Commit Graph

883 Commits

Author SHA1 Message Date
Richard Trieu
e1fef949ae [WebAssembly] Split the checking from the sorting logic.
Move the check for -1 and identical values outside the vector sorting code.
Compare functions need to be able to compare identical elements to be
conforming.

llvm-svn: 350379
2019-01-04 06:49:24 +00:00
Heejin Ahn
777d01c756 [WebAssembly] Optimize Irreducible Control Flow
Summary:
Irreducible control flow is not that rare, e.g. it happens in malloc and
3 other places in the libc portions linked in to a hello world program.
This patch improves how we handle that code: it emits a br_table to
dispatch to only the minimal necessary number of blocks. This reduces
the size of malloc by 33%, and makes it comparable in size to asm2wasm's
malloc output.

Added some tests, and verified this passes the emscripten-wasm tests run
on the waterfall (binaryen2, wasmobj2, other).

Reviewers: aheejin, sunfish

Subscribers: mgrang, jgravelle-google, sbc100, dschuff, llvm-commits

Differential Revision: https://reviews.llvm.org/D55467

Patch by Alon Zakai (kripken)

llvm-svn: 350367
2019-01-03 23:10:11 +00:00
Wouter van Oortmerssen
820c6263d9 [WebAssembly] Fixed disassembler not knowing about new brlist operand
Summary:
The previously introduced new operand type for br_table didn't have
a disassembler implementation, causing an assert.

Reviewers: dschuff, aheejin

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D56227

llvm-svn: 350366
2019-01-03 23:01:30 +00:00
Wouter van Oortmerssen
9843295608 [WebAssembly] Made InstPrinter more robust
Summary:
Instead of asserting on certain kinds of malformed instructions, it
now still print, but instead adds an annotation indicating the
problem, and/or indicates invalid_type etc.

We're using the InstPrinter from many contexts that can't always
guarantee values are within range (e.g. the disassembler), where having
output is more valueable than asserting.

Reviewers: dschuff, aheejin

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D56223

llvm-svn: 350365
2019-01-03 22:59:59 +00:00
Wouter van Oortmerssen
ad72f68501 [WebAssembly] made assembler parse block_type
Summary:
This was previously ignored and an incorrect value generated.

Also fixed Disassembler's handling of block_type.

Reviewers: dschuff, aheejin

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D56092

llvm-svn: 350270
2019-01-02 23:23:51 +00:00
Heejin Ahn
4d98dfb67d [WebAssembly] Fix comments in ExplicitLocals (NFC)
llvm-svn: 350144
2018-12-29 02:42:04 +00:00
Wouter van Oortmerssen
f227621036 [WebAssembly] Added basic support for if/else/end_if in MC layer.
Summary:
These instructions are currently unused in our backend, but for
completeness it is good to support them, so they can be used with
the assembler in hand-written code.

Tests are very basic, signature support missing much like other blocks.

Reviewers: dschuff, aheejin

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D55973

llvm-svn: 350079
2018-12-26 22:55:26 +00:00
Wouter van Oortmerssen
29c6ce5879 [WebAssembly] Make assembler check for proper nesting of control flow.
Summary:
It does so using a simple nesting stack, and gives clear errors upon
violation. This is unique to wasm, since most CPUs do not have
any nested constructs.

Had to add an end of file check to the general assembler for this.

Note: if/else/end instructions are not currently supported in our
tablegen defs, so these tests will be enabled in a follow-up.
They already pass the nesting check.

Reviewers: dschuff, aheejin

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D55797

llvm-svn: 350078
2018-12-26 22:46:18 +00:00
Heejin Ahn
ce1d50f9d7 [WebAssembly] Delete an unnecessary line in RegStackify
`OneUseInst` is set outside of the loop before and `OneUse` does not
change throughout the loop, so this line is not necessary.

llvm-svn: 350076
2018-12-26 22:33:35 +00:00
Heejin Ahn
99d3946398 [WebAssembly] Fix typos in comments in RegStackify (NFC)
llvm-svn: 350075
2018-12-26 22:27:46 +00:00
Simon Pilgrim
ca8bca2ad3 [WebAssembly] Always use the version of computeKnownBits that returns a value. NFCI.
Continues the work started by @bogner in rL340594 to remove uses of the KnownBits output paramater version.

llvm-svn: 349911
2018-12-21 15:25:37 +00:00
Thomas Lively
b6dac89c87 [WebAssembly] Fix invalid machine instrs in -O0, verify in tests
Reviewers: aheejin, dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D55956

llvm-svn: 349889
2018-12-21 06:58:15 +00:00
Thomas Lively
feb18fe927 [WebAssembly] Emit a splat for v128 IMPLICIT_DEF
Summary:
This is a code size savings and is also important to get runnable code
while engines do not support v128.const.

Reviewers: aheejin, dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D55910

llvm-svn: 349724
2018-12-20 04:20:32 +00:00
Thomas Lively
8dbf29af95 [WebAssembly] Gate unimplemented SIMD ops on flag
Summary:
Gates v128.const, f32x4.sqrt, f32x4.div, i8x16.extract_lane_u, and
i16x8.extract_lane_u on the --wasm-enable-unimplemented-simd flag,
since these ops are not implemented yet in V8.

Reviewers: aheejin, dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D55904

llvm-svn: 349720
2018-12-20 02:10:22 +00:00
Wouter van Oortmerssen
d3c544aa6e [WebAssembly] Fix assembler parsing of br_table.
Summary:
We use `variable_ops` in the tablegen defs to denote the list of
branch targets in `br_table`, but unlike other uses of `variable_ops`
(e.g. call) the these branch targets need to actually be encoded in the
instruction. The existing tables for `variable_ops` cause not operands
to be accepted by the assembly matcher.

Following the example of ARM:
2cc0a7da87/lib/Target/ARM/ARMInstrInfo.td (L550-L555)
we introduce a new operand type to capture this list, and we use the
same {} syntax as ARM as well to differentiate them from regular
integer operands.

Also removed definition and use of TSFlags in tablegen defs, since
`br_table` now has a non-variable_ops immediate operand, so the
previous logic of only the variable_ops arguments being labels didn't
make sense anymore.

Reviewers: dschuff, aheejin, sunfish

Subscribers: javed.absar, sbc100, jgravelle-google, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D55401

llvm-svn: 349405
2018-12-17 22:04:44 +00:00
Heejin Ahn
be5e5874f6 [WebAssembly] Add '.eventtype' directive support
Summary:
This patch supports `.eventtype` directive printing and parsing in the
same syntax with `.functype`.

Reviewers: aardappel, sbc100

Subscribers: dschuff, sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D55353

llvm-svn: 348818
2018-12-11 01:11:04 +00:00
Heejin Ahn
21d45a2c98 [WebAssembly] TargetStreamer cleanup (NFC)
Summary:
- Unify mixed argument names (`Symbol` and `Sym`) to `Sym`
- Changed `MCSymbolWasm*` argument of `emit***` functions to `const
  MCSymbolWasm*`. It seems not very intuitive that emit function in the
  streamer modifies symbol contents.
- Moved empty function bodies to the header
- clang-format

Reviewers: aardappel, dschuff, sbc100

Subscribers: jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D55347

llvm-svn: 348816
2018-12-11 00:53:59 +00:00
Heejin Ahn
7ce5edf1ea [WebAssembly] clang-format/clang-tidy AsmParser (NFC)
Summary:
- LLVM clang-format style doesn't allow one-line ifs.
- LLVM clang-tidy style says method names should start with a lowercase
  letter. But currently WebAssemblyAsmParser's parent class
  MCTargetAsmParser is mixing lowercase and uppercase method names
  itself so overridden methods cannot be renamed now.
- Changed else ifs after returns to ifs.
- Added some newlines for readability.

Reviewers: aardappel, sbc100

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

Differential Revision: https://reviews.llvm.org/D55350

llvm-svn: 348648
2018-12-07 21:35:37 +00:00
Heejin Ahn
d2fd70991d Delete registerScope function
`unregisterScope()` is not currently used, so removing it.

llvm-svn: 348647
2018-12-07 21:31:14 +00:00
David Green
ca29c271d2 [Targets] Add errors for tiny and kernel codemodel on targets that don't support them
Adds fatal errors for any target that does not support the Tiny or Kernel
codemodels by rejigging the getEffectiveCodeModel calls.

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

llvm-svn: 348585
2018-12-07 12:10:23 +00:00
Wouter van Oortmerssen
c7b89f0f62 [WebAssembly] Enforce assembler emits to streamer in order.
Summary:
The assembler processes directives and instructions in whatever order
they are in the file, then directly emits them to the streamer. This
could cause badly written (or generated) .s files to produce
incorrect binaries.

It now has state that tracks what it has most recently seen, to
enforce they are emitted in a given order that always produces
correct wasm binaries.

Also added a new test that compares obj2yaml output from llc (the
backend) to that going via .s and the assembler to ensure both paths
generate the same binaries.

The features this test covers could be extended.

Passes all wasm Lit tests.

Fixes: https://bugs.llvm.org/show_bug.cgi?id=39557

Reviewers: sbc100, dschuff, aheejin

Subscribers: jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D55149

llvm-svn: 348185
2018-12-03 20:30:28 +00:00
Thomas Lively
66ea30c7bc [WebAssembly] Expand unavailable integer operations for vectors
Summary:
Expands for vector types all of the integer operations that are
expanded for scalars because they are not supported at all by
WebAssembly.

This CL has no tests because such tests would really be testing the
target-independent expansion, but I'm happy to add tests if reviewers
think it would be helpful.

Reviewers: aheejin, dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D55010

llvm-svn: 347923
2018-11-29 22:01:01 +00:00
Sam Clegg
4791a668f5 [WebAssembly] WebAssemblyLowerEmscriptenEHSjLj: use getter/setter for accessing tempRet0
Rather than assuming that `tempRet0` exists in linear memory only assume
the getter/setter functions exist.  This avoids conflicting with
binaryen which declares a wasm global for this purpose and defines it's
own getter and setter for that.

The other advantage of doing things this way is that it leaving
it up to the linker/finalizer to decide how to actually store this
temporary.  As it happens binaryen uses a wasm global which is more
appropriate since it is thread safe.

This also allows us to change the way this is stored in the future
(memory, TLS memory, wasm global) without modifying LLVM.

This is part of a 4 part change:
LLVM: https://reviews.llvm.org/D53240
fastcomp: https://github.com/kripken/emscripten-fastcomp/pull/237
emscripten: https://github.com/kripken/emscripten/pull/7358
binaryen: https://github.com/WebAssembly/binaryen/pull/1709

Differential Revision: https://reviews.llvm.org/D53240

llvm-svn: 347340
2018-11-20 19:25:07 +00:00
Wouter van Oortmerssen
49482f824a [WebAssembly] replaced .param/.result by .functype
Summary:
This makes it easier/cleaner to generate a single signature from
this directive. Also:
- Adds the symbol name, such that we don't depend on the location
  of this directive anymore.
- Actually constructs the signature in the assembler, and make the
  assembler own it.
- Refactor the use of MVT vs ValType in the streamer and assembler
  to require less conversions overall.
- Changed 700 or so tests to use it.

Reviewers: sbc100, dschuff

Subscribers: jgravelle-google, eraman, aheejin, sunfish, jfb, llvm-commits

Differential Revision: https://reviews.llvm.org/D54652

llvm-svn: 347228
2018-11-19 17:10:36 +00:00
Heejin Ahn
e0f8b9bfc6 [WebAssembly] Add null streamer support
Summary: Now `llc -filetype=null` works.

Reviewers: eush

Subscribers: dschuff, jgravelle-google, sbc100, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D54660

llvm-svn: 347155
2018-11-18 11:58:47 +00:00
Sam Clegg
74f5fd4e32 [WebAssembly] Default to static reloc model
Differential Revision: https://reviews.llvm.org/D54637

llvm-svn: 347073
2018-11-16 18:59:51 +00:00
Heejin Ahn
095796a391 [WebAssembly] Split BBs after throw instructions
Summary:
`throw` instruction is a terminator in wasm, but BBs were not splitted
after `throw` instructions, causing machine instruction verifier to
fail.

This patch
- Splits BBs after `throw` instructions in WasmEHPrepare and adding an
  unreachable instruction after `throw`, which will be deleted in
  LateEHPrepare pass
- Refactors WasmEHPrepare into two member functions
- Changes the semantics of `eraseBBsAndChildren` in LateEHPrepare pass
  to match that of WasmEHPrepare pass, which is newly added. Now
  `eraseBBsAndChildren` does not delete BBs with remaining predecessors.
- Fixes style nits, making static function names conform to clang-tidy
- Re-enables the test temporarily disabled by rL346840 && rL346845

Reviewers: dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D54571

llvm-svn: 347003
2018-11-16 00:47:18 +00:00
Thomas Lively
fc3163b67a [WebAssembly] Fix return type of nextByte
Summary:
The old return type did not allow for correct error reporting and was
causing a compiler warning.

Reviewers: aheejin

Subscribers: dschuff, sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D54586

llvm-svn: 346979
2018-11-15 18:56:49 +00:00
Thomas Lively
77b33c86f5 [WebAssembly] Renumber SIMD bitwise instructions
Summary: Changed to match https://github.com/WebAssembly/simd/pull/54.

Reviewers: aheejin

Subscribers: dschuff, sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D54561

llvm-svn: 346931
2018-11-15 03:38:59 +00:00
Heejin Ahn
da419bdb5e [WebAssembly] Add support for the event section
Summary:
This adds support for the 'event section' specified in the exception
handling proposal. (This was named 'exception section' first, but later
renamed to 'event section' to take possibilities of other kinds of
events into consideration. But currently we only store exception info in
this section.)

The event section is added between the global section and the export
section. This is for ease of validation per request of the V8 team.

This patch:
- Creates the event symbol type, which is a weak symbol
- Makes 'throw' instruction take the event symbol '__cpp_exception'
- Adds relocation support for events
- Adds WasmObjectWriter / WasmObjectFile (Reader) support
- Adds obj2yaml / yaml2obj support
- Adds '.eventtype' printing support

Reviewers: dschuff, sbc100, aardappel

Subscribers: jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D54096

llvm-svn: 346825
2018-11-14 02:46:21 +00:00
Sam Clegg
f98ba05f3d [WebAssembly] Fix broken assumption that all bitcasts are to functions types
Specifically, we can bitcast to void.

Fixes PR39591

Differential Revision: https://reviews.llvm.org/D54447

llvm-svn: 346778
2018-11-13 19:14:02 +00:00
Wouter van Oortmerssen
cc75e77df5 [WebAssembly] Added WasmAsmParser.
Summary:
This is to replace the ELFAsmParser that WebAssembly was using, which
so far was a stub that didn't do anything, and couldn't work correctly
with wasm.

This new class is there to implement generic directives related to
wasm as a binary format. Wasm target specific directives are still
parsed in WebAssemblyAsmParser as before. The two classes now
cooperate more correctly too.

Also implemented .result which was missing. Any unknown directives
will now result in errors.

Reviewers: dschuff, sbc100

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

Differential Revision: https://reviews.llvm.org/D54360

llvm-svn: 346700
2018-11-12 20:15:01 +00:00
Thomas Lively
936734b777 [WebAssembly] Update bleeding-edge cpu features
Reviewers: aheejin, dschuff

Subscribers: sbc100, jgravelle-google, sunfish, jfb, llvm-commits

Differential Revision: https://reviews.llvm.org/D54362

llvm-svn: 346570
2018-11-10 00:11:14 +00:00
Fangrui Song
4955066366 [WebAssembly] Hotfix of WebAssemblyInstructionTableSize after rL346465
llvm-svn: 346535
2018-11-09 18:32:20 +00:00
Thomas Lively
2faf079494 [WebAssembly] Read prefixed opcodes as ULEB128s
Summary: Depends on D54126.

Reviewers: aheejin, dschuff, aardappel

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D54138

llvm-svn: 346465
2018-11-09 01:57:00 +00:00
Thomas Lively
4ddd22581e [WebAssembly][NFC] Reorder SIMD section
Summary:
Reorders the sections in the SIMD tablegen file to roughly match the
new opcode ordering. Depends on D54126.

Reviewers: aheejin, dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D54134

llvm-svn: 346464
2018-11-09 01:49:19 +00:00
Thomas Lively
299d214aba [WebAssembly] Renumber and LEB128-encode SIMD opcodes
Reviewers: aheejin, dschuff, aardappel

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D54126

llvm-svn: 346463
2018-11-09 01:45:56 +00:00
Thomas Lively
38c902bc2e [WebAssembly] Lower select for vectors
Summary:

Reviewers: aheejin, dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D53675

llvm-svn: 346462
2018-11-09 01:38:44 +00:00
Heejin Ahn
0c68a875fa [WebAssembly] Fix LowerEmscriptenEHSjLj when there's only longjmp
Summary:
The pass incorrectly assumed if there's a longjmp declaration in the
module, there is also a setjmp function declaration. Fixed it, and now
the pass only converts longjmp and does not do any other transformation
when there's no setjmp declaration in the module.

Fixes PR39562.

Reviewers: jgravelle-google, sbc100

Subscribers: dschuff, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D54273

llvm-svn: 346445
2018-11-08 22:56:26 +00:00
Thomas Lively
897171902b [WebAssembly] Add V128 to WebAssemblyInstrInfo::copyPhysReg
Reviewers: aheejin, dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D53872

llvm-svn: 346384
2018-11-08 02:35:28 +00:00
Sam Clegg
5292d17ec8 Revert "[WebAssembly] Fixup main signature by default"
This reverts rL345880.  It caused some test failures on the
webassembly waterfall.  e.g. binaryen2.test_mainenv fails due
the fact that `envp` ends up being undef rather than 0.

Differential Revision: https://reviews.llvm.org/D54117

llvm-svn: 346187
2018-11-06 00:31:02 +00:00
Wouter van Oortmerssen
de28b5d17f [WebAssembly] Parsing missing directives to produce valid .o
Summary:
The assembler was able to assemble and then dump back to .s, but
was failing to parse certain directives necessary for valid .o
output:
- .type directives are now recognized to distinguish function symbols
  and others.
- .size is now parsed to provide function size.
- .globaltype (introduced in https://reviews.llvm.org/D54012) is now
  recognized to ensure symbols like __stack_pointer have a proper type
  set for both .s and .o output.

Also added tests for the above.

Reviewers: sbc100, dschuff

Subscribers: jgravelle-google, aheejin, dexonsmith, kristina, llvm-commits, sunfish

Differential Revision: https://reviews.llvm.org/D53842

llvm-svn: 346047
2018-11-02 22:04:33 +00:00
Heejin Ahn
5b023e07ea [WebAssembly] Fix bugs in rethrow depth counting and InstPrinter
Summary:
EH stack depth is incremented at `try` and decremented at `catch`. When
there are more than two catch instructions for a try instruction, we
shouldn't count non-first catches when calculating EH stack depths.

This patch fixes two bugs:
- CFGStackify: Exclude `catch_all` in the terminate catch pad when
  calculating EH pad stack, because when we have multiple catches for a
  try we should count only the first catch instruction when calculating
  EH pad stack.
- InstPrinter: The initial intention was also to exclude non-first
  catches, but it didn't account nested try-catches, so it failed on
  this case:
```
try
  try
  catch
  end
catch    <-- (1)
end
```
In the example, when we are at the catch (1), the last seen EH
instruction is not `try` but `end_try`, violating the wrong assumption.

We don't need these after we switch to the second proposal because there
is gonna be only one `catch` instruction. But anyway before then these
bugfixes are necessary for keep trunk in working state.

Reviewers: dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D53819

llvm-svn: 346029
2018-11-02 18:38:52 +00:00
Wouter van Oortmerssen
3231e518a3 [WebAssembly] Added a .globaltype directive to .s output.
Summary:
Assembly output can use globals like __stack_pointer implicitly,
but has no way of indicating the type of such a global, which makes
it hard for tools processing it (such as the MC Assembler) to
reconstruct this information.

The improved assembler directives parsing (in progress in
https://reviews.llvm.org/D53842) will make use of this information.

Also deleted code for the .import_global directive which was unused.

New test case in userstack.ll

Reviewers: dschuff, sbc100

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

Differential Revision: https://reviews.llvm.org/D54012

llvm-svn: 345917
2018-11-02 00:45:00 +00:00
Thomas Lively
b2382c8bf7 [WebAssembly] General vector shift lowering
Summary: Adds support for lowering non-splat shifts.

Reviewers: aheejin, dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D53625

llvm-svn: 345916
2018-11-02 00:39:57 +00:00
Thomas Lively
fb84fd7c8e [WebAssembly] Expand inserts and extracts with variable indices
Reviewers: aheejin, dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D53964

llvm-svn: 345913
2018-11-02 00:06:56 +00:00
Heejin Ahn
2e398976ba [WebAssembly] Fix signature parsing for 'try' in AsmParser
Summary:
Like `block` or `loop`, `try` can take an optional signature which can
be omitted. This patch allows `try`'s signature to be omitted. Also
added some tests for EH instructions.

Reviewers: aardappel

Subscribers: dschuff, sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D53873

llvm-svn: 345888
2018-11-01 20:32:15 +00:00
Reid Kleckner
4dc0b1ac60 Fix clang -Wimplicit-fallthrough warnings across llvm, NFC
This patch should not introduce any behavior changes. It consists of
mostly one of two changes:
1. Replacing fall through comments with the LLVM_FALLTHROUGH macro
2. Inserting 'break' before falling through into a case block consisting
   of only 'break'.

We were already using this warning with GCC, but its warning behaves
slightly differently. In this patch, the following differences are
relevant:
1. GCC recognizes comments that say "fall through" as annotations, clang
   doesn't
2. GCC doesn't warn on "case N: foo(); default: break;", clang does
3. GCC doesn't warn when the case contains a switch, but falls through
   the outer case.

I will enable the warning separately in a follow-up patch so that it can
be cleanly reverted if necessary.

Reviewers: alexfh, rsmith, lattner, rtrieu, EricWF, bollu

Differential Revision: https://reviews.llvm.org/D53950

llvm-svn: 345882
2018-11-01 19:54:45 +00:00
Sam Clegg
ddf049869a [WebAssembly] Fixup main signature by default
Differential Revision: https://reviews.llvm.org/D53396

llvm-svn: 345880
2018-11-01 19:38:44 +00:00
Thomas Lively
d4891a1b7a [WebAssembly] Lower vselect
Reviewers: aheejin, dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D53630

llvm-svn: 345797
2018-11-01 00:01:02 +00:00