Commit Graph

605 Commits

Author SHA1 Message Date
Fangrui Song d9a0c40bce [MC] Split MCContext::createTempSymbol, default AlwaysAddSuffix to true, and add comments
CanBeUnnamed is rarely false. Splitting to a createNamedTempSymbol makes the
intention clearer and matches the direction of reverted r240130 (to drop the
unneeded parameters).

No behavior change.
2020-12-21 14:04:13 -08:00
Fangrui Song d33abc337c Migrate MCContext::createTempSymbol call sites to AlwaysAddSuffix=true
Most call sites set AlwaysAddSuffix to true. The two use cases do not really
need false and can be more consistent with other temporary symbol usage.
2020-12-21 14:04:13 -08:00
Kristof Beyls 320fd3314e [ARM] Implement harden-sls-retbr for Thumb mode
The only non-trivial consideration in this patch is that the formation
of TBB/TBH instructions, which is done in the constant island pass, does
not understand the speculation barriers inserted by the SLSHardening
pass. As such, when harden-sls-retbr is enabled for a function, the
formation of TBB/TBH instructions in the constant island pass is
disabled.

Differential Revision: https://reviews.llvm.org/D92396
2020-12-19 12:32:47 +00:00
Kristof Beyls 195f44278c [ARM] Implement harden-sls-retbr for ARM mode
Some processors may speculatively execute the instructions immediately
following indirect control flow, such as returns, indirect jumps and
indirect function calls.

To avoid a potential miss-speculatively executed gadget after these
instructions leaking secrets through side channels, this pass places a
speculation barrier immediately after every indirect control flow where
control flow doesn't return to the next instruction, such as returns and
indirect jumps, but not indirect function calls.

Hardening of indirect function calls will be done in a later,
independent patch.

This patch is implementing the same functionality as the AArch64 counter
part implemented in https://reviews.llvm.org/D81400.
For AArch64, returns and indirect jumps only occur on RET and BR
instructions and hence the function attribute to control the hardening
is called "harden-sls-retbr" there. On AArch32, there is a much wider
variety of instructions that can trigger an indirect unconditional
control flow change.  I've decided to stick with the name
"harden-sls-retbr" as introduced for the corresponding AArch64
mitigation.

This patch implements this for ARM mode. A future patch will extend this
to also support Thumb mode.

The inserted barriers are never on the correct, architectural execution
path, and therefore performance overhead of this is expected to be low.
To ensure these barriers are never on an architecturally executed path,
when the harden-sls-retbr function attribute is present, indirect
control flow is never conditionalized/predicated.

On targets that implement that Armv8.0-SB Speculation Barrier extension,
a single SB instruction is emitted that acts as a speculation barrier.
On other targets, a DSB SYS followed by a ISB is emitted to act as a
speculation barrier.

These speculation barriers are implemented as pseudo instructions to
avoid later passes to analyze them and potentially remove them.

The mitigation is off by default and can be enabled by the
harden-sls-retbr subtarget feature.

Differential Revision: https://reviews.llvm.org/D92395
2020-12-19 11:42:39 +00:00
Mircea Trofin bab72dd5d5 [NFC][MC] TargetRegisterInfo::getSubReg is a MCRegister.
Typing the API appropriately.

Differential Revision: https://reviews.llvm.org/D92341
2020-12-02 15:46:38 -08:00
Rahman Lavaee 8955950c12 Exception support for basic block sections
This is part of the Propeller framework to do post link code layout optimizations. Please see the RFC here: https://groups.google.com/forum/#!msg/llvm-dev/ef3mKzAdJ7U/1shV64BYBAAJ and the detailed RFC doc here: https://github.com/google/llvm-propeller/blob/plo-dev/Propeller_RFC.pdf

This patch provides exception support for basic block sections by splitting the call-site table into call-site ranges corresponding to different basic block sections. Still all landing pads must reside in the same basic block section (which is guaranteed by the the core basic block section patch D73674 (ExceptionSection) ). Each call-site table will refer to the landing pad fragment by explicitly specifying @LPstart (which is omitted in the normal non-basic-block section case). All these call-site tables will share their action and type tables.

The C++ ABI somehow assumes that no landing pads point directly to LPStart (which works in the normal case since the function begin is never a landing pad), and uses LP.offset = 0 to specify no landing pad. In the case of basic block section where one section contains all the landing pads, the landing pad offset relative to LPStart could actually be zero. Thus, we avoid zero-offset landing pads by inserting a **nop** operation as the first non-CFI instruction in the exception section.

**Background on Exception Handling in C++ ABI**
https://github.com/itanium-cxx-abi/cxx-abi/blob/master/exceptions.pdf

Compiler emits an exception table for every function. When an exception is thrown, the stack unwinding library queries the unwind table (which includes the start and end of each function) to locate the exception table for that function.

The exception table includes a call site table for the function, which is used to guide the exception handling runtime to take the appropriate action upon an exception. Each call site record in this table is structured as follows:

| CallSite                       |  -->  Position of the call site (relative to the function entry)
| CallSite length           |  -->  Length of the call site.
| Landing Pad               |  -->  Position of the landing pad (relative to the landing pad fragment’s begin label)
| Action record offset  |  -->  Position of the first action record

The call site records partition a function into different pieces and describe what action must be taken for each callsite. The callsite fields are relative to the start of the function (as captured in the unwind table).

The landing pad entry is a reference into the function and corresponds roughly to the catch block of a try/catch statement. When execution resumes at a landing pad, it receives an exception structure and a selector value corresponding to the type of the exception thrown, and executes similar to a switch-case statement. The landing pad field is relative to the beginning of the procedure fragment which includes all the landing pads (@LPStart). The C++ ABI requires all landing pads to be in the same fragment. Nonetheless, without basic block sections, @LPStart is the same as the function @Start (found in the unwind table) and can be omitted.

The action record offset is an index into the action table which includes information about which exception types are caught.

**C++ Exceptions with Basic Block Sections**
Basic block sections break the contiguity of a function fragment. Therefore, call sites must be specified relative to the beginning of the basic block section. Furthermore, the unwinding library should be able to find the corresponding callsites for each section. To do so, the .cfi_lsda directive for a section must point to the range of call-sites for that section.
This patch introduces a new **CallSiteRange** structure which specifies the range of call-sites which correspond to every section:

  `struct CallSiteRange {
    // Symbol marking the beginning of the precedure fragment.
    MCSymbol *FragmentBeginLabel = nullptr;
    // Symbol marking the end of the procedure fragment.
    MCSymbol *FragmentEndLabel = nullptr;
    // LSDA symbol for this call-site range.
    MCSymbol *ExceptionLabel = nullptr;
    // Index of the first call-site entry in the call-site table which
    // belongs to this range.
    size_t CallSiteBeginIdx = 0;
    // Index just after the last call-site entry in the call-site table which
    // belongs to this range.
    size_t CallSiteEndIdx = 0;
    // Whether this is the call-site range containing all the landing pads.
    bool IsLPRange = false;
  };`

With N basic-block-sections, the call-site table is partitioned into N call-site ranges.

Conceptually, we emit the call-site ranges for sections sequentially in the exception table as if each section has its own exception table. In the example below, two sections result in the two call site ranges (denoted by LSDA1 and LSDA2) placed next to each other. However, their call-sites will refer to records in the shared Action Table. We also emit the header fields (@LPStart and CallSite Table Length) for each call site range in order to place the call site ranges in separate LSDAs. We note that with -basic-block-sections, The CallSiteTableLength will not actually represent the length of the call site table, but rather the reference to the action table. Since the only purpose of this field is to locate the action table, correctness is guaranteed.

Finally, every call site range has one @LPStart pointer so the landing pads of each section must all reside in one section (not necessarily the same section). To make this easier, we decide to place all landing pads of the function in one section (hence the `IsLPRange` field in CallSiteRange).

|  @LPStart                   |  --->  Landing pad fragment     ( LSDA1 points here)
| CallSite Table Length | ---> Used to find the action table.
| CallSites                     |
| …                                 |
| …                                 |
| @LPStart                    |  --->  Landing pad fragment ( LSDA2 points here)
| CallSite Table Length |
| CallSites                     |
| …                                 |
| …                                 |
…
…
|      Action Table          |
|      Types Table           |

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D73739
2020-09-30 11:05:55 -07:00
Marek Kurdej 9301e3aaca [Target] Fix typos. NFC 2020-05-22 14:40:43 +02:00
Momchil Velikov bc2e572f51 Re-commit: [ARM] CMSE code generation
This patch implements the final bits of CMSE code generation:

* emit special linker symbols

* restrict parameter passing to no use memory

* emit BXNS and BLXNS instructions for returns from non-secure entry
  functions, and non-secure function calls, respectively

* emit code to save/restore secure floating-point state around calls
  to non-secure functions

* emit code to save/restore non-secure floating-pointy state upon
  entry to non-secure entry function, and return to non-secure state

* emit code to clobber registers not used for arguments and returns

* when switching to no-secure state

Patch by Momchil Velikov, Bradley Smith, Javed Absar, David Green,
possibly others.

Differential Revision: https://reviews.llvm.org/D76518
2020-05-14 16:46:16 +01:00
Momchil Velikov fb18dffaeb Revert "[ARM] CMSE code generation"
This reverts commit 7cbbf89d23.

The regression tests fail with the expensive checks.
2020-05-05 19:05:40 +01:00
Momchil Velikov 7cbbf89d23 [ARM] CMSE code generation
This patch implements the final bits of CMSE code generation:

* emit special linker symbols

* restrict parameter passing to not use memory

* emit BXNS and BLXNS instructions for returns from non-secure entry
  functions, and non-secure function calls, respectively

* emit code to save/restore secure floating-point state around calls
  to non-secure functions

* emit code to save/restore non-secure floating-pointy state upon
  entry to non-secure entry function, and return to non-secure state

* emit code to clobber registers not used for arguments and returns
  when switching to no-secure state

Patch by Momchil Velikov, Bradley Smith, Javed Absar, David Green,
possibly others.

Differential Revision: https://reviews.llvm.org/D76518
2020-05-05 18:23:28 +01:00
Keith Walker 01dc10774e [ARM] unwinding .pad instructions missing in execute-only prologue
If the stack pointer is altered for local variables and we are generating
Thumb2 execute-only code the .pad directive is missing.

Usually the size of the adjustment is stored in a PC-relative location
and loaded into a register which is then added to the stack pointer.
However when we are generating execute-only code code the size of the
adjustment is instead generated using the MOVW/MOVT instruction pair.

As a by product of handling the execute-only case this also fixes an
existing issue that in the none execute-only case the .pad directive was
generated against the load of the constant to a register instruction,
instead of the instruction which adds the register to the stack pointer.

Differential Revision: https://reviews.llvm.org/D76849
2020-04-07 11:51:59 +01:00
Matt Arsenault 0ab5b5b858 Fix denormal-fp-math flag and attribute interaction
Make these behave the same way unsafe-fp-math and co. The command line
flag should add the attribute to functions that do not already have
it, and leave existing attributes. The attribute is the actual
implementation, but the flag is useful in some testing situations.

AMDGPU has a variety of tests with denormals enabled/disabled that
would require a painful level of test duplication without a flag. This
doesn't expose setting the separate input/output modes, or add a flag
for the f32 version yet.

Tests will be included in future patch.
2020-03-27 12:48:58 -07:00
Matt Arsenault c4de8935a5 ARM: Fixup some tests using denormal-fp-math attribute
Don't use the deprecated, single mode form in tests. Also make sure to
parse the attribute, in case of the deprecated form.
2020-03-10 14:02:06 -04:00
Fangrui Song 549b436beb [MC] De-capitalize MCStreamer::Emit{Bundle,Addrsig}* etc
So far, all non-COFF-related Emit* functions have been de-capitalized.
2020-02-15 09:11:48 -08:00
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 1d49eb00d9 [AsmPrinter] De-capitalize all AsmPrinter::Emit* but EmitInstruction
Similar to rL328848.
2020-02-13 17:06:24 -08:00
Fangrui Song 0dce409cee [AsmPrinter] De-capitalize Emit{Function,BasicBlock]* and Emit{Start,End}OfAsmFile 2020-02-13 13:22:49 -08:00
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
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
Diogo Sampaio d94d079a6a [ARM][Thumb2] Fix ADD/SUB invalid writes to SP
Summary:
This patch fixes pr23772  [ARM] r226200 can emit illegal thumb2 instruction: "sub sp, r12, #80".
The violation was that SUB and ADD (reg, immediate) instructions can only write to SP if the source register is also SP. So the above instructions was unpredictable.
To enforce that the instruction t2(ADD|SUB)ri does not write to SP we now enforce the destination register to be rGPR (That exclude PC and SP).
Different than the ARM specification, that defines one instruction that can read from SP, and one that can't, here we inserted one that can't write to SP, and other that can only write to SP as to reuse most of the hard-coded size optimizations.
When performing this change, it uncovered that emitting Thumb2 Reg plus Immediate could not emit all variants of ADD SP, SP #imm instructions before so it was refactored to be able to. (see test/CodeGen/Thumb2/mve-stacksplot.mir where we use a subw sp, sp, Imm12 variant )
It also uncovered a disassembly issue of adr.w instructions, that were only written as SUBW instructions (see llvm/test/MC/Disassembler/ARM/thumb2.txt).

Reviewers: eli.friedman, dmgreen, carwil, olista01, efriedma, andreadb

Reviewed By: efriedma

Subscribers: gbedwell, john.brawn, efriedma, ostannard, kristof.beyls, hiraditya, dmgreen, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70680
2020-01-14 11:47:19 +00:00
Diogo Sampaio b1bb5ce96d Reverting, broke some bots. Need further investigation.
Summary: This reverts commit 8c12769f30.

Reviewers:

Subscribers:
2020-01-10 13:40:41 +00:00
Diogo Sampaio 8c12769f30 [ARM][Thumb2] Fix ADD/SUB invalid writes to SP
Summary:
This patch fixes pr23772  [ARM] r226200 can emit illegal thumb2 instruction: "sub sp, r12, #80".
The violation was that SUB and ADD (reg, immediate) instructions can only write to SP if the source register is also SP. So the above instructions was unpredictable.
To enforce that the instruction t2(ADD|SUB)ri does not write to SP we now enforce the destination register to be rGPR (That exclude PC and SP).
Different than the ARM specification, that defines one instruction that can read from SP, and one that can't, here we inserted one that can't write to SP, and other that can only write to SP as to reuse most of the hard-coded size optimizations.
When performing this change, it uncovered that emitting Thumb2 Reg plus Immediate could not emit all variants of ADD SP, SP #imm instructions before so it was refactored to be able to. (see test/CodeGen/Thumb2/mve-stacksplot.mir where we use a subw sp, sp, Imm12 variant )
It also uncovered a disassembly issue of adr.w instructions, that were only written as SUBW instructions (see llvm/test/MC/Disassembler/ARM/thumb2.txt).

Reviewers: eli.friedman, dmgreen, carwil, olista01, efriedma

Reviewed By: efriedma

Subscribers: john.brawn, efriedma, ostannard, kristof.beyls, hiraditya, dmgreen, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70680
2020-01-10 11:25:44 +00:00
Diogo Sampaio f33fd9648c [ARM][Thumb][FIX] Add unwinding information to t4
Summary:
Add missing part of patch D71361. Now that the stack-frame
can be operated using a addw/subw instruction, they should
appear in the unwinding list.

Reviewers: dmgreen, efriedma

Reviewed By: dmgreen

Subscribers: kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72000
2019-12-30 15:59:48 +00:00
Carey Williams 76fd58d0fe Revert "[ARM] Allocatable Global Register Variables for ARM"
This reverts commit 2d739f98d8.
2019-11-29 17:01:05 +00:00
Anna Welker 2d739f98d8 [ARM] Allocatable Global Register Variables for ARM
Provides support for using r6-r11 as globally scoped
      register variables. This requires a -ffixed-rN flag
      in order to reserve rN against general allocation.

      If for a given GRV declaration the corresponding flag
      is not found, or the the register in question is the
      target's FP, we fail with a diagnostic.

      Differential Revision: https://reviews.llvm.org/D68862
2019-11-18 10:07:37 +00:00
Simon Pilgrim b5f94adbf3 Fix uninitialized variable warnings. NFCI. 2019-11-14 14:21:16 +00:00
Guillaume Chatelet 18f805a7ea [Alignment][NFC] Remove unneeded llvm:: scoping on Align types
llvm-svn: 373081
2019-09-27 12:54:21 +00:00
Guillaume Chatelet 97264366fb [Alignment][NFC] use llvm::Align for AsmPrinter::EmitAlignment
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: dschuff, sdardis, nemanjai, hiraditya, kbarton, jrtc27, MaskRay, atanasyan, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67443

llvm-svn: 371616
2019-09-11 13:37:35 +00:00
Daniel Sanders 0c47611131 Apply llvm-prefer-register-over-unsigned from clang-tidy to LLVM
Summary:
This clang-tidy check is looking for unsigned integer variables whose initializer
starts with an implicit cast from llvm::Register and changes the type of the
variable to llvm::Register (dropping the llvm:: where possible).

Partial reverts in:
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
X86FixupLEAs.cpp - Some functions return unsigned and arguably should be MCRegister
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
HexagonBitSimplify.cpp - Function takes BitTracker::RegisterRef which appears to be unsigned&
MachineVerifier.cpp - Ambiguous operator==() given MCRegister and const Register
PPCFastISel.cpp - No Register::operator-=()
PeepholeOptimizer.cpp - TargetInstrInfo::optimizeLoadInstr() takes an unsigned&
MachineTraceMetrics.cpp - MachineTraceMetrics lacks a suitable constructor

Manual fixups in:
ARMFastISel.cpp - ARMEmitLoad() now takes a Register& instead of unsigned&
HexagonSplitDouble.cpp - Ternary operator was ambiguous between unsigned/Register
HexagonConstExtenders.cpp - Has a local class named Register, used llvm::Register instead of Register.
PPCFastISel.cpp - PPCEmitLoad() now takes a Register& instead of unsigned&

Depends on D65919

Reviewers: arsenm, bogner, craig.topper, RKSimon

Reviewed By: arsenm

Subscribers: RKSimon, craig.topper, lenary, aemerson, wuzish, jholewinski, MatzeB, qcolombet, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, wdng, nhaehnle, sbc100, jgravelle-google, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, javed.absar, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, tpr, PkmX, jocewei, jsji, Petar.Avramovic, asbirlea, Jim, s.egerton, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65962

llvm-svn: 369041
2019-08-15 19:22:08 +00:00
Daniel Sanders 2bea69bf65 Finish moving TargetRegisterInfo::isVirtualRegister() and friends to llvm::Register as started by r367614. NFC
llvm-svn: 367633
2019-08-01 23:27:28 +00:00
Eli Friedman e97aa961d3 [ARM] Fix unwind info for Thumb1 functions that save high registers.
There were two issues here: one, some of the relevant instructions were
missing the expected "FrameSetup" flag, and two,
ARMAsmPrinter::EmitUnwindingInstruction wasn't expecting "mov"
instructions in the prologue.

I'm sticking the additional state into ARMFunctionInfo so it's obvious
it only applies to the current function.

I considered a few alternative approaches where we would compute the
correct unwind information as part of the prologue/epilogue lowering,
but it seems like a lot of work to introduce pseudo-instructions, and
the current code seems to be reliable enough.

Fixes https://bugs.llvm.org/show_bug.cgi?id=42408.

Differential Revision: https://reviews.llvm.org/D63964

llvm-svn: 364970
2019-07-02 21:35:15 +00:00
Mikael Holmen 030df51e27 [ARM] Fix compiler warning
Without this fix clang 3.6 complains with:

../lib/Target/ARM/ARMAsmPrinter.cpp:1473:18: error: variable 'BranchTarget' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
      } else if (MI->getOperand(1).isSymbol()) {
                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
../lib/Target/ARM/ARMAsmPrinter.cpp:1479:22: note: uninitialized use occurs here
      MCInst.addExpr(BranchTarget);
                     ^~~~~~~~~~~~
../lib/Target/ARM/ARMAsmPrinter.cpp:1473:14: note: remove the 'if' if its condition is always true
      } else if (MI->getOperand(1).isSymbol()) {
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../lib/Target/ARM/ARMAsmPrinter.cpp:1465:33: note: initialize the variable 'BranchTarget' to silence this warning
      const MCExpr *BranchTarget;
                                ^
                                 = nullptr
1 error generated.

Discussed here:
 http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20190610/661417.html

llvm-svn: 363166
2019-06-12 14:19:22 +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
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
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
Nick Desaulniers 7ab164c4a4 [AsmPrinter] refactor to support %c w/ GlobalAddress'
Summary:
Targets like ARM, MSP430, PPC, and SystemZ have complex behavior when
printing the address of a MachineOperand::MO_GlobalAddress. Move that
handling into a new overriden method in each base class. A virtual
method was added to the base class for handling the generic case.

Refactors a few subclasses to support the target independent %a, %c, and
%n.

The patch also contains small cleanups for AVRAsmPrinter and
SystemZAsmPrinter.

It seems that NVPTXTargetLowering is possibly missing some logic to
transform GlobalAddressSDNodes for
TargetLowering::LowerAsmOperandForConstraint to handle with "i" extended
inline assembly asm constraints.

Fixes:
- https://bugs.llvm.org/show_bug.cgi?id=41402
- https://github.com/ClangBuiltLinux/linux/issues/449

Reviewers: echristo, void

Reviewed By: void

Subscribers: void, craig.topper, jholewinski, dschuff, jyknight, dylanmckay, sdardis, nemanjai, javed.absar, sbc100, jgravelle-google, eraman, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, jrtc27, atanasyan, jsji, llvm-commits, kees, tpimh, nathanchance, peter.smith, srhines

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60887

llvm-svn: 359337
2019-04-26 18:45:04 +00:00
Nick Desaulniers 9609ce2f33 [AsmPrinter] hoist %a output template to base class for ARM+Aarch64
Summary:
X86 is quite complicated; so I intend to leave it as is. ARM+Aarch64 do
basically the same thing (Aarch64 did not correctly handle immediates,
ARM has a test llvm/test/CodeGen/ARM/2009-04-06-AsmModifier.ll that uses
%a with an immediate) for a flag that should be target independent
anyways.

Reviewers: echristo, peter.smith

Reviewed By: echristo

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60841

llvm-svn: 358618
2019-04-17 22:21:10 +00:00
Nick Desaulniers a2077bab40 [AsmPrinter] defer %c to base class for ARM, PPC, and Hexagon. NFC
Summary:
None of these derived classes do anything that the base class cannot.
If we remove these case statements, then the base class can handle them
just fine.

Reviewers: peter.smith, echristo

Reviewed By: echristo

Subscribers: nemanjai, javed.absar, eraman, kristof.beyls, hiraditya, kbarton, jsji, llvm-commits, srhines

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60803

llvm-svn: 358603
2019-04-17 18:22:48 +00:00
Nick Desaulniers 5277b3ff25 [AsmPrinter] refactor to remove remove AsmVariant. NFC
Summary:
The InlineAsm::AsmDialect is only required for X86; no architecture
makes use of it and as such it gets passed around between arch-specific
and general code while being unused for all architectures but X86.

Since the AsmDialect is queried from a MachineInstr, which we also pass
around, remove the additional AsmDialect parameter and query for it deep
in the X86AsmPrinter only when needed/as late as possible.

This refactor should help later planned refactors to AsmPrinter, as this
difference in the X86AsmPrinter makes it harder to make AsmPrinter more
generic.

Reviewers: craig.topper

Subscribers: jholewinski, arsenm, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, javed.absar, sbc100, jgravelle-google, eraman, hiraditya, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, llvm-commits, peter.smith, srhines

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60488

llvm-svn: 358101
2019-04-10 16:38:43 +00:00
Evandro Menezes 85bd3978ae [IR] Refactor attribute methods in Function class (NFC)
Rename the functions that query the optimization kind attributes.

Differential revision: https://reviews.llvm.org/D60287

llvm-svn: 357731
2019-04-04 22:40:06 +00:00
Evandro Menezes 7c711ccf36 [IR] Create new method in `Function` class (NFC)
Create method `optForNone()` testing for the function level equivalent of
`-O0` and refactor appropriately.

Differential revision: https://reviews.llvm.org/D59852

llvm-svn: 357638
2019-04-03 21:27:03 +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