TrivialMemoryManager currently doesn't check the return type of AllocateRWX --
and returns a 'null' MemoryBlock to its caller. As pointed out by Lang,
this exposes some serious issues with the MemoryManager interface. There's,
in fact, no way to report back an error to clients rather than aborting in
case memory can't be allocated. Eventually the interface will grow to support
this, but for now, fail sooner rather than later.
Differential Revision: http://reviews.llvm.org/D13627
llvm-svn: 250350
Recommit r250342: add -arch=ppc32 to the RUN lines of powerpc tests.
Some background on why we don't have to use *coal* sections anymore:
Long ago when C++ was new and "weak" had not been standardized, an attempt was
made in cctools to support C++ inlines that can be coalesced by putting them
into their own section (TEXT/textcoal_nt instead of TEXT/text).
The current macho linker supports the weak-def bit on any symbol to allow it to
be coalesced, but the compiler still puts weak-def functions/data into alternate
section names, which the linker must map back to the base section name.
This patch makes changes that are necessary to prevent the compiler from using
the "coal" sections and have it use the non-coal sections instead when the
target architecture is not powerpc:
TEXT/textcoal_nt instead use TEXT/text
TEXT/const_coal instead use TEXT/const
DATA/datacoal_nt instead use DATA/data
If the target is powerpc, we continue to use the *coal* sections since anyone
targeting powerpc is probably using an old linker that doesn't have support for
the weak-def bits.
Also, have the assembler issue a warning if it encounters a *coal* section in
the assembly file and inform the users to use the non-coal sections instead.
rdar://problem/14265330
Differential Revision: http://reviews.llvm.org/D13188
llvm-svn: 250349
Currently in JumpThreading pass, the branch weight metadata is not updated after CFG modification. Consider the jump threading on PredBB, BB, and SuccBB. After jump threading, the weight on BB->SuccBB should be adjusted as some of it is contributed by the edge PredBB->BB, which doesn't exist anymore. This patch tries to update the edge weight in metadata on BB->SuccBB by scaling it by 1 - Freq(PredBB->BB) / Freq(BB->SuccBB).
This is the third attempt to submit this patch, while the first two led to failures in some FDO tests. After investigation, it is the edge weight normalization that caused those failures. In this patch the edge weight normalization is fixed so that there is no zero weight in the output and the sum of all weights can fit in 32-bit integer. Several unit tests are added.
Differential revision: http://reviews.llvm.org/D10979
llvm-svn: 250345
If we have a series of branches which are all unlikely to fail, we can possibly combine them into a single check on the fastpath combined with a bit of dispatch logic on the slowpath. We don't want to do this unconditionally since it requires speculating instructions past a branch, but if the profiling metadata on the branch indicates profitability, this can reduce the number of checks needed along the fast path.
The canonical example this is trying to handle is removing the second bounds check implied by the Java code: a[i] + a[i+1]. Note that it can currently only do so for really simple conditions and the values of a[i] can't be used anywhere except in the addition. (i.e. the load has to have been sunk already and not prevent speculation.) I plan on extending this transform over the next few days to handle alternate sequences.
Differential Revision: http://reviews.llvm.org/D13070
llvm-svn: 250343
Some background on why we don't have to use *coal* sections anymore:
Long ago when C++ was new and "weak" had not been standardized, an attempt was
made in cctools to support C++ inlines that can be coalesced by putting them
into their own section (TEXT/textcoal_nt instead of TEXT/text).
The current macho linker supports the weak-def bit on any symbol to allow it to
be coalesced, but the compiler still puts weak-def functions/data into alternate
section names, which the linker must map back to the base section name.
This patch makes changes that are necessary to prevent the compiler from using
the "coal" sections and have it use the non-coal sections instead when the
target architecture is not powerpc:
TEXT/textcoal_nt instead use TEXT/text
TEXT/const_coal instead use TEXT/const
DATA/datacoal_nt instead use DATA/data
If the target is powerpc, we continue to use the *coal* sections since anyone
targeting powerpc is probably using an old linker that doesn't have support for
the weak-def bits.
Also, have the assembler issue a warning if it encounters a *coal* section in
the assembly file and inform the users to use the non-coal sections instead.
rdar://problem/14265330
Differential Revision: http://reviews.llvm.org/D13188
llvm-svn: 250342
This is a cleaned up patch from the one written by John Regehr based on the findings of the Souper superoptimizer.
The basic idea here is that input bits that are known zero reduce the maximum count that the intrinsic could return. We know that the number of bits required to represent a particular count is at most log2(N)+1.
Differential Revision: http://reviews.llvm.org/D13253
llvm-svn: 250338
If an argument for --entry is a number, that's not a symbol name but
an absolute address. If that's the case, the address is directly set
to ELF header's e_entry.
llvm-svn: 250334
CMake's set command overwrites existing values. Package maintainers may want or need to set the version variables manually, so we need to only set them if they are not already defined. Note I use the "if(NOT DEFINED ...)" syntax deliberately in the last case because empty string is a valid value for the suffx, but not the other variables.
llvm-svn: 250333
Most platforms have "/dev/null". Windows has "nul". Instead of
hardcoding the string /dev/null at various places, make a constant
that contains the correct value depending on the platform, and use
that everywhere instead.
llvm-svn: 250331
There were a couple of issues related to string handling that
needed to be fixed. In particular, we cannot get away with
converting `PyUnicode` objects to `PyBytes` objects and storing
the `PyBytes` regardless of Python version. Instead we have to
store a `PyUnicode` on Python 3 and a `PyString` on Python 2.
The reason for this is that if you call `PyObject_Str` on a
`PyBytes` in Python 3, it will return you a string that actually
contains the string value wrappedin the characters b''. So if we
create a `PythonString` with the value "test", and we call Str()
on it, we will get back the string "b'test'", which breaks string
equality. The only way to fix this is to store a native
`PyUnicode` object under Python 3.
With this CL, ScriptInterpreterPythonTests unit tests pass 100%
under Python 2 and Python 3.
llvm-svn: 250327
PR25157 identifies a bug where a load plus a vector shuffle is
incorrectly converted into an LXVDSX instruction. That optimization
is only valid if the load is of a doubleword, and in the noted case,
it was not. This corrects that problem.
Joint patch with Eric Schweitz, who provided the bugpoint-reduced test
case.
llvm-svn: 250324
We now use clang by default and fallback to gcc when requested.
With this commit, names reflect reality. No functional change
intended.
Discussed with: Rafael Espindola.
llvm-svn: 250321
Summary:
IDFCalculator used a DominatorTree instance for its calculations. Since the PostDominatorTree struct is not a subclass of DominatorTree, it wasn't possible to use PDT in IDFCalculator to compute post-dominance frontiers.
This patch makes IDFCalculator work with a DominatorTreeBase<BasicBlock> instead, which enables PDTs to be utilized.
Patch by Victor Campos (vhscampos@gmail.com)
Reviewers: dberlin
Subscribers: dberlin, llvm-commits
Differential Revision: http://reviews.llvm.org/D13725
llvm-svn: 250320
Summary:
Currently on most platforms you have to manually link the c++ abi library used with libc++ whenever you use libc++. So your typical libc++ command like invocation might look like:
```
clang++ -stdlib=libc++ foo.cpp -lc++abi
```
Having to manually link `libc++abi.so` makes it harder for libc++ to be used generically. This patch fixes that by generating a linker script for `libc++.so` that correctly links the ABI library. On linux the linker script for libc++abi would look like:
```
# libc++.so
INPUT(libc++.so.1 -lc++abi)
```
With the linker script you can now use libc++ using only `-stdlib=libc++`. This is the technique that is used on FreeBSD in ordered to link cxxrt and I think it's the best approach to make our users lives simpler.
The CMake option used to enable this is `LIBCXX_ENABLE_ABI_LINKER_SCRIPT`. In future I would like to enable this by default on all platforms except for Darwin.
Reviewers: mclow.lists, danalbert, rsmith, jroelofs, EricWF
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D12508
llvm-svn: 250319
We now rely on gcc only if either of the following is true:
1) -gcc option is passed by the user
2) clang is not found in the default path.
Differential Revision: http://reviews.llvm.org/D13642
llvm-svn: 250318
Previously, we used input section names as output section names.
That resulted that we created lots of sections for comdat
or -f{function,data}-section sections.
This patch reduces the number of sections by dropping suffix from
all section names which start with ".text.", ".rodata.", ".data."
or ".bss.". GNU linker does this using the internal linker script,
but for LLD I chose to do that directly.
Interestingly, this makes the linker faster. Time to link Clang
is this.
Before:
real 0m0.537s
user 0m0.433s
sys 0m0.104s
After:
real 0m0.390s
user 0m0.268s
sys 0m0.120s
It make sense because previously we created 57659 sections now only 27.
llvm-svn: 250315
This adds documentation for the binary profile encoding and moves the
documentation for the text encoding into the header file
SampleProfReader.h.
llvm-svn: 250309
Summary:
This patch changes the tests to use the "__config_site" header if present instead of manually configuring for each option. This patch also removes the test flags for configuring some of these options. For example "lit -sv --param=enable_threads=OFF" no longer works. However lit will still correctly configure if the CMake option "-DLIBCXX_ENABLE_THREADS=OFF" is given at build time.
This patch will fix the libc++abi test configuration for `LIBCXX_ABI_VERSION` and `LIBCXX_ABI_UNSTABLE` one we teach it about 'project_obj_dir' . I would like to land this ASAP to prevent more work blockage.
Reviewers: mclow.lists, danalbert, eugenis, ed, jroelofs
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D13714
llvm-svn: 250308
Python 3 reverses the order in which you must call Py_InitializeEx
and PyEval_InitThreads. Since that log is in itself already a
little nuanced, it is refactored into a function so that the reversal
is more clear. At the same time, there's a lot of logic during
Python initialization to save off a bunch of state and then restore
it after initialization is complete. To express this more cleanly,
it is refactored to an RAII-style pattern where state is saved off
on acquisition and restored on release.
llvm-svn: 250306
Richard Smith