Arm64EC has two different ways to refer to dllimport'ed functions in an
object file. One is using the usual __imp_ prefix, the other is using an
Arm64EC-specific prefix __imp_aux_. As far as I can tell, if a function
is in an x64 DLL, __imp_aux_ refers to the actual x64 address, while
__imp_ points to some linker-generated code that calls the exit thunk.
So __imp_aux_ is used to refer to the address in non-call contexts,
while __imp_ is used for calls to avoid the indirect call checker.
There's one twist to this, though: if an object refers to a symbol using
the __imp_aux_ prefix, the object file's symbol table must also contain
the symbol with the usual __imp_ prefix. The symbol doesn't actually
have to be used anywhere, it just has to exist; otherwise, the linker's
symbol lookup in x64 import libraries doesn't work correctly. Currently,
this is handled by emitting a .globl __imp_foo directive; we could try
to design some better way to handle this.
One minor quirk I haven't figured out: apparently, in Arm64EC mode, MSVC
prefers to use a linker-synthesized stub to call dllimport'ed functions,
instead of branching directly. The linker stub appears to do the same
thing that inline code would do, so not sure if it's just a code-size
optimization, or if the synthesized stub can actually do something other
than just load from the import table in some circumstances.
Differential Revision: https://reviews.llvm.org/D136202
Similar to X86 D73230 & 46788a21f9152be3950e57dc526454655682bdd4
With this change, we can set dso_local in clang's -fpic -fno-semantic-interposition mode,
for default visibility external linkage non-ifunc-non-COMDAT definitions.
For such dso_local definitions, variable access/taking the address of a
function/calling a function will go through a local alias to avoid GOT/PLT.
Note: the 'S' inline assembly constraint refers to an absolute symbolic address
or a label reference (D46745).
Differential Revision: https://reviews.llvm.org/D101872
This makes sure that assembly output actually can be assembled.
Set the correct MCExpr relocations specifier VK_PAGEOFF - and also
set VK_PAGE consistently even though it's not visible in the assembly
output.
Differential Revision: https://reviews.llvm.org/D94365
This feature instructs the backend to allow locally defined global variable
addresses to contain a pointer tag in bits 56-63 that will be ignored by
the hardware (i.e. TBI), but may be used by an instrumentation pass such
as HWASAN. It works by adding a MOVK instruction to the regular ADRP/ADD
sequence that sets bits 48-63 to the corresponding bits of the global, with
the linker bounds check disabled on the ADRP instruction to prevent the tag
from causing a link failure.
This implementation of the feature omits the MOVK when loading from or storing
to a global, which is sufficient for TBI. If the same approach is extended
to MTE, assuming that 0 is not configured as a catch-all tag, we will most
likely also need the MOVK in this case in order to avoid a tag mismatch.
Differential Revision: https://reviews.llvm.org/D65364
llvm-svn: 367475
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
Summary:
D55896 and D56029 add support to emit fixups for :abs_g0: , :abs_g1_s: , etc.
This patch adds the necessary enums and MCExpr needed for lowering these.
Reviewers: rnk, mstorsjo, efriedma
Reviewed By: efriedma
Subscribers: javed.absar, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D56037
llvm-svn: 350798
This patch adds support for funclets in frame lowering and ISel
lowering. Together with D50288 and D50166, it enables C++ exception
handling.
Patch by Sanjin Sijaric, with some fixes by me.
Differential Revision: https://reviews.llvm.org/D51524
llvm-svn: 346568
The runtime pseudo relocations can't handle the AArch64 format PC
relative addressing in adrp+add/ldr pairs. By using stubs, the potentially
dllimported addresses can be touched up by the runtime pseudo relocation
framework.
Differential Revision: https://reviews.llvm.org/D51452
llvm-svn: 341401
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).
llvm-svn: 318490
Previously, the dllimport attribute did the right thing in terms
of treating it as a pointer to a value, but this makes sure the
names get mangled properly, and calls to such functions load the
function from the __imp_ pointer.
This is based on SVN r212431 and r212430 where the same was
implemented for ARM.
Differential Revision: https://reviews.llvm.org/D38530
llvm-svn: 316555
Summary:
This is the llvm part of the initial implementation to support Windows ARM64 COFF format.
I will gradually add more functionality in subsequent patches.
Reviewers: ruiu, rnk, t.p.northover, compnerd
Reviewed By: ruiu, compnerd
Subscribers: aemerson, mgorny, javed.absar, llvm-commits, kristof.beyls
Differential Revision: https://reviews.llvm.org/D34705
llvm-svn: 306490
The summary is that it moves the mangling earlier and replaces a few
calls to .addExternalSymbol with addSym.
I originally wanted to replace all the uses of addExternalSymbol with
addSym, but noticed it was a lot of work and doesn't need to be done
all at once.
llvm-svn: 240395
As is described at http://llvm.org/bugs/show_bug.cgi?id=22408, the GNU linkers
ld.bfd and ld.gold currently only support a subset of the whole range of AArch64
ELF TLS relocations. Furthermore, they assume that some of the code sequences to
access thread-local variables are produced in a very specific sequence.
When the sequence is not as the linker expects, it can silently mis-relaxe/mis-optimize
the instructions.
Even if that wouldn't be the case, it's good to produce the exact sequence,
as that ensures that linkers can perform optimizing relaxations.
This patch:
* implements support for 16MiB TLS area size instead of 4GiB TLS area size. Ideally clang
would grow an -mtls-size option to allow support for both, but that's not part of this patch.
* by default doesn't produce local dynamic access patterns, as even modern ld.bfd and ld.gold
linkers do not support the associated relocations. An option (-aarch64-elf-ldtls-generation)
is added to enable generation of local dynamic code sequence, but is off by default.
* makes sure that the exact expected code sequence for local dynamic and general dynamic
accesses is produced, by making use of a new pseudo instruction. The patch also removes
two (AArch64ISD::TLSDESC_BLR, AArch64ISD::TLSDESC_CALL) pre-existing AArch64-specific pseudo
SDNode instructions that are superseded by the new one (TLSDESC_CALLSEQ).
llvm-svn: 231227
This commit starts with a "git mv ARM64 AArch64" and continues out
from there, renaming the C++ classes, intrinsics, and other
target-local objects for consistency.
"ARM64" test directories are also moved, and tests that began their
life in ARM64 use an arm64 triple, those from AArch64 use an aarch64
triple. Both should be equivalent though.
This finishes the AArch64 merge, and everyone should feel free to
continue committing as normal now.
llvm-svn: 209577
I'm doing this in two phases for a better "git blame" record. This
commit removes the previous AArch64 backend and redirects all
functionality to ARM64. It also deduplicates test-lines and removes
orphaned AArch64 tests.
The next step will be "git mv ARM64 AArch64" and rewire most of the
tests.
Hopefully LLVM is still functional, though it would be even better if
no-one ever had to care because the rename happens straight
afterwards.
llvm-svn: 209576
Patch by Ana Pazos.
- Completed implementation of instruction formats:
AdvSIMD three same
AdvSIMD modified immediate
AdvSIMD scalar pairwise
- Completed implementation of instruction classes
(some of the instructions in these classes
belong to yet unfinished instruction formats):
Vector Arithmetic
Vector Immediate
Vector Pairwise Arithmetic
- Initial implementation of instruction formats:
AdvSIMD scalar two-reg misc
AdvSIMD scalar three same
- Intial implementation of instruction class:
Scalar Arithmetic
- Initial clang changes to support arm v8 intrinsics.
Note: no clang changes for scalar intrinsics function name mangling yet.
- Comprehensive test cases for added instructions
To verify auto codegen, encoding, decoding, diagnosis, intrinsics.
llvm-svn: 187567
The MOVZ/MOVK instruction sequence may not be the most efficient (a
literal-pool load could be better) but adding that would require
reinstating the ConstantIslands pass.
For now the sequence is correct, and that's enough. Beware, as of
commit GNU ld does not appear to support the relocations needed for
this. Its primary purpose (for now) will be to support JITed code,
since in that case there is no guarantee of where your code will end
up in memory relative to external symbols it references.
llvm-svn: 181117
This moves the bit twiddling and string fiddling functions required by other
parts of the backend into a separate library. Previously they resided in
AArch64Desc, which created a circular dependency between various components.
llvm-svn: 174369
This patch adds support for AArch64 (ARM's 64-bit architecture) to
LLVM in the "experimental" category. Currently, it won't be built
unless requested explicitly.
This initial commit should have support for:
+ Assembly of all scalar (i.e. non-NEON, non-Crypto) instructions
(except the late addition CRC instructions).
+ CodeGen features required for C++03 and C99.
+ Compilation for the "small" memory model: code+static data <
4GB.
+ Absolute and position-independent code.
+ GNU-style (i.e. "__thread") TLS.
+ Debugging information.
The principal omission, currently, is performance tuning.
This patch excludes the NEON support also reviewed due to an outbreak of
batshit insanity in our legal department. That will be committed soon bringing
the changes to precisely what has been approved.
Further reviews would be gratefully received.
llvm-svn: 174054
