Commit Graph

1058 Commits

Author SHA1 Message Date
Francis Visoiu Mistrih 2d8fdcae96 Reland: [Remarks] Add support for serializing metadata for every remark streamer
This allows every serializer format to implement metaSerializer() and
return the corresponding meta serializer.

Original llvm-svn: 366946
Reverted llvm-svn: 367004

This fixes the unit tests on Windows bots.

llvm-svn: 367078
2019-07-26 01:33:30 +00:00
Simon Pilgrim 55fd57ba95 Revert rL366946 : [Remarks] Add support for serializing metadata for every remark streamer
This allows every serializer format to implement metaSerializer() and
return the corresponding meta serializer.
........
Fix windows build bots
http://lab.llvm.org:8011/builders/llvm-clang-x86_64-win-fast
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast
http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win

llvm-svn: 367004
2019-07-25 10:20:39 +00:00
Francis Visoiu Mistrih 62388e3846 [Remarks] Add support for serializing metadata for every remark streamer
This allows every serializer format to implement metaSerializer() and
return the corresponding meta serializer.

llvm-svn: 366946
2019-07-24 21:29:44 +00:00
Francis Visoiu Mistrih ff4b515a77 [Remarks][NFC] Rename remarks::Serializer to remarks::RemarkSerializer
llvm-svn: 366939
2019-07-24 19:47:57 +00:00
Francis Visoiu Mistrih cc909812a3 [Remarks][NFC] Combine ParserFormat and SerializerFormat
It's useless to have both.

llvm-svn: 366216
2019-07-16 15:24:59 +00:00
Tim Northover 67828edbbd OpaquePtr: switch to GlobalValue::getValueType in a few places. NFC.
llvm-svn: 365770
2019-07-11 13:13:02 +00:00
Reid Kleckner 2f07c2e9d9 Standardize on MSVC behavior for triples with no environment
Summary:
This makes it so that IR files using triples without an environment work
out of the box, without normalizing them.

Typically, the MSVC behavior is more desirable. For example, it tends to
enable things like constant merging, use of associative comdats, etc.

Addresses PR42491

Reviewers: compnerd

Subscribers: hiraditya, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64109

llvm-svn: 365387
2019-07-08 21:05:20 +00:00
Francis Visoiu Mistrih 6ada11f134 [Remarks][NFC] Move the serialization to lib/Remarks
Separate the remark serialization to YAML from the LLVM Diagnostics.

This adds a new serialization abstraction: remarks::Serializer. It's
completely independent from lib/IR and it provides an easy way to
replace YAML by providing a new remarks::Serializer.

Differential Revision: https://reviews.llvm.org/D62632

llvm-svn: 362160
2019-05-30 21:45:59 +00:00
Peter Collingbourne 31fda09b2d Add IR support, ELF section and user documentation for partitioning feature.
The partitioning feature was proposed here:
http://lists.llvm.org/pipermail/llvm-dev/2019-February/130583.html

This is mostly just documentation. The feature itself will be contributed
in subsequent patches.

Differential Revision: https://reviews.llvm.org/D60242

llvm-svn: 361923
2019-05-29 03:29:01 +00:00
Shoaib Meenai 87226a7202 [AsmPrinter] Treat a narrowing PtrToInt like Trunc
When printing assembly for PtrToInt, AsmPrinter::lowerConstant
incorrectly assumed that if PtrToInt was not converting to an
int with exactly the same number of bits, it must be widening
to a larger int. But this isn't necessarily true; PtrToInt can
also shrink the size, which is useful when you want to produce
a known 32-bit pointer on a 64-bit platform (on x86_64 ELF
this yields a R_X86_64_32 relocation).

The old behavior of falling through to the widening case for a
narrowing PtrToInt yields bogus assembly code like this, which
fails to assemble because the no-op bit and it accidentally
creates is not a valid relocation:

```
        .long   a&-1
```

The fix is to treat a narrowing PtrToInt exactly the same as
it already treats Trunc: just emit the expression and let
the assembler deal with truncating it in the appropriate way.

Patch by Mat Hostetter <mjh@fb.com>.

Differential Revision: https://reviews.llvm.org/D61325

llvm-svn: 361508
2019-05-23 16:29:09 +00:00
Reid Kleckner 4882490349 [codeview] Fix SDNode representation of annotation labels
Before this change, they were erroneously constructed with the EH_LABEL
SDNode opcode, which caused other passes to interact with them in
incorrect ways. See the FIXME about fastisel that this addresses in the
existing test case.

Fixes PR41890

llvm-svn: 360818
2019-05-15 21:46:05 +00:00
Fangrui Song f4dfd63c74 [IR] Disallow llvm.global_ctors and llvm.global_dtors of the 2-field form in textual format
The 3-field form was introduced by D3499 in 2014 and the legacy 2-field
form was planned to be removed in LLVM 4.0

For the textual format, this patch migrates the existing 2-field form to
use the 3-field form and deletes the compatibility code.
test/Verifier/global-ctors-2.ll checks we have a friendly error message.

For bitcode, lib/IR/AutoUpgrade UpgradeGlobalVariables will upgrade the
2-field form (add i8* null as the third field).

Reviewed By: rnk, dexonsmith

Differential Revision: https://reviews.llvm.org/D61547

llvm-svn: 360742
2019-05-15 02:35:32 +00:00
Fangrui Song 7bce25cd7d [AsmPrinter] Make AsmPrinter::HandlerInfo::Handler a unique_ptr
Handlers.clear() in AsmPrinter::doFinalization() will destroy these handlers.
A unique_ptr makes the ownership clearer.

llvm-svn: 359541
2019-04-30 09:14:02 +00:00
Francis Visoiu Mistrih 7fee2b89fd [Remarks] Add string deduplication using a string table
* Add support for uniquing strings in the remark streamer and emitting the string table in the remarks section.

* Add parsing support for the string table in the RemarkParser.

From this remark:

```
--- !Missed
Pass:     inline
Name:     NoDefinition
DebugLoc: { File: 'test-suite/SingleSource/UnitTests/2002-04-17-PrintfChar.c',
            Line: 7, Column: 3 }
Function: printArgsNoRet
Args:
  - Callee:   printf
  - String:   ' will not be inlined into '
  - Caller:   printArgsNoRet
    DebugLoc: { File: 'test-suite/SingleSource/UnitTests/2002-04-17-PrintfChar.c',
                Line: 6, Column: 0 }
  - String:   ' because its definition is unavailable'
...
```

to:

```
--- !Missed
Pass: 0
Name: 1
DebugLoc: { File: 3, Line: 7, Column: 3 }
Function: 2
Args:
  - Callee:   4
  - String:   5
  - Caller:   2
    DebugLoc: { File: 3, Line: 6, Column: 0 }
  - String:   6
...
```

And the string table in the .remarks/__remarks section containing:

```
inline\0NoDefinition\0printArgsNoRet\0
test-suite/SingleSource/UnitTests/2002-04-17-PrintfChar.c\0printf\0
will not be inlined into \0 because its definition is unavailable\0
```

This is mostly supposed to be used for testing purposes, but it gives us
a 2x reduction in the remark size, and is an incremental change for the
updates to the remarks file format.

Differential Revision: https://reviews.llvm.org/D60227

llvm-svn: 359050
2019-04-24 00:06:24 +00:00
Fangrui Song efd94c56ba Use llvm::stable_sort
While touching the code, simplify if feasible.

llvm-svn: 358996
2019-04-23 14:51:27 +00:00
Shiva Chen 7cc03bd064 [RISCV] Put data smaller than eight bytes to small data section
Because of gp = sdata_start_address + 0x800, gp with signed twelve-bit offset
could covert most of the small data section. Linker relaxation could transfer
the multiple data accessing instructions to a gp base with signed twelve-bit
offset instruction.

Differential Revision: https://reviews.llvm.org/D57493

llvm-svn: 358150
2019-04-11 04:59:13 +00:00
Fangrui Song 2c5c12c041 Change some dyn_cast to more apropriate isa. NFC
llvm-svn: 357773
2019-04-05 16:16:23 +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
Alex Bradbury da20f5ca74 [RISCV] Generate address sequences suitable for mcmodel=medium
This patch adds an implementation of a PC-relative addressing sequence to be
used when -mcmodel=medium is specified. With absolute addressing, a 'medium'
codemodel may cause addresses to be out of range. This is because while
'medium' implies a 2 GiB addressing range, this 2 GiB can be at any offset as
opposed to 'small', which implies the first 2 GiB only.

Note that LLVM/Clang currently specifies code models differently to GCC, where
small and medium imply the same functionality as GCC's medlow and medany
respectively.

Differential Revision: https://reviews.llvm.org/D54143
Patch by Lewis Revill.

llvm-svn: 357393
2019-04-01 14:42:56 +00:00
Francis Visoiu Mistrih ee1a6e70fa [Remarks] Emit a section containing remark diagnostics metadata
A section containing metadata on remark diagnostics will be emitted if
the flag (-mllvm) -remarks-section is present.

For now, the metadata is:

* a magic number for remarks: "REMARKS\0"
* the version number: a little-endian uint64_t
* the absolute file path to the serialized remark diagnostics: a
  null-terminated string.

Differential Revision: https://reviews.llvm.org/D59571

llvm-svn: 357043
2019-03-27 01:13:59 +00:00
Francis Visoiu Mistrih 6b622ebea0 Revert "[Remarks] Refactor remark diagnostic emission in a RemarkStreamer"
This reverts commit 2e8c4997a2089f8228c843fd81b148d903472e02.

Breaks bots.

llvm-svn: 355511
2019-03-06 14:52:37 +00:00
Francis Visoiu Mistrih 9052f50cb4 [Remarks] Refactor remark diagnostic emission in a RemarkStreamer
This allows us to store more info about where we're emitting the remarks
without cluttering LLVMContext. This is needed for future support for
the remark section.

Differential Revision: https://reviews.llvm.org/D58996

llvm-svn: 355507
2019-03-06 14:32:08 +00:00
Craig Topper 784929d045 Implementation of asm-goto support in LLVM
This patch accompanies the RFC posted here:
http://lists.llvm.org/pipermail/llvm-dev/2018-October/127239.html

This patch adds a new CallBr IR instruction to support asm-goto
inline assembly like gcc as used by the linux kernel. This
instruction is both a call instruction and a terminator
instruction with multiple successors. Only inline assembly
usage is supported today.

This also adds a new INLINEASM_BR opcode to SelectionDAG and
MachineIR to represent an INLINEASM block that is also
considered a terminator instruction.

There will likely be more bug fixes and optimizations to follow
this, but we felt it had reached a point where we would like to
switch to an incremental development model.

Patch by Craig Topper, Alexander Ivchenko, Mikhail Dvoretckii

Differential Revision: https://reviews.llvm.org/D53765

llvm-svn: 353563
2019-02-08 20:48:56 +00:00
Sam Clegg 1e71b04af6 Remove reference to non-existent function. NFC.
This comment is old. The code in question was removed in rL203174

Differential Revision: https://reviews.llvm.org/D57856

llvm-svn: 353352
2019-02-07 00:11:43 +00:00
Sam Clegg 313f9f54f5 [WebAssembly] MC: Mark more function aliases as functions
Aliases of functions are now marked as function symbols even if
they are bitcast to some other other non-function type.
This is important for WebAssembly where object and function
symbols can't alias each other.

Fixes PR38866

Differential Revision: https://reviews.llvm.org/D57538

llvm-svn: 353109
2019-02-04 23:07:34 +00:00
Wolfgang Pieb 90d856cd5f [DEBUGINFO] Reposting r352642: Handle restore instructions in LiveDebugValues
The LiveDebugValues pass recognizes spills but not restores, which can
cause large gaps in location information for some variables, depending
on control flow. This patch make LiveDebugValues recognize restores and
generate appropriate DBG_VALUE instructions.

This patch was posted previously with r352642 and reverted in r352666 due
to buildbot errors. A missing return statement was the cause for the 
failures.

Reviewers: aprantl, NicolaPrica

Differential Revision: https://reviews.llvm.org/D57271

llvm-svn: 353089
2019-02-04 20:42:45 +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
Wolfgang Pieb facd052e16 Reverting r352642 - Handle restore instructions in LiveDebugValues - as it's causing
assertions on some buildbots.

llvm-svn: 352666
2019-01-30 20:37:14 +00:00
Wolfgang Pieb 5590a4355f [DEBUGINFO] Handle restore instructions in LiveDebugValues
The LiveDebugValues pass recognizes spills but not restores, which can 
cause large gaps in location information for some variables, depending
on control flow. This patch make LiveDebugValues recognize restores and
generate appropriate DBG_VALUE instructions. 

Reviewers: aprantl, NicolaPrica

Differential Revision: https://reviews.llvm.org/D57271

llvm-svn: 352642
2019-01-30 18:34:07 +00:00
Vedant Kumar 13ef84fced [MC] Teach the MachO object writer about N_FUNC_COLD
N_FUNC_COLD is a new MachO symbol attribute. It's a hint to the linker
to order a symbol towards the end of its section, to improve locality.

Example:

```
void a1() {}
__attribute__((cold)) void a2() {}
void a3() {}
int main() {
  a1();
  a2();
  a3();
  return 0;
}
```

A linker that supports N_FUNC_COLD will order _a2 to the end of the text
section. From `nm -njU` output, we see:

```
_a1
_a3
_main
_a2
```

Differential Revision: https://reviews.llvm.org/D57190

llvm-svn: 352227
2019-01-25 18:30:22 +00:00
Alexey Bataev 9d5974a9fc [DEBUG_INFO, NVPTX] Fix relocation info.
Summary: Initial function labels must follow the debug location for the correct relocation info generation.

Reviewers: tra, jlebar, echristo

Subscribers: jholewinski, llvm-commits

Differential Revision: https://reviews.llvm.org/D45784

llvm-svn: 351843
2019-01-22 17:24:16 +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
Yonghong Song 61b189e06f [DebugInfo] Move several private headers to include directory
This patch moved the following files in lib/CodeGen/AsmPrinter/
  AsmPrinterHandler.h
  DbgEntityHistoryCalculator.h
  DebugHandlerBase.h
to include/llvm/CodeGen directory.

Such a change will enable Target to extend DebugHandlerBase
and emit Target specific debug info sections.

Signed-off-by: Yonghong Song <yhs@fb.com>

Differential Revision: https://reviews.llvm.org/D55755

llvm-svn: 349564
2018-12-18 23:10:17 +00:00
Scott Linder de6beb02a5 Implement -frecord-command-line (-frecord-gcc-switches)
Implement options in clang to enable recording the driver command-line
in an ELF section.

Implement a new special named metadata, llvm.commandline, to support
frontends embedding their command-line options in IR/ASM/ELF.

This differs from the GCC implementation in some key ways:

* In GCC there is only one command-line possible per compilation-unit,
  in LLVM it mirrors llvm.ident and multiple are allowed.
* In GCC individual options are separated by NULL bytes, in LLVM entire
  command-lines are separated by NULL bytes. The advantage of the GCC
  approach is to clearly delineate options in the face of embedded
  spaces. The advantage of the LLVM approach is to support merging
  multiple command-lines unambiguously, while handling embedded spaces
  with escaping.

Differential Revision: https://reviews.llvm.org/D54487
Clang Differential Revision: https://reviews.llvm.org/D54489

llvm-svn: 349155
2018-12-14 15:38:15 +00:00
Alex Lorenz afa75d7843 [macho] save the SDK version stored in module metadata into the version min and
build version load commands in the object file

This commit introduces a new metadata node called "SDK Version". It will be set
by the frontend to mark the platform SDK (macOS/iOS/etc) version which was used
during that particular compilation.
This node is used when machine code is emitted, by either saving the SDK version
into the appropriate macho load command (version min/build version), or by
emitting the assembly for these load commands with the SDK version specified as
well.
The assembly for both load commands is extended by allowing it to contain the
sdk_version X, Y [, Z] trailing directive to represent the SDK version
respectively.

rdar://45774000

Differential Revision: https://reviews.llvm.org/D55612

llvm-svn: 349119
2018-12-14 01:14:10 +00:00
Yonghong Song f487334622 Revert "[BTF] Add BTF DebugInfo"
This reverts commit 9c6b970db8bc63b28ce58a129bb1580a6a3c6caf.

llvm-svn: 348004
2018-11-30 16:54:43 +00:00
Yonghong Song 81b77e9159 [BTF] Add BTF DebugInfo
This patch adds BPF Debug Format (BTF) as a standalone
LLVM debuginfo. The BTF related sections are directly
generated from IR. The BTF debuginfo is generated
only when the compilation target is BPF.

What is BTF?
============

First, the BPF is a linux kernel virtual machine
and widely used for tracing, networking and security.
  https://www.kernel.org/doc/Documentation/networking/filter.txt
  https://cilium.readthedocs.io/en/v1.2/bpf/

BTF is the debug info format for BPF, introduced in the below
linux patch
  69b693f0ae (diff-06fb1c8825f653d7e539058b72c83332)
in the patch set mentioned in the below lwn article.
  https://lwn.net/Articles/752047/

The BTF format is specified in the above github commit.
In summary, its layout looks like
  struct btf_header
  type subsection (a list of types)
  string subsection (a list of strings)

With such information, the kernel and the user space is able to
pretty print a particular bpf map key/value. One possible example below:
  Withtout BTF:
    key: [ 0x01, 0x01, 0x00, 0x00 ]
  With BTF:
    key: struct t { a : 1; b : 1; c : 0}
  where struct is defined as
    struct t { char a; char b; short c; };

How BTF is generated?
=====================

Currently, the BTF is generated through pahole.
  https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=68645f7facc2eb69d0aeb2dd7d2f0cac0feb4d69
and available in pahole v1.12
  https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=4a21c5c8db0fcd2a279d067ecfb731596de822d4

Basically, the bpf program needs to be compiled with -g with
dwarf sections generated. The pahole is enhanced such that
a .BTF section can be generated based on dwarf. This format
of the .BTF section matches the format expected by
the kernel, so a bpf loader can just take the .BTF section
and load it into the kernel.
  8a138aed4a

The .BTF section layout is also specified in this patch:
with file include/llvm/BinaryFormat/BTF.h.

What use cases this patch tries to address?
===========================================

Currently, only the bpf instruction stream is required to
pass to the kernel. The kernel verifies it, jits it if configured
to do so, attaches it to a particular kernel attachment point,
and later executes when a particular event happens.

This patch tries to expand BTF to support two more use cases below:
  (1). BPF supports subroutine calls.
       During performance analysis, it would be good to
       differentiate which call is hot instead of just
       providing a virtual address. This would require to
       pass a unique identifier for each subroutine to
       the kernel, the subroutine name is a natual choice.
  (2). If a particular jitted instruction is hot, we want
       user to know which source line this jitted instruction
       belongs to. This would require the source information
       is available to various profiling tools.

Note that in a single ELF file,
  . there may be multiple loadable bpf programs,
  . for a particular to-be-loaded bpf instruction stream,
    its instructions may come from multiple PROGBITS sections,
    the bpf loader needs to merge them together to a single
    consecutive insn stream before loading to the kernel.
For example:
  section .text: subroutines funcFoo
  section _progA: calling funcFoo
  section _progB: calling funcFoo
The bpf loader could construct two loadable bpf instruction
streams and load them into the kernel:
  . _progA funcFoo
  . _progB funcFoo
So per ELF section function offset and instruction offset
will need to be adjusted before passing to the kernel, and
the kernel essentially expect only one code section regardless
of how many in the ELF file.

What do we propose and Why?
===========================

To support the above two use cases, we propose to
add an additional section, .BTF.ext, to the ELF file
which is the input of the bpf loader. A different section
is preferred since loader may need to manipulate it before
loading part of its data to the kernel.

The .BTF.ext section has a similar header to the .BTF section
and it contains two subsections for func_info and line_info.
  . the func_info maps the func insn byte offset to a func
    type in the .BTF type subsection.
  . the line_info maps the insn byte offset to a line info.
  . both func_info and line_info subsections are organized
    by ELF PROGBITS AX sections.

pahole is not a good place to implement .BTF.ext as
pahole is mostly for structure hole information and more
importantly, we want to pass the actual code to the kernel.
  . bpf program typically is small so storage overhead
    should be small.
  . in bpf land, it is totally possible that
    an application loads the bpf program into the
    kernel and then that application quits, so
    holding debug info by the user space application
    is not practical as you may not even know who
    loads this bpf program.
  . having source codes directly kept by kernel
    would ease deployment since the original source
    code does not need ship on every hosts and
    kernel-devel package does not need to be
    deployed even if kernel headers are used.

LLVM is a good place to implement.
  . The only reliable time to get the source code is
    during compilation time. This will result in both more
    accurate information and easier deployment as
    stated in the above.
  . Another consideration is for JIT. The project like bcc
    (https://github.com/iovisor/bcc)
    use MCJIT to compile a C program into bpf insns and
    load them to the kernel. The llvm generated BTF sections
    will be readily available for such cases as well.

Design and implementation of emiting .BTF/.BTF.ext sections
===========================================================

The BTF debuginfo format is defined. Both .BTF and .BTF.ext
sections are generated directly from IR when both
"-target bpf" and "-g" are specified. Note that
dwarf sections are still generated as dwarf is used
by user space tools like llvm-objdump etc. for BPF target.

This patch also contains tests to verify generated
.BTF and .BTF.ext sections for all supported types, func_info
and line_info subsections. The patch is also tested
against linux kernel bpf sample tests and selftests.

Signed-off-by: Yonghong Song <yhs@fb.com>

Differential Revision: https://reviews.llvm.org/D53736

llvm-svn: 347999
2018-11-30 16:22:59 +00:00
Simon Atanasyan af860d44fe [DebugInfo] Rename EmitDebugThreadLocal back to EmitDebugValue. NFC
This reverts r294500. DwarfCompileUnit::addAddressExpr uses DIEExpr
for PCOffset. In that case the expression is unrelated to thread locals
and so emitting a value of the DIEExpr does not have to always mean
emit-debug-thread-local.

llvm-svn: 347744
2018-11-28 11:48:07 +00:00
Than McIntosh 30c804bbb1 [CodeGen] Support custom format of stack maps
Summary:
Add a hook to the GCMetadataPrinter for emitting stack maps in
custom format. The hook will be called at stack map generation
time. The default stack map format is used if there is no hook.

For this to be useful a few data structures and accessors are
exposed from the StackMaps class, so the custom printer can
access the stack map data.

This patch authored by Cherry Zhang <cherryyz@google.com>.

Reviewers: thanm, apilipenko, reames

Reviewed By: reames

Subscribers: reames, apilipenko, nemanjai, javed.absar, kbarton, jsji, llvm-commits

Differential Revision: https://reviews.llvm.org/D53892

llvm-svn: 347584
2018-11-26 18:43:48 +00:00
Heejin Ahn 24faf859e5 Reland "[WebAssembly] LSDA info generation"
Summary:
This adds support for LSDA (exception table) generation for wasm EH.
Wasm EH mostly follows the structure of Itanium-style exception tables,
with one exception: a call site table entry in wasm EH corresponds to
not a call site but a landing pad.

In wasm EH, the VM is responsible for stack unwinding. After an
exception occurs and the stack is unwound, the control flow is
transferred to wasm 'catch' instruction by the VM, after which the
personality function is called from the compiler-generated code. (Refer
to WasmEHPrepare pass for more information on this part.)

This patch:
- Changes wasm.landingpad.index intrinsic to take a token argument, to
make this 1:1 match with a catchpad instruction
- Stores landingpad index info and catch type info MachineFunction in
before instruction selection
- Lowers wasm.lsda intrinsic to an MCSymbol pointing to the start of an
exception table
- Adds WasmException class with overridden methods for table generation
- Adds support for LSDA section in Wasm object writer

Reviewers: dschuff, sbc100, rnk

Subscribers: mgorny, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D52748

llvm-svn: 345345
2018-10-25 23:55:10 +00:00
Krasimir Georgiev 547d824da6 Revert "[WebAssembly] LSDA info generation"
This reverts commit r344575.
Newly introduced test eh-lsda.ll.test fails with use-after-free under
ASAN build.

llvm-svn: 344639
2018-10-16 18:50:09 +00:00
Heejin Ahn 0981eaab47 [WebAssembly] LSDA info generation
Summary:
This adds support for LSDA (exception table) generation for wasm EH.
Wasm EH mostly follows the structure of Itanium-style exception tables,
with one exception: a call site table entry in wasm EH corresponds to
not a call site but a landing pad.

In wasm EH, the VM is responsible for stack unwinding. After an
exception occurs and the stack is unwound, the control flow is
transferred to wasm 'catch' instruction by the VM, after which the
personality function is called from the compiler-generated code. (Refer
to WasmEHPrepare pass for more information on this part.)

This patch:
- Changes wasm.landingpad.index intrinsic to take a token argument, to
make this 1:1 match with a catchpad instruction
- Stores landingpad index info and catch type info MachineFunction in
before instruction selection
- Lowers wasm.lsda intrinsic to an MCSymbol pointing to the start of an
exception table
- Adds WasmException class with overridden methods for table generation
- Adds support for LSDA section in Wasm object writer

Reviewers: dschuff, sbc100, rnk

Subscribers: mgorny, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D52748

llvm-svn: 344575
2018-10-16 00:09:12 +00:00
Sander de Smalen c91b27d9ee Remove FrameAccess struct from hasLoadFromStackSlot
This removes the FrameAccess struct that was added to the interface
in D51537, since the PseudoValue from the MachineMemoryOperand
can be safely casted to a FixedStackPseudoSourceValue.

Reviewers: MatzeB, thegameg, javed.absar

Reviewed By: thegameg

Differential Revision: https://reviews.llvm.org/D51617

llvm-svn: 341454
2018-09-05 08:59:50 +00:00
Sander de Smalen 6cab60fa06 Extend hasStoreToStackSlot with list of FI accesses.
For instructions that spill/fill to and from multiple frame-indices
in a single instruction, hasStoreToStackSlot and hasLoadFromStackSlot
should return an array of accesses, rather than just the first encounter
of such an access.

This better describes FI accesses for AArch64 (paired) LDP/STP
instructions.

Reviewers: t.p.northover, gberry, thegameg, rengolin, javed.absar, MatzeB

Reviewed By: MatzeB

Differential Revision: https://reviews.llvm.org/D51537

llvm-svn: 341301
2018-09-03 09:15:58 +00:00
Martin Storsjo 489993db94 [MinGW] [X86] Add stubs for references to data variables that might end up imported from a dll
Variables declared with the dllimport attribute are accessed via a
stub variable named __imp_<var>. In MinGW configurations, variables that
aren't declared with a dllimport attribute might still end up imported
from another DLL with runtime pseudo relocs.

For x86_64, this avoids the risk that the target is out of range
for a 32 bit PC relative reference, in case the target DLL is loaded
further than 4 GB from the reference. It also avoids having to make the
text section writable at runtime when doing the runtime fixups, which
makes it worthwhile to do for i386 as well.

Add stub variables for all dso local data references where a definition
of the variable isn't visible within the module, since the DLL data
autoimporting might make them imported even though they are marked as
dso local within LLVM.

Don't do this for variables that actually are defined within the same
module, since we then know for sure that it actually is dso local.

Don't do this for references to functions, since there's no need for
runtime pseudo relocations for autoimporting them; if a function from
a different DLL is called without the appropriate dllimport attribute,
the call just gets routed via a thunk instead.

GCC does something similar since 4.9 (when compiling with -mcmodel=medium
or large; from that version, medium is the default code model for x86_64
mingw), but only for x86_64.

Differential Revision: https://reviews.llvm.org/D51288

llvm-svn: 340942
2018-08-29 17:28:34 +00:00
Peter Collingbourne 3f792230cb CodeGen: Add two more conditions for adding symbols to the address-significance table.
Firstly, require the symbol to be used within the module. If a
symbol is unused within a module, then by definition it cannot be
address-significant within that module. This condition is useful on all
platforms because it could make symbol tables smaller -- without this
change, emitting an address-significance table could cause otherwise
unused undefined symbols to be added to the object file.

But this change is necessary with COFF specifically in order to
preserve the property that an unreferenced undefined symbol in an IR
module does not result in a link failure. This is already the case for
ELF because ELF linkers only reject links with unresolved symbols if
there is a relocation to that symbol, but COFF linkers require all
undefined symbols to be resolved regardless of relocations. So if
a module contains an unreferenced undefined symbol, we need to make
sure not to add it to the address-significance table (and thus the
symbol table) in case it doesn't end up resolved at link time.

Secondly, do not add dllimport symbols to the table. These symbols
won't be able to be resolved because their definitions live in another
module and are accessed via the IAT, and the address-significance
table has no effect on other modules anyway. It wouldn't make sense
to add the IAT entry symbol to the address-significance table either
because the IAT entry isn't address-significant -- the generated code
never takes its address.

Differential Revision: https://reviews.llvm.org/D51199

llvm-svn: 340648
2018-08-24 20:37:09 +00:00
Chandler Carruth 75ca6be1c1 [x86/MIR] Implement support for pre- and post-instruction symbols, as
well as MIR parsing support for `MCSymbol` `MachineOperand`s.

The only real way to test pre- and post-instruction symbol support is to
use them in operands, so I ended up implementing that within the patch
as well. I can split out the operand support if folks really want but it
doesn't really seem worth it.

The functional implementation of pre- and post-instruction symbols is
now *completely trivial*. Two tiny bits of code in the (misnamed)
AsmPrinter. It should be completely target independent as well. We emit
these exactly the same way as we emit basic block labels. Most of the
code here is to give full dumping, MIR printing, and MIR parsing support
so that we can write useful tests.

The MIR parsing of MC symbol operands still isn't 100%, as it forces the
symbols to be non-temporary and non-local symbols with names. However,
those names often can encode most (if not all) of the special semantics
desired, and unnamed symbols seem especially annoying to serialize and
de-serialize. While this isn't perfect or full support, it seems plenty
to write tests that exercise usage of these kinds of operands.

The MIR support for pre-and post-instruction symbols was quite
straightforward. I chose to print them out in an as-if-operand syntax
similar to debug locations as this seemed the cleanest way and let me
use nice introducer tokens rather than inventing more magic punctuation
like we use for memoperands.

However, supporting MIR-based parsing of these symbols caused me to
change the design of the symbol support to allow setting arbitrary
symbols. Without this, I don't see any reasonable way to test things
with MIR.

Differential Revision: https://reviews.llvm.org/D50833

llvm-svn: 339962
2018-08-16 23:11:05 +00:00
Hans Wennborg d4090be340 Rename the cfguard module flag to cfguardtable
The previous name sounds like it inserts cfguard implementation, but it
really just emits the table of address-taken functions. Change the name
to better reflect that.

Clang will be updated in the next commit.

llvm-svn: 339419
2018-08-10 09:48:53 +00:00
Martin Storsjo 9dafd6f6d9 Revert "[COFF] Use comdat shared constants for MinGW as well"
This reverts commit r337951.

While that kind of shared constant generally works fine in a MinGW
setting, it broke some cases of inline assembly that worked before:

$ cat const-asm.c
int MULH(int a, int b) {
    int rt, dummy;
    __asm__ (
        "imull %3"
        :"=d"(rt), "=a"(dummy)
        :"a"(a), "rm"(b)
    );
    return rt;
}
int func(int a) {
    return MULH(a, 1);
}
$ clang -target x86_64-win32-gnu -c const-asm.c -O2
const-asm.c:4:9: error: invalid variant '00000001'
        "imull %3"
        ^
<inline asm>:1:15: note: instantiated into assembly here
        imull __real@00000001(%rip)
                     ^

A similar error is produced for i686 as well. The same test with a
target of x86_64-win32-msvc or i686-win32-msvc works fine.

llvm-svn: 338018
2018-07-26 10:48:20 +00:00
Martin Storsjo ff33a95ed4 [COFF] Use comdat shared constants for MinGW as well
GNU binutils tools have no problems with this kind of shared constants,
provided that we actually hook it up completely in AsmPrinter and
produce a global symbol.

This effectively reverts SVN r335918 by hooking the rest of it up
properly.

This feature was implemented originally in SVN r213006, with no reason
for why it can't be used for MinGW other than the fact that GCC doesn't
do it while MSVC does.

Differential Revision: https://reviews.llvm.org/D49646

llvm-svn: 337951
2018-07-25 18:35:42 +00:00