Summary:
D4796 taught LLVM to fold some atomic integer operations into a single
instruction. The pattern was unaware that the instructions clobbered
flags.
This patch adds the missing EFLAGS definition.
Floating point operations don't set flags, the subsequent fadd
optimization is therefore correct. The same applies for surrounding
load/store optimizations.
Reviewers: rsmith, rtrieu
Subscribers: llvm-commits, reames, morisset
Differential Revision: http://reviews.llvm.org/D13680
llvm-svn: 250135
We model predefined declarations as not being from AST files, but in most ways
they act as if they come from some implicit prebuilt module file imported
before all others. Therefore, if we see an update to the predefined 'struct
__va_list_tag' declaration (and we've already loaded any modules), it needs a
corresponding update record, even though it didn't technically come from an AST
file.
llvm-svn: 250134
This basic combine was surprisingly missing.
AMDGPU legalizes many operations in terms of 32-bit vector components,
so not doing this results in many extra copies and subregister extracts
that need to be cleaned up later.
InstCombine already does this for the hasOneUse case. The target hook
is to fix a handful of tests which break (e.g. ARM/vmov.ll) which turn
from a vector materialize repeated immediate instruction to a constant
vector load with more scalar copies from it.
llvm-svn: 250129
Safestack runtime should never be linked on Android targets because
it is implemented directly in libc. This is already the case, but
mostly by chance (collectSanitizerRuntimes would only link shared
sanitizer runtimes, and safestack has only a static one). Protect
this behavior with a test.
llvm-svn: 250128
Under PPC64 ELF v1 ABI, the symbols associated with each function name don't
point directly to the code in the .text section (or similar), but rather to a
function descriptor structure in a special data section named .opd. The
elements in the .opd structure include a pointer to the actual code, and a the
relevant TOC base value. Both of these are themselves set by relocations.
When we have a local call, we need the relevant relocation to refer directly to
the target code, not to the function-descriptor in the .opd section. Only when
we have a .plt stub do we care about the address of the .opd function
descriptor itself.
So we make a few changes here:
1. Always write .opd first, so that its relocated data values are available
for later use when writing the text sections. Record a pointer to the .opd
structure, and its corresponding buffer.
2. When processing a relative branch relocation under ppc64, if the
destination points into the .opd section, read the code pointer out of the
function descriptor structure and use that instead.
This this, I can link, and run, a dynamically-compiled "hello world"
application on big-Endian PPC64/Linux (ELF v1 ABI) using lld.
llvm-svn: 250122
When lowering invoke statement, all unwind destinations are directly added as successors of call site block, and the weight of those new edges are not assigned properly. Actually, default weight 16 are used for those edges. This patch calculates the proper edge weights for those edges when collecting all unwind destinations.
Differential revision: http://reviews.llvm.org/D13354
llvm-svn: 250119
We have a number of functions that implement constant folding of vectors (unary and binary ops) in near identical manners (and the differences don't appear to be critical).
This patch introduces a common implementation (SelectionDAG::FoldConstantVectorArithmetic) and calls this in both the unary and binary op cases.
After this initial patch I intend to begin enabling vector constant folding for a wider number of opcodes in SelectionDAG::getNode().
Differential Revision: http://reviews.llvm.org/D13665
llvm-svn: 250118
that caused aborts. This was because of the characters of the ‘Size’ field in
the archive header did not contain decimal characters.
rdar://22983603
llvm-svn: 250117
Summary:
This check flags all usage of pointer arithmetic, because it could lead
to an
invalid pointer.
Subtraction of two pointers is not flagged by this check.
Pointers should only refer to single objects, and pointer arithmetic is
fragile and easy to get wrong. array_view is a bounds-checked, safe type
for accessing arrays of data.
This rule is part of the "Bounds safety" profile of the C++ Core
Guidelines, see
https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#-bounds1-dont-use-pointer-arithmetic-use-array_view-instead
Depends on D13313
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D13311
llvm-svn: 250116
Old version of sem_init (GLIBC_2.0) fails to initialize parts of
sem_t that are used in sem_timedwait. This is fixed in GLIBC_2.1,
but since ASan interceptors downgrade sem_* to the oldest available
version, this can introduce bugs that are only present in sanitized
build. Workaround by zero-initializing sem_t in sem_init.
llvm-svn: 250113
Under the PPC64 ELF ABI, functions that might call into other modules (and,
thus, need to load a different TOC base value into %r2), need to restore the
old value after the call. The old value is saved by the .plt code, and the
caller only needs to include a nop instruction after the call, which the linker
will transform into a TOC restore if necessary.
In order to do this the relocation handler needs two things:
1. It needs to know whether the call instruction it is modifying is targeting
a .plt stub that will load a new TOC base value (necessitating a restore after
the call).
2. It needs to know where the buffer ends, so that it does not accidentally
run off the end of the buffer when looking for the 'nop' instruction after the
call.
Given these two pieces of information, we can insert the restore instruction in
place of the following nop when necessary.
llvm-svn: 250110
As pointed out by Rui (post-commit review), we need to always return based on
the section type when the types differ to ensure a strict weak ordering.
llvm-svn: 250109
This is mostly an adaptation of the code in LLVM's
lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp, and handles a sufficient
number of relocations to link a 'hello world' program on big-Endian PPC64/Linux
(ELF v1 ABI).
llvm-svn: 250101
PPC64 has several special sections that are intended to be accessed from the
TOC base pointer. When a .got is present, the TOC base pointer is .got + 0x8000
(as specified by the ABI). Furthermore, the glibc startup code contains an
assumption that a 16-bit relocation can hold the offset from the TOC base value
to the beginning of the .toc section. Thus, we need to make sure that .toc
appears after .got. This much, at least, is required in practice. The other
PPC64 special sections (.toc, .toc1, .opd, etc.) should also be close by to
optimize access by smaller TOC-base-pointer offsets.
llvm-svn: 250100
Summary:
This check flags all usages of static_cast, where a base class is casted
to a derived class.
In those cases, a fixit is provided to convert the cast to a
dynamic_cast.
Use of these casts can violate type safety and cause the program to
access a variable that is actually of type X to be accessed as if it
were of an unrelated type Z.
This rule is part of the "Type safety" profile of the C++ Core
Guidelines, see
https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#-type2-dont-use-static_cast-downcasts-use-dynamic_cast-instead
Depends on D13313
Reviewers: alexfh, sbenza, bkramer, aaron.ballman
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D13368
llvm-svn: 250098
Add support for the `-fdebug-prefix-map=` option as in GCC. The syntax is
`-fdebug-prefix-map=OLD=NEW`. When compiling files from a path beginning with
OLD, change the debug info to indicate the path as start with NEW. This is
particularly helpful if you are preprocessing in one path and compiling in
another (e.g. for a build cluster with distcc).
Note that the linearity of the implementation is not as terrible as it may seem.
This is normally done once per file with an expectation that the map will be
small (1-2) entries, making this roughly linear in the number of input paths.
Addresses PR24619.
llvm-svn: 250094
This will allow us to optimize C++ template code with Polly. This support is
mostly for debugging purpose and individual experiments. The ultimate goal is
still to run Polly later in the pass manager when inlining already happened.
llvm-svn: 250092
instead of llvm::PassManagerBuilder::EP_EarlyAsPossible. This will allow us
to run actual module passes in Polly's canonicalization sequence, but should
otherwise have only little impact.
llvm-svn: 250091
This fixes a bug where one can take the address of a conditionally
enabled function to drop its enable_if guards. For example:
int foo(int a) __attribute__((enable_if(a > 0, "")));
int (*p)(int) = &foo;
int result = p(-1); // compilation succeeds; calls foo(-1)
Overloading logic has been updated to reflect this change, as well.
Functions with enable_if attributes that are always true are still
allowed to have their address taken.
Differential Revision: http://reviews.llvm.org/D13607
llvm-svn: 250090
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).
Differential revision: http://reviews.llvm.org/D10979
llvm-svn: 250089
We made them SP relative back in March (r233137) because that's the
value the runtime passes to EH functions. With the new cleanuppad IR,
funclets adjust their frame argument from SP to FP, so our offsets
should now be FP-relative.
llvm-svn: 250088
Function LowerVSETCC (in X86ISelLowering.cpp) worked under the wrong
assumption that for non-AVX512 targets, the source type and destination type
of a type-legalized setcc node were always the same type.
This assumption was unfortunately incorrect; the type legalizer is not always
able to promote the return type of a setcc to the same type as the first
operand of a setcc.
In the case of a vsetcc node, the legalizer firstly checks if the first input
operand has a legal type. If so, then it promotes the return type of the vsetcc
to that same type. Otherwise, the return type is promoted to the 'next legal
type', which, for vectors of MVT::i1 is always a 128-bit integer vector type.
Example (-mattr=+avx):
%0 = trunc <8 x i32> %a to <8 x i23>
%1 = icmp eq <8 x i23> %0, zeroinitializer
The initial selection dag for the code above is:
v8i1 = setcc t5, t7, seteq:ch
t5: v8i23 = truncate t2
t2: v8i32,ch = CopyFromReg t0, Register:v8i32 %vreg1
t7: v8i32 = build_vector of all zeroes.
The type legalizer would firstly check if 't5' has a legal type. If so, then it
would reuse that same type to promote the return type of the setcc node.
Unfortunately 't5' is of illegal type v8i23, and therefore it cannot be used to
promote the return type of the setcc node. Consequently, the setcc return type
is promoted to v8i16. Later on, 't5' is promoted to v8i32 thus leading to the
following dag node:
v8i16 = setcc t32, t25, seteq:ch
where t32 and t25 are now values of type v8i32.
Before this patch, function LowerVSETCC would have wrongly expanded the setcc
to a single X86ISD::PCMPEQ. Surprisingly, ISel was still able to match an
instruction. In our case, ISel would have matched a VPCMPEQWrr:
t37: v8i16 = X86ISD::VPCMPEQWrr t36, t25
However, t36 and t25 are both VR256, while the result type is instead of class
VR128. This inconsistency ended up causing the insertion of COPY instructions
like this:
%vreg7<def> = COPY %vreg3; VR128:%vreg7 VR256:%vreg3
Which is an invalid full copy (not a sub register copy).
Eventually, the backend would have hit an UNREACHABLE "Cannot emit physreg copy
instruction" in the attempt to expand the malformed pseudo COPY instructions.
This patch fixes the problem adding the missing logic in LowerVSETCC to handle
the corner case of a setcc with 128-bit return type and 256-bit operand type.
This problem was originally reported by Dimitry as PR25080. It has been latent
for a very long time. I have added the minimal reproducible from that bugzilla
as test setcc-lowering.ll.
Differential Revision: http://reviews.llvm.org/D13660
llvm-svn: 250085
NAKAMURA Takumi