Existing code tended to assume that counters had type `uint64_t` and
computed size from the number of counters. Fix this code to directly
compute the counters size in number of bytes where possible. When the
number of counters is needed, use `__llvm_profile_counter_entry_size()`
or `getCounterTypeSize()`. In a later diff these functions will depend
on the profile mode.
Change the meaning of `DataSize` and `CountersSize` to make them more clear.
* `DataSize` (`CountersSize`) - the size of the data (counter) section in bytes.
* `NumData` (`NumCounters`) - the number of data (counter) entries.
Reviewed By: kyulee
Differential Revision: https://reviews.llvm.org/D116179
This patch changes the linkage type of a compiler-rt func
(__llvm_write_binary_ids) to fix the sanitizer-windows bot
build issue introduced in change f984ac271.
The issue is as the following:
C:\b\slave\sanitizer-windows\llvm-project\compiler-rt\lib\profile\InstrProfilingInternal.h(201):
error C2496: '__llvm_write_binary_ids': 'selectany' can only be applied
to data items with external linkage
We need the compiler generated variable to override the weak symbol of
the same name inside the profile runtime, but using LinkOnceODRLinkage
results in weak symbol being emitted in which case the symbol selected
by the linker is going to depend on the order of inputs which can be
fragile.
This change replaces the use of weak definition inside the runtime with
a weak alias. We place the compiler generated symbol inside a COMDAT
group so dead definition can be garbage collected by the linker.
We also disable the use of runtime counter relocation on Darwin since
Mach-O doesn't support weak external references, but Darwin already uses
a different continous mode that relies on overmapping so runtime counter
relocation isn't needed there.
Differential Revision: https://reviews.llvm.org/D105176
This avoids the test failure that was introduced in rG32bddad where
this function pulls in the rest of InstrProfilingFile.c which is
undesirable in use cases when profile runtime is being used without
the rest of libc.
This also allows additional cleanup by eliminating another variable
from platforms that don't need it.
Differential Revision: https://reviews.llvm.org/D76750
On Fuchsia, we always use the continuous mode with runtime counter
relocation, so there's no need for atexit hook or support for dumping
the profile manually.
Differential Revision: https://reviews.llvm.org/D76556
This is an alternative to the continous mode that was implemented in
D68351. This mode relies on padding and the ability to mmap a file over
the existing mapping which is generally only available on POSIX systems
and isn't suitable for other platforms.
This change instead introduces the ability to relocate counters at
runtime using a level of indirection. On every counter access, we add a
bias to the counter address. This bias is stored in a symbol that's
provided by the profile runtime and is initially set to zero, meaning no
relocation. The runtime can mmap the profile into memory at abitrary
location, and set bias to the offset between the original and the new
counter location, at which point every subsequent counter access will be
to the new location, which allows updating profile directly akin to the
continous mode.
The advantage of this implementation is that doesn't require any special
OS support. The disadvantage is the extra overhead due to additional
instructions required for each counter access (overhead both in terms of
binary size and performance) plus duplication of counters (i.e. one copy
in the binary itself and another copy that's mmapped).
Differential Revision: https://reviews.llvm.org/D69740
When writing out a profile, avoid allocating a page on the stack for the
purpose of writing out zeroes, as some embedded environments do not have
enough stack space to accomodate this.
Instead, use a small, fixed-size zero buffer that can be written
repeatedly.
For a synthetic file with >100,000 functions, I did not measure a
significant difference in profile write times. We are removing a
page-length zero-fill `memset()` in favor of several smaller buffered
`fwrite()` calls: in practice, I am not sure there is much of a
difference. The performance impact is only expected to affect the
continuous sync mode (%c) -- zero padding is less than 8 bytes in all
other cases.
rdar://57810014
Differential Revision: https://reviews.llvm.org/D71323
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
This includes a few nice bits of refactoring (e.g splitting out the
exclusive locking code into a common utility).
Hopefully the Windows support is fixed now.
Patch by Rainer Orth!
Differential Revision: https://reviews.llvm.org/D40944
llvm-svn: 320731
This includes a few nice bits of refactoring (e.g splitting out the
exclusive locking code into a common utility).
Patch by Rainer Orth!
Differential Revision: https://reviews.llvm.org/D40944
llvm-svn: 320726
The buildbots have shown that -Wstrict-prototypes behaves differently in GCC
and Clang so we should keep it disabled until Clang follows GCC's behaviour
llvm-svn: 312246
Clang 5 supports -Wstrict-prototypes. We should use it to catch any C
declarations that declare a non-prototype function.
rdar://33705313
Differential Revision: https://reviews.llvm.org/D36669
llvm-svn: 312240
Introduces a 'owner' struct to include the overridable write
method and the write context in C.
This allows easy introdution of new member API to help reduce
profile merge time in the follow up patch.
llvm-svn: 306432
The API is intended to be used by user to do fine
grained (per-region) control of profile dumping.
Differential Revision: http://reviews.llvm.org/D23106
llvm-svn: 278092
This is part-3 of the effort to eliminate dependency on
libc allocator in instr profiler runtime. With this change,
the profile dumper is completely free of malloc/calloc.
Value profile instr API implementation is the only remaining
piece with calloc dependency.
llvm-svn: 269576
With this change, dynamic memory allocation is only used
for testing purpose. This change is one of the many steps to
make instrument profiler dynamic allocation free.
llvm-svn: 269453
This reverts commit r268840, as it breaks Thumb2 self-hosting. There is something
unstable in the profiling for Thumb2 that needs to be sorted out before we continue
implementing these changes to the profiler. See PR27667.
llvm-svn: 268864
Extract the buffered filer writer code used by value profile
writer and turn it into common/sharable buffered fileIO
interfaces. Added a test case for the buffered file writer and
rewrite the VP dumping using the new APIs.
llvm-svn: 256604
The profile reader no longer depends on this field to be updated and point
to owning func's vp data. The VP data also no longer needs to be allocated
in a contiguous memory space.
Differential Revision: http://reviews.llvm.org/D15258
llvm-svn: 256543
(patch suggested by silvas)
With this patch, the IO information is wrapped in struct
ProfDataIOVec, and interface of writerCallback takes a vector
of IOVec and a pointer to writer context pointer.
Differential Revision: http://reviews.llvm.org/D14859
llvm-svn: 253764
On Darwin, compiler_rt uses magic linker symbols to find the profile
counters in the __DATA segment. This is a reasonable method for
normal, hosted, userspace programs. However programs with custom
memory layouts, such as the kernel, will need to tell compiler_rt
explicitly where to find these sections.
Patch by Lawrence D'Anna. Thanks!
llvm-svn: 223840
Ellis Hoag