Summary:
This fixes a few things that are connected. It is very hard to provide
an independent test case for each of those fixes, because they are
interconnected and sometimes one masks another. The provided test case
triggers some of those bugs below but not all.
---
1. Background:
`placeBlockMarker` takes a BB, and if the BB is a destination of some
branch, it places `end_block` marker there, and computes the nearest
common dominator of all predecessors (what we call 'header') and places
a `block` marker there.
When we first place markers, we traverse BBs from top to bottom. For
example, when there are 5 BBs A, B, C, D, and E and B, D, and E are
branch destinations, if mark the BB given to `placeBlockMarker` with `*`
and draw a rectangle representing the border of `block` and `end_block`
markers, the process is going to look like
```
-------
----- |-----|
--- |---| ||---||
|A| ||A|| |||A|||
--- --> |---| --> ||---||
*B | B | || B ||
C | C | || C ||
D ----- |-----|
E *D | D |
E -------
*E
```
which means when we first place markers, we go from inner to outer
scopes. So when we place a `block` marker, if the header already
contains other `block` or `try` marker, it has to belong to an inner
scope, so the existing `block`/`try` markers should go _after_ the new
marker. This was the assumption we had.
But after placing all markers we run `fixUnwindMismatches` function.
There we do some control flow transformation and create some branches,
and we call `placeBlockMarker` again to place `block`/`end_block`
markers for those newly created branches. We can't assume that we are
traversing branch destination BBs from top to bottom now because we are
basically inserting some new markers in the middle of existing markers.
Fix:
In `placeBlockMarker`, we don't have the assumption that the BB given is
in the order of top to bottom, and when placing `block` markers,
calculates whether existing `block` or `try` markers are inner or
outer scopes with respect to the current scope.
---
2. Background:
In `fixUnwindMismatches`, when there is a call whose correct unwind
destination mismatches the current destination after initially placing
`try` markers, we wrap that with a new nested `try`/`catch`/`end` and
jump to the correct handler within the new `catch`. The correct handler
code is split as a separate BB from its original EH pad so it can be
branched to. Here's an example:
- Before
```
mbb:
call @foo <- Unwind destination mismatch!
wrong-ehpad:
catch
...
cont:
end_try
...
correct-ehpad:
catch
[handler code]
```
- After
```
mbb:
try (new)
call @foo
nested-ehpad: (new)
catch (new)
local.set n / drop (new)
br %handleri (new)
nested-end: (new)
end_try (new)
wrong-ehpad:
catch
...
cont:
end_try
...
correct-ehpad:
catch
local.set n / drop (new)
handler: (new)
end_try
[handler code]
```
Note that after this transformation, it is possible there are no calls
to actually unwind to `correct-ehpad` here. `call @foo` now
branches to `handler`, and there can be no other calls to unwind to
`correct-ehpad`. In this case `correct-ehpad` does not have any
predecessors anymore.
This can cause a bug in `placeBlockMarker`, because we may need to place
`end_block` marker in `handler`, and `placeBlockMarker` computes the
nearest common dominator of all predecessors. If one of `handler`'s
predecessor (here `correct-ehpad`) does not have any predecessors, i.e.,
no way of reaching it, we cannot correctly compute the common dominator
of predecessors of `handler`, and end up placing no `block`/`end`
markers. This bug actually sometimes masks the bug 1.
Fix:
When we have an EH pad that does not have any predecessors after this
transformation, deletes all its successors, so that its successors don't
have any dangling predecessors.
---
3. Background:
Actually the `handler` BB in the example shown in bug 2 doesn't need
`end_block` marker, despite it being a new branch destination, because
it already has `end_try` marker which can serve the same purpose. I just
put that example there for an illustration purpose. There is a case we
actually need to place `end_block` marker: when the branch dest is the
appendix BB. The appendix BB is created when there is a call that is
supposed to unwind to the caller ends up unwinding to a wrong EH pad. In
this case we also wrap the call with a nested `try`/`catch`/`end`,
create an 'appendix' BB at the very end of the function, and branch to
that BB, where we rethrow the exception to the caller.
Fix:
When we don't actually need to place block markers, we don't.
---
4. In case we fall through to the continuation BB after the catch block,
after extracting handler code in `fixUnwindMismatches` (refer to bug 2
for an example), we now have to add a branch to it to bypass the
handler.
- Before
```
try
...
(falls through to 'cont')
catch
handler body
end
<-- cont
```
- After
```
try
...
br %cont (new)
catch
end
handler body
<-- cont
```
The problem is, we haven't been placing a new `end_block` marker in the
`cont` BB in this case. We should, and this fixes it. But it is hard to
provide a test case that triggers this bug, because the current
compilation pipeline from .ll to .s does not generate this kind of code;
we always have a `br` after `invoke`. But code without `br` is still
valid, and we can have that kind of code if we have some pipeline
changes or optimizations later. Even mir test cases cannot trigger this
part for now, because we don't encode auxiliary EH-related data
structures (such as `WasmEHFuncInfo`) in mir now. Those functionalities
can be added later, but I don't think we should block this fix on that.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D79324
This patch makes the folding of or(A, B) into not(and(not(A), not(B)))
more agressive for I1 vector. This only affects Thumb2 MVE and improves
codegen, because it removes a lot of msr/mrs instructions on VPR.P0.
This patch also adds a xor(vcmp) -> !vcmp fold for MVE.
Differential Revision: https://reviews.llvm.org/D77202
This patch adds an implementation of PerformVSELECTCombine in the
ARM DAG Combiner that transforms vselect(not(cond), lhs, rhs) into
vselect(cond, rhs, lhs).
Normally, this should be done by the target-independent DAG Combiner,
but it doesn't handle the kind of constants that we generate, so we
have to reimplement it here.
Differential Revision: https://reviews.llvm.org/D77712
A linker will create .ARM.exidx sections for InputSections that don't
have them. This can cause a relocation out of range error If the
InputSection happens to be extremely far away from the other sections.
This is often the case for the vector table on older ARM CPUs as the only
two places that the table can be placed is 0 or 0xffff0000. We fix this
by removing InputSections that need a linker generated .ARM.exidx
section if that would cause an error.
Differential Revision: https://reviews.llvm.org/D79289
Summary:
I was surprised to see the LocalOffset can exceed uint32_t, but it
does happen and lead to crashes in one of our internal huge TU with a large
preamble.
with this patch, the crash is gone.
Reviewers: sammccall
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D79397
Adding this pattern reduces code duplication. There is no need to have a
custom implementation for lowering to llvm.cmpxchg.
Differential Revision: https://reviews.llvm.org/D78753
Summary:
I have fixed several places in getSplatSourceVector and isSplatValue
to work correctly with scalable vectors. I added new support for
the ISD::SPLAT_VECTOR DAG node as one of the obvious cases we can
support with scalable vectors. In other places I have tried to do
the sensible thing, such as bail out for vector types we don't yet
support or don't intend to support.
It's not possible to add IR test cases to cover these changes, since
they are currently only ever exercised on certain targets, e.g.
only X86 targets use the result of getSplatSourceVector. I've
assumed that X86 tests already exist to test these code paths for
fixed vectors. However, I have added some AArch64 unit tests that
test the specific functions I have changed.
Differential revision: https://reviews.llvm.org/D79083
The argparse 'append' action concatenates multiple occurrences of an
argument (even when we specify `nargs=1` or `nargs='?'`). This means
that we create multiple identical output files if the `--output`
argument is given more than once. This isn't useful and we instead want
this to behave like a standard optional argument: last occurrence wins.
Portions of MLIR which depend on LLVMIR generally need to depend on
intrinsics_gen, to ensure that tablegen'd header files from LLVM are built
first. Without this, we get errors, typically about llvm/IR/Attributes.inc
not being found.
Note that previously the Linalg Dialect depended on intrinsics_gen, but it
doesn't need to, since it doesn't use LLVMIR.
Differential Revision: https://reviews.llvm.org/D79389
This patch threads the virtual file system through dsymutil.
Currently there is no good way to find out exactly what files are
necessary in order to reproduce a dsymutil link, at least not without
knowledge of how dsymutil's internals. My motivation for this change is
to add lightweight "reproducers" that automatically gather the input
object files through the FileCollectorFileSystem. The files together
with the YAML mapping will allow us to transparently reproduce a
dsymutil link, even without having to mess with the OSO path prefix.
Differential revision: https://reviews.llvm.org/D79376
This revision adds support for merging identical blocks, or those with the same operations that branch to the same successors. Operands that mismatch between the different blocks are replaced with new block arguments added to the merged block.
Differential Revision: https://reviews.llvm.org/D79134
This change removes tabs from the comments printed by the asmprinter after basic
block declarations in favor of two spaces. This is currently the only place in
the printed IR that uses tabs.
Differential Revision: https://reviews.llvm.org/D79377
union ctor does not call ctors of its data members. union dtor does not call dtors of its data members.
Also union does not have base class.
Currently when clang checks whether union has an empty ctor/dtor, it checks the ctors/dtors of its
data members. This causes incorrectly diagnose device side global variables and shared variables as
having non-empty ctors/dtors.
This patch fixes that.
Differential Revision: https://reviews.llvm.org/D79367
Summary:
That unless the user requested an output object (--lto-obj-path), the an
unused empty combined module is not emitted.
This changed is helpful for some target (ex. RISCV-V) which encoded the
ABI info in IR module flags (target-abi). Empty unused module has no ABI
info so the linker would get the linking error during merging
incompatible ABIs.
Reviewers: tejohnson, espindola, MaskRay
Subscribers: emaste, inglorion, arichardson, hiraditya, simoncook, MaskRay, steven_wu, dexonsmith, PkmX, dang, lenary, s.egerton, luismarques, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D78988
Summary:
In the particular case of an insertion in a block without a terminator, the BlockBuilder insertion point should be block->end().
Adding a unit test to exercise this.
Differential Revision: https://reviews.llvm.org/D79363
This allows for walking the operations nested directly within a region, without traversing nested regions.
Differential Revision: https://reviews.llvm.org/D79056
It looks like the new implementation is correct, since there were TODOs
here about getting the new behavior.
I am not sure if "C:..\.." should become "C:" or "C:\", though. The new
output doesn't precisely match the TODO message, but it seems
appropriate given the specification of remove_dots and how .. traversals
work at the root directory.
Refering to the link order of a dylib better matches the terminology used in
static compilation. As upcoming patches will increase the number of places where
link order matters (for example when closing JITDylibs) it's better to get this
name change out of the way early.
This reverts commit fb5fd74685.
Re-instates commit 53913a65b4
The fix is to trim off trailing separators, as in `/foo/bar/` and
produce `/foo/bar`. VFS tests rely on this. I added unit tests for
remove_dots.
Summary:
As D78974, this patch implements the emulation for store op. The emulation is
done with atomic operations. E.g., if the storing value is i8, rewrite the
StoreOp to:
1) load a 32-bit integer
2) clear 8 bits in the loading value
3) store 32-bit value back
4) load a 32-bit integer
5) modify 8 bits in the loading value
6) store 32-bit value back
The step 1 to step 3 are done by AtomicAnd as one atomic step, and the step 4
to step 6 are done by AtomicOr as another atomic step.
Differential Revision: https://reviews.llvm.org/D79272
This std::copy_n copies 8 byte data (APInt raw data) by 1 byte from the
beginning of char array. This is no problem in little endian, but the
data is not copied correctly in big endian because the data should be
copied from the end of the char array.
- Example of 4 byte data (such as float32)
Little endian (First 4 bytes):
Address | 0x01 0x02 0x03 0x04 0x05 0x06 0x07 0x08
Data | 0xcd 0xcc 0x8c 0x3f 0x00 0x00 0x00 0x00
Big endian (Last 4 bytes):
Address | 0x01 0x02 0x03 0x04 0x05 0x06 0x07 0x08
Data | 0x00 0x00 0x00 0x00 0x3f 0x8c 0xcc 0xcd
In general, when it copies N(N<8) byte data in big endian, the start
address should be incremented by (8 - N) bytes.
The original code has no problem when it includes 8 byte data(such as
double) even in big endian.
Differential Revision: https://reviews.llvm.org/D78076
We currently only support extern relocations.
`X86_64_RELOC_SIGNED_{1,2,4}` are like X86_64_RELOC_SIGNED, but with the
implicit addend fixed to 1, 2, and 4, respectively.
See the comment in `lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp RecordX86_64Relocation`.
Reviewed By: int3
Differential Revision: https://reviews.llvm.org/D79311
Register live ranges may have had gaps that after coalescing should be
removed. This is done by adding a new segment to the range, and merging
it with neighboring segments. When doing so, do not assume that each
subrange of the register ended at the same index. If a subrange ended
earlier, adding this segment could make the live range invalid.
Instead, if the subrange is not live at the start of the segment,
extend it first.
Previous patch broken flang, which has some yet-to-be resolved cyclic
dependencies. This patch fixes the breakage by restricting the dependencies
which are generated to public libraries, which is probably more sensible anyway.
Differential Revision: https://reviews.llvm.org/D79366
Summary:
Languages can have different ways of formatting special characters.
E.g. when debugging C++ code a string might look like "\b", but when
debugging Swift code the same string would look like "\u{8}".
To make this work, plugins override GetStringPrinterEscapingHelper.
However, because there's a large amount of subtly divergent work done in
each override, we end up with large amounts of duplicated code. And all
the memory smashers fixed in one copy of the logic (see D73860) don't
get fixed in the others.
IMO the GetStringPrinterEscapingHelper is overly general and hard to
use. I propose deleting it and replacing it with an EscapeStyle enum,
which can be set as needed by each plugin.
A fix for some swift-lldb memory smashers falls out fairly naturally
from this deletion (https://github.com/apple/llvm-project/pull/1046). As
the swift logic becomes really tiny, I propose moving it upstream as
part of this change. I've added unit tests to cover it.
rdar://61419673
Reviewers: JDevlieghere, davide
Subscribers: mgorny, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D77843
Summary:
Constrain which metadata nodes are allowed to be, or contain,
DILocations. This ensures that logic for updating DILocations in a
Module is complete.
Currently, !llvm.loop metadata is the only odd duck which contains
nested DILocations. This has caused problems in the past: some passes
forgot to visit the nested locations, leading to subtly broken debug
info and late verification failures.
If there's a compelling reason for some future metadata to nest
DILocations, we'll need to introduce a generic API for updating the
locations attached to an Instruction before relaxing this check.
Reviewers: aprantl, dsanders
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D79245
The overloaded new operator in TestCppOperators.py are working by accident because of how
we currently deal with artificial methods.
Differential Revision: https://reviews.llvm.org/D79251
It looks like some bots are failing with os log not giving any
output. This might be due to the system under test being heavy
load so the 2 minute window might not be large enough. This
patch makes the window larger in the hope that this test will
be more reliable.
rdar://problem/62141527
There are some lookup oddities with these as reported in PR45780, and
GCC doesn't support these behaviors at all. To be more consistent with
GCC and prevent the crashes caused by our lookup issues, nip the problem
in the bud and prohibit enums here.
abhinavgaba reported that that the custom-result-category.py test hangs
on a Windows build bot [1]. Disable it for now.
[1] https://reviews.llvm.org/D78164#2018178
Heejin Ahn