We generate symbols like `profc`/`profd` for each function, and put them into csects.
When there are weak functions, we generate weak symbols for the functions as well,
with ELF (and some others), linker (binder) will discard and only keep one copy of the weak symbols.
However, on AIX, the current binder can NOT discard the weak symbols if we put all of them into the same csect,
as binder can NOT discard a subset of a csect.
This creates a unique challenge for using those symbols to calculate some relative offsets.
This patch changed the linkage of `profc`/`profd` symbols to be private, so that all the profc/profd for each weak symbol will be *local* to objects, and all kept in the csect, so we won't have problem. Although only one of the counters will be used, all the pointer in the profd is correct.
The downside is that we won't be able to discard the duplicated counters and profile data,
but those can not be discarded even if we keep the weak linkage,
due to the binder limitation of not discarding a subsect of the csect either .
Reviewed By: Whitney, MaskRay
Differential Revision: https://reviews.llvm.org/D110422
Skip stack accesses unless requested, as the memory profiler runtime
does not currently look at or report accesses for these addresses.
Differential Revision: https://reviews.llvm.org/D109868
Change the asan-module pass into a MODULE_PASS_WITH_PARAMS in the
pass registry, and add a single parameter called 'kernel' that
can be set instead of having a special pass name 'kasan-module'
to trigger that special pass config.
Main reason is to make sure that we have a unique mapping from
ClassName to PassName in the new passmanager framework, making it
possible to correctly identify the passes when dealing with options
such as -print-after and -print-pipeline-passes.
This is a follow-up to D105006 and D105007.
Split ThreadSanitizerPass into ThreadSanitizerPass (as a function
pass) and ModuleThreadSanitizerPass (as a module pass).
Main reason is to make sure that we have a unique mapping from
ClassName to PassName in the new passmanager framework, making it
possible to correctly identify the passes when dealing with options
such as -print-after and -print-pipeline-passes.
This is a follow-up to D105006 and D105007.
Split MemorySanitizerPass into MemorySanitizerPass (as a function
pass) and ModuleMemorySanitizerPass (as a module pass).
Main reason is to make sure that we have a unique mapping from
ClassName to PassName in the new passmanager framework, making it
possible to correctly identify the passes when dealing with options
such as -print-after and -print-pipeline-passes.
This is a follow-up to D105006 and D105007.
Added '-print-pipeline-passes' printing of parameters for those passes
declared with *_WITH_PARAMS macro in PassRegistry.def.
Note that it only prints the parameters declared inside *_WITH_PARAMS as
in a few cases there appear to be additional parameters not parsable.
The following passes are now covered (i.e. all of those with *_WITH_PARAMS in
PassRegistry.def).
LoopExtractorPass - loop-extract
HWAddressSanitizerPass - hwsan
EarlyCSEPass - early-cse
EntryExitInstrumenterPass - ee-instrument
LowerMatrixIntrinsicsPass - lower-matrix-intrinsics
LoopUnrollPass - loop-unroll
AddressSanitizerPass - asan
MemorySanitizerPass - msan
SimplifyCFGPass - simplifycfg
LoopVectorizePass - loop-vectorize
MergedLoadStoreMotionPass - mldst-motion
GVN - gvn
StackLifetimePrinterPass - print<stack-lifetime>
SimpleLoopUnswitchPass - simple-loop-unswitch
Differential Revision: https://reviews.llvm.org/D109310
This leads to a statistically significant improvement when using -hwasan-instrument-stack=0: https://bit.ly/3AZUIKI.
When enabling stack instrumentation, the data appears gets better but not statistically significantly so. This is consistent
with the very moderate improvements I have seen for stack safety otherwise, so I expect it to improve when the underlying
issue of that is resolved.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D108457
This is important as with exceptions enabled, non-POD allocas often have
two lifetime ends: the exception handler, and the normal one.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D108365
Similar to D97585.
D25456 used `S_ATTR_LIVE_SUPPORT` to ensure the data variable will be retained
or discarded as a unit with the counter variable, so llvm.compiler.used is
sufficient. It allows ld to dead strip unneeded profc and profd variables.
Reviewed By: vsk
Differential Revision: https://reviews.llvm.org/D105445
The implementation uses the int_asan_check_memaccess intrinsic to instrument the code. The intrinsic is replaced by a call to a function which performs the access check. The generated function names encode the input register name as a number using Reg - X86::NoRegister formula.
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D107850
The NS==0 condition used by D103717 missed a corner case: if the current copy
does not have a hash suffix (e.g. weak_odr), a copy with value profiling (with a
different CFG) may exist. This is super rare, but is possible with pre-inlining
PGO instrumentation (which can make a weak_odr function inlines its callees
differently, sometimes with value profiling while sometimes without).
If the current copy with private profd is prevailing, the non-prevailing copy
may get an undefined symbol if a caller inlining the non-prevailing function
references its profd. If the other copy with non-private profd is prevailing,
the current copy may cause a "relocation to discarded section" linker error.
The fix is straightforward: just keep non-private profd in such a `DataReferencedByCode` case.
With this change, a stage 2 (`-DLLVM_TARGETS_TO_BUILD=X86 -DLLVM_BUILD_INSTRUMENTED=IR`)
clang is 0.08% larger (172431496/172286720-1).
`stat -c %s **/*.o | awk '{s+=$1}END{print s}' is 0.026% larger.
The majority of D103717's benefits remains.
Reviewed By: xur
Differential Revision: https://reviews.llvm.org/D108432
This reverts commit f653beea88.
It broke Windows coverage-inline.cpp because link.exe has a limitation
that external symbols in IMAGE_COMDAT_SELECT_ASSOCIATIVE don't work.
It essentially dropped the previous size optimization for coverage
because coverage doesn't rename comdat by default.
Needs more investigation what we should do.
The NS==0 condition used by D103717 missed a corner case: if the current copy
does not have a hash suffix (e.g. weak_odr), a copy with value profiling (with a
different CFG) may exist. This is super rare, but is possible with pre-inlining
PGO instrumentation (which can make a weak_odr function inlines its callees
differently, sometimes with value profiling while sometimes without).
If the current copy with private profd is prevailing, the non-prevailing copy
may get an undefined symbol if a caller inlining the non-prevailing function
references its profd. If the other copy with non-private profd is prevailing,
the current copy may cause a "relocation to discarded section" linker error.
The fix is straightforward: just keep non-private profd in this case.
With this change, a stage 2 (`-DLLVM_TARGETS_TO_BUILD=X86 -DLLVM_BUILD_INSTRUMENTED=IR`)
clang is 0.08% larger (172431496/172286720-1).
`stat -c %s **/*.o | awk '{s+=$1}END{print s}' is 0.026% larger.
The majority of D103717's benefits remains.
Reviewed By: xur
Differential Revision: https://reviews.llvm.org/D108432
The implementation uses the int_asan_check_memaccess intrinsic to instrument the code. The intrinsic is replaced by a call to a function which performs the access check. The generated function names encode the input register name as a number using Reg - X86::NoRegister formula.
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D107850
The IRPGOFlag symbol (__llvm_profile_raw_version) is dropped when
identified as non-prevailing for either regular or thin LTO during
the mixed-LTO mode compilation. This happens in the module where
IRPGOFlag is marked as non-prevailing. This variable
is emitted in the final object from the prevailing module.
This is still problematic because we currently query this symbol
to coordinate some actions between PGOInstrumentation pass
and InstrProfiling lowering pass, like whether to do value
profiling, whether to do comdat renaming.
This problem is bought up by YolandaCY in
https://reviews.llvm.org/D107034
YolandCY reported unresolved symbol linker errors in
CSPGO instrumentation build for chromium.
This patch let LTO retain IRPGOFlag decl by adding it to
CompilerUsed list and relax the check in isIRPGOFlagSet() when
doing the InstrProfiling lowering.
The test case in the patch is from D107034
<https://reviews.llvm.org/D107034>.
Differential Revision: https://reviews.llvm.org/D108581
The COFF specific `DataReferencedByCode` complexity (D103372 D103717) is due to
a link.exe limitation: an external symbol in IMAGE_COMDAT_SELECT_ASSOCIATIVE is
not really dropped, so it can cause duplicate definition error.
Refactored implementation of AddressSanitizerPass and
HWAddressSanitizerPass to use pass options similar to passes like
MemorySanitizerPass. This makes sure that there is a single mapping
from class name to pass name (needed by D108298), and options like
-debug-only and -print-after makes a bit more sense when (despite
that it is the unparameterized pass name that should be used in those
options).
A result of the above is that some pass names are removed in favor
of the parameterized versions:
- "khwasan" is now "hwasan<kernel;recover>"
- "kasan" is now "asan<kernel>"
- "kmsan" is now "msan<kernel>"
Differential Revision: https://reviews.llvm.org/D105007
This very occasionally causes to an assertion failure in the compiler.
Turning off until we can get to the bottom of this.
Reviewed By: hctim
Differential Revision: https://reviews.llvm.org/D108282
AttributeList::hasAttribute() is confusing. In an attempt to change the
name to something that suggests using other methods, fix up some
existing uses.
When enable CSPGO for ThinLTO, there are profile cfg mismatch warnings that will cause lld-link errors (with /WX)
due to source changes (e.g. `#if` code runs for profile generation but not for profile use)
To disable it we have to use an internal "/mllvm:-no-pgo-warn-mismatch" option.
In contrast clang uses option ”-Wno-backend-plugin“ to avoid such warnings and gcc has an explicit "-Wno-coverage-mismatch" option.
Add "lto-pgo-warn-mismatch" option to lld COFF/ELF to help turn on/off the profile mismatch warnings explicitly when build with ThinLTO and CSPGO.
Differential Revision: https://reviews.llvm.org/D104431
When enable CSPGO for ThinLTO, there are profile cfg mismatch warnings that will cause lld-link errors (with /WX).
To disable it we have to use an internal "/mllvm:-no-pgo-warn-mismatch" option.
In contrast clang uses option ”-Wno-backend-plugin“ to avoid such warnings and gcc has an explicit "-Wno-coverage-mismatch" option.
Add this "lto-pgo-warn-mismatch" option to lld to help turn on/off the profile mismatch warnings explicitly when build with ThinLTO and CSPGO.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D104431
When none of the translation units in the binary have been instrumented
we shouldn't need to link the profile runtime. However, because we pass
-u__llvm_profile_runtime on Linux and Fuchsia, the runtime would still
be pulled in and incur some overhead. On Fuchsia which uses runtime
counter relocation, it also means that we cannot reference the bias
variable unconditionally.
This change modifies the InstrProfiling pass to pull in the profile
runtime only when needed by declaring the __llvm_profile_runtime symbol
in the translation unit only when needed. For now we restrict this only
for Fuchsia, but this can be later expanded to other platforms. This
approach was already used prior to 9a041a7522, but we changed it
to always generate the __llvm_profile_runtime due to a TAPI limitation,
but that limitation may no longer apply, and it certainly doesn't apply
on platforms like Fuchsia.
Differential Revision: https://reviews.llvm.org/D98061
Some files still contained the old University of Illinois Open Source
Licence header. This patch replaces that with the Apache 2 with LLVM
Exception licence.
Differential Revision: https://reviews.llvm.org/D107528
For a very large module, __llvm_gcov_reset can become very large.
__llvm_gcov_reset previously emitted stores to a bunch of globals in one
huge basic block. MemCpyOpt would turn many of these stores into
memsets, and updating MemorySSA would be extremely slow.
Verified that this makes the compile time of certain files go down
drastically (20min -> 5min).
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D107538
Rather than emitting the bias variable lazily as needed, emit it
eagerly. This allows profile runtime to refer to this variable
unconditionally without having to use the weak reference. The bias
variable is in a COMDAT so there'll never be more than one instance,
and if it's not needed, linker should be able to GC it, so the overhead
should be minimal.
Differential Revision: https://reviews.llvm.org/D107377
Kazu Hirata