According to i386 System V ABI 2.1: Structures and unions assume the
alignment of their most strictly aligned component. But current
implementation always takes them as 4-byte aligned which will result
in incorrect code, e.g:
1 #include <immintrin.h>
2 typedef union {
3 int d[4];
4 __m128 m;
5 } M128;
6 extern void foo(int, ...);
7 void test(void)
8 {
9 M128 a;
10 foo(1, a);
11 foo(1, a.m);
12 }
The first call (line 10) takes the second arg as 4-byte aligned while
the second call (line 11) takes the second arg as 16-byte aligned.
There is oxymoron for the alignment of the 2 calls because they should
be the same.
This patch fixes the bug by following i386 System V ABI and apply it to
Linux only since other System V OS (e.g Darwin, PS4 and FreeBSD) don't
want to spend any effort dealing with the ramifications of ABI breaks
at present.
Patch by Wei Xiao (wxiao3)
Differential Revision: https://reviews.llvm.org/D60748
llvm-svn: 361934
Overaligned and underaligned types (i.e. types where the alignment has been
increased or decreased using the aligned and packed attributes) weren't being
correctly handled in all cases, as the unadjusted alignment should be used.
This patch also adjusts getTypeUnadjustedAlign to correctly handle typedefs of
non-aggregate types, which it appears it never had to handle before.
Differential Revision: https://reviews.llvm.org/D62152
llvm-svn: 361372
This patch implements a limited form of autolinking primarily designed to allow
either the --dependent-library compiler option, or "comment lib" pragmas (
https://docs.microsoft.com/en-us/cpp/preprocessor/comment-c-cpp?view=vs-2017) in
C/C++ e.g. #pragma comment(lib, "foo"), to cause an ELF linker to automatically
add the specified library to the link when processing the input file generated
by the compiler.
Currently this extension is unique to LLVM and LLD. However, care has been taken
to design this feature so that it could be supported by other ELF linkers.
The design goals were to provide:
- A simple linking model for developers to reason about.
- The ability to to override autolinking from the linker command line.
- Source code compatibility, where possible, with "comment lib" pragmas in other
environments (MSVC in particular).
Dependent library support is implemented differently for ELF platforms than on
the other platforms. Primarily this difference is that on ELF we pass the
dependent library specifiers directly to the linker without manipulating them.
This is in contrast to other platforms where they are mapped to a specific
linker option by the compiler. This difference is a result of the greater
variety of ELF linkers and the fact that ELF linkers tend to handle libraries in
a more complicated fashion than on other platforms. This forces us to defer
handling the specifiers to the linker.
In order to achieve a level of source code compatibility with other platforms
we have restricted this feature to work with libraries that meet the following
"reasonable" requirements:
1. There are no competing defined symbols in a given set of libraries, or
if they exist, the program owner doesn't care which is linked to their
program.
2. There may be circular dependencies between libraries.
The binary representation is a mergeable string section (SHF_MERGE,
SHF_STRINGS), called .deplibs, with custom type SHT_LLVM_DEPENDENT_LIBRARIES
(0x6fff4c04). The compiler forms this section by concatenating the arguments of
the "comment lib" pragmas and --dependent-library options in the order they are
encountered. Partial (-r, -Ur) links are handled by concatenating .deplibs
sections with the normal mergeable string section rules. As an example, #pragma
comment(lib, "foo") would result in:
.section ".deplibs","MS",@llvm_dependent_libraries,1
.asciz "foo"
For LTO, equivalent information to the contents of a the .deplibs section can be
retrieved by the LLD for bitcode input files.
LLD processes the dependent library specifiers in the following way:
1. Dependent libraries which are found from the specifiers in .deplibs sections
of relocatable object files are added when the linker decides to include that
file (which could itself be in a library) in the link. Dependent libraries
behave as if they were appended to the command line after all other options. As
a consequence the set of dependent libraries are searched last to resolve
symbols.
2. It is an error if a file cannot be found for a given specifier.
3. Any command line options in effect at the end of the command line parsing apply
to the dependent libraries, e.g. --whole-archive.
4. The linker tries to add a library or relocatable object file from each of the
strings in a .deplibs section by; first, handling the string as if it was
specified on the command line; second, by looking for the string in each of the
library search paths in turn; third, by looking for a lib<string>.a or
lib<string>.so (depending on the current mode of the linker) in each of the
library search paths.
5. A new command line option --no-dependent-libraries tells LLD to ignore the
dependent libraries.
Rationale for the above points:
1. Adding the dependent libraries last makes the process simple to understand
from a developers perspective. All linkers are able to implement this scheme.
2. Error-ing for libraries that are not found seems like better behavior than
failing the link during symbol resolution.
3. It seems useful for the user to be able to apply command line options which
will affect all of the dependent libraries. There is a potential problem of
surprise for developers, who might not realize that these options would apply
to these "invisible" input files; however, despite the potential for surprise,
this is easy for developers to reason about and gives developers the control
that they may require.
4. This algorithm takes into account all of the different ways that ELF linkers
find input files. The different search methods are tried by the linker in most
obvious to least obvious order.
5. I considered adding finer grained control over which dependent libraries were
ignored (e.g. MSVC has /nodefaultlib:<library>); however, I concluded that this
is not necessary: if finer control is required developers can fall back to using
the command line directly.
RFC thread: http://lists.llvm.org/pipermail/llvm-dev/2019-March/131004.html.
Differential Revision: https://reviews.llvm.org/D60274
llvm-svn: 360984
Summary:
- `__constant__` variables should not be `hidden` as the linker may turn
them into `LOCAL` symbols.
Reviewers: yaxunl
Subscribers: jvesely, nhaehnle, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D61194
llvm-svn: 359344
with notail on x86-64.
On x86-64, the epilogue code inserted before the tail jump blocks the
autoreleased return optimization.
rdar://problem/38675807
Differential Revision: https://reviews.llvm.org/D59656
llvm-svn: 356705
This allows the global visibility controls to be restrictive while still
populating the dynamic symbol table where required.
Differential Revision: https://reviews.llvm.org/D56871
llvm-svn: 353870
The various EltSize, Offset, DataLayout, and StructLayout arguments
are all computable from the Address's element type and the DataLayout
which the CGBuilder already has access to.
After having previously asserted that the computed values are the same
as those passed in, now remove the redundant arguments from
CGBuilder's Create*GEP functions.
Differential Revision: https://reviews.llvm.org/D57767
llvm-svn: 353629
Some of these functions take some extraneous arguments, e.g. EltSize,
Offset, which are computable from the Type and DataLayout.
Add some asserts to ensure that the computed values are consistent
with the passed-in values, in preparation for eliminating the
extraneous arguments. This also asserts that the Type is an Array for
the calls named "Array" and a Struct for the calls named "Struct".
Then, correct a couple of errors:
1. Using CreateStructGEP on an array type. (this causes the majority
of the test differences, as struct GEPs are created with i32
indices, while array GEPs are created with i64 indices)
2. Passing the wrong Offset to CreateStructGEP in TargetInfo.cpp on
x86-64 NACL (which uses 32-bit pointers).
Differential Revision: https://reviews.llvm.org/D57766
llvm-svn: 353529
This is similar to import_module, but sets the import field name
instead.
By default, the import field name is the same as the C/asm/.o symbol
name. However, there are situations where it's useful to have it be
different. For example, suppose I have a wasm API with a module named
"pwsix" and a field named "read". There's no risk of namespace
collisions with user code at the wasm level because the generic name
"read" is qualified by the module name "pwsix". However in the C/asm/.o
namespaces, the module name is not used, so if I have a global function
named "read", it is intruding on the user's namespace.
With the import_field module, I can declare my function (in libc) to be
"__read", and then set the wasm import module to be "pwsix" and the wasm
import field to be "read". So at the C/asm/.o levels, my symbol is
outside the user namespace.
Differential Revision: https://reviews.llvm.org/D57602
llvm-svn: 352930
This adds a C/C++ attribute which corresponds to the LLVM IR wasm-import-module
attribute. It allows code to specify an explicit import module.
Differential Revision: https://reviews.llvm.org/D57160
llvm-svn: 352106
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
* Accept as an argument constants in range 0..63 (aligned with TI headers and linker scripts provided with TI GCC toolchain).
* Emit function attribute 'interrupt'='xx' instead of aliases (used in the backend to create a section for particular interrupt vector).
* Add more diagnostics.
Patch by Kristina Bessonova!
Differential Revision: https://reviews.llvm.org/D56663
llvm-svn: 351344
Summary:
- This adopts SwiftABIInfo as the base class for WebAssemblyABIInfo, which is in keeping with what is done for other targets for which Swift is supported.
- This is a minimal patch to unblock exploration of WASM support for Swift (https://bugs.swift.org/browse/SR-9307)
Reviewers: rjmccall, sunfish
Reviewed By: rjmccall
Subscribers: ahti, dschuff, sbc100, jgravelle-google, aheejin, cfe-commits
Differential Revision: https://reviews.llvm.org/D56188
llvm-svn: 350372
For arguments, pass it indirectly, since the ABI doc says pretty clearly
that arguments larger than 8 bytes are passed indirectly. This makes
va_list handling easier, anyway.
When returning, GCC returns in XMM0, and we match them.
Fixes PR39492.
llvm-svn: 345676
Adds support for -mno-stack-arg-probe and -mstack-probe-size.
(Not really happy copy-pasting code, but that's what we do for all the
other Windows targets.)
Differential Revision: https://reviews.llvm.org/D53617
llvm-svn: 345354
Summary:
On targets that do not support FP16 natively LLVM currently legalizes
vectors of FP16 values by scalarizing them and promoting to FP32. This
causes problems for the following code:
void foo(int, ...);
typedef __attribute__((neon_vector_type(4))) __fp16 float16x4_t;
void bar(float16x4_t x) {
foo(42, x);
}
According to the AAPCS (appendix A.2) float16x4_t is a containerized
vector fundamental type, so 'foo' expects that the 4 16-bit FP values
are packed into 2 32-bit registers, but instead bar promotes them to
4 single precision values.
Since we already handle scalar FP16 values in the frontend by
bitcasting them to/from integers, this patch adds similar handling for
vector types and homogeneous FP16 vector aggregates.
One existing test required some adjustments because we now generate
more bitcasts (so the patch changes the test to target a machine with
native FP16 support).
Reviewers: eli.friedman, olista01, SjoerdMeijer, javed.absar, efriedma
Reviewed By: javed.absar, efriedma
Subscribers: efriedma, kristof.beyls, cfe-commits, chrib
Differential Revision: https://reviews.llvm.org/D50507
llvm-svn: 342034
- Add a command line options -msign-return-address to enable return address
signing
- Armv8.3a added instructions to sign the return address to help mitigate
against ROP attacks
- This patch adds command line options to generate function attributes that
signal to the back whether return address signing instructions should be
added
Differential revision: https://reviews.llvm.org/D49793
llvm-svn: 340019
The "Procedure Call Procedure Call Standard for the ARM® Architecture"
(https://static.docs.arm.com/ihi0042/f/IHI0042F_aapcs.pdf), specifies that
composite types are passed according to their "natural alignment", i.e. the
alignment before alignment adjustment on the entire composite is applied.
The same applies for AArch64 ABI.
Clang, however, used the adjusted alignment.
GCC already implements the ABI correctly. With this patch Clang becomes
compatible with GCC and passes such arguments in accordance with AAPCS.
Differential Revision: https://reviews.llvm.org/D46013
llvm-svn: 338279
Summary:
Clang supports the GNU style ``__attribute__((interrupt))`` attribute on RISCV targets.
Permissible values for this parameter are user, supervisor, and machine.
If there is no parameter, then it defaults to machine.
Reference: https://gcc.gnu.org/onlinedocs/gcc/RISC-V-Function-Attributes.html
Based on initial patch by Zhaoshi Zheng.
Reviewers: asb, aaron.ballman
Reviewed By: asb, aaron.ballman
Subscribers: rkruppe, the_o, aaron.ballman, MartinMosbeck, brucehoult, rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, mgrang, rogfer01, cfe-commits
Differential Revision: https://reviews.llvm.org/D48412
llvm-svn: 338045
Update clang to treat fp128 as a valid base type for homogeneous aggregate
passing and returning.
Differential Revision: https://reviews.llvm.org/D48044
llvm-svn: 336308
The WebAssembly backend in particular benefits from being
able to distinguish between varargs functions (...) and prototype-less
C functions.
Differential Revision: https://reviews.llvm.org/D48443
llvm-svn: 335510
Currently clang set kernel calling convention for CUDA/HIP after
arranging function, which causes incorrect kernel function type since
it depends on calling convention.
This patch moves setting kernel convention before arranging
function.
Differential Revision: https://reviews.llvm.org/D47733
llvm-svn: 334457
This is similar to the LLVM change https://reviews.llvm.org/D46290.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.
Patch produced by
for i in $(git grep -l '\@brief'); do perl -pi -e 's/\@brief //g' $i & done
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done
Differential Revision: https://reviews.llvm.org/D46320
llvm-svn: 331834
Some targets need special LLVM calling convention for CUDA kernel.
This patch does that through a TargetCodeGenInfo hook.
It only affects amdgcn target.
Patch by Greg Rodgers.
Revised and lit tests added by Yaxun Liu.
Differential Revision: https://reviews.llvm.org/D45223
llvm-svn: 330447
The force_align_arg_pointer attribute was using a hardcoded 16-byte
alignment value which in combination with -mstack-alignment=32 (or
larger) would produce a misaligned stack which could result in crashes
when accessing stack buffers using aligned AVX load/store instructions.
Fix the issue by using the "stackrealign" function attribute instead
of using a hardcoded 16-byte alignment.
Patch By: Gramner
Differential Revision: https://reviews.llvm.org/D45812
llvm-svn: 330331
This reverts r328795 which introduced an issue with referencing __global__
function templates. More details in the original review D44747.
llvm-svn: 329099
This patch sets target specific calling convention for CUDA kernels in IR.
Patch by Greg Rodgers.
Revised and lit test added by Yaxun Liu.
Differential Revision: https://reviews.llvm.org/D44747
llvm-svn: 328795
ObjC and ObjC++ pass non-trivial structs in a way that is incompatible
with each other. For example:
typedef struct {
id f0;
__weak id f1;
} S;
// this code is compiled in c++.
extern "C" {
void foo(S s);
}
void caller() {
// the caller passes the parameter indirectly and destructs it.
foo(S());
}
// this function is compiled in c.
// 'a' is passed directly and is destructed in the callee.
void foo(S a) {
}
This patch fixes the incompatibility by passing and returning structs
with __strong or weak fields using the C ABI in C++ mode. __strong and
__weak fields in a struct do not cause the struct to be destructed in
the caller and __strong fields do not cause the struct to be passed
indirectly.
Also, this patch fixes the microsoft ABI bug mentioned here:
https://reviews.llvm.org/D41039?id=128767#inline-364710
rdar://problem/38887866
Differential Revision: https://reviews.llvm.org/D44908
llvm-svn: 328731
r327219 added wrappers to std::sort which randomly shuffle the container before
sorting. This will help in uncovering non-determinism caused due to undefined
sorting order of objects having the same key.
To make use of that infrastructure we need to invoke llvm::sort instead of
std::sort.
llvm-svn: 328636
Add two additional implicit arguments for OpenCL for the AMDGPU target using the AMDHSA runtime to support device enqueue.
Differential Revision: https://reviews.llvm.org/D44696
llvm-svn: 328350
- Remove use of the opencl and amdopencl environment member of the target triple for the AMDGPU target.
- Use a function attribute to communicate to the AMDGPU backend.
Differential Revision: https://reviews.llvm.org/D43735
llvm-svn: 328347
Pengfei Wang