Includes verifier changes checking the elementtype, clang codegen
changes to emit the elementtype, and ISel changes using the elementtype.
Reviewed By: #opaque-pointers, nikic
Differential Revision: https://reviews.llvm.org/D120527
We should not be using APIs here that try to fetch the attribute
from both the call attributes and the function attributes. Otherwise
we'll try to upgrade a non-existent sret attribute on the call using
the attribute on the function.
Since D101045, allocas are no longer required to be part of the
default alloca address space. There may be allocas in multiple
different address spaces. However, the bitcode reader would
simply assume the default alloca address space, resulting in
either an error or incorrect IR.
Add an optional record for allocas which encodes the address
space.
This will let us start moving away from hard-coded attributes in
MemoryBuiltins.cpp and put the knowledge about various attribute
functions in the compilers that emit those calls where it probably
belongs.
Differential Revision: https://reviews.llvm.org/D117921
This completes the propagation of type IDs through bitcode reading,
and switches remaining uses of getPointerElementType() to use
contained type IDs.
The main new thing here is that sometimes we need to create a type
ID for a type that was not explicitly encoded in bitcode (or we
don't know its ID at the current point). For such types we create a
"virtual" type ID, which is cached based on the type and the
contained type IDs. Luckily, we generally only need zero or one
contained type IDs, and in the one case where we need two, we can
get away with not including it in the cache key.
With this change, we pass the entirety of llvm-test-suite at O3
with opaque pointers.
Differential Revision: https://reviews.llvm.org/D120471
Currently adding attribute no_sanitize("bounds") isn't disabling
-fsanitize=local-bounds (also enabled in -fsanitize=bounds). The Clang
frontend handles fsanitize=array-bounds which can already be disabled by
no_sanitize("bounds"). However, instrumentation added by the
BoundsChecking pass in the middle-end cannot be disabled by the
attribute.
The fix is very similar to D102772 that added the ability to selectively
disable sanitizer pass on certain functions.
In this patch, if no_sanitize("bounds") is provided, an additional
function attribute (NoSanitizeBounds) is attached to IR to let the
BoundsChecking pass know we want to disable local-bounds checking. In
order to support this feature, the IR is extended (similar to D102772)
to make Clang able to preserve the information and let BoundsChecking
pass know bounds checking is disabled for certain function.
Reviewed By: melver
Differential Revision: https://reviews.llvm.org/D119816
This is step two of supporting autoupgrade of old bitcode to opaque
pointers. Rather than tracking the element type ID of pointers in
particular, track all type IDs that a type contains. This allows us
to recover the element type in more complex situations, e.g. when
we need to determine the pointer element type of a vector element
or function type parameter.
Differential Revision: https://reviews.llvm.org/D119339
This introduces a new "ptrauth" operand bundle to be used in
call/invoke. At the IR level, it's semantically equivalent to an
@llvm.ptrauth.auth followed by an indirect call, but it additionally
provides additional hardening, by preventing the intermediate raw
pointer from being exposed.
This mostly adds the IR definition, verifier checks, and support in
a couple of general helper functions. Clang IRGen and backend support
will come separately.
Note that we'll eventually want to support this bundle in indirectbr as
well, for similar reasons. indirectbr currently doesn't support bundles
at all, and the IR data structures need to be updated to allow that.
Differential Revision: https://reviews.llvm.org/D113685
We have the `clang -cc1` command-line option `-funwind-tables=1|2` and
the codegen option `VALUE_CODEGENOPT(UnwindTables, 2, 0) ///< Unwind
tables (1) or asynchronous unwind tables (2)`. However, this is
encoded in LLVM IR by the presence or the absence of the `uwtable`
attribute, i.e. we lose the information whether to generate want just
some unwind tables or asynchronous unwind tables.
Asynchronous unwind tables take more space in the runtime image, I'd
estimate something like 80-90% more, as the difference is adding
roughly the same number of CFI directives as for prologues, only a bit
simpler (e.g. `.cfi_offset reg, off` vs. `.cfi_restore reg`). Or even
more, if you consider tail duplication of epilogue blocks.
Asynchronous unwind tables could also restrict code generation to
having only a finite number of frame pointer adjustments (an example
of *not* having a finite number of `SP` adjustments is on AArch64 when
untagging the stack (MTE) in some cases the compiler can modify `SP`
in a loop).
Having the CFI precise up to an instruction generally also means one
cannot bundle together CFI instructions once the prologue is done,
they need to be interspersed with ordinary instructions, which means
extra `DW_CFA_advance_loc` commands, further increasing the unwind
tables size.
That is to say, async unwind tables impose a non-negligible overhead,
yet for the most common use cases (like C++ exceptions), they are not
even needed.
This patch extends the `uwtable` attribute with an optional
value:
- `uwtable` (default to `async`)
- `uwtable(sync)`, synchronous unwind tables
- `uwtable(async)`, asynchronous (instruction precise) unwind tables
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D114543
Auto-upgrades that rely on the pointer element type do not work in
opaque pointer mode. The idea behind this patch is that we can
instead work with type IDs, for which we can retain the pointer
element type. For typed pointer bitcode, we will have a distinct
type ID for pointers with distinct element type, even if there will
only be a single corresponding opaque pointer type.
The disclaimer here is that this is only the first step of the change,
and there are still more getPointerElementType() calls to remove.
I expect that two more patches will be needed:
1. Track all "contained" type IDs, which will allow us to handle
function params (which are contained in the function type) and GEPs
(which may use vectors of pointers)
2. Track type IDs for values, which is e.g. necessary to handle loads.
Differential Revision: https://reviews.llvm.org/D118694
We only support chunks <= 32 bits regardless of whether we're
running on a 64-bit platform or not. Chunk size > 32 <= 64 would
cause UB in the reading code.
Instead of simply assuming that it will be zero. I double checked
that the bitstream reader doesn't have any special handling for
all-zero blobs, it will always write out the full contents.
DIStringType is used to encode the debug info of a character object
in Fortran. A Fortran deferred-length character object is typically
implemented as a pair of the following two pieces of info: An address
of the raw storage of the characters, and the length of the object.
The stringLocationExp field contains the DIExpression to get to the
raw storage.
This patch also enables the emission of DW_AT_data_location attribute
in a DW_TAG_string_type debug info entry based on stringLocationExp
in DIStringType.
A test is also added to ensure that the bitcode reader is backward
compatible with the old DIStringType format.
Differential Revision: https://reviews.llvm.org/D117586
MSVC currently doesn't support 80 bits long double. ICC supports it when
the option `/Qlong-double` is specified. Changing the alignment of f80
to 16 bytes so that we can be compatible with ICC's option.
Reviewed By: rnk, craig.topper
Differential Revision: https://reviews.llvm.org/D115942
MSVC currently doesn't support 80 bits long double. ICC supports it when
the option `/Qlong-double` is specified. Changing the alignment of f80
to 16 bytes so that we can be compatible with ICC's option.
Reviewed By: rnk, craig.topper
Differential Revision: https://reviews.llvm.org/D115942
In D115311, we're looking to modify clang to emit i constraints rather
than X constraints for callbr's indirect destinations. Prior to doing
so, update all of the existing tests in llvm/ to match.
Reviewed By: void, jyknight
Differential Revision: https://reviews.llvm.org/D115410
This is the autoupgrade part of D116531. If old bitcode is missing
the elementtype attribute for indirect inline asm constraints,
automatically add it. As usual, this only works when upgrading
in typed mode, we haven't figured out upgrade in opaque mode yet.
This patch extends the available uses of the 'align' parameter attribute
to include vectors of pointers. The attribute specifies pointer
alignment element-wise.
This change was previously requested and discussed in D87304.
The vector predication (VP) intrinsics intend to use this for scatter
and gather operations, as they lack the explicit alignment parameter
that the masked versions use.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D115161
The bitcode reader expected that the pointers are typed,
so that it can extract the function type for the assembly
so `bitc::CST_CODE_INLINEASM` did not explicitly store said function type.
I'm not really sure how the upgrade path will look for existing bitcode,
but i think we can easily support opaque pointers going forward,
by simply storing the function type.
Reviewed By: #opaque-pointers, nikic
Differential Revision: https://reviews.llvm.org/D116341
Can't get the pointee type of an opaque pointer,
but in that case said attributes must already be typed,
so just don't try to rewrite them if they already are.
With Control-Flow Integrity (CFI), the LowerTypeTests pass replaces
function references with CFI jump table references, which is a problem
for low-level code that needs the address of the actual function body.
For example, in the Linux kernel, the code that sets up interrupt
handlers needs to take the address of the interrupt handler function
instead of the CFI jump table, as the jump table may not even be mapped
into memory when an interrupt is triggered.
This change adds the no_cfi constant type, which wraps function
references in a value that LowerTypeTestsModule::replaceCfiUses does not
replace.
Link: https://github.com/ClangBuiltLinux/linux/issues/1353
Reviewed By: nickdesaulniers, pcc
Differential Revision: https://reviews.llvm.org/D108478
The default for min is changed to 1. The behaviour of -mvscale-{min,max}
in Clang is also changed such that 16 is the max vscale when targeting
SVE and no max is specified.
Reviewed By: sdesmalen, paulwalker-arm
Differential Revision: https://reviews.llvm.org/D113294
When creating a splat of 0 for scalable vectors we tend to create them
with using a combination of shufflevector and insertelement, i.e.
shufflevector (<vscale x 4 x i32> insertelement (<vscale x 4 x i32> poison, i32 0, i32 0),
<vscale x 4 x i32> poison, <vscale x 4 x i32> zeroinitializer)
However, for the case of a zero splat we can actually just replace the
above with zeroinitializer instead. This makes the IR a lot simpler and
easier to read. I have changed ConstantFoldShuffleVectorInstruction to
use zeroinitializer when creating a splat of integer 0 or FP +0.0 values.
Differential Revision: https://reviews.llvm.org/D113394
Add UNIQUED and DISTINCT properties in Metadata.def and use them to
implement restrictions on the `distinct` property of MDNodes:
* DIExpression can currently be parsed from IR or read from bitcode
as `distinct`, but this property is silently dropped when printing
to IR. This causes accepted IR to fail to round-trip. As DIExpression
appears inline at each use in the canonical form of IR, it cannot
actually be `distinct` anyway, as there is no syntax to describe it.
* Similarly, DIArgList is conceptually always uniqued. It is currently
restricted to only appearing in contexts where there is no syntax for
`distinct`, but for consistency it is treated equivalently to
DIExpression in this patch.
* DICompileUnit is already restricted to always being `distinct`, but
along with adding general support for the inverse restriction I went
ahead and described this in Metadata.def and updated the parser to be
general. Future nodes which have this restriction can share this
support.
The new UNIQUED property applies to DIExpression and DIArgList, and
forbids them to be `distinct`. It also implies they are canonically
printed inline at each use, rather than via MDNode ID.
The new DISTINCT property applies to DICompileUnit, and requires it to
be `distinct`.
A potential alternative change is to forbid the non-inline syntax for
DIExpression entirely, as is done with DIArgList implicitly by requiring
it appear in the context of a function. For example, we would forbid:
!named = !{!0}
!0 = !DIExpression()
Instead we would only accept the equivalent inlined version:
!named = !{!DIExpression()}
This essentially removes the ability to create a `distinct` DIExpression
by construction, as there is no syntax for `distinct` inline. If this
patch is accepted as-is, the result would be that the non-canonical
version is accepted, but the following would be an error and produce a diagnostic:
!named = !{!0}
; error: 'distinct' not allowed for !DIExpression()
!0 = distinct !DIExpression()
Also update some documentation to consistently use the inline syntax for
DIExpression, and to describe the restrictions on `distinct` for nodes
where applicable.
Reviewed By: StephenTozer, t-tye
Differential Revision: https://reviews.llvm.org/D104827
This is to revert commit f95bd18b5f (Revert "[Attr] support
btf_type_tag attribute") plus a bug fix.
Previous change failed to handle cases like below:
$ cat reduced.c
void a(*);
void a() {}
$ clang -c reduced.c -O2 -g
In such cases, during clang IR generation, for function a(),
CGCodeGen has numParams = 1 for FunctionType. But for
FunctionTypeLoc we have FuncTypeLoc.NumParams = 0. By using
FunctionType.numParams as the bound to access FuncTypeLoc
params, a random crash is triggered. The bug fix is to
check against FuncTypeLoc.NumParams before accessing
FuncTypeLoc.getParam(Idx).
Differential Revision: https://reviews.llvm.org/D111199
Arthur Eubanks