Commit Graph

19 Commits

Author SHA1 Message Date
Sam Clegg
3207e11ca3 [WebAssembly] Remove unneeded target operand flags
This change is in preparation for the addition of new target
operand flags for new relocation types.  Have a symbol type as part
of the flag set makes it harder to use and AFAICT these are serving
no purpose.

Differential Revision: https://reviews.llvm.org/D60014

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357548 91177308-0d34-0410-b5e6-96231b3b80d8
2019-04-03 00:17:29 +00:00
Heejin Ahn
421f4e7b6a [WebAssembly] Make rethrow take an except_ref type argument
Summary:
In the new wasm EH proposal, `rethrow` takes an `except_ref` argument.
This change was missing in r352598.

This patch adds `llvm.wasm.rethrow.in.catch` intrinsic. This is an
intrinsic that's gonna eventually be lowered to wasm `rethrow`
instruction, but this intrinsic can appear only within a catchpad or a
cleanuppad scope. Also this intrinsic needs to be invokable - otherwise
EH pad successor for it will not be correctly generated in clang.

This also adds lowering logic for this intrinsic in
`SelectionDAGBuilder::visitInvoke`. This routine is basically a
specialized and simplified version of
`SelectionDAGBuilder::visitTargetIntrinsic`, but we can't use it
because if is only for `CallInst`s.

This deletes the previous `llvm.wasm.rethrow` intrinsic and related
tests, which was meant to be used within a `__cxa_rethrow` library
function. Turned out this needs some more logic, so the intrinsic for
this purpose will be added later.

LateEHPrepare takes a result value of `catch` and inserts it into
matching `rethrow` as an argument.

`RETHROW_IN_CATCH` is a pseudo instruction that serves as a link between
`llvm.wasm.rethrow.in.catch` and the real wasm `rethrow` instruction. To
generate a `rethrow` instruction, we need an `except_ref` argument,
which is generated from `catch` instruction. But `catch` instrutions are
added in LateEHPrepare pass, so we use `RETHROW_IN_CATCH`, which takes
no argument, until we are able to correctly lower it to `rethrow` in
LateEHPrepare.

Reviewers: dschuff

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59352

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356316 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-16 05:38:57 +00:00
Heejin Ahn
c1447a1911 [WebAssembly] Method order change in LateEHPrepare (NFC)
Summary:
Currently the order of these methods does not matter, but the following
CL needs to have this order changed. Merging the order change and the
semantics change within a CL complicates the diff, so submitting the
order change first.

Reviewers: dschuff

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59342

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356315 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-16 04:46:05 +00:00
Heejin Ahn
81f5bd5c08 [WebAssembly] Place 'try' and 'catch' correctly wrt EH_LABELs
Summary:
After instruction selection phase, possibly-throwing calls, which were
previously invoke, are wrapped in `EH_LABEL` instructions. For example:
```
  EH_LABEL <mcsymbol .Ltmp0>
  CALL_VOID @foo ...
  EH_LABEL <mcsymbol .Ltmp1>
```

`EH_LABEL` is placed also in the beginning of EH pads:
```
bb.1 (landing-pad):
  EH_LABEL <mcsymbol .Ltmp2>
  ...
```

And we'd like to maintian this relationship, so when we place a `try`,
```
  TRY ...
  EH_LABEL <mcsymbol .Ltmp0>
  CALL_VOID @foo ...
  EH_LABEL <mcsymbol .Ltmp1>
```

When we place a `catch`,
```
bb.1 (landing-pad):
  EH_LABEL <mcsymbol .Ltmp2>
  %0:except_ref = CATCH ...
  ...
```

Previously we didn't treat EH_LABELs specially, so `try` was placed
right before a call, and `catch` was placed in the beginning of an EH
pad.

Reviewers: dschuff

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58914

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355996 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-13 00:37:31 +00:00
Heejin Ahn
097c1aa112 [WebAssembly] Simplify iterator navigations (NFC)
Summary:
- Replaces some uses of `MachineFunction::iterator(MBB)` with
  `MBB->getIterator()` and `MachineBasicBlock::iterator(MI)` with
  `MI->getIterator()`, which are simpler.
- Replaces some uses of `std::prev` of `std::next` that takes a
  MachineFunction or MachineBasicBlock iterator with `getPrevNode` and
  `getNextNode`, which are also simpler.

Reviewers: sbc100

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58913

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355444 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-05 21:05:09 +00:00
Heejin Ahn
8aac5e9929 [WebAssembly] Rename a variable in LateEHPrepare (NFC)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355387 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-05 11:11:34 +00:00
Heejin Ahn
ba7414dc84 [WebAssembly] Delete ThrowUnwindDest map from WasmEHFuncInfo
Summary:
Before when we implemented the first EH proposal, 'catch <tag>'
instruction may not catch an exception so there were multiple EH pads an
exception can unwind to. That means a BB could have multiple EH pad
successors.

Now after we switched to the new proposal, every 'catch' instruction
catches an exception, and there is only one catchpad per catchswitch, so
we at most have one EH pad successor, making `ThrowUnwindDest` map in
`WasmEHInfo` unnecessary.

Keeping `ThrowUnwindDest` map in `WasmEHInfo` has its own problems,
because other optimization passes can split a BB that contains possibly
throwing calls (previously invokes), and we have to update the map every
time that happens, which is not easy for common CodeGen passes.

This also correctly updates successor info in LateEHPrepare when we add
a rethrow instruction.

Reviewers: dschuff

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58486

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355296 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-03 22:35:56 +00:00
Heejin Ahn
330395ea4f [WebAssembly] Fix a bug deleting instruction in a ranged for loop
Summary: We shouldn't delete elements while iterating a ranged for loop.

Reviewers: dschuff

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58519

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354844 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-26 04:08:49 +00:00
Heejin Ahn
dd854ba81b [WebAssembly] Restore stack pointer right after catch instruction
Summary:
After the staack is unwound due to a thrown exxception,
`__stack_pointer` global can point to an invalid address. So
a `global.set` to restore `__stack_pointer` should be inserted right
after `catch` instruction.

But after r352598 the `global.set` instruction is inserted not right
after `catch` but after `block` - `br-on-exn` - `end_block` -
`extract_exception` sequence. This CL fixes it.

While doing that, we can actually move ReplacePhysRegs pass after
LateEHPrepare and merge EHRestoreStackPointer pass into LateEHPrepare,
and now placing `global.set` to `__stack_pointer` right after `catch` is
much easier. Otherwise it is hard to guarantee that `global.set` is
still right after `catch` and not touched with other transformations, in
which case we have to do something to hoist it.

Reviewers: dschuff

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

Differential Revision: https://reviews.llvm.org/D57421

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@352681 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-30 22:44:45 +00:00
Heejin Ahn
cceb4ae4ea [WebAssembly] Exception handling: Switch to the new proposal
Summary:
This switches the EH implementation to the new proposal:
https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md
(The previous proposal was
 https://github.com/WebAssembly/exception-handling/blob/master/proposals/old/Exceptions.md)

- Instruction changes
  - Now we have one single `catch` instruction that returns a except_ref
    value
  - `throw` now can take variable number of operations
  - `rethrow` does not have 'depth' argument anymore
  - `br_on_exn` queries an except_ref to see if it matches the tag and
    branches to the given label if true.
  - `extract_exception` is a pseudo instruction that simulates popping
    values from wasm stack. This is to make `br_on_exn`, a very special
    instruction, work: `br_on_exn` puts values onto the stack only if it
    is taken, and the # of values can vay depending on the tag.

- Now there's only one `catch` per `try`, this patch removes all special
  handling for terminate pad with a call to `__clang_call_terminate`.
  Before it was the only case there are two catch clauses (a normal
  `catch` and `catch_all` per `try`).

- Make `rethrow` act as a terminator like `throw`. This splits BB after
  `rethrow` in WasmEHPrepare, and deletes an unnecessary `unreachable`
  after `rethrow` in LateEHPrepare.

- Now we stop at all catchpads (because we add wasm `catch` instruction
  that catches all exceptions), this creates new
  `findWasmUnwindDestinations` function in SelectionDAGBuilder.

- Now we use `br_on_exn` instrution to figure out if an except_ref
  matches the current tag or not, LateEHPrepare generates this sequence
  for catch pads:
```
  catch
  block i32
  br_on_exn $__cpp_exception
  end_block
  extract_exception
```

- Branch analysis for `br_on_exn` in WebAssemblyInstrInfo

- Other various misc. changes to switch to the new proposal.

Reviewers: dschuff

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

Differential Revision: https://reviews.llvm.org/D57134

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@352598 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-30 03:21:57 +00:00
Chandler Carruth
6b547686c5 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351636 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-19 08:50:56 +00:00
Heejin Ahn
e7d4cc83c7 [WebAssembly] Print a debug message at the start of each pass
Summary:
Looks like many passes print its pass description as a debug message at
the start of each pass, so added that to (mostly newly added) other
passes as well.

Reviewers: dschuff

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

Differential Revision: https://reviews.llvm.org/D56142

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350771 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-09 23:05:21 +00:00
Thomas Lively
37a984b8bc [WebAssembly] Massive instruction renaming
Summary:
An automated renaming of all the instructions listed at
https://github.com/WebAssembly/spec/issues/884#issuecomment-426433329
as well as some similarly-named identifiers.

Reviewers: aheejin, dschuff, aardappel

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

Differential Revision: https://reviews.llvm.org/D56338

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350609 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-08 06:25:55 +00:00
Heejin Ahn
204bd90e5d [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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@347003 91177308-0d34-0410-b5e6-96231b3b80d8
2018-11-16 00:47:18 +00:00
Benjamin Kramer
3898e47d1e Move some helpers from the global namespace into anonymous ones.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@344468 91177308-0d34-0410-b5e6-96231b3b80d8
2018-10-13 22:18:22 +00:00
Heejin Ahn
65c237b70d [WebAssembly] Don't modify preds/succs iterators while erasing from them
Summary:
This caused out-of-bound bugs. Found by
`-DLLVM_ENABLE_EXPENSIVE_CHECKS=ON`.

Reviewers: dschuff

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

Differential Revision: https://reviews.llvm.org/D52902

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@343814 91177308-0d34-0410-b5e6-96231b3b80d8
2018-10-04 21:03:35 +00:00
Heejin Ahn
3c76da17f7 [WebAssembly] Modify LateEHPrepare one-line description (NFC)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339972 91177308-0d34-0410-b5e6-96231b3b80d8
2018-08-17 00:12:04 +00:00
Benjamin Kramer
6c395a1b58 [Wasm] Don't iterate over MachineBasicBlock::successors while erasing from it
This will read out of bounds. Found by asan.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339230 91177308-0d34-0410-b5e6-96231b3b80d8
2018-08-08 10:13:19 +00:00
Heejin Ahn
6aa7ab2443 [WebAssembly] Add WebAssemblyLateEHPrepare pass
Summary:
Add WebAssemblyLateEHPrepare pass that does several small jobs for
exception handling. This runs before CFGSort, and is different from
WasmEHPrepare pass that runs before ISel, even though the names are
similar.

Reviewers: dschuff, majnemer

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

Differential Revision: https://reviews.llvm.org/D46803

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335438 91177308-0d34-0410-b5e6-96231b3b80d8
2018-06-25 01:07:11 +00:00