The _GLOBAL_OFFSET_TABLE_ in SysVr4 ELF is conventionally the base of the
.got or .got.prel sections. Expressions such as _GLOBAL_OFFSET_TABLE_
- (.L1 +8) are used in assembler code to calculate offsets into the .got.
At present MC outputs a R_ARM_REL32 with respect to the
_GLOBAL_OFFSET_TABLE_ symbol, whereas gas outputs a R_ARM_BASE_PREL
relocation with respect to the _GLOBAL_OFFSET_TABLE_ symbol. While both are
correct the R_ARM_REL32 depends on the value of the _GLOBAL_OFFSET_TABLE_
symbol, wheras te R_ARM_BASE_PREL relocation is idependent of the symbol.
The R_ARM_BASE_PREL is therefore slightly more robust to linker's that may
not follow the conventional placement of _GLOBAL_OFFSET_TABLE_; for example
LLD for some time defined _GLOBAL_OFFSET_TABLE_ to 0.
Differential Revision: https://reviews.llvm.org/D46319
Leverage ARM ELF build attribute section to create ELF attribute section
for RISC-V. Extract the common part of parsing logic for this section
into ELFAttributeParser.[cpp|h] and ELFAttributes.[cpp|h].
Differential Revision: https://reviews.llvm.org/D74023
Generalizes D61992. In GNU as, the .reloc directive supports arbitrary relocation types.
A MCFixupKind value `V` larger than or equal to FirstLiteralRelocationKind
is used to represent the relocation type whose number is V-FirstLiteralRelocationKind.
This is useful for linker tests. Without the feature the assembler
cannot produce certain relocation records (e.g. R_ARM_ALU_PC_G0/R_ARM_LDR_PC_G0)
This helps move forward D75349 and D76575.
Differential Revision: https://reviews.llvm.org/D76746
Add a flag for those instructions which read from the top/bottom
halves of their inputs and produce a vector of results with double
width elements.
Differential Revision: https://reviews.llvm.org/D76762
Follow-up of D72172 and D72180
This patch passes `uint64_t Address` to print methods of PC-relative
operands so that subsequent target specific patches can change
`*InstPrinter::print{Operand,PCRelImm,...}` to customize the output.
Add MCInstPrinter::PrintBranchImmAsAddress which is set to true by
llvm-objdump.
```
// Current llvm-objdump -d output
aarch64: 20000: bl #0
ppc: 20000: bl .+4
x86: 20000: callq 0
// Ideal output
aarch64: 20000: bl 0x20000
ppc: 20000: bl 0x20004
x86: 20000: callq 0x20005
// GNU objdump -d. The lack of 0x is not ideal because the result cannot be re-assembled
aarch64: 20000: bl 20000
ppc: 20000: bl 0x20004
x86: 20000: callq 20005
```
In `lib/Target/X86/X86GenAsmWriter1.inc` (generated by `llvm-tblgen -gen-asm-writer`):
```
case 12:
// CALL64pcrel32, CALLpcrel16, CALLpcrel32, EH_SjLj_Setup, JCXZ, JECXZ, J...
- printPCRelImm(MI, 0, O);
+ printPCRelImm(MI, Address, 0, O);
return;
```
Some targets have 2 `printOperand` overloads, one without `Address` and
one with `Address`. They should annotate derived `Operand` properly with
`let OperandType = "OPERAND_PCREL"`.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D76574
Summary:
This patch introduces command-line support for the Armv8.6-a architecture and assembly support for BFloat16. Details can be found
https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/arm-architecture-developments-armv8-6-a
in addition to the GCC patch for the 8..6-a CLI:
https://gcc.gnu.org/legacy-ml/gcc-patches/2019-11/msg02647.html
In detail this patch
- march options for armv8.6-a
- BFloat16 assembly
This is part of a patch series, starting with command-line and Bfloat16
assembly support. The subsequent patches will upstream intrinsics
support for BFloat16, followed by Matrix Multiplication and the
remaining Virtualization features of the armv8.6-a architecture.
Based on work by:
- labrinea
- MarkMurrayARM
- Luke Cheeseman
- Javed Asbar
- Mikhail Maltsev
- Luke Geeson
Reviewers: SjoerdMeijer, craig.topper, rjmccall, jfb, LukeGeeson
Reviewed By: SjoerdMeijer
Subscribers: stuij, kristof.beyls, hiraditya, dexonsmith, danielkiss, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D76062
Add a target flag for instructions that reduce into one, or more,
scalar reg(s), including variants of:
- VADDV
- VABAV
- VMINV/VMAXV
- VMLADAV
Differential Revision: https://reviews.llvm.org/D76683
Add a flag, 'RetainsPreviousHalfElement', for operations that operate
on top/bottom halves of their input and only write to half of their
destination, leaving the other half to retain its previous value.
Differential Revision: https://reviews.llvm.org/D76608
Add ELF relocations for the following fixups:
fixup_thumb_adr_pcrel_10 -> R_ARM_THM_PC8
fixup_thumb_cp -> R_ARM_THM_PC8
fixup_t2_adr_pcrel_12 -> R_ARM_THM_PREL_11_0
fixup_t2_ldst_pcrel_12 -> R_ARM_THM_PC12
While these relocations are short-ranged there is support in the open
source ELF linker's in binutils and soon to be in LLD. MC will no longer
resolve pc-relative fixups to global symbols due to interpositioning
concerns. We can handle these at link time by implementing the relocations.
The R_ARM_THM_PC8 has some extra encoding rules for addends that llvm-mc
sidesteps by not supporting addends for these instructions, using the wide
Thumb 2 instruction if it is available. I think that this is a reasonable
compromise given that these are rare.
This partiall reverts D72892, the Thumb fixups no longer need to be
evaluated at assembly time.
Differential Revision: https://reviews.llvm.org/D75039
MC currently does not emit these relocation types, and lld does not
handle them. Add FKF_Constant as a work-around of some ARM code after
D72197. Eventually we probably should implement these relocation types.
By Fangrui Song!
Differential revision: https://reviews.llvm.org/D72892
Fixed an issue exposed by D74006.
In clang cc1as, MCContext::UseNamesOnTempLabels is true.
When parsing a .fnstart directive, FnStart gets redefined to a temporary symbol of a different name (.Ltmp0, .Ltmp1, ...).
MCContext::getELFSection() called by SwitchToEHSection() will create a different .ARM.exidx each time.
llvm-mc uses `Ctx.setUseNamesOnTempLabels(false);` and FnStart is unnamed.
MCContext::getELFSection() called by SwitchToEHSection() will reuse the same .ARM.exidx .
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D75095
This moves all the logic of converting LLVM Triples to
MachO::CPU_(SUB_)TYPE from the specific target (Target)AsmBackend to
more convenient functions in lib/BinaryFormat.
This also gets rid of the separate two X86AsmBackend classes.
The previous attempt was to add it to libObject, but that adds an
unnecessary dependency to libObject from all the targets.
Differential Revision: https://reviews.llvm.org/D74808
The code at https://reviews.llvm.org/D74808 has broken builds that are
configured with -DBUILD_SHARED_LIBS=On.
This patch adds the correct library dependencies.
This moves all the logic of converting LLVM Triples to
MachO::CPU_(SUB_)TYPE from the specific target (Target)AsmBackend to
more convenient functions in libObject.
This also gets rid of the separate two X86AsmBackend classes.
Differential Revision: https://reviews.llvm.org/D74808
Summary:
This patch adds assembly-level support for a new Arm M-profile
architecture extension, Custom Datapath Extension (CDE).
A brief description of the extension is available at
https://developer.arm.com/architectures/instruction-sets/custom-instructions
The latest specification for CDE is currently a beta release and is
available at
https://static.docs.arm.com/ddi0607/aa/DDI0607A_a_armv8m_arm_supplement_cde.pdf
CDE allows chip vendors to add custom CPU instructions. The CDE
instructions re-use the same encoding space as existing coprocessor
instructions (such as MRC, MCR, CDP etc.). Each coprocessor in range
cp0-cp7 can be configured as either general purpose (GCP) or custom
datapath (CDEv1). This configuration is defined by the CPU vendor and
is provided to LLVM using 8 subtarget features: cdecp0 ... cdecp7.
The semantics of CDE instructions are implementation-defined, but the
instructions are guaranteed to be pure (that is, they are stateless,
they do not access memory or any registers except their explicit
inputs/outputs).
CDE requires the CPU to support at least Armv8.0-M mainline
architecture. CDE includes 3 sets of instructions:
* Instructions that operate on general purpose registers and NZCV
flags
* Instructions that operate on the S or D register file (require
either FP or MVE extension)
* Instructions that operate on the Q register file, require MVE
The user-facing names that can be specified on the command line are
the same as the 8 subtarget feature names. For example:
$ clang -target arm-none-none-eabi -march=armv8m.main+cdecp0+cdecp3
tells the compiler that the coprocessors 0 and 3 are configured as
CDEv1 and the remaining coprocessors are configured as GCP (which is
the default).
Reviewers: simon_tatham, ostannard, dmgreen, eli.friedman
Reviewed By: simon_tatham
Subscribers: kristof.beyls, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D74044
Summary:
After following Simon's suggestion about additional testing posted at
https://reviews.llvm.org/D73906, I found several more places that
need to be updated.
Reviewers: simon_tatham, dmgreen, ostannard, eli.friedman
Reviewed By: simon_tatham
Subscribers: merge_guards_bot, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73963
This adds some missing MVE opcodes to evaluateBranch, which results in
llvm-objdump being able to print the PC relative branch target as an
annotation.
Differential Revision: https://reviews.llvm.org/D73553
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
Summary:
In NEON, the immediate forms of VBIC and VORR are each represented as
a single MC instruction, which takes its immediate operand already
encoded in a NEON-friendly format: 8 data bits, plus some control bits
indicating how to expand them into a full vector.
In MVE, we represented immediate VBIC and VORR as four separate MC
instructions each, for an 8-bit immediate shifted left by 0, 8, 16 or
24 bits. For each one, the value of the immediate operand is in the
'natural' form, i.e. the numerical value that would actually be BICed
or ORRed into each vector lane (and also the same value shown in
assembly). For example, MVE_VBICIZ16v4i32 takes an operand such as
0xab0000, which NEON would represent as 0xab | (control bits << 8).
The MVE approach is superficially nice (it makes assembly input and
output easy, and it's also nice if you're manually constructing
immediate VBICs). But it turns out that it's better for isel if we
make the NEON and MVE instructions work the same, because the
ARMISD::VBICIMM and VORRIMM node types already encode their immediate
into the NEON format, so it's easier if we can just use it.
Also, this commit reduces the total amount of code rather than
increasing it, which is surely an indication that it really is simpler
to do it this way!
Reviewers: dmgreen, ostannard, miyuki, MarkMurrayARM
Reviewed By: dmgreen
Subscribers: kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73205
Summary:
For builds with LLVM_BUILD_LLVM_DYLIB=ON and BUILD_SHARED_LIBS=OFF
this change makes all symbols in the target specific libraries hidden
by default.
A new macro called LLVM_EXTERNAL_VISIBILITY has been added to mark symbols in these
libraries public, which is mainly needed for the definitions of the
LLVMInitialize* functions.
This patch reduces the number of public symbols in libLLVM.so by about
25%. This should improve load times for the dynamic library and also
make abi checker tools, like abidiff require less memory when analyzing
libLLVM.so
One side-effect of this change is that for builds with
LLVM_BUILD_LLVM_DYLIB=ON and LLVM_LINK_LLVM_DYLIB=ON some unittests that
access symbols that are no longer public will need to be statically linked.
Before and after public symbol counts (using gcc 8.2.1, ld.bfd 2.31.1):
nm before/libLLVM-9svn.so | grep ' [A-Zuvw] ' | wc -l
36221
nm after/libLLVM-9svn.so | grep ' [A-Zuvw] ' | wc -l
26278
Reviewers: chandlerc, beanz, mgorny, rnk, hans
Reviewed By: rnk, hans
Subscribers: merge_guards_bot, luismarques, smeenai, ldionne, lenary, s.egerton, pzheng, sameer.abuasal, MaskRay, wuzish, echristo, Jim, hiraditya, michaelplatings, chapuni, jholewinski, arsenm, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, javed.absar, sbc100, jgravelle-google, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, mgrang, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, kristina, jsji, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D54439
printInst prints a branch/call instruction as `b offset` (there are many
variants on various targets) instead of `b address`.
It is a convention to use address instead of offset in most external
symbolizers/disassemblers. This difference makes `llvm-objdump -d`
output unsatisfactory.
Add `uint64_t Address` to printInst(), so that it can pass the argument to
printInstruction(). `raw_ostream &OS` is moved to the last to be
consistent with other print* methods.
The next step is to pass `Address` to printInstruction() (generated by
tablegen from the instruction set description). We can gradually migrate
targets to print addresses instead of offsets.
In any case, downstream projects which don't know `Address` can pass 0 as
the argument.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D72172
This simplifies the generic interface and also makes SHF_ARM_PURECODE
more robust (fixes a TODO). Inspecting MCDataFragment contents covers
more cases than MCObjectStreamer::EmitBytes.
Summary:
Most libraries are defined in the lib/ directory but there are also a
few libraries defined in tools/ e.g. libLLVM, libLTO. I'm defining
"Component Libraries" as libraries defined in lib/ that may be included in
libLLVM.so. Explicitly marking the libraries in lib/ as component
libraries allows us to remove some fragile checks that attempt to
differentiate between lib/ libraries and tools/ libraires:
1. In tools/llvm-shlib, because
llvm_map_components_to_libnames(LIB_NAMES "all") returned a list of
all libraries defined in the whole project, there was custom code
needed to filter out libraries defined in tools/, none of which should
be included in libLLVM.so. This code assumed that any library
defined as static was from lib/ and everything else should be
excluded.
With this change, llvm_map_components_to_libnames(LIB_NAMES, "all")
only returns libraries that have been added to the LLVM_COMPONENT_LIBS
global cmake property, so this custom filtering logic can be removed.
Doing this also fixes the build with BUILD_SHARED_LIBS=ON
and LLVM_BUILD_LLVM_DYLIB=ON.
2. There was some code in llvm_add_library that assumed that
libraries defined in lib/ would not have LLVM_LINK_COMPONENTS or
ARG_LINK_COMPONENTS set. This is only true because libraries
defined lib lib/ use LLVMBuild.txt and don't set these values.
This code has been fixed now to check if the library has been
explicitly marked as a component library, which should now make it
easier to remove LLVMBuild at some point in the future.
I have tested this patch on Windows, MacOS and Linux with release builds
and the following combinations of CMake options:
- "" (No options)
- -DLLVM_BUILD_LLVM_DYLIB=ON
- -DLLVM_LINK_LLVM_DYLIB=ON
- -DBUILD_SHARED_LIBS=ON
- -DBUILD_SHARED_LIBS=ON -DLLVM_BUILD_LLVM_DYLIB=ON
- -DBUILD_SHARED_LIBS=ON -DLLVM_LINK_LLVM_DYLIB=ON
Reviewers: beanz, smeenai, compnerd, phosek
Reviewed By: beanz
Subscribers: wuzish, jholewinski, arsenm, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, mgorny, mehdi_amini, sbc100, jgravelle-google, hiraditya, aheejin, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, steven_wu, rogfer01, MartinMosbeck, brucehoult, the_o, dexonsmith, PkmX, jocewei, jsji, dang, Jim, lenary, s.egerton, pzheng, sameer.abuasal, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70179
In MCObjectStreamer, when there is no current fragment, initially
symbols are created in a "pending" state and assigned to a dummy
empty fragment.
Previously, they were not being assigned an offset, and thus
evaluateAbsolute would fail if trying to evaluate an expression 'a -
b', where both 'a' and 'b' were in this pending state.
Also slightly refactored the EmitLabel overload which takes an
MCFragment for clarity.
Fixes: https://llvm.org/PR41825
Differential Revision: https://reviews.llvm.org/D70062
These relocations are specified by the ARM EHABI (section 6.3). As I understand
it, their purpose is to accommodate unwinder implementations that wish to
reduce code size by placing the implementations of the compact unwinding
decoders in a separate translation unit, and using extern weak symbols to
refer to them from the main unwinder implementation, so that they are only
linked when something in the binary needs them in order to unwind.
However, neither of the unwinders used on Android (libgcc, LLVM libunwind)
use this technique, and in fact emitting these relocations ends up being
counterproductive to code size because they cause a copy of the unwinder
to be statically linked into most binaries, regardless of whether it is
actually needed. Furthermore, these relocations create circular dependencies
(between libc and the unwinder) in cases where the unwinder is dynamically
linked and libc contains compact unwind info.
Therefore, deviate from the EHABI here and stop emitting these relocations
on Android.
Differential Revision: https://reviews.llvm.org/D70027
MipsMCAsmInfo was using '$' prefix for Mips32 and '.L' for Mips64
regardless of -target-abi option. By passing MCTargetOptions to MCAsmInfo
we can find out Mips ABI and pick appropriate prefix.
Tags: #llvm, #clang, #lldb
Differential Revision: https://reviews.llvm.org/D66795
Reverse the logic for valid tail predication instructions and create
a whitelist instead. Added other instruction groups that aren't
obviously safe:
- instructions that 'narrow' their result.
- lane moves.
- byte swapping instructions.
- interleaving loads and stores.
- cross-beat carries.
- top/bottom instructions.
- complex operations.
Hopefully we should be able to add more of these instructions to the
whitelist, once we have a more concrete idea of the transform.
Differential Revision: https://reviews.llvm.org/D67904
llvm-svn: 374887
Summary:
The functions different in two ways:
- getLLVMRegNum could return both "eh" and "other" dwarf register
numbers, while getLLVMRegNumFromEH only returned the "eh" number.
- getLLVMRegNum asserted if the register was not found, while the second
function returned -1.
The second distinction was pretty important, but it was very hard to
infer that from the function name. Aditionally, for the use case of
dumping dwarf expressions, we needed a function which can work with both
kinds of number, but does not assert.
This patch solves both of these issues by merging the two functions into
one, returning an Optional<unsigned> value. While the same thing could
be achieved by adding an "IsEH" argument to the (renamed)
getLLVMRegNumFromEH function, it seemed better to avoid the confusion of
two functions and put the choice of asserting into the hands of the
caller -- if he checks the Optional value, he can safely process
"untrusted" input, and if he blindly dereferences the Optional, he gets
the assertion.
I've updated all call sites to the new API, choosing between the two
options according to the function they were calling originally, except
that I've updated the usage in DWARFExpression.cpp to use the "safe"
method instead, and added a test case which would have previously
triggered an assertion failure when processing (incorrect?) dwarf
expressions.
Reviewers: dsanders, arsenm, JDevlieghere
Subscribers: wdng, aprantl, javed.absar, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67154
llvm-svn: 372710
r361845 changed the way we handle "D16" vs. "D32" targets; there used to
be a negative "d16" which removed instructions from the instruction set,
and now there's a "d32" feature which adds instructions to the
instruction set. This is good, but there was an oversight in the
implementation: the behavior of VFPv2 was changed. In particular, the
"vfp2" feature was changed to imply "d32". This is wrong: VFPv2 only
supports 16 D registers.
In practice, this means if you specify -mfpu=vfpv2, the compiler will
generate illegal instructions.
This patch gets rid of "vfp2d16" and "vfp2d16sp", and fixes "vfp2" and
"vfp2sp" so they don't imply "d32".
Differential Revision: https://reviews.llvm.org/D67375
llvm-svn: 372186
Set this bit for the MVE reduction instructions to prevent a loop from
becoming tail predicated in their presence.
Differential Revision: https://reviews.llvm.org/D67444
llvm-svn: 372076
These flags should simply be passed through to the target, which will do
the right thing. Add an MC/X86 test that uses these directives with the
three primary object file formats and shows that they disassemble the
same everywhere.
There is a missing test for .code32 on Windows ARM, since I'm not sure
exactly how to construct one.
Fixes PR43203
llvm-svn: 370805
Prefer `MCFixupKind` where possible and add getTargetKind() to
convert to `unsigned` when needed rather than scattering cast
operators around the place.
Differential Revision: https://reviews.llvm.org/D59890
llvm-svn: 369720
Fangrui Song