Do not instrument direct accesses to stack variables that can be
proven to be inbounds, e.g. accesses to fields of structs on stack.
But it eliminates 33% of instrumentation on webrtc/modules_unittests
(number of memory accesses goes down from 290152 to 193998) and
reduces binary size by 15% (from 74M to 64M) and improved compilation time by 6-12%.
The optimization is guarded by asan-opt-stack flag that is off by default.
http://reviews.llvm.org/D7583
llvm-svn: 231241
Summary:
Use more reasonable names for these pseudo-instructions.
As there's only one definition tied to any one of these classes, I named them with abbreviated versions of their respective class' name.
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D7831
llvm-svn: 231240
Summary:
Move the "Filler" parameter to the end of the parameter list as it is,
conceptually, the only output parameter of that function.
Reviewers: dsanders
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D7726
llvm-svn: 231239
a flag for now.
First off, thanks to Daniel Jasper for really pointing out the issue
here. It's been here forever (at least, I think it was there when
I first wrote this code) without getting really noticed or fixed.
The key problem is what happens when two reasonably common patterns
happen at the same time: we outline multiple cold regions of code, and
those regions in turn have diamonds or other CFGs for which we can't
just topologically lay them out. Consider some C code that looks like:
if (a1()) { if (b1()) c1(); else d1(); f1(); }
if (a2()) { if (b2()) c2(); else d2(); f2(); }
done();
Now consider the case where a1() and a2() are unlikely to be true. In
that case, we might lay out the first part of the function like:
a1, a2, done;
And then we will be out of successors in which to build the chain. We go
to find the best block to continue the chain with, which is perfectly
reasonable here, and find "b1" let's say. Laying out successors gets us
to:
a1, a2, done; b1, c1;
At this point, we will refuse to lay out the successor to c1 (f1)
because there are still un-placed predecessors of f1 and we want to try
to preserve the CFG structure. So we go get the next best block, d1.
... wait for it ...
Except that the next best block *isn't* d1. It is b2! d1 is waaay down
inside these conditionals. It is much less important than b2. Except
that this is exactly what we didn't want. If we keep going we get the
entire set of the rest of the CFG *interleaved*!!!
a1, a2, done; b1, c1; b2, c2; d1, f1; d2, f2;
So we clearly need a better strategy here. =] My current favorite
strategy is to actually try to place the block whose predecessor is
closest. This very simply ensures that we unwind these kinds of CFGs the
way that is natural and fitting, and should minimize the number of cache
lines instructions are spread across.
It also happens to be *dead simple*. It's like the datastructure was
specifically set up for this use case or something. We only push blocks
onto the work list when the last predecessor for them is placed into the
chain. So the back of the worklist *is* the nearest next block.
Unfortunately, a change like this is going to cause *soooo* many
benchmarks to swing wildly. So for now I'm adding this under a flag so
that we and others can validate that this is fixing the problems
described, that it seems possible to enable, and hopefully that it fixes
more of our problems long term.
llvm-svn: 231238
This commit fixes a bug introduced in r230956 where we were creating
CMovFP_{T,F} nodes with multiple return value types (one for each operand).
With this change the return value type of the new node is the same as the
value type of the True/False operands of the original node.
llvm-svn: 231237
Setting it from the Target architecture cause problems when the target
archiutecture is filled just by examining the executable because in that
case the OS isn't set.
Differential revision: http://reviews.llvm.org/D8035
llvm-svn: 231234
The deadlock occurred when the Attach or the Launch operation failed for
any reason.
Differential revision: http://reviews.llvm.org/D8030
llvm-svn: 231231
In a CFG with the edges A->B->C and A->C, B is an optional branch.
LLVM's default behavior is to lay the blocks out naturally, i.e. A, B,
C, in order to improve code locality and fallthroughs. However, if a
function contains many of those optional branches only a few of which
are taken, this leads to a lot of unnecessary icache misses. Moving B
out of line can work around this.
Review: http://reviews.llvm.org/D7719
llvm-svn: 231230
Summary:
Symbol table generation code was failing to take into account the debug symbols because
the object file was looking only into its own section list when doing the generation, even though
the debug symbols from another object file were correctly detected and loaded by the
SymbolVendor. This changes the code to use the unified section list, which fixes this problem.
Test Plan:
I do not intend do submit this yet since it causes (or more like, exposes) the issue
in D7884, but I wanted to put this out here, so that anyone who wants to take a look at it can do
so. (And I also wanted to know if this is the right approach to the problem :).
Reviewers: clayborg, zturner
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D7913
llvm-svn: 231229
Summary:
Symbols in ELF files can be versioned, but LLDB currently does not understand these. This problem
becomes apparent once one loads glibc with debug info. Here (in the .symtab section) the versions
are embedded in the name (name@VERSION), which causes issues when evaluating expressions
referencing memcpy for example (current glibc contains memcpy@@GLIBC_2.14 and
memcpy@GLIBC_2.2.5).
This problem was not evident without debug symbols as the .dynsym section
stores the bare names and the actual versions are present in a separate section (.gnu.version_d),
which LLDB ignores. This resulted in two definitions of memcpy in the symbol table.
This patch adds support for storing annotated names to the Symbol class. If
Symbol.m_contains_linker_annotations is true then this symbol is annotated. Unannotated name can
be obtained by calling StripLinkerAnnotations on the corresponding ObjectFile. ObjectFileELF
implements this to strip @VERSION suffixes when requested. Symtab uses this function to add the
bare name as well as the annotated name to the name lookup table.
To preserve the size of the Symbol class, I had to steal one bit from the m_type field.
Test Plan:
This fixes TestExprHelpExamples.py when run with a glibc with debug symbols. Writing
an environment agnostic test case would require building a custom shared library with symbol
versions and testing symbol resolution against that, which is somewhat challenging.
Reviewers: clayborg, jingham
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D8036
llvm-svn: 231228
As is described at http://llvm.org/bugs/show_bug.cgi?id=22408, the GNU linkers
ld.bfd and ld.gold currently only support a subset of the whole range of AArch64
ELF TLS relocations. Furthermore, they assume that some of the code sequences to
access thread-local variables are produced in a very specific sequence.
When the sequence is not as the linker expects, it can silently mis-relaxe/mis-optimize
the instructions.
Even if that wouldn't be the case, it's good to produce the exact sequence,
as that ensures that linkers can perform optimizing relaxations.
This patch:
* implements support for 16MiB TLS area size instead of 4GiB TLS area size. Ideally clang
would grow an -mtls-size option to allow support for both, but that's not part of this patch.
* by default doesn't produce local dynamic access patterns, as even modern ld.bfd and ld.gold
linkers do not support the associated relocations. An option (-aarch64-elf-ldtls-generation)
is added to enable generation of local dynamic code sequence, but is off by default.
* makes sure that the exact expected code sequence for local dynamic and general dynamic
accesses is produced, by making use of a new pseudo instruction. The patch also removes
two (AArch64ISD::TLSDESC_BLR, AArch64ISD::TLSDESC_CALL) pre-existing AArch64-specific pseudo
SDNode instructions that are superseded by the new one (TLSDESC_CALLSEQ).
llvm-svn: 231227
Asserting that the source and destination iterators are from the same
region is unnecessary - there's no reason to disallow reassignment from
any regions, so long as they aren't compared.
llvm-svn: 231224
When trying to convert a BUILD_VECTOR into a shuffle, we try to split a single source vector that is twice as wide as the destination vector.
We can not do this when we also need the zero vector to create a blend.
This fixes PR22774.
Differential Revision: http://reviews.llvm.org/D8040
llvm-svn: 231219
Since OptionValue (& its base classes) have user-declared dtors, use of
the implicit copy ctor/assignment operator is deprecated in C++11.
Provide them explicitly (defaulted) to avoid depending on this
deprecated feature.
llvm-svn: 231218
These objects are never polymorphically owned, so there's no need for
virtual dtors - just make the dtor protected in the base classes, and
make the derived classes final.
llvm-svn: 231217
This will now display enum definitions both at the global
scope as well as nested inside of classes. Additionally,
it will no longer display enums at the global scope if the
enum is nested. Instead, it will omit the definition of
the enum globally and instead emit it in the corresponding
class definition.
llvm-svn: 231215
File objects are not really const in the resolver. We set ordinals to
them and call beforeLink hooks. Also, File's member functions marked
as const are not really const. ArchiveFile never returns the same
member file twice, so it remembers files returned before. find() has
side effects.
In order to deal with the inconsistencies, we sprinkled const_casts
and marked member varaibles as mutable.
This patch removes const from there to reflect the reality.
llvm-svn: 231212
GCC -pedantic produces a format warning when the "%p" specifier is used with
arguments that are not void*. It's useful for portability to be able to
catch such warnings with clang as well. The warning is off by default in
both gcc and with this patch. This patch enables it either when extensions
are disabled with -pedantic, or with the specific flag -Wformat-pedantic.
The C99 and C11 specs do appear to require arguments corresponding to 'p'
specifiers to be void*: "If any argument is not the correct type for the
corresponding conversion specification, the behavior is undefined."
[7.19.6.1 p9], and of the 'p' format specifier "The argument shall be a
pointer to void." [7.19.6.1 p8]
Both printf and scanf format checking are covered.
llvm-svn: 231211
(They are called emitDwarfDIE and emitDwarfAbbrevs in their new home)
llvm-dsymutil wants to reuse that code, but it doesn't have a DwarfUnit or
a DwarfDebug object to call those. It has access to an AsmPrinter though.
Having emitDIE in the AsmPrinter also removes the DwarfFile dependency
on DwarfDebug, and thus the patch drops that field.
Differential Revision: http://reviews.llvm.org/D8024
llvm-svn: 231210
Daniel Jasper