LoopUtils.h needs ICFLoopSafetyInfo but relies on a forward
declaration of ICFLoopSafetyInfo in IVDescriptors.h. This patch adds
a forward declaration right in LoopUtils.h.
While we are at it, this patch removes the one in IVDescriptors.h,
where it is unnecessary.
Some utilities used by InstCombine, like SimplifyLibCalls, may add new
instructions and replace the uses of a call, but return nullptr because
the inserted call produces multiple results.
Previously, the replaced library calls would get removed by
InstCombine's deleter, but after
292077072e this may not happen, if the
willreturn attribute is missing.
As a work-around, update replaceInstUsesWith to set MadeIRChange, if it
replaces any uses. This catches the cases where it is used as replacer
by utilities used by InstCombine and seems useful in general; updating
uses will modify the IR.
This fixes an expensive-check failure when replacing
@__sinpif/@__cospifi with @__sincospif_sret.
Implements parts of:
- P0898R3 Standard Library Concepts
- P1754 Rename concepts to standard_case for C++20, while we still can
Reviewed By: ldionne, miscco, #libc
Differential Revision: https://reviews.llvm.org/D91004
As shown in the test diffs, we could miscompile by
propagating flags that did not exist in the original
code.
The flags required for fmin/fmax reductions will be
fixed in a follow-up patch.
With the addition of the `willreturn` attribute, functions that may
not return (e.g. due to an infinite loop) are well defined, if they are
not marked as `willreturn`.
This patch updates `wouldInstructionBeTriviallyDead` to not consider
calls that may not return as dead.
This patch still provides an escape hatch for intrinsics, which are
still assumed as willreturn unconditionally. It will be removed once
all intrinsics definitions have been reviewed and updated.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D94106
This patch adds the integer handling typemaps and the typemap for
string returning functions.
The integer handling typemaps overrides SWIG's own typemaps to distinct
the handling of integers from floating point.
The typemap for string returning functions is a port of Python's
typemap.
Differential Revision: https://reviews.llvm.org/D94937
If i change it to AssertingVH instead, a number of existing tests fail,
which means we don't consistently remove from the set when deleting blocks,
which means newly-created blocks may happen to appear in that set
if they happen to occupy the same memory chunk as did some block
that was in the set originally.
There are many places where we delete blocks,
and while we could probably consistently delete from LoopHeaders
when deleting a block in transforms located in SimplifyCFG.cpp itself,
transforms located elsewhere (Local.cpp/BasicBlockUtils.cpp) also may
delete blocks, and it doesn't seem good to teach them to deal with it.
Since we at most only ever delete from LoopHeaders,
let's just delegate to WeakVH to do that automatically.
But to be honest, personally, i'm not sure that the idea
behind LoopHeaders is sound.
This change adds an AssemblerInvocation class, similar to the
CompilerInvocation class. It can be used to invoke cc1as directly.
The project I'm working on wants to compile Clang and use it as a static
library. For that to work, there must be a way to invoke the assembler
programmatically, using the same arguments as you would otherwise pass
to cc1as.
Differential Revision: https://reviews.llvm.org/D63852
The target features are obtained as a list of features/attributes.
Instead of storing them in a single string, store the vector. This
matches lto::Config's behavior and simplifies the transition to
lto::backend().
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D95224
Insert a llvm.experimental.noalias.scope.decl intrinsic that identifies where a noalias argument was inlined.
This patch includes some refactorings from D90104.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D93040
In RISC-V there is a single addressing mode of the form imm(reg) where
imm is a signed integer of 12-bit with a range of [-2048..2047] bytes
from reg.
The test MultiSource/UnitTests/C++11/frame_layout of the LLVM test-suite
exercises several scenarios with the stack, including function calls
where the stack will need to be realigned to to a local variable having
a large alignment of 4096 bytes.
In situations of large stacks, the RISC-V backend (in
RISCVFrameLowering) reserves an extra emergency spill slot which can be
used (if no free register is found) by the register scavenger after the
frame indexes have been eliminated. PrologEpilogInserter already takes
care of keeping the emergency spill slots as close as possible to the
stack pointer or frame pointer (depending on what the function will
use). However there is a final alignment step to honour the maximum
alignment of the stack that, when using the stack pointer to access the
emergency spill slots, has the side effect of setting them farther from
the stack pointer.
In the case of the frame_layout testcase, the net result is that we do
have an emergency spill slot but it is so far from the stack pointer
(more than 2048 bytes due to the extra alignment of a variable to 4096
bytes) that it becomes unreachable via any immediate offset.
During elimination of the frame index, many (regular) offsets of the
stack may be immediately unreachable already. Their address needs to be
computed using a register. A virtual register is created and later
RegisterScavenger should be able to find an unused (physical) register.
However if no register is available, RegisterScavenger will pick a
physical register and spill it onto an emergency stack slot, while we
compute the offset (restoring the chosen register after all this). This
assumes that the emergency stack slot is easily reachable (this is,
without requiring another register!).
This is the assumption we seem to break when we perform the extra
alignment in PrologEpilogInserter.
We can "float" the emergency spill slots by increasing (in absolute
value) their offsets from the incoming stack pointer. This way the
emergency spill slots will remain close to the stack pointer (once the
function has allocated storage for the stack, including the needed
realignment). The new size computed in PrologEpilogInserter is padding
so it should be OK to move the emergency spill slots there. Also because
we're increasing the alignment, the new location should stay aligned for
the purpose of the emergency spill slots.
Note that this change also impacts other backends as shown by the tests.
Changes are minor adjustments to the emergency stack slot offset.
Differential Revision: https://reviews.llvm.org/D89239
This patch fixes llvm-link assertion when linking external variable
declaration with a definition with appending linkage.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D95126
Previously in ASan's `pthread_create` interceptor we would block in the
`pthread_create` interceptor waiting for the child thread to start.
Unfortunately this has bad performance characteristics because the OS
scheduler doesn't know the relationship between the parent and child
thread (i.e. the parent thread cannot make progress until the child
thread makes progress) and may make the wrong scheduling decision which
stalls progress.
It turns out that ASan didn't use to block in this interceptor but was
changed to do so to try to address
http://llvm.org/bugs/show_bug.cgi?id=21621/.
In that bug the problem being addressed was a LeakSanitizer false
positive. That bug concerns a heap object being passed
as `arg` to `pthread_create`. If:
* The calling thread loses a live reference to the object (e.g.
`pthread_create` finishes and the thread no longer has a live
reference to the object).
* Leak checking is triggered.
* The child thread has not yet started (once it starts it will have a
live reference).
then the heap object will incorrectly appear to be leaked.
This bug is covered by the `lsan/TestCases/leak_check_before_thread_started.cpp` test case.
In b029c5101f ASan was changed to block
in `pthread_create()` until the child thread starts so that `arg` is
kept alive for the purposes of leaking check.
While this change "works" its problematic due to the performance
problems it causes. The change is also completely unnecessary if leak
checking is disabled (via detect_leaks runtime option or
CAN_SANITIZE_LEAKS compile time config).
This patch does two things:
1. Takes a different approach to solving the leak false positive by
making LSan's leak checking mechanism treat the `arg` pointer of
created but not started threads as reachable. This is done by
implementing the `ForEachRegisteredThreadContextCb` callback for
ASan.
2. Removes the blocking behaviour in the ASan `pthread_create`
interceptor.
rdar://problem/63537240
Differential Revision: https://reviews.llvm.org/D95184
In the PPC32 SVR4 ABI, a va_list has copies of registers from the function call.
va_arg looked in the wrong registers for (the pointer representation of) an
object in Objective-C, and for some types in C++. Fix va_arg to look in the
general-purpose registers, not the floating-point registers. Also fix va_arg
for some C++ types, like a member function pointer, that are aggregates for
the ABI.
Anthony Richardby found the problem in Objective-C. Eli Friedman suggested
part of this fix.
Fixes https://bugs.llvm.org/show_bug.cgi?id=47921
Reviewed By: efriedma, nemanjai
Differential Revision: https://reviews.llvm.org/D90329
The test wasn't sensitive to alias analysis. As you can seen from D95117 when AA is added by default this is affected.
Updating the test so that it coveres both cases for AA analysis.
Note that this patch depends on D95117 to land first.
Differential Revision: https://reviews.llvm.org/D95247
This mechanism is intended to provide a way to treat the `arg` pointer
of a created (but not yet started) thread as reachable. In future
patches this will be implemented in `GetAdditionalThreadContextPtrs`.
A separate implementation of `GetAdditionalThreadContextPtrs` exists
for ASan and LSan runtimes because they need to be implemented
differently in future patches.
rdar://problem/63537240
Differential Revision: https://reviews.llvm.org/D95183
Michael Kruse