Commit Graph

295009 Commits

Author SHA1 Message Date
Matthias Braun bde0806d5f CodeGen.cpp: Sort initializers; NFC
llvm-svn: 337988
2018-07-26 00:27:49 +00:00
Matthias Braun 531457a17a InitializePasses: Sort declarations; NFC
llvm-svn: 337987
2018-07-26 00:27:48 +00:00
Matthias Braun 57dd5b3dea CodeGen: Cleanup regmask construction; NFC
- Avoid duplication of regmask size calculation.
- Simplify allocateRegisterMask() call.
- Rename allocateRegisterMask() to allocateRegMask() to be consistent
  with naming in MachineOperand.

llvm-svn: 337986
2018-07-26 00:27:47 +00:00
Dean Michael Berris bcbb032d55 [MCA] Avoid an InstrDesc copy in mca::LSUnit::reserve.
Summary:
InstrDesc contains 4 vectors (as well as some other data), so it's
expensive to copy.

Authored By: orodley

Reviewers: andreadb, mattd, dberris

Reviewed By: mattd, dberris

Subscribers: dberris, gbedwell, llvm-commits

Differential Revision: https://reviews.llvm.org/D49775

llvm-svn: 337985
2018-07-26 00:02:54 +00:00
Alex Lorenz 70cf5c4c62 [libc++] Follow-up to r337968: use an explicit cast as suggested by Eric
llvm-svn: 337984
2018-07-25 23:59:54 +00:00
Fangrui Song 31cc084619 [ELF] Fix linker-script-in-search-path.s
llvm-svn: 337983
2018-07-25 23:29:15 +00:00
Sam Clegg 77c99ee5d9 [CMake] Don't use LIBCXXABI_ENABLE_STATIC option before its declared
Summary:
rL337867 introduced two new cmake_dependent_option options:
- LIBCXXABI_INSTALL_STATIC_LIBRARY
- LIBCXXABI_INSTALL_SHARED_LIBRARY

They depend on LIBCXXABI_ENABLE_STATIC and LIBCXXABI_ENABLE_SHARED
and so therefore need to (it seems) come after the declaration of
these two options.

Subscribers: mgorny, aheejin, christof, ldionne, cfe-commits

Differential Revision: https://reviews.llvm.org/D49825

llvm-svn: 337982
2018-07-25 23:13:00 +00:00
Wolfgang Pieb c42087df7c [DWARF v5] Don't emit multiple DW_AT_rnglists_base attributes. Some refactoring of
range lists emissions and added test cases.

Reviewer: dblaikie

Differential Revision: https://reviews.llvm.org/D49522

llvm-svn: 337981
2018-07-25 23:03:22 +00:00
Jonas Devlieghere 743d351120 [dsymutil] Add support for generating DWARF5 accelerator tables.
This patch add support for emitting DWARF5 accelerator tables
(.debug_names) from dsymutil. Just as with the Apple style accelerator
tables, it's possible to update existing dSYMs. This patch includes a
test that show how you can convert back and forth between the two types.

If no kind of table is specified, dsymutil will default to generating
Apple-style accelerator tables whenever it finds those in its input. The
same is true when there are no accelerator tables at all. Finally, in
the remaining case, where there's at least one DWARF v5 table and no
Apple ones, the output will contains a DWARF accelerator tables
(.debug_names).

Differential revision: https://reviews.llvm.org/D49137

llvm-svn: 337980
2018-07-25 23:01:38 +00:00
Petr Hosek 9d1bcc2a88 [CMake] Don't install c++abi headers in standalone libc++ build
This is a refinement on r337833. Previously we were installing two
copies of c++abi headers in libc++ build directory, one in
include/c++build and another one in include/c++/v1. However, the
second copy is unnecessary when building libc++ standalone.

Differential Revision: https://reviews.llvm.org/D49752

llvm-svn: 337979
2018-07-25 22:57:39 +00:00
Richard Trieu ab4d730f14 [ODRHash] Support hashing enums.
llvm-svn: 337978
2018-07-25 22:52:05 +00:00
Yonghong Song 71d81e5c8f bpf: new option -bpf-expand-memcpy-in-order to expand memcpy in order
Some BPF JIT backends would want to optimize memcpy in their own
architecture specific way.

However, at the moment, there is no way for JIT backends to see memcpy
semantics in a reliable way. This is due to LLVM BPF backend is expanding
memcpy into load/store sequences and could possibly schedule them apart from
each other further. So, BPF JIT backends inside kernel can't reliably
recognize memcpy semantics by peephole BPF sequence.

This patch introduce new intrinsic expand infrastructure to memcpy.

To get stable in-order load/store sequence from memcpy, we first lower
memcpy into BPF::MEMCPY node which then expanded into in-order load/store
sequences in expandPostRAPseudo pass which will happen after instruction
scheduling. By this way, kernel JIT backends could reliably recognize
memcpy through scanning BPF sequence.

This new memcpy expand infrastructure is gated by a new option:

  -bpf-expand-memcpy-in-order

Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 337977
2018-07-25 22:40:02 +00:00
Eric Fiselier 99ca3c0a61 Work around GCC bug in constexpr function
llvm-svn: 337976
2018-07-25 22:21:47 +00:00
Fangrui Song 7610b4d64c [ELF] Make linker-script-in-search-path.s robust per r337972
llvm-svn: 337975
2018-07-25 22:11:00 +00:00
Eric Fiselier b7e6c1d238 Fix GCC build in C++14 w/o c++14 constexpr
llvm-svn: 337974
2018-07-25 22:07:36 +00:00
Eli Friedman d6baff65f7 [GlobalMerge] Handle llvm.compiler.used correctly.
Reuse the handling for llvm.used, and don't transform such globals.

Fixes a failure on the asan buildbot caused by my previous commit.

llvm-svn: 337973
2018-07-25 22:03:35 +00:00
Rui Ueyama 5a0a83daaf Make a test more robust.
Previously, this test fails if there's other test that happens to
create "t.script" in the current directory.

llvm-svn: 337972
2018-07-25 22:01:54 +00:00
Eric Fiselier ceb33cd519 Remove test which shouldn't have been committed
llvm-svn: 337971
2018-07-25 21:58:37 +00:00
Eric Fiselier ce34437cc8 Fix failing test under C++14
llvm-svn: 337970
2018-07-25 21:53:43 +00:00
Fangrui Song c60f85d073 [ELF] Use search paths for --version-script=
Summary: This behavior matches ld.bfd -Ld --version-script=t.script a.o

Reviewers: ruiu, espindola

Subscribers: emaste, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D49820

llvm-svn: 337969
2018-07-25 21:53:18 +00:00
Alex Lorenz 33b4c8a18f [libc++] Follow-up to r337960: specify lambda's return type to avoid
-Wc++11-narrowing warning on Darwin

The internal CI produced the following diagnostic:
error: non-constant-expression cannot be narrowed from type 'long long' to '__darwin_suseconds_t' (aka 'int') in initializer list [-Wc++11-narrowing]
  struct ::timeval ConvertedTS[2] = {{TS[0].tv_sec, Convert(TS[0].tv_nsec)},
                                                    ^~~~~~~~~~~~~~~~~~~~~~

llvm-svn: 337968
2018-07-25 21:50:44 +00:00
Peter Collingbourne 6a5368eadb ELF: Do not ICF SHF_LINK_ORDER sections.
We are already ICF'ing these sections as a unit with their dependent
sections, so they don't need to be considered for ICF individually.

This change also "fixes" slowness caused by our quadratic-in-group-size
relocation segregation algorithm on 32-bit ARM platforms with unwind
data and ICF on rodata. In this scenario almost every function's
.ARM.exidx is identical except for the targets of the relocations
that refer to the function and its .ARM.extab, which causes almost
all of the program's .ARM.exidx sections to be initially added to the
same class, which causes us to compare every such section with every
other such section.

Differential Revision: https://reviews.llvm.org/D49716

llvm-svn: 337967
2018-07-25 21:40:54 +00:00
Sanjay Patel 215dcbf4db [SelectionDAG] try to convert funnel shift directly to rotate if legal
If the DAGCombiner's rotate matching was working as expected, 
I don't think we'd see any test diffs here. 

This sidesteps the issue of custom lowering for rotates raised in PR38243:
https://bugs.llvm.org/show_bug.cgi?id=38243
...by only dealing with legal operations.

llvm-svn: 337966
2018-07-25 21:38:30 +00:00
Roman Tereshin 4f10a9d3a3 [LSV] Look through selects for consecutive addresses
In some cases LSV sees (load/store _ (select _ <pointer expression>
<pointer expression>)) patterns in input IR, often due to sinking and
other forms of CFG simplification, sometimes interspersed with
bitcasts and all-constant-indices GEPs. With this
patch`areConsecutivePointers` method would attempt to handle select
instructions. This leads to an increased number of successful
vectorizations.

Technically, select instructions could appear in index arithmetic as
well, however, we don't see those in our test suites / benchmarks.
Also, there is a lot more freedom in IR shapes computing integral
indices in general than in what's common in pointer computations, and
it appears that it's quite unreliable to do anything short of making
select instructions first class citizens of Scalar Evolution, which
for the purposes of this patch is most definitely an overkill.

Reviewed By: rampitec

Differential Revision: https://reviews.llvm.org/D49428

llvm-svn: 337965
2018-07-25 21:33:00 +00:00
Sanjay Patel f94c4c84e6 [AArch, PowerPC] add more tests for legal rotate ops; NFC
llvm-svn: 337964
2018-07-25 21:25:50 +00:00
Davide Italiano 4b58867d06 Revert "[DataFormatters] Add formatter for C++17 std::optional."
I forgot to git add some files. I'm going to recommit the correct
version at once soon.

llvm-svn: 337963
2018-07-25 21:18:20 +00:00
Eric Fiselier d77f3ef4a4 Make <experimental/filesystem> compile with gcc 4.8.5
Patch by Victor Zverovich.

This fixes an error when compiling `<experimental/filesystem>` with gcc 4.8.5:

```
.../libcxx/src/experimental/filesystem/filesystem_common.h:137:34:
error: redeclaration ‘T
std::experimental::filesystem::v1::detail::{anonymous}::error_value() [with T =
bool]’ d
iffers in ‘constexpr’
 constexpr bool error_value<bool>() {
                                  ^
.../libcxx/src/experimental/filesystem/filesystem_common.h:133:3:
error: from previous declaration ‘T
std::experimental::filesystem::v1::detail::{anonymous}::error_value() [with T
 = bool]’
 T error_value();
   ^
```

Reviewed as https://reviews.llvm.org/D49813

llvm-svn: 337962
2018-07-25 21:01:45 +00:00
Eli Friedman 0887cf9cab [GlobalMerge] Allow merging globals with arbitrary alignment.
Instead of depending on implicit padding from the structure layout code,
use a packed struct and emit the padding explicitly.

Differential Revision: https://reviews.llvm.org/D49710

llvm-svn: 337961
2018-07-25 20:58:01 +00:00
Eric Fiselier c55ac1055a [libc++] Use __int128_t to represent file_time_type.
Summary:
The ``file_time_type`` time point is used to represent the write times for files.
Its job is to act as part of a C++ wrapper for less ideal system interfaces. The
underlying filesystem uses the ``timespec`` struct for the same purpose.

However, the initial implementation of ``file_time_type`` could not represent
either the range or resolution of ``timespec``, making it unsuitable. Fixing
this requires an implementation which uses more than 64 bits to store the
time point.

I primarily considered two solutions: Using ``__int128_t`` and using a
arithmetic emulation of ``timespec``. Each has its pros and cons, and both
come with more than one complication.

However, after a lot of consideration, I decided on using `__int128_t`. This patch implements that change.

Please see the [FileTimeType Design Document](http://libcxx.llvm.org/docs/DesignDocs/FileTimeType.html) for more information.

Reviewers: mclow.lists, ldionne, joerg, arthur.j.odwyer, EricWF

Reviewed By: EricWF

Subscribers: christof, K-ballo, cfe-commits, BillyONeal

Differential Revision: https://reviews.llvm.org/D49774

llvm-svn: 337960
2018-07-25 20:51:49 +00:00
Davide Italiano 1d4a78ef04 [DataFormatters] Add formatter for C++17 std::optional.
<rdar://problem/41471112>

Patch by Shafik Yaghmour.

Differential Revision:  https://reviews.llvm.org/D49271

llvm-svn: 337959
2018-07-25 20:46:29 +00:00
Alexey Bataev 8521ff6ec4 [OPENMP] ThreadId in serialized parallel regions is 0.
The first argument for the parallel outlined functions, called as
serialized parallel regions, should be a pointer to the global thread id
that always is 0.

llvm-svn: 337957
2018-07-25 20:03:01 +00:00
Florian Hahn b6613ac665 Revert r337904: [IPSCCP] Use PredicateInfo to propagate facts from cmp instructions.
I suspect it is causing the clang-stage2-Rthinlto failures.

llvm-svn: 337956
2018-07-25 19:44:19 +00:00
Louis Dionne 8b6a5bf916 [libc++] Factor duplicate code into function templates
Summary:
The exact same code was replicated 11 times for implementing the basic_istream
input operators (those that don't use numeric_limits). The same code was also
duplicated twice for implementing the basic_istream input operators that take
numeric_limits into account.

This commit factors the common code into function templates to avoid
the duplication.

Reviewers: mclow.lists, EricWF

Subscribers: christof, dexonsmith, cfe-commits

Differential Revision: https://reviews.llvm.org/D49808

llvm-svn: 337955
2018-07-25 19:40:01 +00:00
Mikhail R. Gadelha 3c94b65cb0 [analyzer] Update SMT API documentation and methods
Summary:
Update the documentation of all the classes introduced with the new generic SMT API, most of them were referencing Z3 and how previous operations were being done (like including the context as parameter in a few methods).

Renamed the following methods, so it's clear that the operate on bitvectors:
*`mkSignExt` -> `mkBVSignExt`
*`mkZeroExt` -> `mkBVZeroExt`
*`mkExtract` -> `mkBVExtract`
*`mkConcat` -> `mkBVConcat`

Removed the unecessary methods:
* `getDataExpr`: it was an one line method that called `fromData`
* `mkBitvector(const llvm::APSInt Int)`: it was not being used anywhere

Reviewers: NoQ, george.karpenkov

Reviewed By: george.karpenkov

Subscribers: xazax.hun, szepet, a.sidorin

Differential Revision: https://reviews.llvm.org/D49799

llvm-svn: 337954
2018-07-25 19:34:48 +00:00
Volodymyr Sapsai 482070b40a [Preprocessor] Stop entering included files after hitting a fatal error.
Fixes a problem when we have multiple inclusion cycles and try to
enumerate all possible ways to reach the max inclusion depth.

rdar://problem/38871876

Reviewers: bruno, rsmith, jkorous, aaron.ballman

Reviewed By: bruno, jkorous, aaron.ballman

Subscribers: dexonsmith, cfe-commits

Differential Revision: https://reviews.llvm.org/D48786

llvm-svn: 337953
2018-07-25 19:16:26 +00:00
Martin Storsjo d78b394543 Add missing 'override', fixing compilation with some compilers since SVN r337950
llvm-svn: 337952
2018-07-25 19:01:36 +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
Martin Storsjo d2662c32fb [COFF] Hoist constant pool handling from X86AsmPrinter into AsmPrinter
In SVN r334523, the first half of comdat constant pool handling was
hoisted from X86WindowsTargetObjectFile (which despite the name only
was used for msvc targets) into the arch independent
TargetLoweringObjectFileCOFF, but the other half of the handling was
left behind in X86AsmPrinter::GetCPISymbol.

With only half of the handling in place, inconsistent comdat
sections/symbols are created, causing issues with both GNU binutils
(avoided for X86 in SVN r335918) and with the MS linker, which
would complain like this:

fatal error LNK1143: invalid or corrupt file: no symbol for COMDAT section 0x4

Differential Revision: https://reviews.llvm.org/D49644

llvm-svn: 337950
2018-07-25 18:35:31 +00:00
Max Moroz f55b8c6e91 [libFuzzer] Disable handle-unstable.test for ARM and delete duplicated test file.
Summary:
This change should fix the failures mentioned in
https://reviews.llvm.org/D49684#1175245

Reviewers: kevinwkt, morehouse, metzman

Reviewed By: kevinwkt, morehouse

Subscribers: kristof.beyls, delcypher, chrib, #sanitizers, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D49810

llvm-svn: 337949
2018-07-25 18:34:20 +00:00
Mikhail R. Gadelha 36027a3812 [analyzer] Fix compilation when LLVM_ENABLE_MODULES=ON
llvm-svn: 337948
2018-07-25 18:26:50 +00:00
Eli Friedman 0f522bdbac [LangRef] Clarify undefined behavior for function attributes.
Violating the invariants specified by attributes is undefined behavior.
Maybe we could use poison instead for some of the parameter attributes,
but I don't think it's worthwhile.

Differential Revision: https://reviews.llvm.org/D49041

llvm-svn: 337947
2018-07-25 18:26:38 +00:00
Martin Storsjo c89c9c7b63 [windows] Fix warning about comparing ints of different signs
This fixes a warning like this:

warning: comparison of integers of different signs:
      'std::__1::__libcpp_tls_key' (aka 'long') and 'DWORD'
      (aka 'unsigned long') [-Wsign-compare]
  if (*__key == FLS_OUT_OF_INDEXES)
      ~~~~~~ ^  ~~~~~~~~~~~~~~~~~~

Differential Revision: https://reviews.llvm.org/D49782

llvm-svn: 337946
2018-07-25 18:24:23 +00:00
Eli Friedman 733f4ed1bb [ARM] Prefer lsls+lsrs over lsls+ands or lsrs+ands in Thumb1.
Saves materializing the immediate for the "ands".

Corresponding patterns exist for lsrs+lsls, but that seems less common
in practice.

Now implemented as a DAGCombine.

Differential Revision: https://reviews.llvm.org/D49585

llvm-svn: 337945
2018-07-25 18:22:22 +00:00
Nick Desaulniers c9588578c4 [clang:sema] de-duplicate getDepthAndIndex helpers
Summary:
Continuing off of:
https://reviews.llvm.org/D38382

Fixes:
https://bugs.llvm.org/show_bug.cgi?id=12176

Reviewers: srhines, pirama, vsk

Reviewed By: vsk

Subscribers: cfe-commits, vsk, maitesin

Differential Revision: https://reviews.llvm.org/D49760

llvm-svn: 337944
2018-07-25 18:11:01 +00:00
Roman Tereshin ed047b0184 [SCEV] Add [zs]ext{C,+,x} -> (D + [zs]ext{C-D,+,x})<nuw><nsw> transform
as well as sext(C + x + ...) -> (D + sext(C-D + x + ...))<nuw><nsw>
similar to the equivalent transformation for zext's

if the top level addition in (D + (C-D + x * n)) could be proven to
not wrap, where the choice of D also maximizes the number of trailing
zeroes of (C-D + x * n), ensuring homogeneous behaviour of the
transformation and better canonicalization of such AddRec's

(indeed, there are 2^(2w) different expressions in `B1 + ext(B2 + Y)` form for
the same Y, but only 2^(2w - k) different expressions in the resulting `B3 +
ext((B4 * 2^k) + Y)` form, where w is the bit width of the integral type)

This patch generalizes sext(C1 + C2*X) --> sext(C1) + sext(C2*X) and
sext{C1,+,C2} --> sext(C1) + sext{0,+,C2} transformations added in
r209568 relaxing the requirements the following way:

1. C2 doesn't have to be a power of 2, it's enough if it's divisible by 2
 a sufficient number of times;
2. C1 doesn't have to be less than C2, instead of extracting the entire
  C1 we can split it into 2 terms: (00...0XXX + YY...Y000), keep the
  second one that may cause wrapping within the extension operator, and
  move the first one that doesn't affect wrapping out of the extension
  operator, enabling further simplifications;
3. C1 and C2 don't have to be positive, splitting C1 like shown above
 produces a sum that is guaranteed to not wrap, signed or unsigned;
4. in AddExpr case there could be more than 2 terms, and in case of
  AddExpr the 2nd and following terms and in case of AddRecExpr the
  Step component don't have to be in the C2*X form or constant
  (respectively), they just need to have enough trailing zeros,
  which in turn could be guaranteed by means other than arithmetics,
  e.g. by a pointer alignment;
5. the extension operator doesn't have to be a sext, the same
  transformation works and profitable for zext's as well.

Apparently, optimizations like SLPVectorizer currently fail to
vectorize even rather trivial cases like the following:

 double bar(double *a, unsigned n) {
   double x = 0.0;
   double y = 0.0;
   for (unsigned i = 0; i < n; i += 2) {
     x += a[i];
     y += a[i + 1];
   }
   return x * y;
 }

If compiled with `clang -std=c11 -Wpedantic -Wall -O3 main.c -S -o - -emit-llvm`
(!{!"clang version 7.0.0 (trunk 337339) (llvm/trunk 337344)"})

it produces scalar code with the loop not unrolled with the unsigned `n` and
`i` (like shown above), but vectorized and unrolled loop with signed `n` and
`i`. With the changes made in this commit the unsigned version will be
vectorized (though not unrolled for unclear reasons).

How it all works:

Let say we have an AddExpr that looks like (C + x + y + ...), where C
is a constant and x, y, ... are arbitrary SCEVs. Let's compute the
minimum number of trailing zeroes guaranteed of that sum w/o the
constant term: (x + y + ...). If, for example, those terms look like
follows:

        i
XXXX...X000
YYYY...YY00
   ...
ZZZZ...0000

then the rightmost non-guaranteed-zero bit (a potential one at i-th
position above) can change the bits of the sum to the left (and at
i-th position itself), but it can not possibly change the bits to the
right. So we can compute the number of trailing zeroes by taking a
minimum between the numbers of trailing zeroes of the terms.

Now let's say that our original sum with the constant is effectively
just C + X, where X = x + y + .... Let's also say that we've got 2
guaranteed trailing zeros for X:

         j
CCCC...CCCC
XXXX...XX00  // this is X = (x + y + ...)

Any bit of C to the left of j may in the end cause the C + X sum to
wrap, but the rightmost 2 bits of C (at positions j and j - 1) do not
affect wrapping in any way. If the upper bits cause a wrap, it will be
a wrap regardless of the values of the 2 least significant bits of C.
If the upper bits do not cause a wrap, it won't be a wrap regardless
of the values of the 2 bits on the right (again).

So let's split C to 2 constants like follows:

0000...00CC  = D
CCCC...CC00  = (C - D)

and represent the whole sum as D + (C - D + X). The second term of
this new sum looks like this:

CCCC...CC00
XXXX...XX00
-----------  // let's add them up
YYYY...YY00

The sum above (let's call it Y)) may or may not wrap, we don't know,
so we need to keep it under a sext/zext. Adding D to that sum though
will never wrap, signed or unsigned, if performed on the original bit
width or the extended one, because all that that final add does is
setting the 2 least significant bits of Y to the bits of D:

YYYY...YY00 = Y
0000...00CC = D
-----------  <nuw><nsw>
YYYY...YYCC

Which means we can safely move that D out of the sext or zext and
claim that the top-level sum neither sign wraps nor unsigned wraps.

Let's run an example, let's say we're working in i8's and the original
expression (zext's or sext's operand) is 21 + 12x + 8y. So it goes
like this:

0001 0101  // 21
XXXX XX00  // 12x
YYYY Y000  // 8y

0001 0101  // 21
ZZZZ ZZ00  // 12x + 8y

0000 0001  // D
0001 0100  // 21 - D = 20
ZZZZ ZZ00  // 12x + 8y

0000 0001  // D
WWWW WW00  // 21 - D + 12x + 8y = 20 + 12x + 8y

therefore zext(21 + 12x + 8y) = (1 + zext(20 + 12x + 8y))<nuw><nsw>

This approach could be improved if we move away from using trailing
zeroes and use KnownBits instead. For instance, with KnownBits we could
have the following picture:

    i
10 1110...0011  // this is C
XX X1XX...XX00  // this is X = (x + y + ...)

Notice that some of the bits of X are known ones, also notice that
known bits of X are interspersed with unknown bits and not grouped on
the rigth or left.

We can see at the position i that C(i) and X(i) are both known ones,
therefore the (i + 1)th carry bit is guaranteed to be 1 regardless of
the bits of C to the right of i. For instance, the C(i - 1) bit only
affects the bits of the sum at positions i - 1 and i, and does not
influence if the sum is going to wrap or not. Therefore we could split
the constant C the following way:

    i
00 0010...0011  = D
10 1100...0000  = (C - D)

Let's compute the KnownBits of (C - D) + X:

XX1 1            = carry bit, blanks stand for known zeroes
 10 1100...0000  = (C - D)
 XX X1XX...XX00  = X
--- -----------
 XX X0XX...XX00

Will this add wrap or not essentially depends on bits of X. Adding D
to this sum, however, is guaranteed to not to wrap:

0    X
 00 0010...0011  = D
 sX X0XX...XX00  = (C - D) + X
--- -----------
 sX XXXX   XX11

As could be seen above, adding D preserves the sign bit of (C - D) +
X, if any, and has a guaranteed 0 carry out, as expected.

The more bits of (C - D) we constrain, the better the transformations
introduced here canonicalize expressions as it leaves less freedom to
what values the constant part of ((C - D) + x + y + ...) can take.

Reviewed By: mzolotukhin, efriedma

Differential Revision: https://reviews.llvm.org/D48853

llvm-svn: 337943
2018-07-25 18:01:41 +00:00
Stella Stamenova bb9fd461a9 [windows] Don't inline fieldFromInstruction on Windows
Summary:
The VS compiler (on Windows) has a bug which results in fieldFromInstruction being optimized out in some circumstances. This only happens in *release no debug info* builds that have assertions *turned off* - in all other situations the function is not inlined, so the functionality is correct. All of the bots have assertions turned on, so this path is not regularly tested. The workaround is to not inline the function on Windows - if the bug is fixed in a later release of the VS compiler, the noinline specification can be removed.

The test that consistently reproduces this is Lanai v11.txt test.

Reviewers: asmith, labath, zturner

Subscribers: dblaikie, stella.stamenova, aprantl, JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D49753

llvm-svn: 337942
2018-07-25 17:33:20 +00:00
Alexey Bataev a36aec9f83 [OPENMP] Exclude service expressions/statements from the list of
the children.

Special internal helper expressions/statements for the OpenMP directives
should not be exposed as children, only the main substatement must be
represented as the child.

llvm-svn: 337941
2018-07-25 17:27:45 +00:00
Xinliang David Li 45a607e563 Add an option to specify the name of
an function whose CFG is to be viewed/printed.

Differential Revision: https://reviews.llvm.org/D49447

llvm-svn: 337940
2018-07-25 17:22:12 +00:00
Ulrich Weigand 5f75371c5d Fix corruption of result number in LegalizeVectorOps.cpp
When VectorLegalizer::LegalizeOp creates a new SDValue after iterating
over its arguments, we need to refer to the same result number of the
new node that the original value used.

Reviewed by: cameron.mcinally

Differential Revision: https://reviews.llvm.org/D49805

llvm-svn: 337939
2018-07-25 17:08:13 +00:00
Stanislav Mekhanoshin 7e7268ac1c [AMDGPU] Use AssumptionCacheTracker in the divrem32 expansion
Differential Revision: https://reviews.llvm.org/D49761

llvm-svn: 337938
2018-07-25 17:02:11 +00:00