Commit Graph

3794 Commits

Author SHA1 Message Date
Fangrui Song d9b948b6eb Rename F_{None,Text,Append} to OF_{None,Text,Append}. NFC
F_{None,Text,Append} are kept for compatibility since r334221.

llvm-svn: 367800
2019-08-05 05:43:48 +00:00
Tim Northover a009a60a91 IR: print value numbers for unnamed function arguments
For consistency with normal instructions and clarity when reading IR,
it's best to print the %0, %1, ... names of function arguments in
definitions.

Also modifies the parser to accept IR in that form for obvious reasons.

llvm-svn: 367755
2019-08-03 14:28:34 +00:00
Roman Lebedev 081e990d08 [IR] Value: add replaceUsesWithIf() utility
Summary:
While there is always a `Value::replaceAllUsesWith()`,
sometimes the replacement needs to be conditional.

I have only cleaned a few cases where `replaceUsesWithIf()`
could be used, to both add test coverage,
and show that it is actually useful.

Reviewers: jdoerfert, spatel, RKSimon, craig.topper

Reviewed By: jdoerfert

Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, aheejin, george.burgess.iv, asbirlea, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65528

llvm-svn: 367548
2019-08-01 12:32:08 +00:00
Djordje Todorovic b9973f87c6 Reland "[DwarfDebug] Dump call site debug info"
The build failure found after the rL365467 has been
resolved.

Differential Revision: https://reviews.llvm.org/D60716

llvm-svn: 367446
2019-07-31 16:51:28 +00:00
Francis Visoiu Mistrih 84e80979b5 Reland: [Remarks] Add an LLVM-bitstream-based remark serializer
Add a new serializer, using a binary format based on the LLVM bitstream
format.

This format provides a way to serialize the remarks in two modes:

1) Separate mode: the metadata is separate from the remark entries.
2) Standalone mode: the metadata and the remark entries are in the same
file.

The format contains:

* a meta block: container version, container type, string table,
external file path, remark version
* a remark block: type, remark name, pass name, function name, debug
file, debug line, debug column, hotness, arguments (key, value, debug
file, debug line, debug column)

A string table is required for this format, which will be dumped in the
meta block to be consumed before parsing the remark blocks.

On clang itself, we noticed a size reduction of 13.4x compared to YAML,
and a compile-time reduction of between 1.7% and 3.5% on CTMark.

Differential Revision: https://reviews.llvm.org/D63466

Original llvm-svn: 367364
Revert llvm-svn: 367370

llvm-svn: 367372
2019-07-31 00:13:51 +00:00
Francis Visoiu Mistrih d8e7967a22 Revert "[Remarks] Add an LLVM-bitstream-based remark serializer"
This reverts commit r367364.

Breaks some bots: http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-gn/builds/3161/steps/annotate/logs/stdio

llvm-svn: 367370
2019-07-31 00:01:34 +00:00
Francis Visoiu Mistrih 6c3c9483e7 [Remarks] Add an LLVM-bitstream-based remark serializer
Add a new serializer, using a binary format based on the LLVM bitstream
format.

This format provides a way to serialize the remarks in two modes:

1) Separate mode: the metadata is separate from the remark entries.
2) Standalone mode: the metadata and the remark entries are in the same
file.

The format contains:

* a meta block: container version, container type, string table,
external file path, remark version
* a remark block: type, remark name, pass name, function name, debug
file, debug line, debug column, hotness, arguments (key, value, debug
file, debug line, debug column)

A string table is required for this format, which will be dumped in the
meta block to be consumed before parsing the remark blocks.

On clang itself, we noticed a size reduction of 13.4x compared to YAML,
and a compile-time reduction of between 1.7% and 3.5% on CTMark.

Differential Revision: https://reviews.llvm.org/D63466

llvm-svn: 367364
2019-07-30 23:11:57 +00:00
Francis Visoiu Mistrih 5ed3d146f8 [Remarks] Add two serialization modes for remarks: separate and standalone
The default mode is separate, where the metadata is serialized
separately from the remarks.

Another mode is the standalone mode, where the metadata is serialized
before the remarks, on the same stream.

llvm-svn: 367328
2019-07-30 16:01:40 +00:00
Vedant Kumar d01ae675af [IR] Consolidate fixed metadata kind definitions (NFC)
Put the list of fixed metadata kinds in one place.

Testing: check-llvm with+without LLVM_ENABLE_MODULES=On

Differential Revision: https://reviews.llvm.org/D64437

llvm-svn: 367257
2019-07-29 20:24:20 +00:00
Hideto Ueno afd4a37b2a [IR] Fix getPointerAlignment for CallBase
Summary:
In current getPointerAlignemnt implementation, CallBase.getPointerAlignement(..) checks only parameter attriutes in the callsite.  For example,

```
declare align 8 i8* @foo()

define void @bar() {
    %a = tail call align 8 i8* @foo() ; getPointerAlignment returns 8
    %b = tail call i8* @foo() ; getPointerAlignemnt returns 0
    ret void
}
```

This patch will fix the problem.

Reviewers: jdoerfert

Reviewed By: jdoerfert

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65281

llvm-svn: 367185
2019-07-28 06:17:46 +00:00
JF Bastien dbc0a5df8d Allow prefetching from non-zero address spaces
Summary:
This is useful for targets which have prefetch instructions for non-default address spaces.

<rdar://problem/42662136>

Subscribers: nemanjai, javed.absar, hiraditya, kbarton, jkorous, dexonsmith, cfe-commits, llvm-commits, RKSimon, hfinkel, t.p.northover, craig.topper, anemet

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D65254

llvm-svn: 367032
2019-07-25 16:11:57 +00:00
Peter Collingbourne 72391ab4f1 IR: Teach GlobalIndirectSymbol::getBaseObject() to handle more kinds of expressions.
For aliases, any expression that lowers at the MC level to global_object or
global_object+constant is valid at the object file level. getBaseObject()
should return a result if the aliasee ends up being of that form even if
the IR used to produce it is somewhat unconventional.

Note that this is different from what stripInBoundsOffsets() and that family
of functions is doing. Those functions are concerned about semantic properties
of IR, whereas here we only care about the lowering result.

Therefore reimplement getBaseObject() in a way that matches the lowering
result. This fixes a crash when producing a summary for aliases such as
that in the included test case.

Differential Revision: https://reviews.llvm.org/D65115

llvm-svn: 366952
2019-07-24 22:23:05 +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 c5cc9efa07 [Remarks] Simplify the creation of remark serializers
Introduce two new functions to create a serializer, and add support for
more combinations to the YAMLStrTabSerializer.

llvm-svn: 366919
2019-07-24 16:36:35 +00:00
Simon Pilgrim 78b1e777f5 Fix "control reaches end of non-void function" warning. NFCI.
llvm-svn: 366856
2019-07-23 21:59:48 +00:00
Francis Visoiu Mistrih c5b5cc4575 [Remarks] Introduce a new format: yaml-strtab
This exposes better support to use a string table with a format through
an actual new remark::Format, called yaml-strtab.

This can now be used with -fsave-optimization-record=yaml-strtab.

llvm-svn: 366849
2019-07-23 20:42:46 +00:00
Francis Visoiu Mistrih cbbdc41838 [Remarks][NFC] Move the YAML serializer to its own header
llvm-svn: 366842
2019-07-23 19:28:03 +00:00
Ryan Taylor 6f13637a3e [IR][Verifier] Allow IntToPtrInst to be !dereferenceable
Summary:
Allow IntToPtrInst to carry !dereferenceable metadata tag.
This is valid since !dereferenceable can be only be applied to
pointer type values.

Change-Id: If8a6e3c616f073d51eaff52ab74535c29ed497b4

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64954

llvm-svn: 366826
2019-07-23 17:19:56 +00:00
Peter Collingbourne 68f3fc2d91 Fix typo in r366494. Spotted by Yuanfang Chen.
llvm-svn: 366497
2019-07-18 21:03:37 +00:00
Peter Collingbourne d1ec8eb84f IR: Teach Constant::needsRelocation() that relative pointers don't need to be relocated.
This causes sections with relative pointers to be marked as read only,
which means that they won't end up sharing pages with writable data.

Differential Revision: https://reviews.llvm.org/D64948

llvm-svn: 366494
2019-07-18 20:56:21 +00:00
Francis Visoiu Mistrih 94bad22c2c [Remarks] Simplify and refactor the RemarkParser interface
Before, everything was based on some kind of type erased parser
implementation which container a lot of boilerplate code when multiple
formats were to be supported.

This simplifies it by:

* the remark now owns its arguments
* *always* returning an error from the implementation side
* working around the way the YAML parser reports errors: catch them through
callbacks and re-insert them in a proper llvm::Error
* add a CParser wrapper that is used when implementing the C API to
avoid cluttering the C++ API with useless state
* LLVMRemarkParserGetNext now returns an object that needs to be
released to avoid leaking resources
* add a new API to dispose of a remark entry: LLVMRemarkEntryDispose

llvm-svn: 366217
2019-07-16 15:25:05 +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
Rui Ueyama 49a3ad21d6 Fix parameter name comments using clang-tidy. NFC.
This patch applies clang-tidy's bugprone-argument-comment tool
to LLVM, clang and lld source trees. Here is how I created this
patch:

$ git clone https://github.com/llvm/llvm-project.git
$ cd llvm-project
$ mkdir build
$ cd build
$ cmake -GNinja -DCMAKE_BUILD_TYPE=Debug \
    -DLLVM_ENABLE_PROJECTS='clang;lld;clang-tools-extra' \
    -DCMAKE_EXPORT_COMPILE_COMMANDS=On -DLLVM_ENABLE_LLD=On \
    -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ ../llvm
$ ninja
$ parallel clang-tidy -checks='-*,bugprone-argument-comment' \
    -config='{CheckOptions: [{key: StrictMode, value: 1}]}' -fix \
    ::: ../llvm/lib/**/*.{cpp,h} ../clang/lib/**/*.{cpp,h} ../lld/**/*.{cpp,h}

llvm-svn: 366177
2019-07-16 04:46:31 +00:00
Evgeniy Stepanov c5e7f56249 ARM MTE stack sanitizer.
Add "memtag" sanitizer that detects and mitigates stack memory issues
using armv8.5 Memory Tagging Extension.

It is similar in principle to HWASan, which is a software implementation
of the same idea, but there are enough differencies to warrant a new
sanitizer type IMHO. It is also expected to have very different
performance properties.

The new sanitizer does not have a runtime library (it may grow one
later, along with a "debugging" mode). Similar to SafeStack and
StackProtector, the instrumentation pass (in a follow up change) will be
inserted in all cases, but will only affect functions marked with the
new sanitize_memtag attribute.

Reviewers: pcc, hctim, vitalybuka, ostannard

Subscribers: srhines, mehdi_amini, javed.absar, kristof.beyls, hiraditya, cryptoad, steven_wu, dexonsmith, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D64169

llvm-svn: 366123
2019-07-15 20:02:23 +00:00
Evgeniy Stepanov 41c22b4390 Extend function attributes bitset size from 64 to 96.
Summary: We are going to add a function attribute number 64.

Reviewers: pcc, jdoerfert, lebedev.ri

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64663

llvm-svn: 365980
2019-07-13 00:29:03 +00:00
Fangrui Song 38cd364007 [LegacyPassManager] Small ModuleCount cleanup
llvm-svn: 365907
2019-07-12 15:18:29 +00:00
Djordje Todorovic 0739ccd3b5 Revert "[DwarfDebug] Dump call site debug info"
A build failure was found on the SystemZ platform.

This reverts commit 9e7e73578e54cd22b3c7af4b54274d743b6607cc.

llvm-svn: 365886
2019-07-12 09:45:12 +00:00
Stefan Stipanovic 0626367202 [Attributor] Deduce "nosync" function attribute.
Introduce and deduce "nosync" function attribute to indicate that a function
does not synchronize with another thread in a way that other thread might free memory.

Reviewers: jdoerfert, jfb, nhaehnle, arsenm

Subscribers: wdng, hfinkel, nhaenhle, mehdi_amini, steven_wu,
dexonsmith, arsenm, uenoku, hiraditya, jfb, llvm-commits

Differential Revision: https://reviews.llvm.org/D62766

llvm-svn: 365830
2019-07-11 21:37:40 +00:00
Benjamin Kramer fa1a4e4de5 [NVPTX] Use atomicrmw fadd instead of intrinsics
AutoUpgrade the old intrinsics to atomicrmw fadd.

llvm-svn: 365796
2019-07-11 17:11:25 +00:00
Johannes Doerfert 3ed286a388 Replace three "strip & accumulate" implementations with a single one
This patch replaces the three almost identical "strip & accumulate"
implementations for constant pointer offsets with a single one,
combining the respective functionalities. The old interfaces are kept
for now.

Differential Revision: https://reviews.llvm.org/D64468

llvm-svn: 365723
2019-07-11 01:14:48 +00:00
Philip Reames f47a313e71 Add a transform pass to make the executable semantics of poison explicit in the IR
Implements a transform pass which instruments IR such that poison semantics are made explicit. That is, it provides a (possibly partial) executable semantics for every instruction w.r.t. poison as specified in the LLVM LangRef. There are obvious parallels to the sanitizer tools, but this pass is focused purely on the semantics of LLVM IR, not any particular source language.

The target audience for this tool is developers working on or targetting LLVM from a frontend. The idea is to be able to take arbitrary IR (with the assumption of known inputs), and evaluate it concretely after having made poison semantics explicit to detect cases where either a) the original code executes UB, or b) a transform pass introduces UB which didn't exist in the original program.

At the moment, this is mostly the framework and still needs to be fleshed out. By reusing existing code we have decent coverage, but there's a lot of cases not yet handled. What's here is good enough to handle interesting cases though; for instance, one of the recent LFTR bugs involved UB being triggered by integer induction variables with nsw/nuw flags would be reported by the current code.

(See comment in PoisonChecking.cpp for full explanation and context)

Differential Revision: https://reviews.llvm.org/D64215

llvm-svn: 365536
2019-07-09 18:49:29 +00:00
Djordje Todorovic 01eaae6dd1 [DwarfDebug] Dump call site debug info
Dump the DWARF information about call sites and call site parameters into
debug info sections.

The patch also provides an interface for the interpretation of instructions
that could load values of a call site parameters in order to generate DWARF
about the call site parameters.

([13/13] Introduce the debug entry values.)

Co-authored-by: Ananth Sowda <asowda@cisco.com>
Co-authored-by: Nikola Prica <nikola.prica@rt-rk.com>
Co-authored-by: Ivan Baev <ibaev@cisco.com>

Differential Revision: https://reviews.llvm.org/D60716

llvm-svn: 365467
2019-07-09 11:33:56 +00:00
Yevgeny Rouban 592f44a7e7 Prepare for making SwitchInstProfUpdateWrapper strict
This patch removes the test part that relates to the non-strict
behavior of SwitchInstProfUpdateWrapper and changes
the assertion to llvm_unreachable() to allow the check in
release builds.
This patch prepares SwitchInstProfUpdateWrapper to become
strict with one line change. That is need to revert it easily
if any failure will arise.

llvm-svn: 365439
2019-07-09 05:07:28 +00:00
Yonghong Song e3919c6baf [BPF] add new intrinsics preserve_{array,union,struct}_access_index
For background of BPF CO-RE project, please refer to
  http://vger.kernel.org/bpfconf2019.html
In summary, BPF CO-RE intends to compile bpf programs
adjustable on struct/union layout change so the same
program can run on multiple kernels with adjustment
before loading based on native kernel structures.

In order to do this, we need keep track of GEP(getelementptr)
instruction base and result debuginfo types, so we
can adjust on the host based on kernel BTF info.
Capturing such information as an IR optimization is hard
as various optimization may have tweaked GEP and also
union is replaced by structure it is impossible to track
fieldindex for union member accesses.

Three intrinsic functions, preserve_{array,union,struct}_access_index,
are introducted.
  addr = preserve_array_access_index(base, index, dimension)
  addr = preserve_union_access_index(base, di_index)
  addr = preserve_struct_access_index(base, gep_index, di_index)
here,
  base: the base pointer for the array/union/struct access.
  index: the last access index for array, the same for IR/DebugInfo layout.
  dimension: the array dimension.
  gep_index: the access index based on IR layout.
  di_index: the access index based on user/debuginfo types.

For example, for the following example,
  $ cat test.c
  struct sk_buff {
     int i;
     int b1:1;
     int b2:2;
     union {
       struct {
         int o1;
         int o2;
       } o;
       struct {
         char flags;
         char dev_id;
       } dev;
       int netid;
     } u[10];
  };

  static int (*bpf_probe_read)(void *dst, int size, const void *unsafe_ptr)
      = (void *) 4;

  #define _(x) (__builtin_preserve_access_index(x))

  int bpf_prog(struct sk_buff *ctx) {
    char dev_id;
    bpf_probe_read(&dev_id, sizeof(char), _(&ctx->u[5].dev.dev_id));
    return dev_id;
  }
  $ clang -target bpf -O2 -g -emit-llvm -S -mllvm -print-before-all \
    test.c >& log

The generated IR looks like below:

  ...
  define dso_local i32 @bpf_prog(%struct.sk_buff*)  !dbg  {
    %2 = alloca %struct.sk_buff*, align 8
    %3 = alloca i8, align 1
    store %struct.sk_buff* %0, %struct.sk_buff** %2, align 8, !tbaa 
    call void @llvm.dbg.declare(metadata %struct.sk_buff** %2, metadata , metadata !DIExpression()), !dbg 
    call void @llvm.lifetime.start.p0i8(i64 1, i8* %3) , !dbg 
    call void @llvm.dbg.declare(metadata i8* %3, metadata , metadata !DIExpression()), !dbg 
    %4 = load i32 (i8*, i32, i8*)*, i32 (i8*, i32, i8*)** @bpf_probe_read, align 8, !dbg , !tbaa 
    %5 = load %struct.sk_buff*, %struct.sk_buff** %2, align 8, !dbg , !tbaa 
    %6 = call [10 x %union.anon]* @llvm.preserve.struct.access.index.p0a10s_union.anons.p0s_struct.sk_buffs(
         %struct.sk_buff* %5, i32 2, i32 3), !dbg , !llvm.preserve.access.index 
    %7 = call %union.anon* @llvm.preserve.array.access.index.p0s_union.anons.p0a10s_union.anons(
         [10 x %union.anon]* %6, i32 1, i32 5), !dbg 
    %8 = call %union.anon* @llvm.preserve.union.access.index.p0s_union.anons.p0s_union.anons(
         %union.anon* %7, i32 1), !dbg , !llvm.preserve.access.index 
    %9 = bitcast %union.anon* %8 to %struct.anon.0*, !dbg 
    %10 = call i8* @llvm.preserve.struct.access.index.p0i8.p0s_struct.anon.0s(
         %struct.anon.0* %9, i32 1, i32 1), !dbg , !llvm.preserve.access.index 
    %11 = call i32 %4(i8* %3, i32 1, i8* %10), !dbg 
    %12 = load i8, i8* %3, align 1, !dbg , !tbaa 
    %13 = sext i8 %12 to i32, !dbg 
    call void @llvm.lifetime.end.p0i8(i64 1, i8* %3) , !dbg 
    ret i32 %13, !dbg 
  }

   = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "sk_buff", file: , line: 1, size: 704, elements: )
   = distinct !DICompositeType(tag: DW_TAG_union_type, scope: , file: , line: 5, size: 64, elements: )
   = distinct !DICompositeType(tag: DW_TAG_structure_type, scope: , file: , line: 10, size: 16, elements: )

Note that @llvm.preserve.{struct,union}.access.index calls have metadata llvm.preserve.access.index
attached to instructions to provide struct/union debuginfo type information.

For &ctx->u[5].dev.dev_id,
  . The "%6 = ..." represents struct member "u" with index 2 for IR layout and index 3 for DI layout.
  . The "%7 = ..." represents array subscript "5".
  . The "%8 = ..." represents union member "dev" with index 1 for DI layout.
  . The "%10 = ..." represents struct member "dev_id" with index 1 for both IR and DI layout.

Basically, traversing the use-def chain recursively for the 3rd argument of bpf_probe_read() and
examining all preserve_*_access_index calls, the debuginfo struct/union/array access index
can be achieved.

The intrinsics also contain enough information to regenerate codes for IR layout.
For array and structure intrinsics, the proper GEP can be constructed.
For union intrinsics, replacing all uses of "addr" with "base" should be enough.

The test case ThinLTO/X86/lazyload_metadata.ll is adjusted to reflect the
new addition of the metadata.

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

Differential Revision: https://reviews.llvm.org/D61810

llvm-svn: 365423
2019-07-09 01:51:36 +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
Yonghong Song 0d566dbbae Revert "[BPF] add new intrinsics preserve_{array,union,struct}_access_index"
This reverts commit r365352.

Test ThinLTO/X86/lazyload_metadata.ll failed. Revert the commit
and at the same time to fix the issue.

llvm-svn: 365360
2019-07-08 17:47:43 +00:00
Yonghong Song 75c2a6709e [BPF] add new intrinsics preserve_{array,union,struct}_access_index
For background of BPF CO-RE project, please refer to
  http://vger.kernel.org/bpfconf2019.html
In summary, BPF CO-RE intends to compile bpf programs
adjustable on struct/union layout change so the same
program can run on multiple kernels with adjustment
before loading based on native kernel structures.

In order to do this, we need keep track of GEP(getelementptr)
instruction base and result debuginfo types, so we
can adjust on the host based on kernel BTF info.
Capturing such information as an IR optimization is hard
as various optimization may have tweaked GEP and also
union is replaced by structure it is impossible to track
fieldindex for union member accesses.

Three intrinsic functions, preserve_{array,union,struct}_access_index,
are introducted.
  addr = preserve_array_access_index(base, index, dimension)
  addr = preserve_union_access_index(base, di_index)
  addr = preserve_struct_access_index(base, gep_index, di_index)
here,
  base: the base pointer for the array/union/struct access.
  index: the last access index for array, the same for IR/DebugInfo layout.
  dimension: the array dimension.
  gep_index: the access index based on IR layout.
  di_index: the access index based on user/debuginfo types.

For example, for the following example,
  $ cat test.c
  struct sk_buff {
     int i;
     int b1:1;
     int b2:2;
     union {
       struct {
         int o1;
         int o2;
       } o;
       struct {
         char flags;
         char dev_id;
       } dev;
       int netid;
     } u[10];
  };

  static int (*bpf_probe_read)(void *dst, int size, const void *unsafe_ptr)
      = (void *) 4;

  #define _(x) (__builtin_preserve_access_index(x))

  int bpf_prog(struct sk_buff *ctx) {
    char dev_id;
    bpf_probe_read(&dev_id, sizeof(char), _(&ctx->u[5].dev.dev_id));
    return dev_id;
  }
  $ clang -target bpf -O2 -g -emit-llvm -S -mllvm -print-before-all \
    test.c >& log

The generated IR looks like below:

  ...
  define dso_local i32 @bpf_prog(%struct.sk_buff*)  !dbg  {
    %2 = alloca %struct.sk_buff*, align 8
    %3 = alloca i8, align 1
    store %struct.sk_buff* %0, %struct.sk_buff** %2, align 8, !tbaa 
    call void @llvm.dbg.declare(metadata %struct.sk_buff** %2, metadata , metadata !DIExpression()), !dbg 
    call void @llvm.lifetime.start.p0i8(i64 1, i8* %3) , !dbg 
    call void @llvm.dbg.declare(metadata i8* %3, metadata , metadata !DIExpression()), !dbg 
    %4 = load i32 (i8*, i32, i8*)*, i32 (i8*, i32, i8*)** @bpf_probe_read, align 8, !dbg , !tbaa 
    %5 = load %struct.sk_buff*, %struct.sk_buff** %2, align 8, !dbg , !tbaa 
    %6 = call [10 x %union.anon]* @llvm.preserve.struct.access.index.p0a10s_union.anons.p0s_struct.sk_buffs(
         %struct.sk_buff* %5, i32 2, i32 3), !dbg , !llvm.preserve.access.index 
    %7 = call %union.anon* @llvm.preserve.array.access.index.p0s_union.anons.p0a10s_union.anons(
         [10 x %union.anon]* %6, i32 1, i32 5), !dbg 
    %8 = call %union.anon* @llvm.preserve.union.access.index.p0s_union.anons.p0s_union.anons(
         %union.anon* %7, i32 1), !dbg , !llvm.preserve.access.index 
    %9 = bitcast %union.anon* %8 to %struct.anon.0*, !dbg 
    %10 = call i8* @llvm.preserve.struct.access.index.p0i8.p0s_struct.anon.0s(
         %struct.anon.0* %9, i32 1, i32 1), !dbg , !llvm.preserve.access.index 
    %11 = call i32 %4(i8* %3, i32 1, i8* %10), !dbg 
    %12 = load i8, i8* %3, align 1, !dbg , !tbaa 
    %13 = sext i8 %12 to i32, !dbg 
    call void @llvm.lifetime.end.p0i8(i64 1, i8* %3) , !dbg 
    ret i32 %13, !dbg 
  }

   = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "sk_buff", file: , line: 1, size: 704, elements: )
   = distinct !DICompositeType(tag: DW_TAG_union_type, scope: , file: , line: 5, size: 64, elements: )
   = distinct !DICompositeType(tag: DW_TAG_structure_type, scope: , file: , line: 10, size: 16, elements: )

Note that @llvm.preserve.{struct,union}.access.index calls have metadata llvm.preserve.access.index
attached to instructions to provide struct/union debuginfo type information.

For &ctx->u[5].dev.dev_id,
  . The "%6 = ..." represents struct member "u" with index 2 for IR layout and index 3 for DI layout.
  . The "%7 = ..." represents array subscript "5".
  . The "%8 = ..." represents union member "dev" with index 1 for DI layout.
  . The "%10 = ..." represents struct member "dev_id" with index 1 for both IR and DI layout.

Basically, traversing the use-def chain recursively for the 3rd argument of bpf_probe_read() and
examining all preserve_*_access_index calls, the debuginfo struct/union/array access index
can be achieved.

The intrinsics also contain enough information to regenerate codes for IR layout.
For array and structure intrinsics, the proper GEP can be constructed.
For union intrinsics, replacing all uses of "addr" with "base" should be enough.

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

Differential Revision: https://reviews.llvm.org/D61810

llvm-svn: 365352
2019-07-08 17:08:28 +00:00
Kevin P. Neal 472e5dda11 Teach the IRBuilder about fadd and friends.
The IRBuilder has calls to create floating point instructions like fadd.
It does not have calls to create constrained versions of them. This patch
adds support for constrained creation of fadd, fsub, fmul, fdiv, and frem.

Reviewed by:	John McCall, Sanjay Patel
Approved by:	John McCall
Differential Revision:	https://reviews.llvm.org/D53157

llvm-svn: 365339
2019-07-08 16:18:18 +00:00
Brian Homerding b4b21d807e Add, and infer, a nofree function attribute
This patch adds a function attribute, nofree, to indicate that a function does
not, directly or indirectly, call a memory-deallocation function (e.g., free,
C++'s operator delete).

Reviewers: jdoerfert

Differential Revision: https://reviews.llvm.org/D49165

llvm-svn: 365336
2019-07-08 15:57:56 +00:00
Eugene Leviant 3aef35288b [ThinLTO] Attempt to recommit r365188 after alignment fix
llvm-svn: 365215
2019-07-05 15:25:05 +00:00
Eugene Leviant e91f86f0ac Reverted r365188 due to alignment problems on i686-android
llvm-svn: 365206
2019-07-05 13:26:05 +00:00
Graham Hunter 957c40db6a Scalable Vector IR Type with further LTO fixes
Reintroduces the scalable vector IR type from D32530, after it was reverted
a couple of times due to increasing chromium LTO build times. This latest
incarnation removes the walk over aggregate types from the verifier entirely,
in favor of rejecting scalable vectors in the isValidElementType methods in
ArrayType and StructType. This removes the 70% degradation observed with
the second repro tarball from PR42210.

Reviewers: thakis, hans, rengolin, sdesmalen

Reviewed By: sdesmalen

Differential Revision: https://reviews.llvm.org/D64079

llvm-svn: 365203
2019-07-05 12:48:16 +00:00
Eugene Leviant 820cc01d1e [ThinLTO] Attempt to recommit r365040 after caching fix
It's possible that some function can load and store the same
variable using the same constant expression:

store %Derived* @foo, %Derived** bitcast (%Base** @bar to %Derived**)
%42 = load %Derived*, %Derived** bitcast (%Base** @bar to %Derived**)

The bitcast expression was mistakenly cached while processing loads,
and never examined later when processing store. This caused @bar to
be mistakenly treated as read-only variable. See load-store-caching.ll.

llvm-svn: 365188
2019-07-05 12:00:10 +00:00
Reid Kleckner f7e52fbdb5 Revert [ThinLTO] Optimize writeonly globals out
This reverts r365040 (git commit 5cacb91475)

Speculatively reverting, since this appears to have broken check-lld on
Linux. Partial analysis in https://crbug.com/981168.

llvm-svn: 365097
2019-07-04 00:03:30 +00:00
Eugene Leviant 5cacb91475 [ThinLTO] Optimize writeonly globals out
Differential revision: https://reviews.llvm.org/D63444

llvm-svn: 365040
2019-07-03 14:14:52 +00:00
Teresa Johnson a700436323 [ThinLTO] Add summary entries for index-based WPD
Summary:
If LTOUnit splitting is disabled, the module summary analysis computes
the summary information necessary to perform single implementation
devirtualization during the thin link with the index and no IR. The
information collected from the regular LTO IR in the current hybrid WPD
algorithm is summarized, including:
1) For vtable definitions, record the function pointers and their offset
within the vtable initializer (subsumes the information collected from
IR by tryFindVirtualCallTargets).
2) A record for each type metadata summarizing the vtable definitions
decorated with that metadata (subsumes the TypeIdentiferMap collected
from IR).

Also added are the necessary bitcode records, and the corresponding
assembly support.

The follow-on index-based WPD patch is D55153.

Depends on D53890.

Reviewers: pcc

Subscribers: mehdi_amini, Prazek, inglorion, eraman, steven_wu, dexonsmith, arphaman, llvm-commits

Differential Revision: https://reviews.llvm.org/D54815

llvm-svn: 364960
2019-07-02 19:38:02 +00:00
Jeremy Morse d2b6665e33 [DebugInfo] Avoid adding too much indirection to pointer-valued variables
This patch addresses PR41675, where a stack-pointer variable is dereferenced
too many times by its location expression, presenting a value on the stack as
the pointer to the stack.

The difference between a stack *pointer* DBG_VALUE and one that refers to a
value on the stack, is currently the indirect flag. However the DWARF backend
will also try to guess whether something is a memory location or not, based
on whether there is any computation in the location expression. By simply
prepending the stack offset to existing expressions, we can accidentally
convert a register location into a memory location, which introduces a
suprise (and unintended) dereference.

The solution is to add DW_OP_stack_value whenever we add a DIExpression
computation to a stack *pointer*. It's an implicit location computed on the
expression stack, thus needs to be flagged as a stack_value.

For the edge case where the offset is zero and the location could be a register
location, DIExpression::prepend will still generate opcodes, and thus
DW_OP_stack_value must still be added.

Differential Revision: https://reviews.llvm.org/D63429

llvm-svn: 364736
2019-07-01 09:38:23 +00:00
Fangrui Song 78ee2fbf98 Cleanup: llvm::bsearch -> llvm::partition_point after r364719
llvm-svn: 364720
2019-06-30 11:19:56 +00:00
Johannes Doerfert 3b77583e95 [Attr] Add "willreturn" function attribute
This patch introduces a new function attribute, willreturn, to indicate
that a call of this function will either exhibit undefined behavior or
comes back and continues execution at a point in the existing call stack
that includes the current invocation.

This attribute guarantees that the function does not have any endless
loops, endless recursion, or terminating functions like abort or exit.

Patch by Hideto Ueno (@uenoku)

Reviewers: jdoerfert

Subscribers: mehdi_amini, hiraditya, steven_wu, dexonsmith, lebedev.ri, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62801

llvm-svn: 364555
2019-06-27 15:51:40 +00:00
Hans Wennborg 408fc0849e Revert r363658 "[SVE][IR] Scalable Vector IR Type with pr42210 fix"
We saw a 70% ThinLTO link time increase in Chromium for Android, see
crbug.com/978817. Sounds like more of PR42210.

> Recommit of D32530 with a few small changes:
>   - Stopped recursively walking through aggregates in
>     the verifier, so that we don't impose too much
>     overhead on large modules under LTO (see PR42210).
>   - Changed tests to match; the errors are slightly
>     different since they only report the array or
>     struct that actually contains a scalable vector,
>     rather than all aggregates which contain one in
>     a nested member.
>   - Corrected an older comment
>
> Reviewers: thakis, rengolin, sdesmalen
>
> Reviewed By: sdesmalen
>
> Differential Revision: https://reviews.llvm.org/D63321

llvm-svn: 364543
2019-06-27 13:55:02 +00:00