Currently, AnalyzeBranch() fails non-equality comparison between floating points
on X86 (see https://llvm.org/bugs/show_bug.cgi?id=23875). This is because this
function can modify the branch by reversing the conditional jump and removing
unconditional jump if there is a proper fall-through. However, in the case of
non-equality comparison between floating points, this can turn the branch
"unanalyzable". Consider the following case:
jne.BB1
jp.BB1
jmp.BB2
.BB1:
...
.BB2:
...
AnalyzeBranch() will reverse "jp .BB1" to "jnp .BB2" and then "jmp .BB2" will be
removed:
jne.BB1
jnp.BB2
.BB1:
...
.BB2:
...
However, AnalyzeBranch() cannot analyze this branch anymore as there are two
conditional jumps with different targets. This may disable some optimizations
like block-placement: in this case the fall-through behavior is enforced even if
the fall-through block is very cold, which is suboptimal.
Actually this optimization is also done in block-placement pass, which means we
can remove this optimization from AnalyzeBranch(). However, currently
X86::COND_NE_OR_P and X86::COND_NP_OR_E are not reversible: there is no defined
negation conditions for them.
In order to reverse them, this patch defines two new CondCode X86::COND_E_AND_NP
and X86::COND_P_AND_NE. It also defines how to synthesize instructions for them.
Here only the second conditional jump is reversed. This is valid as we only need
them to do this "unconditional jump removal" optimization.
Differential Revision: http://reviews.llvm.org/D11393
llvm-svn: 264199
The goal is to enhance this script to be used with opt and clang:
Group all of the regexes together, so it's easier to see what's going on.
This will make it easier to break main() up into pieces too.
Also, note that some of the regexes are for x86-specific asm.
llvm-svn: 264197
Summary:
Adds strnlen to the common interceptors, under the existing flag
intercept_strlen.
Removes the now-duplicate strnlen interceptor from asan and msan.
This adds strnlen to tsan, which previously did not intercept it.
Adds a new test of strnlen to the sanitizer_common test cases.
Reviewers: samsonov
Subscribers: zhaoqin, llvm-commits, kcc
Differential Revision: http://reviews.llvm.org/D18397
llvm-svn: 264195
If a comdat is dropped, all symbols in it are dropped.
If a comdat is kept, the symbols survive to pass regular symbol
resolution.
With this patch we do that for all global symbols.
The added test is a copy of test/tools/gold/X86/comdat.ll that we now
pass.
llvm-svn: 264192
This is necessary to support the dynamic CRT (/MD) with VS2015. In
VS2015, these symbols are no longer imported from a DLL, they provided
statically by msvcrt.lib. This means our approach of hotpatching the DLL
no longer works.
By exporting the symbols, we end up relying on the same mechanism that
we use to intercept symbols in the static CRT (/MT) case. The ASan
runtime always needs to appear first on the link line, and the linker
searches for symbol definitions from left to right. This means we can
stop hotpatching operator new and delete in the CRT, which is nice.
I think that the only reason we weren't exporting the symbols already is
because MSVC doesn't allow you to do it directly with
__declspec(dllexport). Instead, we can use
`#pragma comment(linker, "/export:foo")`, which is most of what the
attribute does under the hood. It does mean we have to write down the
mangled names of the operators, but that's not too bad.
llvm-svn: 264190
in the test suite. While this is not really an interesting tool and option to run
on a Mach-O file to show the symbol table in a generic libObject format
it shouldn’t crash.
The reason for the crash was in MachOObjectFile::getSymbolType() when it was
calling MachOObjectFile::getSymbolSection() without checking its return value
for the error case.
What makes this fix require a fair bit of diffs is that the method getSymbolType() is
in the class ObjectFile defined without an ErrorOr<> so I needed to add that all
the sub classes. And all of the uses needed to be updated and the return value
needed to be checked for the error case.
The MachOObjectFile version of getSymbolType() “can” get an error in trying to
come up with the libObject’s internal SymbolRef::Type when the Mach-O symbol
symbol type is an N_SECT type because the code is trying to select from the
SymbolRef::ST_Data or SymbolRef::ST_Function values for the SymbolRef::Type.
And it needs the Mach-O section to use isData() and isBSS to determine if
it will return SymbolRef::ST_Data.
One other possible fix I considered is to simply return SymbolRef::ST_Other
when MachOObjectFile::getSymbolSection() returned an error. But since in
the past when I did such changes that “ate an error in the libObject code” I
was asked instead to push the error out of the libObject code I chose not
to implement the fix this way.
As currently written both the COFF and ELF versions of getSymbolType()
can’t get an error. But if isReservedSectionNumber() wanted to check for
the two known negative values rather than allowing all negative values or
the code wanted to add the same check as in getSymbolAddress() to use
getSection() and check for the error then these versions of getSymbolType()
could return errors.
At the end of the day the error printed now is the generic “Invalid data was
encountered while parsing the file” for object_error::parse_failed. In the
future when we thread Lang’s new TypedError for recoverable error handling
though libObject this will improve. And where the added // Diagnostic(…
comment is, it would be changed to produce and error message
like “bad section index (42) for symbol at index 8” for this case.
llvm-svn: 264187
This should be hoisted further up so it can be used in DAGCombiner and other backends,
but I'm limiting the scope in the interest of patch minimalism.
It's not quite NFC because some of the replaced code was using an 'if' check rather
than a 'while' loop, so those cases would only look through a single bitcast.
llvm-svn: 264186
lambda-expression. We don't actually instantiate the closure type / operator()
in the template in order to produce the closure type / operator() in the
instantiation, so this isn't caught by the normal path.
llvm-svn: 264184
Instead of putting the /Yc header into ExtraDeps, give DependencyOutputOptions
a dedicated field for /Yc mode, and let HeaderIncludesCallback hang on to the
full DependencyOutputOptions object, not just ExtraDeps.
Reverts parts of r263352 that are now no longer needed.
llvm-svn: 264182
There are a few bugs in the walker that this patch addresses.
Primarily:
- Caching can break when we have multiple BBs without phis
- We weren't optimizing some phis properly
- Because of how the DFS iterator works, there were times where we
wouldn't cache any results of our DFS
I left the test cases with FIXMEs in, because I'm not sure how much
effort it will take to get those to work (read: We'll probably
ultimately have to end up redoing the walker, or we'll have to come up
with some creative caching tricks), and more test coverage = better.
Differential Revision: http://reviews.llvm.org/D18065
llvm-svn: 264180
Most things even work; see the included FIXMEs for things that need polishing.
Also don't warn about unused flags for the `/Yuh2.h /FIh1.h /FIh2.h`. The
common case is that the pch was built with `/Ych2.h /FIh1.h /FIh2.h`, so h1.h
is in the PCH, and we shouldn't warn about /FIh1.h not having an effect.
(If we wanted to get fancy, we could store the list of -include flags in the
pch and then check that it matches later on.)
llvm-svn: 264178
-H in gcc mode doesn't print -include headers, but they are included in
depfiles written by MMD and friends. Since /showIncludes is what's used instead
of depfiles, printing /FI there seems important (and matches cl.exe).
Instead of giving HeaderIncludeGen more options, just switch on ShowAllHeaders
in clang-cl mode and let clang::InitializePreprocessor() not put -include flags
in the <command line> block. This changes the behavior of -E slightly, and it
removes the <command line> flag from the output triggered by setting the
obscure CC_PRINT_HEADERS=1 env var to true while running clang. Both of these
seem ok to change.
http://reviews.llvm.org/D18401
llvm-svn: 264174
We were already copying this data to a temporary for endian swaps. Now
we just always copy it, but still only do the endian swaps when needed.
llvm-svn: 264172
Before this commit, we assert failure in ImplicitCastExpr
"unheralded conversion to bool". This commit fixes the assertion by using
the correct cast type when the fixed type is boolean.
This commit also fixes the behavior for Microsoft mode as well, since
Obj-C and Microsoft mode share the same code path.
rdar://24999533
llvm-svn: 264167
Have Visual Studio use MemoryBarrier() instead of _mm_mfence() and remove
__declspec align attribute from function parameters in kmp_atomic.h
llvm-svn: 264166
This patch adds ThreadSanitizer support into LLDB:
- Adding a new InstrumentationRuntime plugin, ThreadSanitizerRuntime, in the same way ASan is implemented.
- A breakpoint stops in `__tsan_on_report`, then we extract all sorts of information by evaluating an expression. We then populate this into StopReasonExtendedInfo.
- SBThread gets a new API, SBThread::GetStopReasonExtendedBacktraces(), which returns TSan’s backtraces in the form of regular SBThreads. Non-TSan stop reasons return an empty collection.
- Added some test cases.
Reviewed by Greg Clayton.
llvm-svn: 264162
Summary:
This changes the conversion functions from SCEV * to SCEVAddRecExpr from
ScalarEvolution and PredicatedScalarEvolution to return a SCEVAddRecExpr*
instead of a SCEV* (which removes the need of most clients to do a
dyn_cast right after calling these functions).
We also don't add new predicates if the transformation was not successful.
This is not entirely a NFC (as it can theoretically remove some predicates
from LAA when we have an unknown dependece), but I couldn't find an obvious
regression test for it.
Reviewers: sanjoy
Subscribers: sanjoy, mzolotukhin, llvm-commits
Differential Revision: http://reviews.llvm.org/D18368
llvm-svn: 264161
If we can't handle a relocation type, report it as an error in the source,
rather than asserting. I've added a more descriptive message and a test for the
only cases of this that I've been able to trigger.
Differential Revision: http://reviews.llvm.org/D18388
llvm-svn: 264156
This reverts commits r264068 and r264079, and they were breaking the build and
weren't reverted in time, nor they exhibited expected behaviour from the
reviewers. There is more to discuss than just a test fix.
llvm-svn: 264150
Cong Hou