Commit Graph

809 Commits

Author SHA1 Message Date
Mark Murray 3ce0ad1b33 [ARM][MC][Thumb] Revert relocation for some pc-relative fixups.
Summary:
This commit reverts https://reviews.llvm.org/D75039. Concensus appears to
be in favour of assembly-time resolution of these ADR and LDR relocations,
in line with GNU.

Reviewers: psmith

Subscribers: kristof.beyls, hiraditya, danielkiss, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D78301
2020-04-20 09:38:12 +01:00
Fangrui Song 7d1ff446b6 [MC] Rename MCSection*::getSectionName() to getName(). NFC
A pending change will merge MCSection*::getName() to MCSection::getName().
2020-04-15 16:48:14 -07:00
Sam Parker dd8153b757 [ARM][MVE] Tail predicate VML[A|S]LDAV
Make the non-exchanging versions of the multiply add/sub instructions
validForTailPredication.

Differential Revision: https://reviews.llvm.org/D77648
2020-04-15 11:34:39 +01:00
Peter Smith 31c8e11896 [MC][ARM] Emit R_ARM_BASE_PREL for _GLOBAL_OFFSET_TABLE_ expressions
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
2020-04-14 10:13:21 +01:00
Fangrui Song 0a55d3f557 [MC] Default MCAsmInfo::UseIntegratedAssembler to true 2020-04-11 10:13:52 -07:00
Kai Wang 581ba35291 [RISCV] ELF attribute section for RISC-V.
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
2020-03-31 16:16:19 +08:00
Fangrui Song c389526171 [MC][ARM] Make .reloc support arbitrary relocation types
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
2020-03-27 12:29:49 -07:00
Sam Parker 0e6aa08381 [ARM][MVE] Add DoubleWidthResult flag
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
2020-03-27 13:44:04 +00:00
Fangrui Song 6728a9ae19 [MCInstPrinter] Add parameter `Address` to printCustomAliasOperand. NFC
Follow-up of D72172 and llvmorg-11-init-6896-gb3cc5dcef0f.
2020-03-27 00:38:20 -07:00
Fangrui Song b3cc5dcef0 [MCInstPrinter] Add parameter `Address` to MCInstPrinter::printAliasInstr. NFC
Follow-up of D72172.
2020-03-27 00:03:32 -07:00
Fangrui Song 5fad05e80d [MCInstPrinter] Pass `Address` parameter to MCOI::OPERAND_PCREL typed operands. NFC
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
2020-03-26 08:21:15 -07:00
Ties Stuij 71ae267d1f [PATCH] [ARM] ARMv8.6-a command-line + BFloat16 Asm Support
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
2020-03-26 09:17:20 +00:00
Sam Parker e87250202d [ARM][MVE] Add HorizontalReduction flag
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
2020-03-25 11:12:03 +00:00
Sam Parker 6f86e6bf40 [ARM][MVE] Add target flag for narrowing insts
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
2020-03-24 08:36:44 +00:00
Fangrui Song 692e0c9648 [MC] Add MCStreamer::emitInt{8,16,32,64}
Similar to AsmPrinter::emitInt{8,16,32,64}.
2020-02-29 09:40:21 -08:00
Peter Smith 2a92fc9b8e [MC][ELF][ARM] Add relocations for some pc-relative fixups
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
2020-02-28 11:29:29 +00:00
Hans Wennborg 2e24219d3c [MC][ARM] Resolve some pcrel fixups at assembly time (PR44929)
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
2020-02-27 12:43:29 +01:00
Fangrui Song d0c4277d38 [MC][ARM] Don't create multiple .ARM.exidx associated to one .text
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
2020-02-25 18:18:13 -08:00
Fangrui Song fad1c750f1 [AArch64][SVE] Fix -DBUILD_SHARED_LIBS=on builds after -D74808/1874dee5662603c9251228c71b66de72cec0c979 2020-02-21 13:59:47 -08:00
Francis Visoiu Mistrih 1874dee566 [macho][NFC] Extract all CPU_(SUB_)TYPE logic to BinaryFormat
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
2020-02-21 12:43:29 -08:00
Francesco Petrogalli 0c8fa6db90 [llvm][build] Fix shared lib builds. [NFC]
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.
2020-02-20 19:42:53 +00:00
Francis Visoiu Mistrih 3f785212e9 Revert "[macho][NFC] Extract all CPU_(SUB_)TYPE logic to libObject"
This reverts commit 726c342ce2.

This breaks the windows bots with linker errors.
2020-02-20 10:51:25 -08:00
Francis Visoiu Mistrih 726c342ce2 [macho][NFC] Extract all CPU_(SUB_)TYPE logic to libObject
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
2020-02-20 10:28:07 -08:00
Mikhail Maltsev dd4d093762 [ARM] Add initial support for Custom Datapath Extension (CDE)
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
2020-02-17 15:39:16 +00:00
Fangrui Song 774971030d [MCStreamer] De-capitalize EmitValue EmitIntValue{,InHex} 2020-02-14 23:08:40 -08:00
Fangrui Song 6d2d589b06 [MC] De-capitalize another set of MCStreamer::Emit* functions
Emit{ValueTo,Code}Alignment Emit{DTP,TP,GP}* EmitSymbolValue etc
2020-02-14 19:26:52 -08:00
Fangrui Song a55daa1461 [MC] De-capitalize some MCStreamer::Emit* functions 2020-02-14 19:11:53 -08:00
Fangrui Song bcd24b2d43 [AsmPrinter][MCStreamer] De-capitalize EmitInstruction and EmitCFI* 2020-02-13 22:08:55 -08:00
Fangrui Song 0bc77a0f0d [AsmPrinter] De-capitalize some AsmPrinter::Emit* functions
Similar to rL328848.
2020-02-13 13:38:33 -08:00
David Spickett a05566c994 [ARM] Correct missing newline after outputting .tlsdescseq directive.
Differential Revision: https://reviews.llvm.org/D73972
2020-02-04 17:38:09 +00:00
Mikhail Maltsev 65b3b6c0ac [ARM] Make ARM::ArchExtKind use 64-bit underlying type (part 2), NFCI
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
2020-02-04 14:48:10 +00:00
Sjoerd Meijer f719b0ba13 [MVE][MC] evaluateBranch: add missing MVE opcode
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
2020-01-29 13:19:45 +00:00
Benjamin Kramer adcd026838 Make llvm::StringRef to std::string conversions explicit.
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.
2020-01-28 23:25:25 +01:00
Simon Tatham 772e493193 [ARM,MVE] Revise immediate VBIC/VORR to look more like NEON.
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
2020-01-23 11:53:52 +00:00
Tom Stellard 0dbcb36394 CMake: Make most target symbols hidden by default
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
2020-01-14 19:46:52 -08:00
Fangrui Song 3d87d0b925 [MC] Add parameter `Address` to MCInstrPrinter::printInstruction
Follow-up of D72172.

Reviewed By: jhenderson, rnk

Differential Revision: https://reviews.llvm.org/D72180
2020-01-06 20:44:14 -08:00
Fangrui Song aa708763d3 [MC] Add parameter `Address` to MCInstPrinter::printInst
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
2020-01-06 20:42:22 -08:00
James Henderson d68904f957 [NFC] Fix trivial typos in comments
Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D72143

Patch by Kazuaki Ishizaki.
2020-01-06 10:50:26 +00:00
Fangrui Song 5511861e6d [MC][ARM] Delete MCSection::HasData and move SHF_ARM_PURECODE logic to ARMELFObjectWriter::addTargetSectionFlags
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.
2020-01-05 14:20:34 -08:00
Tom Stellard ab411801b8 [cmake] Explicitly mark libraries defined in lib/ as "Component Libraries"
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
2019-11-21 10:48:08 -08:00
James Y Knight bf142fc433 MCObjectStreamer: assign MCSymbols in the dummy fragment to offset 0.
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
2019-11-16 09:52:07 -05:00
Peter Collingbourne 1549b4699a ARM: Don't emit R_ARM_NONE relocations to compact unwinding decoders in .ARM.exidx on Android.
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
2019-11-12 10:52:59 -08:00
Jian Cai a6b0219fc4 Revert "[ARM] Uses "Sun Style" syntax for section switching"
This reverts commit 03de2f84fc.
2019-10-25 14:03:07 -07:00
Jian Cai 03de2f84fc [ARM] Uses "Sun Style" syntax for section switching
Summary:
Support "Sun Style" syntax for section switching ("#alloc,#write" etc).
https://bugs.llvm.org/show_bug.cgi?id=43759

Reviewers: peter.smith, eli.friedman, kristof.beyls, t.p.northover

Reviewed By: peter.smith

Subscribers: MaskRay, llozano, manojgupta, nickdesaulniers, kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69296
2019-10-25 13:27:35 -07:00
Mirko Brkusanin 4b63ca1379 [Mips] Use appropriate private label prefix based on Mips ABI
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
2019-10-23 12:24:35 +02:00
Sam Parker ce39278f25 [ARM][MVE] validForTailPredication insts
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
2019-10-15 13:12:51 +00:00
Pavel Labath aaff1a631a MCRegisterInfo: Merge getLLVMRegNum and getLLVMRegNumFromEH
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
2019-09-24 09:31:02 +00:00
Eli Friedman ddf5e86c22 [ARM] VFPv2 only supports 16 D registers.
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
2019-09-17 21:42:38 +00:00
Sam Parker 26a475afe5 [ARM][MVE] Add invalidForTailPredication to TSFlags
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
2019-09-17 07:43:04 +00:00
Reid Kleckner b2d10cf22e [MC] Pass through .code16/32/64 and .syntax unified for COFF
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
2019-09-03 18:16:52 +00:00
Sam Clegg 90b6bb75e8 [MC] Minor cleanup to MCFixup::Kind handling. NFC.
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
2019-08-23 01:00:55 +00:00
Jonas Devlieghere 0eaee545ee [llvm] Migrate llvm::make_unique to std::make_unique
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.

llvm-svn: 369013
2019-08-15 15:54:37 +00:00
Momchil Velikov f990e4a4c7 [ARM] Fix encoding of APSR in CLRM instruction
The APSR is encoded by setting bit 15 in the register list of the CLRM
instruction (cf. https://static.docs.arm.com/ddi0553/bh/DDI0553B_h_armv8m_arm.pdf).

Differential Revision: https://reviews.llvm.org/D65873

llvm-svn: 368711
2019-08-13 16:12:46 +00:00
David Green fdedf240f8 [ARM] Rename NEONModImm to VMOVModImm. NFC
Rename NEONModImm to VMOVModImm as it is used in both NEON and MVE.

llvm-svn: 366790
2019-07-23 09:19:24 +00:00
Mikhail Maltsev 0b001f94a5 [ARM] Add <saturate> operand to SQRSHRL and UQRSHLL
Summary:
According to the new Armv8-M specification
https://static.docs.arm.com/ddi0553/bh/DDI0553B_h_armv8m_arm.pdf the
instructions SQRSHRL and UQRSHLL now have an additional immediate
operand <saturate>. The new assembly syntax is:

SQRSHRL<c> RdaLo, RdaHi, #<saturate>, Rm
UQRSHLL<c> RdaLo, RdaHi, #<saturate>, Rm

where <saturate> can be either 64 (the existing behavior) or 48, in
that case the result is saturated to 48 bits.

The new operand is encoded as follows:
  #64 Encoded as sat = 0
  #48 Encoded as sat = 1
sat is bit 7 of the instruction bit pattern.

This patch adds a new assembler operand class MveSaturateOperand which
implements parsing and encoding. Decoding is implemented in
DecodeMVEOverlappingLongShift.

Reviewers: ostannard, simon_tatham, t.p.northover, samparker, dmgreen, SjoerdMeijer

Reviewed By: simon_tatham

Subscribers: javed.absar, kristof.beyls, hiraditya, pbarrio, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64810

llvm-svn: 366555
2019-07-19 09:46:28 +00:00
Simon Tatham 29ff1b4f46 [ARM] Fix integer UB in MVE load/store immediate handling.
llvm-svn: 364635
2019-06-28 09:28:39 +00:00
Mikhail Maltsev 6dcbb3161e [ARM] Handle fixup_arm_pcrel_9 correctly on big-endian targets
Summary:
The getFixupKindContainerSizeBytes function returns the size of the
instruction containing a given fixup. Currently fixup_arm_pcrel_9 is
not handled in this function, this causes an assertion failure in
the debug build and incorrect codegen in the release build.

This patch fixes the problem.

Reviewers: ostannard, simon_tatham

Reviewed By: ostannard

Subscribers: javed.absar, kristof.beyls, hiraditya, pbarrio, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63778

llvm-svn: 364404
2019-06-26 10:48:40 +00:00
Simon Tatham 287f0403e3 [ARM] Fix buildbot failure due to -Werror.
Including both 'case ARM_AM::uxtw' and 'default' in the getShiftOp
switch caused a buildbot to fail with

error: default label in switch which covers all enumeration values [-Werror,-Wcovered-switch-default]
llvm-svn: 364300
2019-06-25 12:23:46 +00:00
Simon Tatham e6824160dd [ARM] Add MVE vector load/store instructions.
This adds the rest of the vector memory access instructions. It
includes contiguous loads/stores, with an ordinary addressing mode
such as [r0,#offset] (plus writeback variants); gather loads and
scatter stores with a scalar base address register and a vector of
offsets from it (written [r0,q1] or similar); and gather/scatters with
a vector of base addresses (written [q0,#offset], again with
writeback). Additionally, some of the loads can widen each loaded
value into a larger vector lane, and the corresponding stores narrow
them again.

To implement these, we also have to add the addressing modes they
need. Also, in AsmParser, the `isMem` query function now has
subqueries `isGPRMem` and `isMVEMem`, according to which kind of base
register is used by a given memory access operand.

I've also had to add an extra check in `checkTargetMatchPredicate` in
the AsmParser, without which our last-minute check of `rGPR` register
operands against SP and PC was failing an assertion because Tablegen
had inserted an immediate 0 in place of one of a pair of tied register
operands. (This matches the way the corresponding check for `MCK_rGPR`
in `validateTargetOperandClass` is guarded.) Apparently the MVE load
instructions were the first to have ever triggered this assertion, but
I think only because they were the first to have a combination of the
usual Arm pre/post writeback system and the `rGPR` class in particular.

Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover

Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62680

llvm-svn: 364291
2019-06-25 11:24:18 +00:00
Simon Tatham fe8017621e [ARM] Add MVE interleaving load/store family.
This adds the family of loads and stores with names like VLD20.8 and
VST42.32, which load and store parts of multiple q-registers in such a
way that executing both VLD20 and VLD21, or all four of VLD40..VLD43,
will distribute 2 or 4 vectors' worth of memory data across the lanes
of the same number of registers but in a transposed order.

In addition to the Tablegen descriptions of the instructions
themselves, this patch also adds encode and decode support for the
QQPR and QQQQPR register classes (representing the range of loaded or
stored vector registers), and tweaks to the parsing system for lists
of vector registers to make it return the right format in this case
(since, unlike NEON, MVE regards q-registers as primitive, and not
just an alias for two d-registers).

llvm-svn: 364172
2019-06-24 10:00:39 +00:00
Simon Tatham 0c7af66450 [ARM] Add MVE 64-bit GPR <-> vector move instructions.
These instructions let you load half a vector register at once from
two general-purpose registers, or vice versa.

The assembly syntax for these instructions mentions the vector
register name twice. For the move _into_ a vector register, the MC
operand list also has to mention the register name twice (once as the
output, and once as an input to represent where the unchanged half of
the output register comes from). So we can conveniently assign one of
the two asm operands to be the output $Qd, and the other $QdSrc, which
avoids confusing the auto-generated AsmMatcher too much. For the move
_from_ a vector register, there's no way to get round the fact that
both instances of that register name have to be inputs, so we need a
custom AsmMatchConverter to avoid generating two separate output MC
operands. (And even that wouldn't have worked if it hadn't been for
D60695.)

Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover

Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62679

llvm-svn: 364041
2019-06-21 13:17:23 +00:00
Simon Tatham bafb105e96 [ARM] Add MVE vector instructions that take a scalar input.
This adds the `MVE_qDest_rSrc` superclass and all its instances, plus
a few other instructions that also take a scalar input register or two.

I've also belatedly added custom diagnostic messages to the operand
classes for odd- and even-numbered GPRs, which required matching
changes in two of the existing MVE assembly test files.

Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover

Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62678

llvm-svn: 364040
2019-06-21 13:17:08 +00:00
Simon Tatham 2f5188fd58 [ARM] Add MVE vector bit-operations (register inputs).
This includes all the obvious bitwise operations (AND, OR, BIC, ORN,
MVN) in register-to-register forms, and the immediate forms of
AND/OR/BIC/ORN; byte-order reverse instructions; and the VMOVs that
access a single lane of a vector.

Some of those VMOVs (specifically, the ones that access a 32-bit lane)
share an encoding with existing instructions that were disassembled as
accessing half of a d-register (e.g. `vmov.32 r0, d1[0]`), but in
8.1-M they're now written as accessing a quarter of a q-register (e.g.
`vmov.32 r0, q0[2]`). The older syntax is still accepted by the
assembler.

Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover

Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62673

llvm-svn: 363838
2019-06-19 16:43:53 +00:00
Simon Tatham cfc70782d7 [ARM] Add MVE vector shift instructions.
This includes saturating and non-saturating shifts, both with
immediate shift count and with the shift counts given by another
vector register; VSHLC (in which the bits shifted out of each active
vector lane are shifted in to the next active lane); and also VMOVL,
which is enough like an immediate shift that it didn't fit too badly
in this category.

Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover

Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62672

llvm-svn: 363696
2019-06-18 16:19:59 +00:00
Simon Tatham 286e1d2c2d [ARM] Set up infrastructure for MVE vector instructions.
This commit prepares the way to start adding the main collection of
MVE instructions, which operate on the 128-bit vector registers.

The most obvious thing that's needed, and the simplest, is to add the
MQPR register class, which is like the existing QPR except that it has
fewer registers in it.

The more complicated part: MVE defines a system of vector predication,
in which instructions operating on 128-bit vector registers can be
constrained to operate on only a subset of the lanes, using a system
of prefix instructions similar to the existing Thumb IT, in that you
have one prefix instruction which designates up to 4 following
instructions as subject to predication, and within that sequence, the
predicate can be inverted by means of T/E suffixes ('Then' / 'Else').

To support instructions of this type, we've added two new Tablegen
classes `vpred_n` and `vpred_r` for standard clusters of MC operands
to add to a predicated instruction. Both include a flag indicating how
the instruction is predicated at all (options are T, E and 'not
predicated'), and an input register field for the register controlling
the set of active lanes. They differ from each other in that `vpred_r`
also includes an input operand for the previous value of the output
register, for instructions that leave inactive lanes unchanged.
`vpred_n` lacks that extra operand; it will be used for instructions
that don't preserve inactive lanes in their output register (either
because inactive lanes are zeroed, as the MVE load instructions do, or
because the output register isn't a vector at all).

This commit also adds the family of prefix instructions themselves
(VPT / VPST), and all the machinery needed to work with them in
assembly and disassembly (e.g. generating the 't' and 'e' mnemonic
suffixes on disassembled instructions within a predicated block)

I've added a couple of demo instructions that derive from the new
Tablegen base classes and use those two operand clusters. The bulk of
the vector instructions will come in followup commits small enough to
be manageable. (One exception is that I've added the full version of
`isMnemonicVPTPredicable` in the AsmParser, because it seemed
pointless to carefully split it up.)

Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover

Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62669

llvm-svn: 363258
2019-06-13 13:11:13 +00:00
Simon Tatham 848d3d0d2c [ARM] Refactor handling of IT mask operands.
During assembly, the mask operand to an IT instruction (storing the
sequence of T/E for 'Then' and 'Else') is parsed out of the mnemonic
into a representation that encodes 'Then' and 'Else' in the same way
regardless of the condition code. At some point during encoding it has
to be converted into the instruction encoding used in the
architecture, in which the mask encodes a sequence of replacement
low-order bits for the condition code, so that which bit value means
'then' and which 'else' depends on whether the original condition code
had its low bit set.

Previously, that transformation was done by processInstruction(), half
way through assembly. So an MCOperand storing an IT mask would
sometimes store it in one format, and sometimes in the other,
depending on where in the assembly pipeline you were. You can see this
in diagnostics from `llvm-mc -debug -triple=thumbv8a -show-inst`, for
example: if you give it an instruction such as `itete eq`, you'd see
an `<MCOperand Imm:5>` in a diagnostic become `<MCOperand Imm:11>` in
the final output.

Having the same data structure store values with time-dependent
semantics is confusing already, and it will get more confusing when we
introduce the MVE VPT instruction which reuses the Then/Else bitmask
idea in a different context. So I'm refactoring: now, all `ARMOperand`
and `MCOperand` representations of an IT mask work exactly the same
way, namely, 0 means 'Then' and 1 means 'Else', regardless of what
original predicate is being referred to. The architectural encoding of
IT that depends on the original condition is now constructed at the
point when we turn the `MCOperand` into the final instruction bit
pattern, and decoded similarly in the disassembler.

The previous condition-independent parse-time format used 0 for Else
and 1 for Then. I've taken the opportunity to flip the sense of it
while I'm changing all of this anyway, because it seems to me more
natural to use 0 for 'leave the starting condition unchanged' and 1
for 'invert it', as if those bits were an XOR mask.

Reviewers: ostannard

Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63219

llvm-svn: 363244
2019-06-13 10:01:52 +00:00
Simon Tatham 8c865cacda [ARM] Add the non-MVE instructions in Arm v8.1-M.
This adds support for the new family of conditional selection /
increment / negation instructions; the low-overhead branch
instructions (e.g. BF, WLS, DLS); the CLRM instruction to zero a whole
list of registers at once; the new VMRS/VMSR and VLDR/VSTR
instructions to get data in and out of 8.1-M system registers,
particularly including the new VPR register used by MVE vector
predication.

To support this, we also add a register name 'zr' (used by the CSEL
family to force one of the inputs to the constant 0), and operand
types for lists of registers that are also allowed to include APSR or
VPR (used by CLRM). The VLDR/VSTR instructions also need a new
addressing mode.

The low-overhead branch instructions exist in their own separate
architecture extension, which we treat as enabled by default, but you
can say -mattr=-lob or equivalent to turn it off.

Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover

Reviewed By: samparker

Subscribers: miyuki, javed.absar, kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62667

llvm-svn: 363039
2019-06-11 09:29:18 +00:00
Tom Stellard 4b0b26199b Revert CMake: Make most target symbols hidden by default
This reverts r362990 (git commit 374571301d)

This was causing linker warnings on Darwin:

ld: warning: direct access in function 'llvm::initializeEvexToVexInstPassPass(llvm::PassRegistry&)'
from file '../../lib/libLLVMX86CodeGen.a(X86EvexToVex.cpp.o)' to global weak symbol
'void std::__1::__call_once_proxy<std::__1::tuple<void* (&)(llvm::PassRegistry&),
std::__1::reference_wrapper<llvm::PassRegistry>&&> >(void*)' from file '../../lib/libLLVMCore.a(Verifier.cpp.o)'
means the weak symbol cannot be overridden at runtime. This was likely caused by different translation
units being compiled with different visibility settings.

llvm-svn: 363028
2019-06-11 03:21:13 +00:00
Tom Stellard 374571301d CMake: Make most target symbols hidden by default
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: Jim, hiraditya, michaelplatings, chapuni, jholewinski, arsenm, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, 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

llvm-svn: 362990
2019-06-10 22:12:56 +00:00
Simon Tatham 67065c5c70 Revert rL362953 and its followup rL362955.
These caused a build failure because I managed not to notice they
depended on a later unpushed commit in my current stack. Sorry about
that.

llvm-svn: 362956
2019-06-10 15:58:19 +00:00
Simon Tatham baeea91933 [ARM] Add the non-MVE instructions in Arm v8.1-M.
This adds support for the new family of conditional selection /
increment / negation instructions; the low-overhead branch
instructions (e.g. BF, WLS, DLS); the CLRM instruction to zero a whole
list of registers at once; the new VMRS/VMSR and VLDR/VSTR
instructions to get data in and out of 8.1-M system registers,
particularly including the new VPR register used by MVE vector
predication.

To support this, we also add a register name 'zr' (used by the CSEL
family to force one of the inputs to the constant 0), and operand
types for lists of registers that are also allowed to include APSR or
VPR (used by CLRM). The VLDR/VSTR instructions also need some new
addressing modes.

The low-overhead branch instructions exist in their own separate
architecture extension, which we treat as enabled by default, but you
can say -mattr=-lob or equivalent to turn it off.

Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover

Reviewed By: samparker

Subscribers: miyuki, javed.absar, kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62667

llvm-svn: 362953
2019-06-10 15:36:34 +00:00
Sjoerd Meijer 930dee2c0b [ARM] add target arch definitions for 8.1-M and MVE
This adds:
- LLVM subtarget features to make all the new instructions conditional on,
- CPU and FPU names for use on clang's command line, with default FPUs set
  so that "armv8.1-m.main+fp" and "armv8.1-m.main+fp.dp" will select the right
  FPU features,
- architecture extension names "mve" and "mve.fp",
- ABI build attribute support for v8.1-M (a new value for Tag_CPU_arch) and MVE
  (a new actual tag).

Patch mostly by Simon Tatham.

Differential Revision: https://reviews.llvm.org/D60698

llvm-svn: 362090
2019-05-30 12:57:04 +00:00
Sjoerd Meijer 5857bf5d1e [ARM] Add an MVE execution domain
MVE architecturally specifies a 'beat' system in which a vector
instruction executed now will complete its actual operation over the
next four cycles, so it can overlap with the execution of the previous
and next MVE instruction.

This makes it generally an advantage to avoid moving values back and
forth between MVE registers and anywhere else, if there's any sensible
way to do the same processing in whatever register type the values
already occupied.

That's just what the 'execution domain' system is supposed to achieve.
So here we add a new execution domain which will contain all the MVE
vector instructions when they are added.

Patch by: Simon Tatham

Differential Revision: https://reviews.llvm.org/D60703

llvm-svn: 362068
2019-05-30 08:07:06 +00:00
Simon Tatham 760df47b77 [ARM] Replace fp-only-sp and d16 with fp64 and d32.
Those two subtarget features were awkward because their semantics are
reversed: each one indicates the _lack_ of support for something in
the architecture, rather than the presence. As a consequence, you
don't get the behavior you want if you combine two sets of feature
bits.

Each SubtargetFeature for an FP architecture version now comes in four
versions, one for each combination of those options. So you can still
say (for example) '+vfp2' in a feature string and it will mean what
it's always meant, but there's a new string '+vfp2d16sp' meaning the
version without those extra options.

A lot of this change is just mechanically replacing positive checks
for the old features with negative checks for the new ones. But one
more interesting change is that I've rearranged getFPUFeatures() so
that the main FPU feature is appended to the output list *before*
rather than after the features derived from the Restriction field, so
that -fp64 and -d32 can override defaults added by the main feature.

Reviewers: dmgreen, samparker, SjoerdMeijer

Subscribers: srhines, javed.absar, eraman, kristof.beyls, hiraditya, zzheng, Petar.Avramovic, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D60691

llvm-svn: 361845
2019-05-28 16:13:20 +00:00
Fangrui Song 43ca0e9eb8 [ARM] Support .reloc *, R_ARM_NONE, *
R_ARM_NONE can be used to create references among sections. When
--gc-sections is used, the referenced section will be retained if the
origin section is retained.

Add a generic MCFixupKind FK_NONE as this kind of no-op relocation is
ubiquitous on ELF and COFF, and probably available on many other binary
formats. See D62014.

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D61992

llvm-svn: 360980
2019-05-17 02:51:54 +00:00
Richard Trieu f3011b9b10 [ARM] Create a TargetInfo header. NFC
Move the declarations of getThe<Name>Target() functions into a new header in
TargetInfo and make users of these functions include this new header.
This fixes a layering problem.

llvm-svn: 360718
2019-05-14 22:29:50 +00:00
Richard Trieu 5e3ee4b84e [ARM] Move InstPrinter files to MCTargetDesc. NFC
For some targets, there is a circular dependency between InstPrinter and
MCTargetDesc.  Merging them together will fix this.  For the other targets,
the merging is to maintain consistency so all targets will have the same
structure.

llvm-svn: 360490
2019-05-11 00:34:07 +00:00
Sam Clegg b2978c0203 [ARM] Remove dead function ARMMCCodeEmitter::getSOImmOpValue
The last reference to this function was removed from the ARM
td files in 2015 in rL225266.

Differential Revision: https://reviews.llvm.org/D59868

llvm-svn: 357130
2019-03-27 23:00:12 +00:00
Andrea Di Biagio edbf06a767 [AsmPrinter] Remove hidden flag -print-schedule.
This patch removes hidden codegen flag -print-schedule effectively reverting the
logic originally committed as r300311
(https://llvm.org/viewvc/llvm-project?view=revision&revision=300311).

Flag -print-schedule was originally introduced by r300311 to address PR32216
(https://bugs.llvm.org/show_bug.cgi?id=32216). That bug was about adding "Better
testing of schedule model instruction latencies/throughputs".

These days, we can use llvm-mca to test scheduling models. So there is no longer
a need for flag -print-schedule in LLVM. The main use case for PR32216 is
now addressed by llvm-mca.
Flag -print-schedule is mainly used for debugging purposes, and it is only
actually used by x86 specific tests. We already have extensive (latency and
throughput) tests under "test/tools/llvm-mca" for X86 processor models. That
means, most (if not all) existing -print-schedule tests for X86 are redundant.

When flag -print-schedule was first added to LLVM, several files had to be
modified; a few APIs gained new arguments (see for example method
MCAsmStreamer::EmitInstruction), and MCSubtargetInfo/TargetSubtargetInfo gained
a couple of getSchedInfoStr() methods.

Method getSchedInfoStr() had to originally work for both MCInst and
MachineInstr. The original implmentation of getSchedInfoStr() introduced a
subtle layering violation (reported as PR37160 and then fixed/worked-around by
r330615).
In retrospect, that new API could have been designed more optimally. We can
always query MCSchedModel to get the latency and throughput. More importantly,
the "sched-info" string should not have been generated by the subtarget.
Note, r317782 fixed an issue where "print-schedule" didn't work very well in the
presence of inline assembly. That commit is also reverted by this change.

Differential Revision: https://reviews.llvm.org/D57244

llvm-svn: 353043
2019-02-04 12:51:26 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
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
2019-01-19 08:50:56 +00:00
Jonas Devlieghere ccf7d4b4aa Produce an error on non-encodable offsets for darwin ARM scattered relocations.
Scattered ARM relocations for Mach-O's only have 24 bits available to
encode the offset. This is not checked but just truncated and can result
in corrupt binaries after linking because the relocations are applied to
the wrong offset. This patch will check and error out in those
situations instead of emitting a wrong relocation.

Patch by: Sander Bogaert (dzn)

Differential revision: https://reviews.llvm.org/D54776

llvm-svn: 347922
2018-11-29 21:58:23 +00:00
Peter Smith 6f36cd4d76 [ARM] Account for implicit IT when calculating inline asm size
When deciding if it is safe to optimize a conditional branch to a CBZ or
CBNZ the offsets of the BasicBlocks from the start of the function are
estimated. For inline assembly the generic getInlineAsmLength() function is
used to get a worst case estimate of the inline assembly by multiplying the
number of instructions by the max instruction size of 4 bytes. This
unfortunately doesn't take into account the generation of Thumb implicit IT
instructions. In edge cases such as when all the instructions in the block
are 4-bytes in size and there is an implicit IT then the size is
underestimated. This can cause an out of range CBZ or CBNZ to be generated.

The patch takes a conservative approach and assumes that every instruction
in the inline assembly block may have an implicit IT.

Fixes pr31805

Differential Revision: https://reviews.llvm.org/D52834

llvm-svn: 343960
2018-10-08 09:38:28 +00:00
Diogo N. Sampaio eb9ca5ab18 [ARM] Emmit data symbol for constant pool data
The ARM elf emitter would omit printing data
symbol when constant data. This patch
overrides the emitFill method as to enforce that
the symbol is correctly printed.

Differential revision: https://reviews.llvm.org/D52737

llvm-svn: 343594
2018-10-02 14:55:48 +00:00
Fangrui Song 0cac726a00 llvm::sort(C.begin(), C.end(), ...) -> llvm::sort(C, ...)
Summary: The convenience wrapper in STLExtras is available since rL342102.

Reviewers: dblaikie, javed.absar, JDevlieghere, andreadb

Subscribers: MatzeB, sanjoy, arsenm, dschuff, mehdi_amini, sdardis, nemanjai, jvesely, nhaehnle, sbc100, jgravelle-google, eraman, aheejin, kbarton, JDevlieghere, javed.absar, gbedwell, jrtc27, mgrang, atanasyan, steven_wu, george.burgess.iv, dexonsmith, kristina, jsji, llvm-commits

Differential Revision: https://reviews.llvm.org/D52573

llvm-svn: 343163
2018-09-27 02:13:45 +00:00
Oliver Stannard 7c3c4baa3f [ARM/AArch64][v8.5A] Add Armv8.5-A target
This patch allows targeting Armv8.5-A, adding the architecture to
tablegen and setting the options to be identical to Armv8.4-A for the
time being. Subsequent patches will add support for the different
features included in the Armv8.5-A Reference Manual.

Patch by Pablo Barrio!

Differential revision: https://reviews.llvm.org/D52470

llvm-svn: 343102
2018-09-26 12:48:21 +00:00
Saleem Abdulrasool aaa72c547b ARM: correct the relocation type for `bl` on WoA
The `IMAGE_REL_ARM_BRANCH20T` applies only to a `b.w` instruction.  A
thumb-2 `bl` should be relocated using a `IMAGE_REL_ARM_BRANCH24T`.
Correct the relocation that we emit in such a case.

Resolves PR38620!  Based on the patch by Jordan Rhee!

llvm-svn: 342109
2018-09-13 04:55:08 +00:00
Benjamin Kramer 27c769d28a [Target] Untangle disassemblers
Disassemblers cannot depend on main target headers. The same is true for
MCTargetDesc, but there's a lot more cleanup needed for that.

llvm-svn: 341822
2018-09-10 12:53:46 +00:00
JF Bastien f03058e178 Fix typo in previous commit
llvm-svn: 341742
2018-09-08 04:07:41 +00:00
JF Bastien c4986cef12 ADT: add <bit> header, implement C++20 bit_cast, use
Summary: I saw a few places that were punning through a union of FP and integer, and that made me sad. Luckily, C++20 adds bit_cast for exactly that purpose. Implement our own version in ADT (without constexpr, leaving us a bit sad), and use it in the few places my grep-fu found silly union punning.

This was originally committed as r341728 and reverted in r341730.

Reviewers: javed.absar, steven_wu, srhines

Subscribers: dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D51693

llvm-svn: 341741
2018-09-08 03:55:25 +00:00
JF Bastien 05430cc6e5 Revert "ADT: add <bit> header, implement C++20 bit_cast, use"
Bots sad. Looks like missing std::is_trivially_copyable.

llvm-svn: 341730
2018-09-07 23:23:47 +00:00
JF Bastien 28655081a4 ADT: add <bit> header, implement C++20 bit_cast, use
Summary: I saw a few places that were punning through a union of FP and integer, and that made me sad. Luckily, C++20 adds bit_cast for exactly that purpose. Implement our own version in ADT (without constexpr, leaving us a bit sad), and use it in the few places my grep-fu found silly union punning.

Reviewers: javed.absar

Subscribers: dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D51693

llvm-svn: 341728
2018-09-07 23:08:26 +00:00
Tim Northover bb7d7b3d33 ARM: fix Thumb2 CodeGen for ldrex with folded frame-index.
Because t2LDREX (& t2STREX) were marked as AddrModeNone, but did allow a
FrameIndex operand, rewriteT2FrameIndex asserted. This gives them a
proper addressing-mode and tells the rewriter about it so that encodable
offsets are exploited and others are rejected.

Should fix PR38828.

llvm-svn: 341642
2018-09-07 09:21:25 +00:00
Eric Christopher fe83270ee9 The initial .text section generated in object files was missing the
SHF_ARM_PURECODE flag when being built with the -mexecute-only flag.
All code sections of an ELF must have the flag set for the final .text
section to be execute-only, otherwise the flag gets removed.

A HasData flag is added to MCSection to aid in the determination that
the section is empty. A virtual setTargetSectionFlags is added to
MCELFObjectTargetWriter to allow subclasses to set target specific
section flags to be added to sections which we then use in the ARM
backend to set SHF_ARM_PURECODE.

Patch by Ivan Lozano!

Reviewed By: echristo

Differential Revision: https://reviews.llvm.org/D48792

llvm-svn: 341593
2018-09-06 22:09:31 +00:00
Martin Storsjo 2dcaa41e1e [MinGW] [ARM] Add stubs for potential automatic dllimported variables
The runtime pseudo relocations can't handle the ARM format embedded
addresses in movw/movt pairs. By using stubs, the potentially
dllimported addresses can be touched up by the runtime pseudo relocation
framework.

Differential Revision: https://reviews.llvm.org/D51450

llvm-svn: 341176
2018-08-31 08:00:25 +00:00
Tim Northover 9956e4a24b ARM-MachO: don't add Thumb bit for addend to non-external relocation.
ld64 supplies its own Thumb bit for Thumb functions, and intentionally zeroes
out that part of any addend in an object file. But it only does that for
symbols marked N_EXT -- i.e. external symbols. So LLVM should avoid setting
that extra bit in other cases.

llvm-svn: 339007
2018-08-06 11:32:44 +00:00
Martin Storsjo af18947f0a [ARM] Support the .inst directive for MachO and COFF targets
Contrary to ELF, we don't add any markers that distinguish data generated
with .short/.long from normal instructions, so the .inst directive only
adds compatibility with assembly that uses it.

Differential Revision: https://reviews.llvm.org/D49936

llvm-svn: 338356
2018-07-31 09:27:01 +00:00
Fangrui Song f78650a8de Remove trailing space
sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h}

llvm-svn: 338293
2018-07-30 19:41:25 +00:00
Sjoerd Meijer 2a57b357a3 [AArch64][ARM] Armv8.4-A: Trace synchronization barrier instruction
This adds the Armv8.4-A Trace synchronization barrier (TSB) instruction.

Differential Revision: https://reviews.llvm.org/D48918

llvm-svn: 336418
2018-07-06 08:03:12 +00:00
Sjoerd Meijer 195e904002 [ARM][AArch64] Armv8.4-A Enablement
Initial patch adding assembly support for Armv8.4-A.

Besides adding v8.4 as a supported architecture to the usual places, this also
adds target features for the different crypto algorithms. Armv8.4-A introduced
new crypto algorithms, made them optional, and allows different combinations:

- none of the v8.4 crypto functions are supported, which is independent of the
  implementation of the Armv8.0 SHA1 and SHA2 instructions.
- the v8.4 SHA512 and SHA3 support is implemented, in this case the Armv8.0
  SHA1 and SHA2 instructions must also be implemented.
- the v8.4 SM3 and SM4 support is implemented, which is independent of the
  implementation of the Armv8.0 SHA1 and SHA2 instructions.
- all of the v8.4 crypto functions are supported, in this case the Armv8.0 SHA1
  and SHA2 instructions must also be implemented.

The v8.4 crypto instructions are added to AArch64 only, and not AArch32,
and are made optional extensions to Armv8.2-A.

The user-facing Clang options will map on these new target features, their
naming will be compatible with GCC and added in follow-up patches.

The Armv8.4-A instruction sets can be downloaded here:
https://developer.arm.com/products/architecture/a-profile/exploration-tools

Differential Revision: https://reviews.llvm.org/D48625

llvm-svn: 335953
2018-06-29 08:43:19 +00:00
Peter Smith 57f661bd7d [MC] Pass MCSubtargetInfo to fixupNeedsRelaxation and applyFixup
On targets like Arm some relaxations may only be performed when certain
architectural features are available. As functions can be compiled with
differing levels of architectural support we must make a judgement on
whether we can relax based on the MCSubtargetInfo for the function. This
change passes through the MCSubtargetInfo for the function to
fixupNeedsRelaxation so that the decision on whether to relax can be made
per function. In this patch, only the ARM backend makes use of this
information. We must also pass the MCSubtargetInfo to applyFixup because
some fixups skip error checking on the assumption that relaxation has
occurred, to prevent code-generation errors applyFixup must see the same
MCSubtargetInfo as fixupNeedsRelaxation.

Differential Revision: https://reviews.llvm.org/D44928

llvm-svn: 334078
2018-06-06 09:40:06 +00:00