When combining a pair of shuffle nodes, check if the combined shuffle mask is
trivially Undef. In case, immediately fold that pair of shuffles to Undef.
The lack of checks for undef masks was the root-cause of a poor-codegen bug
in the dag combiner.
Example:
%1 = shufflevector <4 x i32> %A, <4 x i32> %B, <4 x i32> <i32 4, i32 1, i32 1, i32 6>
%2 = shufflevector <4 x i32> %1, <4 x i32> undef, <4 x i32> <i32 0, i32 4, i32 1, i32 6>
%3 = shufflevector <4 x i32> %2, <4 x i32> undef, <4 x i32> <i32 1, i32 5, i32 3, i32 3>
Before this patch, on x86 (with -mcpu=corei7) we failed to fold the entire
sequence to Undef value and therefore we generated:
shufps $-123, %xmm1, $xmm0
pshufd $-46, %xmm0, %xmm0
With this patch, the entire shuffle sequence is folded to Undef and no
shuffles are generated in the output assembly.
Added new test cases to test 'combine-vec-shuffle-5.ll'.
llvm-svn: 215797
A byval object, even if allocated at a fixed offset (prescribed by the ABI) is
pointed to by IR values. Most fixed-offset stack objects are not pointed-to by
IR values, so the default is to assume this is not possible. However, we need
to override the default in this case (instruction scheduling can cause
miscompiles otherwise).
Fixes PR20280.
llvm-svn: 215795
We used to assume that any fixed-offset stack object was not aliased. This
meant that no IR value could point to the memory contained in such an object.
This is a reasonable default, but is not a universally-correct
target-independent fact. For example, on PowerPC (both Darwin and non-Darwin),
some byval arguments are allocated at fixed offsets by the ABI. These, however,
certainly can be pointed to by IR values. This change moves the 'isAliased'
logic out of FixedStackPseudoSourceValue and into MFI, and allows the isAliased
property to be overridden for fixed-offset objects.
This will be used by an upcoming commit to the PowerPC backend to fix PR20280.
No functionality change intended (the behavior of
FixedStackPseudoSourceValue::isAliased has been made more conservative for
callers that don't pass an MFI object, but I don't see any in-tree callers that
do that).
llvm-svn: 215794
On PPC/Darwin, byval arguments occur at fixed stack offsets in the callee's
frame, but are not immutable -- the pointer value is directly available to the
higher-level code as the address of the argument, and the value of the byval
argument can be modified at the IR level.
This is necessary, but not sufficient, to fix PR20280. When PR20280 is fixed in
a follow-up commit, its test case will cover this change.
llvm-svn: 215793
Previously lldbHost was built as multiple static libraries such as
lldbHostCommon, lldbHostLinux, etc. With this patch, the CMake
build produces only a single static library, lldbHost, whose file
set is dynamically created based on the platform.
llvm-svn: 215792
This reverts commit r215785 / 170ebf4f19459ae51a9561d0e65c87ee4c9b2c97.
LLD has some StringSavers that need to be updated. One of which takes a
lock and I need to investigate that more closely.
llvm-svn: 215791
This reverts commit r215784 / 3f8a26f6fe16cc76c98ab21db2c600bd7defbbaa.
LLD has 3 StringSaver's, one of which takes a lock when saving the
string... Need to investigate more closely.
llvm-svn: 215790
This fixes PR20671, see the bug for details. In short, ActOnTranslationUnit()
calls DefineUsedVTables() and only then PerformPendingInstantiations(). But
PerformPendingInstantiations() is what does delayed template parsing, so
vtables only references from late-parsed templates weren't marked used.
As a fix, move the SavePendingInstantiationsAndVTableUsesRAII in
PerformPendingInstantiations() up above the delayed template parsing code.
That way, vtables referenced from templates end up in the RAII object, and the
call to DefineUsedVTables() in PerformPendingInstantiations() marks them used.
llvm-svn: 215786
There is more cleanup to be done here. Once
llvm::sys::Process::GetArgumentVector is switched over to StringSaver,
we can simplify this code a fair amount.
llvm-svn: 215785
This class is generally useful.
In breaking it out, the primary change is that it has been made
non-virtual. It seems like being abstract led to there being 3 different
(2 in llvm + 1 in clang) concrete implementations which disagreed about
the ownership of the saved strings (see the manual call to free() in the
unittest StrDupSaver; yes this is different from the CommandLine.cpp
StrDupSaver which owns the stored strings; which is different from
Clang's StringSetSaver which just holds a reference to a
std::set<std::string> which owns the strings).
I've identified 2 other places in the
codebase that are open-coding this pattern:
memcpy(Alloc.Allocate<char>(strlen(S)+1), S, strlen(S)+1)
I'll be switching them over. They are
* llvm::sys::Process::GetArgumentVector
* The StringAllocator member of YAMLIO's Input class
This also will allow simplifying Clang's driver.cpp quite a bit.
Let me know if there are any other places that could benefit from
StringSaver. I'm also thinking of adding a saveStringRef member for
getting a stable StringRef.
llvm-svn: 215784
More specifically, this change can be summarized as follows:
1) Makes an lldbHostPosix library which contains code common to
all posix platforms.
2) Creates Host/FileSystem.h which defines a common FileSystem
interface.
3) Implements FileSystem.h in Host/windows and Host/posix.
4) Creates Host/FileCache.h, implemented in Host/common, which
defines a class useful for storing handles to open files needed
by the debugger.
Differential Revision: http://reviews.llvm.org/D4889
llvm-svn: 215775
Currently, if you use a MultiArg<> option, then printing out the help/usage
message will cause an assert. This fixes getOptionHelpName() to work with
MultiArg Options.
llvm-svn: 215770
A little test case simplification - this could be simplified further,
though there are certainly interesting connections to the if/else
construct so I'm hesitant to remove that entirely though it does appear
somewhat unrelated.
(similar fix to r215766, related to PR19864)
llvm-svn: 215768
This avoids debuggers stepping to strange places (like the last
statement in the loop body, or the first statement in the if).
This is not the whole answer, though - similar bugs no doubt exist in
other loops (patches to follow) and attributing exception handling code
to the correct line is also tricky (based on the previous fix to
PR19864, exception handling is still erroneously attributed to the 'if'
line).
llvm-svn: 215766
We were setting the comdat when functions were copied in the initial pass, but
not when they were linked only when we found out that they are needed.
llvm-svn: 215765
The darwin linker has an option, heavily used by Xcode, in which, instead
of listing all input files on the command line, the input file paths are
written to a text file and the path of that text file is passed to the linker
with the -filelist option (similar to @file).
In order to make test cases for this, I generalized the -test_libresolution
option to become -test_file_usage.
llvm-svn: 215762
This also suggests some refactoring to simplify this code. Basically, a
ton of complexity in this argument handling code comes from the need to
save const char *'s in stable storage for pushing onto argv.
It seems like llvm:🆑:StringSaver can be improved to cover all the
needs here.
llvm-svn: 215761
The floating-point value positive zero (+0.0) is a valid immedate value
according to isFPImmLegal. As a result AArch64 FastISel went ahead and
used the immediate version of fmov to materialize the constant.
The problem is that the immediate version of fmov cannot encode an imediate for
postive zero. Instead a fmov from the zero register was supposed to be used in
this case.
This fix adds handling for this special case and uses fmov from the zero
register to materialize a positive zero (negative zeroes go to the constant
pool).
There is no test case for this, because this code is currently dead. It will be
enabled in a future commit and I will add a test case in a separate commit
after that.
This fixes <rdar://problem/18027157>.
llvm-svn: 215753
Note: This reapplies r215582 without any modifications. The refactoring wasn't
responsible for the buildbot failures.
Original commit message:
Cleanup and prepare constant materialization code for future commits.
llvm-svn: 215752
The core logic in main() is actually pretty simple, but there's lots of
stuff that has been added over time which obscures the flow of the code.
In upcoming patches, I'll be pulling more stuff out of the main
codepath.
I'm open to naming suggestions for these helper functions.
llvm-svn: 215751
Andrea Di Biagio