__builtin_constant_p used to be short-cut evaluated to false when
building with -O0. This is undesirable as it means that constant folding
in the front-end can give different results than folding in the back-end.
It can also create conditional branches on constant conditions that don't
get folded away. With the pending improvements to the llvm.is.constant
handling on the LLVM side, the short-cut is no longer useful.
Adjust various codegen tests to not depend on the short-cut or the
backend optimisations.
Differential Revision: https://reviews.llvm.org/D67638
llvm-svn: 374742
The behavior from the original patch has changed, since we're no longer
allowing LLVM to just ignore the alignment. Instead, we're just
assuming the maximum possible alignment.
Differential Revision: https://reviews.llvm.org/D68824
llvm-svn: 374562
Summary:
If we insert them from function pass some analysis may be missing or invalid.
Fixes PR42877.
Reviewers: eugenis, leonardchan
Reviewed By: leonardchan
Subscribers: hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D68832
> llvm-svn: 374481
Signed-off-by: Vitaly Buka <vitalybuka@google.com>
llvm-svn: 374527
These intrinsics use llvm.cttz intrinsics so are always available
even without the bmi feature. We already don't check for the bmi
feature on the intrinsics themselves. But we were blocking the
include of the header file with _MSC_VER unless BMI was enabled
on the command line.
Fixes PR30506.
llvm-svn: 374516
Summary:
If we insert them from function pass some analysis may be missing or invalid.
Fixes PR42877.
Reviewers: eugenis, leonardchan
Reviewed By: leonardchan
Subscribers: hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D68832
llvm-svn: 374481
Just running -fsyntax-only over arm_neon.h doesn't cover some intrinsics
which are defined using macros. Add more test coverage for that.
arm-neon-header.c wasn't checking the full set of available NEON target
features; change the target architecture of the test to account for
that.
Fix the generator for arm_neon.h to generate casts in more cases where
they are necessary.
Fix VFMLAL_LOW etc. to express their signatures differently, so the
builtins have the expected type. Maybe the TableGen backend should
detect intrinsics that are defined the wrong way, and produce an error.
The rules here are sort of strange.
Differential Revision: https://reviews.llvm.org/D68743
llvm-svn: 374419
Summary:
Quote from http://eel.is/c++draft/expr.add#4:
```
4 When an expression J that has integral type is added to or subtracted
from an expression P of pointer type, the result has the type of P.
(4.1) If P evaluates to a null pointer value and J evaluates to 0,
the result is a null pointer value.
(4.2) Otherwise, if P points to an array element i of an array object x with n
elements ([dcl.array]), the expressions P + J and J + P
(where J has the value j) point to the (possibly-hypothetical) array
element i+j of x if 0≤i+j≤n and the expression P - J points to the
(possibly-hypothetical) array element i−j of x if 0≤i−j≤n.
(4.3) Otherwise, the behavior is undefined.
```
Therefore, as per the standard, applying non-zero offset to `nullptr`
(or making non-`nullptr` a `nullptr`, by subtracting pointer's integral value
from the pointer itself) is undefined behavior. (*if* `nullptr` is not defined,
i.e. e.g. `-fno-delete-null-pointer-checks` was *not* specified.)
To make things more fun, in C (6.5.6p8), applying *any* offset to null pointer
is undefined, although Clang front-end pessimizes the code by not lowering
that info, so this UB is "harmless".
Since rL369789 (D66608 `[InstCombine] icmp eq/ne (gep inbounds P, Idx..), null -> icmp eq/ne P, null`)
LLVM middle-end uses those guarantees for transformations.
If the source contains such UB's, said code may now be miscompiled.
Such miscompilations were already observed:
* https://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20190826/687838.html
* https://github.com/google/filament/pull/1566
Surprisingly, UBSan does not catch those issues
... until now. This diff teaches UBSan about these UB's.
`getelementpointer inbounds` is a pretty frequent instruction,
so this does have a measurable impact on performance;
I've addressed most of the obvious missing folds (and thus decreased the performance impact by ~5%),
and then re-performed some performance measurements using my [[ https://github.com/darktable-org/rawspeed | RawSpeed ]] benchmark:
(all measurements done with LLVM ToT, the sanitizer never fired.)
* no sanitization vs. existing check: average `+21.62%` slowdown
* existing check vs. check after this patch: average `22.04%` slowdown
* no sanitization vs. this patch: average `48.42%` slowdown
Reviewers: vsk, filcab, rsmith, aaron.ballman, vitalybuka, rjmccall, #sanitizers
Reviewed By: rsmith
Subscribers: kristof.beyls, nickdesaulniers, nikic, ychen, dtzWill, xbolva00, dberris, arphaman, rupprecht, reames, regehr, llvm-commits, cfe-commits
Tags: #clang, #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D67122
llvm-svn: 374293
Really, we were already 99% of the way there; just needed a couple minor
fixes that affected 64-bit-only builtins. Based on D61717.
Note that the change to builtin_str changes the type of a few
__builtin_neon_* intrinsics that had the "wrong" type.
Fixes https://bugs.llvm.org/show_bug.cgi?id=43341
Differential Revision: https://reviews.llvm.org/D68683
llvm-svn: 374191
Summary:
This clang builtin and corresponding LLVM intrinsic are necessary to
expose the exact semantics of the underlying WebAssembly instruction
to users. LLVM produces a poison value if the dynamic swizzle indices
are greater than the vector size, but the WebAssembly instruction sets
the corresponding output lane to zero. Users who depend on this
behavior can safely use this builtin.
Depends on D68527.
Reviewers: aheejin, dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D68531
llvm-svn: 374189
ARM and AArch64 SelectionDAG support for tacking parameter forwarding
register is implemented so we can allow clang invocations for those two
targets.
Beside that restrict debug entry value support to be emitted for
LimitedDebugInfo info and FullDebugInfo. Other types of debug info do
not have functions nor variables debug info.
Reviewers: aprantl, probinson, dstenb, vsk
Reviewed By: vsk
Differential Revision: https://reviews.llvm.org/D67004
llvm-svn: 374153
Also revert follow-up changes to the test.
Reason: the patch breaks our internal clang-tidy integration.
It's also unclear why we should use getRealPath instead of plumbing the
VFS to SanitizerBlacklist, see original commit thread of cfe-commits for
a discussion.
llvm-svn: 374151
When passing arguments using temporary allocas, we need to add the
appropriate lifetime markers so that the stack coloring passes can
re-use the stack space.
This patch keeps track of all the lifetime.start calls emited before the
codegened call, and adds the corresponding lifetime.end calls after the
call.
Differential Revision: https://reviews.llvm.org/D68611
llvm-svn: 374126
A user pointed out to me in private email that this test will fail if
it sees the letter 's' followed by a digit in any part of clang's
assembly output after the function label. That includes the .ident at
the end, which can include a full pathname or hostname or both from
the system clang was built on. So if that path or hostname includes
any text like 's5' then it will cause the test to fail.
Fixed by adding a check for `.fnend`, to limit the scope of the
`CHECK-NOT` to only the actual generated code for the test function.
(Committed without prior review on the basis that it's a simple and
obvious pure test-suite fix and also in a test I contributed myself.)
llvm-svn: 373744
This matches how GCC handles it, see e.g. https://gcc.godbolt.org/z/HPplnl.
GCC documents the gnu_inline attribute with "In C++, this attribute does
not depend on extern in any way, but it still requires the inline keyword
to enable its special behavior."
The previous behaviour of gnu_inline in C++, without the extern
keyword, can be traced back to the original commit that added
support for gnu_inline, SVN r69045.
Differential Revision: https://reviews.llvm.org/D67414
llvm-svn: 373078
Commit c15aa241f8 ("[CLANG][BPF] change __builtin_preserve_access_index()
signature") changed the builtin function signature to
PointerT __builtin_preserve_access_index(PointerT ptr)
with a pointer type as the argument/return type, where argument and
return types must be the same.
There is really no reason for this constraint. The builtin just
presented a code region so that IR builtins
__builtin_{array, struct, union}_preserve_access_index
can be applied.
This patch removed the pointer type restriction to permit any
argument type as long as it is permitted by the compiler.
Differential Revision: https://reviews.llvm.org/D67883
llvm-svn: 372516
The recently announced IBM z15 processor implements the architecture
already supported as "arch13" in LLVM. This patch adds support for
"z15" as an alternate architecture name for arch13.
Corrsponding LLVM support was committed as rev. 372435.
llvm-svn: 372436
This test is broken by design. Clang codegen tests should not depend
on llvm middle-end behaviour, they should *only* test clang codegen.
Yet this test runs whole optimization pipeline.
I've really tried to fix it, but there isn't just a few things
that depend on passes, but everything there does.
llvm-svn: 372015
That test is broken by design.
It depends on llvm middle-end behavior.
No clang codegen test should be doing that.
This one is salvageable by relaxing check lines.
llvm-svn: 372014
The signature of __builtin_rotateright64 was by misstake changed from
unsigned to signed in r360863, this patch will change it back to
unsigned as intended.
This fixes pr43309
Reviewers: efriedma, hans
Reviewed By: hans
Differential Revision: https://reviews.llvm.org/D67606
llvm-svn: 371969
levels:
-- none: no lax vector conversions [new GCC default]
-- integer: only conversions between integer vectors [old GCC default]
-- all: all conversions between same-size vectors [Clang default]
For now, Clang still defaults to "all" mode, but per my proposal on
cfe-dev (2019-04-10) the default will be changed to "integer" as soon as
that doesn't break lots of testcases. (Eventually I'd like to change the
default to "none" to match GCC and general sanity.)
Following GCC's behavior, the driver flag -flax-vector-conversions is
translated to -flax-vector-conversions=integer.
This reinstates r371805, reverted in r371813, with an additional fix for
lldb.
llvm-svn: 371817
levels:
-- none: no lax vector conversions [new GCC default]
-- integer: only conversions between integer vectors [old GCC default]
-- all: all conversions between same-size vectors [Clang default]
For now, Clang still defaults to "all" mode, but per my proposal on
cfe-dev (2019-04-10) the default will be changed to "integer" as soon as
that doesn't break lots of testcases. (Eventually I'd like to change the
default to "none" to match GCC and general sanity.)
Following GCC's behavior, the driver flag -flax-vector-conversions is
translated to -flax-vector-conversions=integer.
llvm-svn: 371805
Summary:
* Don't bother using a thread wrapper when the variable is known to
have constant initialization.
* Emit the thread wrapper as discardable-if-unused in TUs that don't
contain a definition of the thread_local variable.
* Don't emit the thread wrapper at all if the thread_local variable
is unused and discardable; it will be emitted by all TUs that need
it.
Reviewers: rjmccall, jdoerfert
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D67429
llvm-svn: 371767
Summary:
r369705 did not consider the addition of gnu_inline on function
declarations of alias attributed functions. This resulted in a reported
regression in the clang-9-rc4 release from the Zig developers building
glibc, which was observable as a failed assertion:
llvm-project/clang/lib/AST/Decl.cpp:3336: bool
clang::FunctionDecl::isInlineDefinitionExternallyVisible() const:
Assertion `(doesThisDeclarationHaveABody() || willHaveBody()) && "Must
be a function definition"' failed.
Alias function declarations do not have bodies, so allow us to proceed
if we have the alias function attribute but no body/definition, and add
a test case. The emitted symbols and their linkage matches GCC for the
added test case.
Link: https://bugs.llvm.org/show_bug.cgi?id=43268
Reviewers: aaron.ballman, rsmith, erichkeane, andrewrk
Reviewed By: andrewrk
Subscribers: cfe-commits, andrewrk, hans, srhines
Tags: #clang
Differential Revision: https://reviews.llvm.org/D67455
llvm-svn: 371766
Multi-versioned functions defined by cpu_dispatch and implemented with IFunc
can not be called outside the translation units where they are defined due to
lack of symbols. This patch add function aliases for these functions and thus
make them visible outside.
Differential Revision: https://reviews.llvm.org/D67058
Patch by Senran Zhang
llvm-svn: 371586
Cameron McInally