Commit Graph

886 Commits

Author SHA1 Message Date
Thomas Lively fd0557dbf1 [WebAssembly] More convert_low and promote_low codegen
The convert_low and promote_low instructions can widen the lower two lanes of a
four-lane vector, but we were previously scalarizing patterns that widened lanes
besides the low two lanes. The commit adds a shuffle to move the widened lanes
into the low lane positions so the convert_low and promote_low instructions can
be used instead of scalarizing.

Depends on D108266.

Differential Revision: https://reviews.llvm.org/D108341
2021-08-19 15:37:12 -07:00
Thomas Lively b311a040ef [WebAssembly] Pattern match SIMD convert_low and promote_low during ISel
Since the simplest DAG patterns for convert_low and promote_low instructions
involved v2i32, v2f32, v4i64, and v4f64 types, which are not legal in the
WebAssembly backend and would be eliminated by type legalization, we were
previously matching those patterns in a DAG combine before the type legalization
stage. However in cases where the vectors were wider than 128 bits, the patterns
we matched were not created until the type legalization stage when the wide
vectors were split up. Type legalization would continue to eliminate the illegal
types we were matching as well, so the code ended up scalarized.

To make the ISel for these instructions more robust, match the scalarized
patterns rather than the patterns containing illegal types. Add tests with
double-wide vectors to show that this works as intended.

Fixes PR51098.
Depends on D107502.

Differential Revision: https://reviews.llvm.org/D108266
2021-08-19 15:24:28 -07:00
Thomas Lively b69374ca58 [WebAssembly] Legalize vector types by widening
The default legalization of unsupported vector types is to promote the integers
in each lane, which leads to extra sign or zero extending and masking when
moving data into and out of vectors. Switch our preferred type legalization from
the default to vector widening, which keeps the data in the low lanes of the
vector rather than in the low bits of each lane. The unused high lanes can be
ignored.

Half-wide vectors are now loaded from memory into the low 64 bits of the v128
rather than spread out among the lanes. As a result, v128.load64_splat is a much
more common operation, so add new patterns to support it.

Differential Revision: https://reviews.llvm.org/D107502
2021-08-19 12:07:33 -07:00
Thomas Lively 4ade3af133 [WebAssembly] Autogenerate checks for simd-conversions.ll
In preparation for adding more tests more simply.

Differential Revision: https://reviews.llvm.org/D108264
2021-08-17 21:35:23 -07:00
Heejin Ahn adb96d2e76 [WebAssembly] Fix leak in Emscripten SjLj
For SjLj, we allocate a table to record setjmp buffer info in the entry
of each setjmp-calling function by inserting a `malloc` call, and insert
a `free` call to free the buffer before each `ret` instruction.

But this is not sufficient; we have to free the buffer before we throw.
In SjLj handling, normal functions that can possibly throw or longjmp
are wrapped with an invoke and caught within the function so they don't
end up escaping the function. But three functions throw and escape the
function:
- `__resumeException` (Emscripten library function used for Emscripten
  EH)
- `emscripten_longjmp` (Emscripten library function used for Emscripten
  SjLj)
- `__cxa_throw` (libc++abi function called when for C++ `throw` keyword)

The first two functions are used to rethrow the current
exception/longjmp when the caught exception/longjmp is not for the
current function. `__cxa_throw` is used for exception, and because we
consider that a function that cannot longjmp, it escapes the function
right away, before which we should free the buffer.

Currently `lsan.test_longjmp3` and `lsan.test_exceptions_longjmp3` fail
in Emscripten; this CL fixes these.

Reviewed By: dschuff

Differential Revision: https://reviews.llvm.org/D107852
2021-08-12 16:32:46 -07:00
Heejin Ahn aca198cf74 [WebAssembly] Error out when Emscripten SjLj setjmp is used with Wasm EH
Currently, when Wasm EH is used with Emscripten SjLj, Emscripten SjLj
cannot handle `invoke` instructions - it assumes all `invoke`s have been
lowered away with Emscripten EH. But in Wasm EH they are lowered in
instruction selection, so they are still present in the IR stage. This
happens when
1. Wasm EH and Emscripten SjLj are used together
2. A function that calls `setjmp` uses exceptions, i.e., has `invoke`s

We were already erroring out with an assertion failure in this case, but
this CL makes it error out more properly with a valid error message.

Wasm EH + Wasm SjLj will not have this restrictions. (it will have
another restriction though, e.g., `setjmp` cannot be called within
`catch`. But why would anyone do that..)

Reviewed By: dschuff

Differential Revision: https://reviews.llvm.org/D107687
2021-08-12 16:19:04 -07:00
Heejin Ahn 78e87970af [WebAssembly] Disable offset folding for function addresses
Wasm does not support function addresses with offsets, but isel can
generate folded SDValues in the form of (@func + offset) without this
patch.

Fixes https://bugs.llvm.org/show_bug.cgi?id=43133.

Reviewed By: dschuff, sbc100

Differential Revision: https://reviews.llvm.org/D107940
2021-08-12 13:40:41 -07:00
Heejin Ahn 41ba39dfcd [WebAssembly] Don't do SjLj transformation when there's only setjmp
When there is a `setjmp` call in a function, we transform every callsite
of `setjmp` to record its information by calling `saveSetjmp` function,
and we also transform every callsite of a function that can longjmp to
to check if a longjmp occurred and if so jump to the corresponding
post-setjmp BB. Currently we are doing this for every function that
contains a call to `setjmp`, but if there is no other function call
within that function that can longjmp, this transformation of `setjmp`
callsite and all the preparation of `setjmpTable` in the entry of the
function are not necessary.

This checks if a setjmp-calling function has any other calls that can
longjmp, and if not, skips the function for the SjLj transformation.

Reviewed By: dschuff

Differential Revision: https://reviews.llvm.org/D107530
2021-08-05 15:28:02 -07:00
Heejin Ahn 9c3345ad10 [WebAssembly] Cleanup Emscripten SjLj tests
- Remove a redundant test: there were `longjmp_only` and `only_longjmp`,
  which do the same thing
- Add `CHECK-LABEL` lines for function names

Reviewed By: tlively

Differential Revision: https://reviews.llvm.org/D107511
2021-08-04 21:16:08 -07:00
Heejin Ahn 9bd02c433b [WebAssembly] Misc. cosmetic changes in EH (NFC)
- Rename `wasm.catch` intrinsic to `wasm.catch.exn`, because we are
  planning to add a separate `wasm.catch.longjmp` intrinsic which
  returns two values.
- Rename several variables
- Remove an unnecessary parameter from `canLongjmp` and `isEmAsmCall`
  from LowerEmscriptenEHSjLj pass
- Add `-verify-machineinstrs` in a test for a safety measure
- Add more comments + fix some errors in comments
- Replace `std::vector` with `SmallVector` for cases likely with small
  number of elements
- Renamed `EnableEH`/`EnableSjLj` to `EnableEmEH`/`EnableEmSjLj`: We are
  soon going to add `EnableWasmSjLj`, so this makes the distincion
  clearer

Reviewed By: tlively

Differential Revision: https://reviews.llvm.org/D107405
2021-08-03 21:03:46 -07:00
Paulo Matos d3a0a65bf0 Reland: "[WebAssembly] Add new pass to lower int/ptr conversions of reftypes"
Add new pass LowerRefTypesIntPtrConv to generate debugtrap
instruction for an inttoptr and ptrtoint of a reference type instead
of erroring, since calling these instructions on non-integral pointers
has been since allowed (see ac81cb7e6).

Differential Revision: https://reviews.llvm.org/D107102
2021-08-03 09:20:51 +02:00
Paulo Matos 245f2ee647 Revert "[WebAssembly] Add new pass to lower int/ptr conversions of reftypes"
This reverts commit ce1c59dea6.
2021-08-02 20:12:25 +02:00
Paulo Matos ce1c59dea6 [WebAssembly] Add new pass to lower int/ptr conversions of reftypes
Add new pass LowerRefTypesIntPtrConv to generate trap
instruction for an inttoptr and ptrtoint of a reference type instead
of erroring, since calling these instructions on non-integral pointers
has been since allowed (see ac81cb7e6).

Differential Revision: https://reviews.llvm.org/D107102
2021-08-02 19:40:00 +02:00
Thomas Lively 417e500668 [WebAssembly] Compute known bits for SIMD bitmask intrinsics
This optimizes out the mask when the result of a bitmask is interpreted as an i8
or i16 value. Resolves PR50507.

Differential Revision: https://reviews.llvm.org/D107103
2021-08-02 09:52:34 -07:00
Thomas Lively 33786576fd [WebAssembly] Codegen for extmul SIMD instructions
Replace the clang builtins and LLVM intrinsics for the SIMD extmul instructions
with normal codegen patterns.

Differential Revision: https://reviews.llvm.org/D106724
2021-07-27 08:41:30 -07:00
Heejin Ahn c285a11efd [WebAssembly] Make Emscripten EH work with Emscripten SjLj
When Emscripten EH mixes with Emscripten SjLj, we are not currently
handling some of them correctly. There are three cases:
1. The current function calls `setjmp` and there is an `invoke` to a
   function that can either throw or longjmp. In this case, we have to
   check both for exception and longjmp. We are currently handling this
   case correctly:
   0c0eb76782/llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp (L1058-L1090)
   When inserting routines for functions that can longjmp, which we do
   only for setjmp-calling functions, we check if the function was
   previously an `invoke` and handle it correctly.

2. The current function does NOT call `setjmp` and there is an `invoke`
   to a function that can either throw or longjmp. Because there is no
   `setjmp` call, we haven't been doing any check for functions that can
   longjmp. But in that case, for `invoke`, we only check for an
   exception and if it is not an exception we reset `__THREW__` to 0,
   which can silently swallow the longjmp:
   0c0eb76782/llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp (L70-L80)
   This CL fixes this.

3. The current function calls `setjmp` and there is no `invoke`. Because
   it is not an `invoke`, we haven't been doing any check for functions
   that can throw, and only insert longjmp-checking routines for
   functions that can longjmp. But in that case, if a longjmpable
   function throws, we only check for a longjmp so if it is not a
   longjmp we reset `__THREW__` to 0, which can silently swallow the
   exception:
   0c0eb76782/llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp (L156-L169)
   This CL fixes this.

To do that, this moves around some code, so we register necessary
functions for both EH and SjLj and precompute some data (the set of
functions that contains `setjmp`) before doing actual EH or SjLj
transformation.

This CL makes 2nd and 3rd tests in
https://github.com/emscripten-core/emscripten/pull/14732 work.

Reviewed By: dschuff

Differential Revision: https://reviews.llvm.org/D106525
2021-07-26 13:48:31 -07:00
Thomas Lively 85157c0079 [WebAssembly] Codegen for pmin and pmax
Replace the clang builtins and LLVM intrinsics for {f32x4,f64x2}.{pmin,pmax}
with standard codegen patterns. Since wasm_simd128.h uses an integer vector as
the standard single vector type, the IR for the pmin and pmax intrinsic
functions contains bitcasts that would not be there otherwise. Add extra codegen
patterns that can still select the pmin and pmax instructions in the presence of
these bitcasts.

Differential Revision: https://reviews.llvm.org/D106612
2021-07-23 14:49:21 -07:00
Paulo Matos 46667a1003 [WebAssembly] Implementation of global.get/set for reftypes in LLVM IR
Reland of 31859f896.

This change implements new DAG notes GLOBAL_GET/GLOBAL_SET, and
lowering methods for load and stores of reference types from IR
globals. Once the lowering creates the new nodes, tablegen pattern
matches those and converts them to Wasm global.get/set.

Reviewed By: tlively

Differential Revision: https://reviews.llvm.org/D104797
2021-07-22 22:07:24 +02:00
Thomas Lively 8af333cf1a [WebAssembly] Replace @llvm.wasm.popcnt with @llvm.ctpop.v16i8
Use the standard target-independent intrinsic to take advantage of standard
optimizations.

Differential Revision: https://reviews.llvm.org/D106506
2021-07-21 16:45:54 -07:00
Thomas Lively 1a57ee1276 [WebAssembly] Codegen for v128.load{32,64}_zero
Replace the experimental clang builtins and LLVM intrinsics for these
instructions with normal instruction selection patterns. The wasm_simd128.h
intrinsics header was already using portable code for the corresponding
intrinsics, so now it produces the correct instructions.

Differential Revision: https://reviews.llvm.org/D106400
2021-07-21 09:02:12 -07:00
Thomas Lively 4a4229f70f [WebAssembly] Codegen for v128.storeX_lane instructions
Replace the experimental clang builtins and LLVM intrinsics for these
instructions with normal codegen patterns. Resolves PR50435.

Differential Revision: https://reviews.llvm.org/D106019
2021-07-14 16:15:25 -07:00
Thomas Lively 970e090010 [WebAssembly] Codegen for v128.loadX_lane instructions
Replace the experimental clang builtin and LLVM intrinsics for these
instructions with normal codegen patterns. Resolves PR50433.

Differential Revision: https://reviews.llvm.org/D105950
2021-07-14 11:31:53 -07:00
Thomas Lively 122b0220fd [WebAssembly] Remove datalayout strings from llc tests
The data layout strings do not have any effect on llc tests and will become
misleadingly out of date as we continue to update the canonical data layout, so
remove them from the tests.

Differential Revision: https://reviews.llvm.org/D105842
2021-07-14 11:17:08 -07:00
Derek Schuff d4e2693a67 [WebAssembly] Run varargs codegen test with non-emscripten triple
This is a followup from D105749 to cover both triples in the case
where they differ.
2021-07-13 14:31:19 -07:00
Thomas Lively 308d381283 [WebAssembly] Generate checks for simd-load-store-alignment.ll
This will make it easier to update these tests as we add support for generating
more SIMD loads and stores with custom alignments.

Differential Revision: https://reviews.llvm.org/D105862
2021-07-13 11:25:33 -07:00
Thomas Lively cbabfc63b1 [WebAssembly] Custom combines for f32x4.demote_zero_f64x2
Replace the clang builtin function and LLVM intrinsic for
f32x4.demote_zero_f64x2 with combines from normal SDNodes. Also add missing
combines for i32x4.trunc_sat_zero_f64x2_{s,u}, which share the same pattern.

Differential Revision: https://reviews.llvm.org/D105755
2021-07-12 10:32:18 -07:00
Thomas Lively e5220104d0 [WebAssembly] Custom combines for f64x2.promote_low_f32x4
Replace the clang builtin function and LLVM intrinsic previously used to select
the f64x2.promote_low_f32x4 instruction with custom combines from standard
SelectionDAG nodes. Implement the new combines to share code with the similar
combines for f64x2.convert_low_i32x4_{s,u}. Resolves PR50232.

Differential Revision: https://reviews.llvm.org/D105675
2021-07-09 18:59:29 -07:00
Derek Schuff ac02baab48 WebAssembly: Update datalayout to match fp128 ABI change
This fix goes along with d1a96e906c
and makes the fp128 alignment match clang's long double alignment.

Differential Revision: https://reviews.llvm.org/D105749
2021-07-09 16:51:36 -07:00
Wouter van Oortmerssen 9647a6f719 [WebAssembly] Added initial type checker to MC Assembler
This to protect against non-sensical instruction sequences being assembled,
which would either cause asserts/crashes further down, or a Wasm module being output that doesn't validate.

Unlike a validator, this type checker is able to give type-errors as part of the parsing process, which makes the assembler much friendlier to be used by humans writing manual input.

Because the MC system is single pass (instructions aren't even stored in MC format, they are directly output) the type checker has to be single pass as well, which means that from now on .globaltype and .functype decls must come before their use. An extra pass is added to Codegen to collect information for this purpose, since AsmPrinter is normally single pass / streaming as well, and would otherwise generate this information on the fly.

A `-no-type-check` flag was added to llvm-mc (and any other tools that take asm input) that surpresses type errors, as a quick escape hatch for tests that were not intended to be type correct.

This is a first version of the type checker that ignores control flow, i.e. it checks that types are correct along the linear path, but not the branch path. This will still catch most errors. Branch checking could be added in the future.

Differential Revision: https://reviews.llvm.org/D104945
2021-07-09 14:07:25 -07:00
Thomas Lively 3dd75f5371 [WebAssembly] Scalarize extract_vector_elt of binops
Override the `shouldScalarizeBinop` target lowering hook using the same
implementation used in the x86 backend. This causes `extract_vector_elt`s of
vector binary ops to be scalarized if the scalarized version would be supported.

Differential Revision: https://reviews.llvm.org/D105646
2021-07-08 14:31:53 -07:00
Thomas Lively f8c5a4c670 [WebAssembly] Optimize out shift masks
WebAssembly's shift instructions implicitly masks the shift count, so optimize
out redundant explicit masks of the shift count. For vector shifts, this
currently only works if the mask is applied before splatting the shift count,
but this should be addressed in a future commit. Resolves PR49655.

Differential Revision: https://reviews.llvm.org/D105600
2021-07-07 23:14:31 -07:00
Roman Lebedev c2c0d3ea89
Revert "[WebAssembly] Implementation of global.get/set for reftypes in LLVM IR"
This reverts commit 4facbf213c.

```
********************
FAIL: LLVM :: CodeGen/WebAssembly/funcref-call.ll (44466 of 44468)
******************** TEST 'LLVM :: CodeGen/WebAssembly/funcref-call.ll' FAILED ********************
Script:
--
: 'RUN: at line 1';   /builddirs/llvm-project/build-Clang12/bin/llc < /repositories/llvm-project/llvm/test/CodeGen/WebAssembly/funcref-call.ll --mtriple=wasm32-unknown-unknown -asm-verbose=false -mattr=+reference-types | /builddirs/llvm-project/build-Clang12/bin/FileCheck /repositories/llvm-project/llvm/test/CodeGen/WebAssembly/funcref-call.ll
--
Exit Code: 2

Command Output (stderr):
--
llc: /repositories/llvm-project/llvm/include/llvm/Support/LowLevelTypeImpl.h:44: static llvm::LLT llvm::LLT::scalar(unsigned int): Assertion `SizeInBits > 0 && "invalid scalar size"' failed.

```
2021-07-02 11:49:51 +03:00
Paulo Matos 4facbf213c [WebAssembly] Implementation of global.get/set for reftypes in LLVM IR
Reland of 31859f896.

This change implements new DAG notes GLOBAL_GET/GLOBAL_SET, and
lowering methods for load and stores of reference types from IR
globals. Once the lowering creates the new nodes, tablegen pattern
matches those and converts them to Wasm global.get/set.

Differential Revision: https://reviews.llvm.org/D104797
2021-07-02 09:46:28 +02:00
Nikita Popov f8aaec19e6 [OpaquePtr] Support forward references in textual IR
Currently, LLParser will create a Function/GlobalVariable forward
reference based on the desired pointer type and then modify it when
it is declared. With opaque pointers, we generally do not know the
correct type to use until we see the declaration.

Solve this by creating the forward reference with a dummy type, and
then performing a RAUW with the correct Function/GlobalVariable when
it is declared. The approach is adopted from
b5b55963f6.

This results in a change to the use list order, which is why we see
test changes on some module passes that are not stable under use list
reordering.

Differential Revision: https://reviews.llvm.org/D104950
2021-06-29 20:10:31 +02:00
Heejin Ahn 1d891d44f3 [WebAssembly] Rename event to tag
We recently decided to change 'event' to 'tag', and 'event section' to
'tag section', out of the rationale that the section contains a
generalized tag that references a type, which may be used for something
other than exceptions, and the name 'event' can be confusing in the web
context.

See
- https://github.com/WebAssembly/exception-handling/issues/159#issuecomment-857910130
- https://github.com/WebAssembly/exception-handling/pull/161

Reviewed By: tlively

Differential Revision: https://reviews.llvm.org/D104423
2021-06-17 20:34:19 -07:00
Bjorn Pettersson 4c7f820b2b Update @llvm.powi to handle different int sizes for the exponent
This can be seen as a follow up to commit 0ee439b705,
that changed the second argument of __powidf2, __powisf2 and
__powitf2 in compiler-rt from si_int to int. That was to align with
how those runtimes are defined in libgcc.
One thing that seem to have been missing in that patch was to make
sure that the rest of LLVM also handle that the argument now depends
on the size of int (not using the si_int machine mode for 32-bit).
When using __builtin_powi for a target with 16-bit int clang crashed.
And when emitting libcalls to those rtlib functions, typically when
lowering @llvm.powi), the backend would always prepare the exponent
argument as an i32 which caused miscompiles when the rtlib was
compiled with 16-bit int.

The solution used here is to use an overloaded type for the second
argument in @llvm.powi. This way clang can use the "correct" type
when lowering __builtin_powi, and then later when emitting the libcall
it is assumed that the type used in @llvm.powi matches the rtlib
function.

One thing that needed some extra attention was that when vectorizing
calls several passes did not support that several arguments could
be overloaded in the intrinsics. This patch allows overload of a
scalar operand by adding hasVectorInstrinsicOverloadedScalarOpd, with
an entry for powi.

Differential Revision: https://reviews.llvm.org/D99439
2021-06-17 09:38:28 +02:00
David Spickett 64de8763aa Revert "Implementation of global.get/set for reftypes in LLVM IR"
This reverts commit 31859f896c.

Causing SVE and RISCV-V test failures on bots.
2021-06-10 10:11:17 +00:00
Paulo Matos 31859f896c Implementation of global.get/set for reftypes in LLVM IR
This change implements new DAG notes GLOBAL_GET/GLOBAL_SET, and
lowering methods for load and stores of reference types from IR
globals. Once the lowering creates the new nodes, tablegen pattern
matches those and converts them to Wasm global.get/set.

Reviewed By: tlively

Differential Revision: https://reviews.llvm.org/D95425
2021-06-10 10:07:45 +02:00
Andy Wingo 82f92e35c6 [WebAssembly][CodeGen] IR support for WebAssembly local variables
This patch adds TargetStackID::WasmLocal.  This stack holds locations of
values that are only addressable by name -- not via a pointer to memory.
For the WebAssembly target, these objects are lowered to WebAssembly
local variables, which are managed by the WebAssembly run-time and are
not addressable by linear memory.

For the WebAssembly target IR indicates that an AllocaInst should be put
on TargetStackID::WasmLocal by putting it in the non-integral address
space WASM_ADDRESS_SPACE_WASM_VAR, with value 1.  SROA will mostly lift
these allocations to SSA locals, but any alloca that reaches instruction
selection (usually in non-optimized builds) will be assigned the new
TargetStackID there.  Loads and stores to those values are transformed
to new WebAssemblyISD::LOCAL_GET / WebAssemblyISD::LOCAL_SET nodes,
which then lower to the type-specific LOCAL_GET_I32 etc instructions via
tablegen patterns.

Differential Revision: https://reviews.llvm.org/D101140
2021-06-01 11:31:39 +02:00
Andy Wingo bc1ad6e3c4 Revert "[WebAssembly][CodeGen] IR support for WebAssembly local variables"
This reverts commit bf35f4af51.  There was
an error in a shared-library build.
2021-05-31 10:55:15 +02:00
Andy Wingo bf35f4af51 [WebAssembly][CodeGen] IR support for WebAssembly local variables
This patch adds TargetStackID::WasmLocal.  This stack holds locations of
values that are only addressable by name -- not via a pointer to memory.
For the WebAssembly target, these objects are lowered to WebAssembly
local variables, which are managed by the WebAssembly run-time and are
not addressable by linear memory.

For the WebAssembly target IR indicates that an AllocaInst should be put
on TargetStackID::WasmLocal by putting it in the non-integral address
space WASM_ADDRESS_SPACE_WASM_VAR, with value 1.  SROA will mostly lift
these allocations to SSA locals, but any alloca that reaches instruction
selection (usually in non-optimized builds) will be assigned the new
TargetStackID there.  Loads and stores to those values are transformed
to new WebAssemblyISD::LOCAL_GET / WebAssemblyISD::LOCAL_SET nodes,
which then lower to the type-specific LOCAL_GET_I32 etc instructions via
tablegen patterns.

Differential Revision: https://reviews.llvm.org/D101140
2021-05-31 10:40:38 +02:00
Andy Wingo ca5f07f8c4 Revert "[WebAssembly][CodeGen] IR support for WebAssembly local variables"
This reverts commit 00ecf18979, as it
broke the AMDGPU build.  Will reland later with a fix.
2021-05-28 12:42:12 +02:00
Andy Wingo 00ecf18979 [WebAssembly][CodeGen] IR support for WebAssembly local variables
This patch adds TargetStackID::WasmLocal.  This stack holds locations of
values that are only addressable by name -- not via a pointer to memory.
For the WebAssembly target, these objects are lowered to WebAssembly
local variables, which are managed by the WebAssembly run-time and are
not addressable by linear memory.

For the WebAssembly target IR indicates that an AllocaInst should be put
on TargetStackID::WasmLocal by putting it in the non-integral address
space WASM_ADDRESS_SPACE_WASM_VAR, with value 1.  SROA will mostly lift
these allocations to SSA locals, but any alloca that reaches instruction
selection (usually in non-optimized builds) will be assigned the new
TargetStackID there.  Loads and stores to those values are transformed
to new WebAssemblyISD::LOCAL_GET / WebAssemblyISD::LOCAL_SET nodes,
which then lower to the type-specific LOCAL_GET_I32 etc instructions via
tablegen patterns.

Differential Revision: https://reviews.llvm.org/D101140
2021-05-28 11:07:41 +02:00
Heejin Ahn a64ebb8637 [WebAssembly] Add NullifyDebugValueLists pass
`WebAssemblyDebugValueManager` does not currently handle
`DBG_VALUE_LIST`, which is a recent addition to LLVM. We tried to
nullify them within the constructor of `WebAssemblyDebugValueManager` in
D102589, but it made the class error-prone to use because it deletes
instructions within the constructor and thus invalidates existing
iterators within the BB, so the user of the class should take special
care not to use invalidated iterators. This actually caused a bug in
ExplicitLocals pass.

Instead of trying to fix ExplicitLocals pass to make the iterator usage
correct, which is possible but error-prone, this adds
NullifyDebugValueLists pass that nullifies all `DBG_VALUE_LIST`
instructions before we run WebAssembly specific passes in the backend.
We can remove this pass after we implement handlers for
`DBG_VALUE_LIST`s in `WebAssemblyDebugValueManager` and elsewhere.

Fixes https://github.com/emscripten-core/emscripten/issues/14255.

Reviewed By: dschuff

Differential Revision: https://reviews.llvm.org/D102999
2021-05-24 11:36:01 -07:00
serge-sans-paille 4ab3041acb Revert "[NFC] remove explicit default value for strboolattr attribute in tests"
This reverts commit bda6e5bee0.

See https://lab.llvm.org/buildbot/#/builders/109/builds/15424 for instance
2021-05-24 19:43:40 +02:00
serge-sans-paille bda6e5bee0 [NFC] remove explicit default value for strboolattr attribute in tests
Since d6de1e1a71, no attributes is quivalent to
setting attribute to false.

This is a preliminary commit for https://reviews.llvm.org/D99080
2021-05-24 19:31:04 +02:00
Heejin Ahn 412a3381f7 [WebAssembly] Ignore filters in Emscripten EH landingpads
We have been handling filters and landingpads incorrectly all along. We
pass clauses' (catches') types to `__cxa_find_matching_catch` in JS glue
code, which returns the thrown pointer and sets the selector using
`setTempRet0()`.

We apparently have been doing the same for filters' (exception specs')
types; we pass them to `__cxa_find_matching_catch` just the same way as
clauses. And `__cxa_find_matching_catch` treats all given types as
clauses. So it is a little surprising; maybe we intended to do something
from the JS side and didn't end up doing?

So anyway, I don't think supporting exception specs in Emscripten EH is
a priority, but this can actually cause incorrect results for normal
catches when functions are inlined and the inlined spec type has a
parent-child relationship with the catch's type.

---

The below is an example of a bug that can happen when inlining and class
hierarchy is mixed. If you are busy you can skip this part:
```
struct A {};
struct B : A {};

void bar() throw (B) { throw B(); }

void foo() {
  try {
    bar();
  } catch (A &) {
    fputs ("Expected result\n", stdout);
  }
}
```

In the unoptimized code, `bar`'s landingpad will have a filter for `B`
and `foo`'s landingpad will have a clause for `A`. But when `bar` is
inlined into `foo`, `foo`'s landingpad has both a filter for `B` and a
clause for `A`, and it passes the both types to
`__cxa_find_matching_catch`:
```
__cxa_find_matching_catch(typeinfo for B, typeinfo for A)
```
`__cxa_find_matching_catch` thinks both are clauses, and looks at the
first type `B`, which belongs to a filter. And the thrown type is `B`,
so it thinks the first type `B` is caught. But this makes it return an
incorrect selector, because it is supposed to catch the exception using
the second type `A`, which is a parent of `B`. As a result, the `foo` in
the example program above does not print "Expected result" but just
throws the exception to the caller. (This wouldn't have happened if `A`
and `B` are completely disjoint types, such as `float` and `int`)

Fixes https://bugs.llvm.org/show_bug.cgi?id=50357.

Reviewed By: dschuff, kripken

Differential Revision: https://reviews.llvm.org/D102795
2021-05-20 01:28:16 -07:00
Heejin Ahn 6e1c1dac4c [WebAssembly] Nullify DBG_VALUE_LISTs in DebugValueManager
WebAssemblyDebugValueManager class currently does not handle
DBG_VALUE_LIST instructions correctly for two reasons, which are
explained in https://bugs.llvm.org/show_bug.cgi?id=50361.

This effectively nullifies DBG_VALUE_LISTs in
WebAssemblyDebugValueManager so that the info will appear as "optimized
out" in debuggers but still be at least correct in the meantime.

Reviewed By: dschuff, jmorse

Differential Revision: https://reviews.llvm.org/D102589
2021-05-17 13:47:36 -07:00
Heejin Ahn 71fbfb499a [WebAssembly] Omit DBG_VALUE after terminator
When a stackified variable has an associated `DBG_VALUE` instruction,
DebugFixup pass adds a `DBG_VALUE` instruction after the stackified
value's last use to clear the variable's debug range info. But when the
last use instruction is a terminator, it can cause a verification
failure (when run with `-verify-machineinstrs`) because there are no
instructions allowed after a terminator.

For example:
```
%myvar = ...
DBG_VALUE target-index(wasm-operand-stack), $noreg, !"myvar", ...
BR_IF 0, %myvar, ...
DBG_VALUE $noreg, $noreg, !"myvar", ...
```
In this test, `%myvar` is stackified, so the first `DBG_VALUE`
instruction's first operand has changed to `wasm-operand-stack` to
denote it. And an additional `DBG_VALUE` instruction is added after its
last use, `BR_IF`, to signal variable `myvar` is not in the operand
stack anymore. But because the `DBG_VALUE` instruction is added after
the `BR_IF`, a terminator, it fails MachineVerifier.

`DBG_VALUE` instructions are used in `DbgEntityHistoryCalculator` to
compute value ranges to emit DWARF info, and it turns out the
`DbgEntityHistoryCalculator` terminates ranges at the end of a BB, so we
don't need to emit `DBG_VALUE` after a terminator.

Fixes https://bugs.llvm.org/show_bug.cgi?id=50175.

Reviewed By: dschuff

Differential Revision: https://reviews.llvm.org/D102309
2021-05-14 03:48:19 -07:00
Heejin Ahn 8e35a18e4a [WebAssembly] Support Emscripten EH/SjLj in Wasm64
In wasm64, the signatures of some library functions and global variables
defined in Emscripten change:
- `emscripten_longjmp`: `(i32, i32) -> ()` -> `(i64, i32) -> ()`
  This changes because the first argument is the address of a memory
  buffer. This in turn causes more changes below.
- `setThrew`: `(i32, i32) -> ()` -> `(i64, i32) -> ()`
  `emscripten_longjmp` calls `setThrew` with the i64 buffer argument as
  the first parameter.
- `__THREW__` (global var): `i32` to `i64`
  `setThrew`'s first argument is set to this `__THREW__` variable, so it
  should change to i64 as well.
- `testSetjmp`: `(i32, i32*, i32) -> (i32)` -> `(i64, i32*, i32) -> (i32)`
  In the code transformation done in this pass, the value of `__THREW__`
  is passed as the first parameter of `testSetjmp`.

This patch creates some helper functions to easily get types that become
different depending on the wasm32/wasm64, and uses them to change
various function signatures and code transformations. Also updates the
tests with WASM32/WASM64 check lines.

(Untested) Emscripten side patch: https://github.com/emscripten-core/emscripten/pull/14108

Reviewed By: aardappel

Differential Revision: https://reviews.llvm.org/D101985
2021-05-14 03:45:09 -07:00