In this
case instrumentation of non-base structors has little sense, this
fix remove it. Now profile data of a declaration corresponds to
exactly one function in IR, it agrees with the current logic of the
profile data loading.
This change fixes PR24996.
Differential Revision: http://reviews.llvm.org/D15158
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@254876 91177308-0d34-0410-b5e6-96231b3b80d8
The pattern was born out of the lack of range-based for loops in C++98
and is somewhat obscure. No functionality change intended.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@241300 91177308-0d34-0410-b5e6-96231b3b80d8
The patch is generated using this command:
$ tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
-checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
work/llvm/tools/clang
To reduce churn, not touching namespaces spanning less than 10 lines.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@240270 91177308-0d34-0410-b5e6-96231b3b80d8
The fact that PGO has a say in how these branch weights are determined
isn't interesting to most of CodeGen, so it makes more sense for this
API to be accessible via CodeGenFunction rather than CodeGenPGO.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@236380 91177308-0d34-0410-b5e6-96231b3b80d8
No functional change. This just makes it more obvious that the logic
in ComputeRegionCounts only depends on the counter map and local
state.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@236370 91177308-0d34-0410-b5e6-96231b3b80d8
This removes the RegionCounter class, which is only used as a helper
in teh ComputeRegionCounts stmt visitor. This class is just an extra
layer of abstraction that makes the code harder to follow at this
point, and removing it makes the logic quite a bit more direct.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@236364 91177308-0d34-0410-b5e6-96231b3b80d8
We were assigning the counter for the body of the loop to the loop
variable initialization for some reason here, but our tests completely
lacked coverage for range-for loops. This fixes that and makes the
logic generally more similar to the logic for a regular for.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@236277 91177308-0d34-0410-b5e6-96231b3b80d8
We weren't setting regions as being unreachable after C++ throw
expressions, leading to incorrect count propagations.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@235967 91177308-0d34-0410-b5e6-96231b3b80d8
The RegionCounter type does a lot of legwork, but most of it is only
meaningful within the implementation of CodeGenPGO. The uses elsewhere
in CodeGen generally just want to increment or read counters, so do
that directly.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@235664 91177308-0d34-0410-b5e6-96231b3b80d8
We try to use the member variable "FuncName" here, but we've also used
that name as a parameter. This ends with us getting the length of the
function name wrong when we generate the coverage data.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@235565 91177308-0d34-0410-b5e6-96231b3b80d8
When we instrument a program for profiling, we copy the linkage of an
instrumented function so that our datastructures merge in the same way
as the function. This avoids redundant copies for things like
linkonce, but ends up emitting names we never need to reference for
normal and internal symbols. Promoting internal and external linkage
to private for these variables reduces the size overhead of profiling
drastically.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@232799 91177308-0d34-0410-b5e6-96231b3b80d8
Zachary Turner