This change is the first in a series of changes improving LLVM's Block
Frequency propogation implementation to not lose probability mass in
branchy code when propogating block frequency information from a basic
block to its successors. This patch is a simple infrastructure
improvement that does not actually modify the block frequency
algorithm. The specific changes are:
1. Changes the division algorithm used when scaling block frequencies by
branch probabilities to a short division algorithm. This gives us the
remainder for free as well as provides a nice speed boost. When I
benched the old routine and the new routine on a Sandy Bridge iMac with
disabled turbo mode performing 8192 iterations on an array of length
32768, I saw ~600% increase in speed in mean/median performance.
2. Exposes a scale method that returns a remainder. This is important so
we can ensure that when we scale a block frequency by some branch
probability BP = N/D, the remainder from the division by D can be
retrieved and propagated to other children to ensure no probability mass
is lost (more to come on this).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194950 91177308-0d34-0410-b5e6-96231b3b80d8
Including only Debug.h did not cause a compilation error, but you couldn't
do anything (like writing something with <<) to raw_ostreams returned by
llvm::dbgs() or llvm::errs() without including raw_ostream.h. So including
it from Debug.h should make sense.
Differential Revision: http://llvm-reviews.chandlerc.com/D2183
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194759 91177308-0d34-0410-b5e6-96231b3b80d8
- readInt() should check all 4 bytes can be read, not just 1.
- In the event of false data in the gcno file, it was possible to index
into a non-existent index of SmallVector, causing assertion error.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194639 91177308-0d34-0410-b5e6-96231b3b80d8
According to the hazy gcov documentation, it appeared to be technically
possible for lines within a block to belong to different source files.
However, upon further investigation, gcov does not actually support
multiple source files for a single block.
This change removes a level of separation between blocks and lines by
replacing the StringMap of GCOVLines with a SmallVector of ints
representing line numbers. This also means that the GCOVLines class is
no longer needed.
This paves the way for supporting the "-a" option, which will output
block information.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194637 91177308-0d34-0410-b5e6-96231b3b80d8
Unified the interface for read functions. They all return a boolean
indicating if the read from file succeeded. Functions that previously
returned the read value now store it into a variable that is passed in
by reference instead. Callers will need to check the return value to
detect if an error occurred.
Also added a new test which ensures that no assertions occur when file
contains invalid data. llvm-cov should return with error code 1 upon
failure.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194635 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r194485.
The variable is unused in some macro instantiations, but not others. We should
probably fix clang to not warn on this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194486 91177308-0d34-0410-b5e6-96231b3b80d8
One of the uses of the IsValid flag is to support default constructing
a ErrorOr that is not a Error or a Value. There is not much value in
doing that IMHO. If ErrorOr was to have a default constructor, it
should be implemented by default constructing the value, but even that
looks unnecessary.
The other use is to avoid calling destructors on moved objects. This
looks wrong. If the data being moved has non trivial treatment of
moves (an std::vector for example), it is its destructor that should
handle it, not ~ErrorOr.
With this change ErrorOr becomes a fairly simple wrapper and should
always be better than using an error_code + value in an API.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194109 91177308-0d34-0410-b5e6-96231b3b80d8
This patch enables llvm-cov to correctly output the run count stored in
the GCDA file. GCOVProfiling currently does not generate this
information, so the GCDA run data had to be hacked on from a GCDA file
generated by gcc. This is corrected by a subsequent patch.
With the run and program data included, both llvm-cov and gcov produced
the same output.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194033 91177308-0d34-0410-b5e6-96231b3b80d8
ErrorOr had quiet a bit of complexity and indirection to be able to hold a user
type with the error.
That feature is not used anymore. This patch removes it, it will live in svn
history if we ever need it again.
If we do need it again, IMHO there is one thing that should be done
differently: Holding extra info in the error is not a property a function also
returning a value or not. The ability to hold extra info should be in the error
type and ErrorOr templated over it so that we don't need the funny looking
ErrorOr<void>.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194030 91177308-0d34-0410-b5e6-96231b3b80d8
stack traces by default if you use PrettyStackTraceProgram, so that existing LLVM-based
tools will continue to get it without any changes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193971 91177308-0d34-0410-b5e6-96231b3b80d8
llvm-cov will now be able to read program counts from the GCDA file and
output it in the same format as gcov. The program summary tag was
identified from gcov-io.h as "\0\0\0\a3".
There is currently a bug in GCOVProfiling.cpp which does not generate
the
run- or program-counting IR, so this change was tested manually by
modifying the GCDA file and comparing the gcov and llvm-cov outputs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193389 91177308-0d34-0410-b5e6-96231b3b80d8
This was a fundamental flaw in llvm-cov where it treated the values in
the GCDA files as block counts instead of edge counts. This created
incorrect line counts when branching was present. Instead, the edge
counts should be summed to obtain the correct block count.
The fix was tested using custom test files as well as single source
files from the test-suite directory. The behaviour can be verified by
reading the GCOV documentation that describes the GCDA spec ("ARC_COUNTS
gives the counter values for those arcs that are instrumented") and the
header description provided by GCOVProfiling.cpp ("instruments the code
that runs to records (sic) the edges between blocks that run and emit a
complementary "gcda" file on exit").
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193299 91177308-0d34-0410-b5e6-96231b3b80d8
There are a few motivations for this:
- Using a map allows for checking if line is in map. This differentiates
unexecutable lines (such as comments) from unexecuted logical lines of
code. "#####" is now outputted in this case, in line with gcov.
- Source files are no longer read in twice: once when storing the line
counts, and once when outputting the data.
- Greatly simplifies the function FileInfo::addLineCount().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193264 91177308-0d34-0410-b5e6-96231b3b80d8
Line counts in llvm-cov are read in as 64-bit integers but were being truncated
to 32-bit in collectLineCounts(), which caused overflow for large counts.
This patch fixes all counts to be uint64_t.
Patch by Yuchen Wu!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193172 91177308-0d34-0410-b5e6-96231b3b80d8
- Replaced tabs with proper padding
- print() takes two arguments, which are the GCNO and GCDA filenames
- Files are listed at the top of output, appended by line 0
- Stripped strings of trailing \0s
- Removed last two lines of whitespace in output
Patch by Yuchen Wu!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193148 91177308-0d34-0410-b5e6-96231b3b80d8
This allows various variables to be more self-documenting and easier to
debug by being of specific types without overlapping enum values.
Precommit review by Eric Christopher.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193091 91177308-0d34-0410-b5e6-96231b3b80d8
Our use of -fvisibility-inlines-hidden means we cannot check function pointers
against non null values.
Unfortunately, we also cannot assert that the callbacks are initialized only
once. The problem is that lldb has multiple subsystems that need to call this
and they don't have a unique initialization order.
Thanks to Sean Callanan for reporting it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192835 91177308-0d34-0410-b5e6-96231b3b80d8
Before this patch we would assert when building llvm as multiple shared
libraries (cmake's BUILD_SHARED_LIBS). The problem was the line
if (T.AsmStreamerCtorFn == Target::createDefaultAsmStreamer)
which returns false because of -fvisibility-inlines-hidden. It is easy
to fix just this one case, but I decided to try to also make the
registration more strict. It looks like the old logic for ignoring
followup registration was just a temporary hack that outlived its
usefulness.
This patch converts the ifs to asserts, fixes the few cases that were
registering twice and makes sure all the asserts compare with null.
Thanks for Joerg for reporting the problem and reviewing the patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192803 91177308-0d34-0410-b5e6-96231b3b80d8
Some background: One can pass compiled resource files (.res files) directly
to the linker on Windows. If a resource file is given, the linker will run
"cvtres" command in background to convert the resource file to a COFF file
to link it.
What I'm trying to do with this patch is to make the linker to recognize
the resource file by file magic, so that it can run cvtres command.
Differential Revision: http://llvm-reviews.chandlerc.com/D1943
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192742 91177308-0d34-0410-b5e6-96231b3b80d8
This patch fixes an old FIXME by creating a MCTargetStreamer interface
and moving the target specific functions for ARM, Mips and PPC to it.
The ARM streamer is still declared in a common place because it is
used from lib/CodeGen/ARMException.cpp, but the Mips and PPC are
completely hidden in the corresponding Target directories.
I will send an email to llvmdev with instructions on how to use this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192181 91177308-0d34-0410-b5e6-96231b3b80d8
