Commit Graph

202 Commits

Author SHA1 Message Date
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
KAWASHIMA Takahiro
10c11e4e2d This option allows selecting the TLS size in the local exec TLS model,
which is the default TLS model for non-PIC objects. This allows large/
many thread local variables or a compact/fast code in an executable.

Specification is same as that of GCC. For example, the code model
option precedes the TLS size option.

TLS access models other than local-exec are not changed. It means
supoort of the large code model is only in the local exec TLS model.

Patch By KAWASHIMA Takahiro (kawashima-fj <t-kawashima@fujitsu.com>)
Reviewers: dmgreen, mstorsjo, t.p.northover, peter.smith, ostannard
Reviewd By: peter.smith
Committed by: peter.smith

Differential Revision: https://reviews.llvm.org/D71688
2020-01-13 10:16:53 +00:00
Nate Voorhies
bc16666de4 [NFC][AArch64] Fix typo.
Summary: Coaleascer should be coalescer.

Reviewers: qcolombet, Jim

Reviewed By: Jim

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70731
2019-12-13 10:25:36 +08:00
Adam Kallai
dc3ee33089 ExecutionEngine: add preliminary support for COFF ARM64
Differential Revision: https://reviews.llvm.org/D69434
2019-11-20 10:59:42 +02:00
Reid Kleckner
05da2fe521 Sink all InitializePasses.h includes
This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of recompilation.

I found this fact by looking at this table, which is sorted by the
number of times a file was changed over the last 100,000 git commits
multiplied by the number of object files that depend on it in the
current checkout:
  recompiles    touches affected_files  header
  342380        95      3604    llvm/include/llvm/ADT/STLExtras.h
  314730        234     1345    llvm/include/llvm/InitializePasses.h
  307036        118     2602    llvm/include/llvm/ADT/APInt.h
  213049        59      3611    llvm/include/llvm/Support/MathExtras.h
  170422        47      3626    llvm/include/llvm/Support/Compiler.h
  162225        45      3605    llvm/include/llvm/ADT/Optional.h
  158319        63      2513    llvm/include/llvm/ADT/Triple.h
  140322        39      3598    llvm/include/llvm/ADT/StringRef.h
  137647        59      2333    llvm/include/llvm/Support/Error.h
  131619        73      1803    llvm/include/llvm/Support/FileSystem.h

Before this change, touching InitializePasses.h would cause 1345 files
to recompile. After this change, touching it only causes 550 compiles in
an incremental rebuild.

Reviewers: bkramer, asbirlea, bollu, jdoerfert

Differential Revision: https://reviews.llvm.org/D70211
2019-11-13 16:34:37 -08:00
Momchil Velikov
d91ea7fc6f [AArch64] Move the branch relaxation pass after BTI insertion
Summary:
Inserting BTI instructions can push branch destinations out of range.

The branch relaxation pass itself cannot insert indirect branches since `TargetInstrInfo::insertIndirecrtBranch` is not implemented for AArch64 (guess +/-128 MB direct branch range is more than enough in practice).

Testing this is a bit tricky.

The original test case we have is 155kloc/6.1M. I've generated a test case using this program:
```

int main() {
  std::cout << R"src(int test();
void g0(), g1(), g2(), g3(), g4(), e();

void f(int v) {
  if ((test() & 2) == 0) {
  switch (v) {
  case 0:
    g0();
  case 1:
    g1();
  case 2:
    g2();
  case 3:
    g3();
  }
)src";

  const int N = 8176;

  for (int i = 0; i < N; ++i)
    std::cout << "    void h" << i << "();\n";
  for (int i = 0; i < N; ++i)
    std::cout << "    h" << i << "();\n";

  std::cout << R"src(
  } else {
    e();
  }
}
)src";
}
```
which is still a bit too much to commit as a regression test, IMHO.

Reviewers: t.p.northover, ostannard

Reviewed By: ostannard

Subscribers: kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69118

Change-Id: Ide5c922bcde08ff4cf635da5e52365525a997a0a
2019-11-06 12:46:50 +00:00
Andrew Paverd
d157a9bc8b Add Windows Control Flow Guard checks (/guard:cf).
Summary:
A new function pass (Transforms/CFGuard/CFGuard.cpp) inserts CFGuard checks on
indirect function calls, using either the check mechanism (X86, ARM, AArch64) or
or the dispatch mechanism (X86-64). The check mechanism requires a new calling
convention for the supported targets. The dispatch mechanism adds the target as
an operand bundle, which is processed by SelectionDAG. Another pass
(CodeGen/CFGuardLongjmp.cpp) identifies and emits valid longjmp targets, as
required by /guard:cf. This feature is enabled using the `cfguard` CC1 option.

Reviewers: thakis, rnk, theraven, pcc

Subscribers: ychen, hans, metalcanine, dmajor, tomrittervg, alex, mehdi_amini, mgorny, javed.absar, kristof.beyls, hiraditya, steven_wu, dexonsmith, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D65761
2019-10-28 15:19:39 +00:00
Lang Hames
366ab0d086 [AArch64] Don't implicitly enable global isel on Darwin if code-model==large.
Summary:
AArch64 GlobalISel doesn't support MachO's large code model, so this patch
adds a check for that combination before implicitly enabling it.

Reviewers: paquette

Subscribers: kristof.beyls, ributzka, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67724

llvm-svn: 372256
2019-09-18 19:56:55 +00:00
Tim Northover
f1c2892912 AArch64: support arm64_32, an ILP32 slice for watchOS.
This is the main CodeGen patch to support the arm64_32 watchOS ABI in LLVM.
FastISel is mostly disabled for now since it would generate incorrect code for
ILP32.

llvm-svn: 371722
2019-09-12 10:22:23 +00:00
Tim Northover
36147adc0b GlobalISel: add combiner to form indexed loads.
Loosely based on DAGCombiner version, but this part is slightly simpler in
GlobalIsel because all address calculation is performed by G_GEP. That makes
the inc/dec distinction moot so there's just pre/post to think about.

No targets can handle it yet so testing is via a special flag that overrides
target hooks.

llvm-svn: 371384
2019-09-09 10:04:23 +00:00
Amara Emerson
a1cf4d9795 [AArch64][GlobalISel] Enable the localizer for optimized builds.
Despite the fact that the localizer's original motivation was to fix horrendous
constant spilling at -O0, shortening live ranges still has net benefits even
with optimizations enabled.

On an -Os build of CTMark, doing this improves code size by 0.5% geomean.

There are a few regressions, bullet increasing in size by 0.5%. One example from
bullet where code size increased slightly was due to GlobalISel actually now
generating the same code as SelectionDAG. So we actually have an opportunity
in future to implement better heuristics for localization and therefore be
*better* than SDAG in some cases. In relation to other optimizations though that
one is relatively minor.

Differential Revision: https://reviews.llvm.org/D67303

llvm-svn: 371266
2019-09-06 22:27:09 +00:00
Evgeniy Stepanov
04647f5e22 MemTag: unchecked load/store optimization.
Summary:
MTE allows memory access to bypass tag check iff the address argument
is [SP, #imm]. This change takes advantage of this to demote uses of
tagged addresses to regular FrameIndex operands, reducing register
pressure in large functions.

MO_TAGGED target flag is used to signal that the FrameIndex operand
refers to memory that might be tagged, and needs to be handled with
care. Such operand must be lowered to [SP, #imm] directly, without a
scratch register.

The transformation pass attempts to predict when the offset will be
out of range and disable the optimization.
AArch64RegisterInfo::eliminateFrameIndex has an escape hatch in case
this prediction has been wrong, but it is quite inefficient and should
be avoided.

Reviewers: pcc, vitalybuka, ostannard

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66457

llvm-svn: 370490
2019-08-30 17:23:02 +00:00
Evgeniy Stepanov
50affbe47f MemTag: stack initializer merging.
Summary:
MTE provides instructions to update memory tags and data at the same
time. This change makes use of those to generate more compact code for
stack variable tagging + initialization.

We collect memory store and memset instructions following an alloca or a
lifetime.start call, and replace them with the corresponding MTE
intrinsics. Since the intrinsics work on 16-byte aligned chunks, the
stored values are combined as necessary.

Reviewers: pcc, vitalybuka, ostannard

Subscribers: srhines, javed.absar, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66167

llvm-svn: 369297
2019-08-19 20:47:09 +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
Evgeniy Stepanov
851339fb29 Basic MTE stack tagging instrumentation.
Summary:
Use MTE intrinsics to tag stack variables in functions with
sanitize_memtag attribute.

Reviewers: pcc, vitalybuka, hctim, ostannard

Subscribers: srhines, mgorny, javed.absar, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64173

llvm-svn: 366361
2019-07-17 19:24:12 +00:00
Sjoerd Meijer
de73404b8c [AArch64] Merge globals when optimising for size
Extern global merging is good for code-size. There's definitely potential for
performance too, but there's one regression in a benchmark that needs
investigating, so that's why we enable it only when we optimise for size for
now.

Patch by Ramakota Reddy and Sjoerd Meijer.

Differential Revision: https://reviews.llvm.org/D61947

llvm-svn: 363130
2019-06-12 08:28:35 +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
Richard Trieu
b26592e04d [AArch64] 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: 360709
2019-05-14 21:33:53 +00:00
Amara Emerson
d189680baa [GlobalISel] Introduce a CSEConfigBase class to allow targets to define their own CSE configs.
Because CodeGen can't depend on GlobalISel, we need a way to encapsulate the CSE
configs that can be passed between TargetPassConfig and the targets' custom
pass configs. This CSEConfigBase allows targets to create custom CSE configs
which is then used by the GISel passes for the CSEMIRBuilder.

This support will be used in a follow up commit to allow constant-only CSE for
-O0 compiles in D60580.

llvm-svn: 358368
2019-04-15 04:53:46 +00:00
Martin Storsjo
f5884d255e [COFF, ARM64] Don't put jump table into a separate COFF section for EK_LabelDifference32
Windows ARM64 has PIC relocation model and uses jump table kind
EK_LabelDifference32. This produces jump table entry as
".word LBB123 - LJTI1_2" which represents the distance between the block
and jump table.

A new relocation type (IMAGE_REL_ARM64_REL32) is needed to do the fixup
correctly if they are in different COFF section.

This change saves the jump table to the same COFF section as the
associated code. An ideal fix could be utilizing IMAGE_REL_ARM64_REL32
relocation type.

Patch by Tom Tan!

Differential Revision: https://reviews.llvm.org/D57277

llvm-svn: 352465
2019-01-29 09:36:48 +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
Kristof Beyls
e66bc1f756 Introduce control flow speculation tracking pass for AArch64
The pass implements tracking of control flow miss-speculation into a "taint"
register. That taint register can then be used to mask off registers with
sensitive data when executing under miss-speculation, a.k.a. "transient
execution".
This pass is aimed at mitigating against SpectreV1-style vulnarabilities.

At the moment, it implements the tracking of miss-speculation of control
flow into a taint register, but doesn't implement a mechanism yet to then
use that taint register to mask off vulnerable data in registers (something
for a follow-on improvement). Possible strategies to mask out vulnerable
data that can be implemented on top of this are:
- speculative load hardening to automatically mask of data loaded
  in registers.
- using intrinsics to mask of data in registers as indicated by the
  programmer (see https://lwn.net/Articles/759423/).

For AArch64, the following implementation choices are made.
Some of these are different than the implementation choices made in
the similar pass implemented in X86SpeculativeLoadHardening.cpp, as
the instruction set characteristics result in different trade-offs.
- The speculation hardening is done after register allocation. With a
  relative abundance of registers, one register is reserved (X16) to be
  the taint register. X16 is expected to not clash with other register
  reservation mechanisms with very high probability because:
  . The AArch64 ABI doesn't guarantee X16 to be retained across any call.
  . The only way to request X16 to be used as a programmer is through
    inline assembly. In the rare case a function explicitly demands to
    use X16/W16, this pass falls back to hardening against speculation
    by inserting a DSB SYS/ISB barrier pair which will prevent control
    flow speculation.
- It is easy to insert mask operations at this late stage as we have
  mask operations available that don't set flags.
- The taint variable contains all-ones when no miss-speculation is detected,
  and contains all-zeros when miss-speculation is detected. Therefore, when
  masking, an AND instruction (which only changes the register to be masked,
  no other side effects) can easily be inserted anywhere that's needed.
- The tracking of miss-speculation is done by using a data-flow conditional
  select instruction (CSEL) to evaluate the flags that were also used to
  make conditional branch direction decisions. Speculation of the CSEL
  instruction can be limited with a CSDB instruction - so the combination of
  CSEL + a later CSDB gives the guarantee that the flags as used in the CSEL
  aren't speculated. When conditional branch direction gets miss-speculated,
  the semantics of the inserted CSEL instruction is such that the taint
  register will contain all zero bits.
  One key requirement for this to work is that the conditional branch is
  followed by an execution of the CSEL instruction, where the CSEL
  instruction needs to use the same flags status as the conditional branch.
  This means that the conditional branches must not be implemented as one
  of the AArch64 conditional branches that do not use the flags as input
  (CB(N)Z and TB(N)Z). This is implemented by ensuring in the instruction
  selectors to not produce these instructions when speculation hardening
  is enabled. This pass will assert if it does encounter such an instruction.
- On function call boundaries, the miss-speculation state is transferred from
  the taint register X16 to be encoded in the SP register as value 0.

Future extensions/improvements could be:
- Implement this functionality using full speculation barriers, akin to the
  x86-slh-lfence option. This may be more useful for the intrinsics-based
  approach than for the SLH approach to masking.
  Note that this pass already inserts the full speculation barriers if the
  function for some niche reason makes use of X16/W16.
- no indirect branch misprediction gets protected/instrumented; but this
  could be done for some indirect branches, such as switch jump tables.

Differential Revision: https://reviews.llvm.org/D54896

llvm-svn: 349456
2018-12-18 08:50:02 +00:00
Alexandros Lamprineas
490ae11717 [AArch64] Re-run load/store optimizer after aggressive tail duplication
The Load/Store Optimizer runs before Machine Block Placement. At O3 the
Tail Duplication Threshold is set to 4 instructions and this can create
new opportunities for the Load/Store Optimizer. It seems worthwhile to
run it once again.

llvm-svn: 349338
2018-12-17 10:45:43 +00:00
David Green
ca29c271d2 [Targets] Add errors for tiny and kernel codemodel on targets that don't support them
Adds fatal errors for any target that does not support the Tiny or Kernel
codemodels by rejigging the getEffectiveCodeModel calls.

Differential Revision: https://reviews.llvm.org/D50141

llvm-svn: 348585
2018-12-07 12:10:23 +00:00
Petr Pavlu
e6406d568c [GlobalISel] Make EnableGlobalISel always set when GISel is enabled
Change meaning of TargetOptions::EnableGlobalISel. The flag was
previously set only when a target switched on GlobalISel but it is now
always set when the GlobalISel pipeline is enabled. This makes the flag
consistent with TargetOptions::EnableFastISel and allows its use in
other parts of the compiler to determine when GlobalISel is enabled.

The EnableGlobalISel flag had previouly only one use in
TargetPassConfig::isGlobalISelAbortEnabled(). The method used its value
to determine if GlobalISel was enabled by a target and returned false in
such a case. To preserve the current behaviour, a new flag
TargetOptions::GlobalISelAbort is introduced to separately record the
abort behaviour.

Differential Revision: https://reviews.llvm.org/D54518

llvm-svn: 347861
2018-11-29 12:56:32 +00:00
Martin Elshuber
fef3036d37 Subject: [PATCH] [CodeGen] Add pass to combine interleaved loads.
This patch defines an interleaved-load-combine pass. The pass searches
for ShuffleVector instructions that represent interleaved loads. Matches are
converted such that they will be captured by the InterleavedAccessPass.

The pass extends LLVMs capabilities to use target specific instruction
selection of interleaved load patterns (e.g.: ld4 on Aarch64
architectures).

Differential Revision: https://reviews.llvm.org/D52653

llvm-svn: 347208
2018-11-19 14:26:10 +00:00
Eli Friedman
0917d0c80c [AArch64] [Windows] Address post-commit review comment on r346358.
In this context, usesWindowsCFI() is basically the same thing as
isOSWindows(), but it makes the relevant property of the target
more explicit.

llvm-svn: 346366
2018-11-07 22:30:56 +00:00
Eli Friedman
d00fb2e0a8 [AArch64] [Windows] Trap after noreturn calls.
Like the comment says, this isn't the most efficient fix in terms of
codesize, but it works.

Differential Revision: https://reviews.llvm.org/D54129

llvm-svn: 346358
2018-11-07 21:31:14 +00:00
Tim Northover
1c353419ab AArch64: add a pass to compress jump-table entries when possible.
llvm-svn: 345188
2018-10-24 20:19:09 +00:00
Oliver Stannard
250e5a5b65 [AArch64][v8.5A] Branch Target Identification code-generation pass
The Branch Target Identification extension, introduced to AArch64 in
Armv8.5-A, adds the BTI instruction, which is used to mark valid targets
of indirect branches. When enabled, the processor will trap if an
instruction in a protected page tries to perform an indirect branch to
any instruction other than a BTI. The BTI instruction uses encodings
which were NOPs in earlier versions of the architecture, so BTI-enabled
code will still run on earlier hardware, just without the extra
protection.

There are 3 variants of the BTI instruction, which are valid targets for
different kinds or branches:
- BTI C can be targeted by call instructions, and is inteneded to be
  used at function entry points. These are the BLR instruction, as well
  as BR with x16 or x17. These BR instructions are allowed for use in
  PLT entries, and we can also use them to allow indirect tail-calls.
- BTI J can be targeted by BR only, and is intended to be used by jump
  tables.
- BTI JC acts ab both a BTI C and a BTI J instruction, and can be
  targeted by any BLR or BR instruction.

Note that RET instructions are not restricted by branch target
identification, the reason for this is that return addresses can be
protected more effectively using return address signing. Direct branches
and calls are also unaffected, as it is assumed that an attacker cannot
modify executable pages (if they could, they wouldn't need to do a
ROP/JOP attack).

This patch adds a MachineFunctionPass which:
- Adds a BTI C at the start of every function which could be indirectly
  called (either because it is address-taken, or externally visible so
  could be address-taken in another translation unit).
- Adds a BTI J at the start of every basic block which could be
  indirectly branched to. This could be either done by a jump table, or
  by taking the address of the block (e.g. the using GCC label values
  extension).

We only need to use BTI JC when a function is indirectly-callable, and
takes the address of the entry block. I've not been able to trigger this
from C or IR, but I've included a MIR test just in case.

Using BTI C at function entries relies on the fact that no other code in
BTI-protected pages uses indirect tail-calls, unless they use x16 or x17
to hold the address. I'll add that code-generation restriction as a
separate patch.

Differential revision: https://reviews.llvm.org/D52867

llvm-svn: 343967
2018-10-08 14:04:24 +00:00
Daniel Sanders
c973ad1878 Re-commit: [globalisel] Add a combiner helpers for extending loads and use them in a pre-legalize combiner for AArch64
Summary: Depends on D45541

Reviewers: ab, aditya_nandakumar, bogner, rtereshin, volkan, rovka, javed.absar, aemerson

Subscribers: aemerson, rengolin, mgorny, javed.absar, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D45543

The previous commit failed portions of the test-suite on GreenDragon due to
duplicate COPY instructions and iterator invalidation. Both issues have now
been fixed. To assist with this, a helper (cloneVirtualRegister) has been added
to MachineRegisterInfo that can be used to get another register that has the same
type and class/bank as an existing one.

llvm-svn: 343654
2018-10-03 02:12:17 +00:00
Daniel Sanders
33f42f97af Revert: r343521 and r343541: [globalisel] Add a combiner helpers for extending loads and use them in a pre-legalize combiner for AArch64
There's a strange assertion on two of the Green Dragon bots that goes away when
this is reverted. The assertion is in RegBankAlloc and if it is this commit then
-verify-machine-instrs should have caught it earlier in the pipeline.

llvm-svn: 343546
2018-10-01 22:32:08 +00:00
Daniel Sanders
9659bfda5a [globalisel] Add a combiner helpers for extending loads and use them in a pre-legalize combiner for AArch64
Summary: Depends on D45541

Reviewers: ab, aditya_nandakumar, bogner, rtereshin, volkan, rovka, javed.absar, aemerson

Subscribers: aemerson, rengolin, mgorny, javed.absar, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D45543

llvm-svn: 343521
2018-10-01 18:56:47 +00:00
David Green
9dd1d451d9 [AArch64] Add Tiny Code Model for AArch64
This adds the plumbing for the Tiny code model for the AArch64 backend. This,
instead of loading addresses through the normal ADRP;ADD pair used in the Small
model, uses a single ADR. The 21 bit range of an ADR means that the code and
its statically defined symbols need to be within 1MB of each other.

This makes it mostly interesting for embedded applications where we want to fit
as much as we can in as small a space as possible.

Differential Revision: https://reviews.llvm.org/D49673

llvm-svn: 340397
2018-08-22 11:31:39 +00:00
Jessica Paquette
f90edbe3d6 Recommit "Enable MachineOutliner by default under -Oz for AArch64"
Fixed the ASAN failure from before in r338148, so recommiting.

This patch enables the MachineOutliner by default in AArch64 under -Oz.

The MachineOutliner offers around a 4.5% improvement on the current -Oz code
size improvements.

We have done work into improving the debuggability of outlined code, so that
users of -Oz won't be surprised by the optimization. We have also been executing
the LLVM test suite and common external tests such as the SPEC suites
continuously with no issue. The outliner has a low compile-time overhead of
roughly 1%. At this point, the outliner would be a really good addition to the
-Oz pass pipeline!

llvm-svn: 338160
2018-07-27 20:18:27 +00:00
Jessica Paquette
faea2d3130 Revert "Enable MachineOutliner by default under -Oz for AArch64"
It failed an Asan test on a bot:

http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/21543/steps/check-llvm%20asan/logs/stdio

Fixing that before recommitting.

llvm-svn: 338136
2018-07-27 17:25:38 +00:00
Jessica Paquette
d4229b985c Enable MachineOutliner by default under -Oz for AArch64
This patch enables the MachineOutliner by default in AArch64 under -Oz.

The MachineOutliner offers around a 4.5% improvement on the current -Oz code
size improvements.

We have done work into improving the debuggability of outlined code, so that
users of -Oz won't be surprised by the optimization. We have also been executing
the LLVM test suite and common external tests such as the SPEC suites
continuously with no issue. The outliner has a low compile-time overhead of
roughly 1%. At this point, the outliner would be a really good addition to the
-Oz pass pipeline!

llvm-svn: 338133
2018-07-27 16:44:42 +00:00
Jessica Paquette
dafa198c96 [MachineOutliner] Define MachineOutliner support in TargetOptions
Targets should be able to define whether or not they support the outliner
without the outliner being added to the pass pipeline. Before this, the
outliner pass would be added, and ask the target whether or not it supports the
outliner.

After this, it's possible to query the target in TargetPassConfig, before the
outliner pass is created. This ensures that passing -enable-machine-outliner
will not modify the pass pipeline of any target that does not support it.

https://reviews.llvm.org/D48683

llvm-svn: 335887
2018-06-28 17:45:43 +00:00
Matthias Braun
da5e7e11d1 SelectionDAGBuilder, mach-o: Skip trap after noreturn call (for Mach-O)
Add NoTrapAfterNoreturn target option which skips emission of traps
behind noreturn calls even if TrapUnreachable is enabled.

Enable the feature on Mach-O to save code size; Comments suggest it is
not possible to enable it for the other users of TrapUnreachable.

rdar://41530228

DifferentialRevision: https://reviews.llvm.org/D48674
llvm-svn: 335877
2018-06-28 17:00:45 +00:00
Daniel Sanders
618437459c Revert r331816 and r331820 - [globalisel] Add a combiner helpers for extending loads and use them in a pre-legalize combiner for AArch64
Reverting this to see if the clang-cmake-aarch64-global-isel and
clang-cmake-aarch64-quick bots are failing because of this commit.
We know it wasn't r331819.

llvm-svn: 331846
2018-05-09 05:00:17 +00:00
Daniel Sanders
d24dcdd1f7 [globalisel] Add a combiner helpers for extending loads and use them in a pre-legalize combiner for AArch64
Summary: Depends on D45541

Reviewers: ab, aditya_nandakumar, bogner, rtereshin, volkan, rovka, javed.absar, aemerson

Reviewed By: aemerson

Subscribers: aemerson, rengolin, mgorny, javed.absar, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D45543

llvm-svn: 331816
2018-05-08 22:26:39 +00:00
Tim Northover
271d3d2771 MachO: trap unreachable instructions
Debugability is more important than saving 4 bytes to let us to fall
through to nonense.

llvm-svn: 330073
2018-04-13 22:25:20 +00:00
David Blaikie
8ad9a97310 Plumb useAA through TargetTransformInfo to remove Transforms->CodeGen header dependency
Thanks to echristo for the pointers on direction.

llvm-svn: 328737
2018-03-28 22:28:50 +00:00
David Blaikie
6054e650ff Move TargetLoweringObjectFile from CodeGen to Target to fix layering
It's implemented in Target & include from other Target headers, so the
header should be in Target.

llvm-svn: 328392
2018-03-23 23:58:19 +00:00
Volkan Keles
a79b0620a0 Add a TargetOption to enable/disable GlobalISel
Summary:
This patch adds a new target option in order to control GlobalISel.
This will allow the users to enable/disable GlobalISel prior to the
backend by calling `TargetMachine::setGlobalISel(bool Enable)`.

No test case as there is already a test to check GlobalISel
command line options.
See: CodeGen/AArch64/GlobalISel/gisel-commandline-option.ll.

Reviewers: qcolombet, aemerson, ab, dsanders

Reviewed By: qcolombet

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

Differential Revision: https://reviews.llvm.org/D42137

llvm-svn: 322773
2018-01-17 22:34:21 +00:00
Amara Emerson
854d10d10b [AArch64][GlobalISel] Enable GlobalISel at -O0 by default
Tests updated to explicitly use fast-isel at -O0 instead of implicitly.

This change also allows an explicit -fast-isel option to override an
implicitly enabled global-isel. Otherwise -fast-isel would have no effect at -O0.

Differential Revision: https://reviews.llvm.org/D41362

llvm-svn: 321655
2018-01-02 16:30:47 +00:00
Sanjoy Das
26d11ca4b0 (Re-landing) Expose a TargetMachine::getTargetTransformInfo function
Re-land r321234.  It had to be reverted because it broke the shared
library build.  The shared library build broke because there was a
missing LLVMBuild dependency from lib/Passes (which calls
TargetMachine::getTargetIRAnalysis) to lib/Target.  As far as I can
tell, this problem was always there but was somehow masked
before (perhaps because TargetMachine::getTargetIRAnalysis was a
virtual function).

Original commit message:

This makes the TargetMachine interface a bit simpler.  We still need
the std::function in TargetIRAnalysis to avoid having to add a
dependency from Analysis to Target.

See discussion:
http://lists.llvm.org/pipermail/llvm-dev/2017-December/119749.html

I avoided adding all of the backend owners to this review since the
change is simple, but let me know if you feel differently about this.

Reviewers: echristo, MatzeB, hfinkel

Reviewed By: hfinkel

Subscribers: jholewinski, jfb, arsenm, dschuff, mcrosier, sdardis, nemanjai, nhaehnle, javed.absar, sbc100, jgravelle-google, aheejin, kbarton, llvm-commits

Differential Revision: https://reviews.llvm.org/D41464

llvm-svn: 321375
2017-12-22 18:21:59 +00:00
Sanjoy Das
747d1114d6 Revert "Expose a TargetMachine::getTargetTransformInfo function"
This reverts commit r321234.  It breaks the -DBUILD_SHARED_LIBS=ON build.

llvm-svn: 321243
2017-12-21 02:34:39 +00:00
Sanjoy Das
0c3de350b4 Expose a TargetMachine::getTargetTransformInfo function
Summary:
This makes the TargetMachine interface a bit simpler.  We still need
the std::function in TargetIRAnalysis to avoid having to add a
dependency from Analysis to Target.

See discussion:
http://lists.llvm.org/pipermail/llvm-dev/2017-December/119749.html

I avoided adding all of the backend owners to this review since the
change is simple, but let me know if you feel differently about this.

Reviewers: echristo, MatzeB, hfinkel

Reviewed By: hfinkel

Subscribers: jholewinski, jfb, arsenm, dschuff, mcrosier, sdardis, nemanjai, nhaehnle, javed.absar, sbc100, jgravelle-google, aheejin, kbarton, llvm-commits

Differential Revision: https://reviews.llvm.org/D41464

llvm-svn: 321234
2017-12-21 01:06:58 +00:00