Inlining functions with block addresses can cause many problem and requires a
rich infrastructure to support including escape analysis. At this point the
safest approach to address these problems is by blocking inlining from
happening.
Background:
There have been reports on Ruby segmentation faults triggered by inlining
functions with block addresses like
//Ruby code snippet
vm_exec_core() {
finish_insn_seq_0 = &&INSN_LABEL_finish;
INSN_LABEL_finish:
;
}
This kind of scenario can also happen when LLVM picks a subset of blocks for
inlining, which is the case with the actual code in the Ruby environment.
LLVM suppresses inlining for such functions when there is an indirect branch.
The attached patch does so even when there is no indirect branch. Note that
user code like above would not make much sense: using the global for jumping
across function boundaries would be illegal.
Why was there a segfault:
In the snipped above the block with the label is recognized as dead So it is
eliminated. Instead of a block address the cloner stores a constant (sic!) into
the global resulting in the segfault (when the global is used in a goto).
Why had it worked in the past then:
By luck. In older versions vm_exec_core was also inlined but the label address
used was the block label address in vm_exec_core. So the global jump ended up
in the original function rather than in the caller which accidentally happened
to work.
Test case ./tools/clang/test/CodeGen/indirect-goto.c will fail as a result
of this commit.
rdar://17245966
llvm-svn: 212077
In r212073 I missed a call of `use_begin()` that assumed the wrong
semantics. It's not clear to me at all what this code does without the
fix, so I'm not sure how to write a testcase.
llvm-svn: 212075
AArch64AddressTypePromotion was doing nothing because it was using the
old semantics of `Use` and `uses()`, when it really wanted to get at the
`users()`.
llvm-svn: 212073
This both improves basic debug info quality, but also fixes a larger
hole whenever we inline a call/invoke without a location (debug info for
the entire inlining is lost and other badness that the debug info
emission code is currently working around but shouldn't have to).
llvm-svn: 212065
Some versions of Android don't have futimes/futimens and this code wasn't
updated during the recent errc refactoring.
Patch by Luqman Aden!
llvm-svn: 212055
universal file. This also includes support for -arch all, selecting the host
architecture by default from a universal file and checking if -arch is used
with a standard Mach-O it matches that architecture.
llvm-svn: 212054
separate MDNode so they can be uniqued via folding set magic. To conserve
space, DIVariable nodes are still variable-length, with the last two
fields being optional.
No functional change.
http://reviews.llvm.org/D3526
llvm-svn: 212050
This patch adds support for a new builtin instruction called
__builtin_ia32_rdpmc.
Builtin '__builtin_ia32_rdpmc' is defined as a 'GCC builtin'; on X86, it can
be used to read performance monitoring counters. It takes as input the index
of the performance counter to read, and returns the value of the specified
performance counter as a 64-bit number.
Calls to this new builtin will map to instruction RDPMC.
The index in input to the builtin call is moved to register %ECX. The result
of the builtin call is the value of the specified performance counter (RDPMC
would return that quantity in registers RDX:RAX).
This patch:
- Adds builtin int_x86_rdpmc as a GCCBuiltin;
- Adds a new x86 DAG node called 'RDPMC_DAG';
- Teaches how to lower this new builtin;
- Adds an ISel pattern to select instruction RDPMC;
- Fixes the definition of instruction RDPMC adding %RAX and %RDX as
implicit definitions, and adding %ECX as implicit use;
- Adds a LLVM test to verify that the new builtin is correctly selected.
llvm-svn: 212049
This exception format is not specific to Windows x64. A similar approach is
taken on nearly all architectures. Generalise the name to reflect reality.
This will eventually be used for Windows on ARM data emission as well.
Switch the enum and namespace into an enum class.
llvm-svn: 212000
Rename the routines to reflect the reality that they are more related to call
frame information than to Win64 EH. Although EH is implemented in an intertwined
manner by augmenting with an exception handler and an associated parameter, the
majority of these routines emit information required to unwind the frames. This
also helps identify that these routines are generic for most windows platforms
(they apply equally to nearly all architectures except x86) although the
encoding of the information is architecture dependent.
Unwinding data is emitted via EmitWinCFI* and exception handling information via
EmitWinEH*.
llvm-svn: 211994
lowering for v16i8.
ASan and some bots caught this bug with existing test cases. Fixing it
even fixed a miscompile with one of the test cases. I'm still a bit
suspicious of this test case as I've not taken a proper amount of time
to think about it, but the fix here is strict goodness.
llvm-svn: 211976
These show up really frequently, not the least with actual splats. =] We
lowered these quite badly before. The new code path tries to widen i8
shuffles to i16 shuffles in a splat-like way. There are still some
inefficiencies in our i16 splat logic though, so we aren't really done
here.
Also, for certain patterns (bit of a gather-and-splat) we still
generate pretty silly code, and I've left a fixme for addressing it.
However, I'm not actually worried about this code pattern as much. The
old shuffle lowering generates a 29 instruction monstrosity for it that
should execute much more slowly.
llvm-svn: 211974
Make llvm-cov compatible with gcov for cases where multiple files are
specified on the command line. That is, loop over each one and report
coverage, and report errors on stderr only rather than via return
code.
llvm-svn: 211959
This patch adds a "-verify" mode to the llvm-rtdyld utility. In verify mode,
llvm-rtdyld will test supplied expressions against the linked program images
that it creates in memory. This scheme can be used to verify the correctness
of the relocation logic applied by RuntimeDyld.
The expressions to test will be read out of files passed via the -check option
(there may be more than one of these). Expressions to check are extracted from
lines of the form:
# rtdyld-check: <expression>
This system is designed to fit the llvm-lit regression test workflow. It is
format and target agnostic, and supports verification of images linked for
remote targets. The expression language is defined in
llvm/include/llvm/RuntimeDyldChecker.h . Examples can be found in
test/ExecutionEngine/RuntimeDyld.
llvm-svn: 211956
lowering.
For maximum irony, I had already discovered this bug, diagnosed it, and
left FIXMEs about it in the test cases. =[ I just failed to go back over
those until after i had reduced a bootstrap miscompile down to a single
TU, stared at the assembly for an hour, and figured out the bug. Again.
Oh well.
llvm-svn: 211955
