Reland of 00bf4755.
This patches fixes the visibility and linkage information of symbols
referring to IR globals.
Emission of external declarations is now done in the first execution
of emitConstantPool rather than in emitLinkage (and a few other
places). This is the point where we have already gathered information
about used symbols (by running the MC Lower PrePass) and not yet
started emitting any functions so that any declarations that need to
be emitted are done so at the top of the file before any functions.
This changes the order of a few directives in the final asm file which
required an update to a few tests.
Reviewed By: sbc100
Differential Revision: https://reviews.llvm.org/D118995
This reverts commit 00bf4755e90c89963a135739218ef49c2417109f.
This change broke the emscripten builder (among other things):
https://ci.chromium.org/ui/p/emscripten-releases/builders/try/linux/b8823500584349280721/overview
Sample failure:
```
test_unistd_unlink (test_core.core0) ...
wasm-ld: error: symbol type mismatch: __stdio_write
>>> defined as WASM_SYMBOL_TYPE_FUNCTION in /usr/local/google/home/sbc/dev/wasm/emscripten/cache/sysroot/lib/wasm32-emscripten/libc-debug.a(__stdio_write.o)
>>> defined as WASM_SYMBOL_TYPE_DATA in /usr/local/google/home/sbc/dev/wasm/emscripten/cache/sysroot/lib/wasm32-emscripten/libc-debug.a(stderr.o)
```
This patches fixes the visibility and linkage information of symbols
referring to IR globals.
Emission of external declarations is now done in the first execution
of emitConstantPool rather than in emitLinkage (and a few other
places). This is the point where we have already gathered information
about used symbols (by running the MC Lower PrePass) and not yet
started emitting any functions so that any declarations that need to
be emitted are done so at the top of the file before any functions.
This changes the order of a few directives in the final asm file which
required an update to a few tests.
Reviewed By: sbc100
Differential Revision: https://reviews.llvm.org/D118122
This is similar to D116619, but now it handles `invoke`s. The reason we
didn't handle `invoke`s back then was we didn't support Wasm EH + Wasm
SjLj together, and the only case SjLj transformation will see `invoke`s
is when we are using Wasm EH. (In Emscripten EH, they would have been
transformed to `call`s to invoke wrappers.)
But after D117610 we support Wasm EH + Wasm SjLj together and we can
nullify `invoke`s to `setjmp` when there is no other longjmpable calls
within the function. Actually this is very unlikely to happen in
practice, because we treat destructors as longjmpable and also treat
`__cxa_end_catch` as longjmpable even if it is not.
Reviewed By: dschuff
Differential Revision: https://reviews.llvm.org/D118408
Wasm SjLj converts longjmpable calls into `invoke`s that unwind to
`%catch.longjmp.dispatch` BB, from where we check if the thrown
exception is a `longjmp`. But in case a call already has a `funclet`
attribute, i.e., it is within a catch scope, we have to unwind to its
unwind destination first to preserve the scoping structure. That will
eventually unwind to `%catch.longjmp.dispatch`, because all
`catchswitch` and `cleanupret` that unwind to caller are redirected to
`%catch.dispatch.longjmp` during Wasm SjLj transformation.
But the prevous code assumed `cleanuppad`'s parent pad was always an
instruction, and didn't handle when a `cleanuppad`'s parent is `none`.
This CL handles this case, and makes the `while` loop more intuitive by
removing `FromPad` condition and explicitly inserting `break`s.
Reviewed By: dschuff
Differential Revision: https://reviews.llvm.org/D118407
Wasm EH, used with either of Emscripten SjLj or Wasm SjLj, does not
allow `setjmp` calls to be placed within a `catch` clause, because we
don't support jumping into a `catch` block. Emscripten EH does not have
this restriction. But I think this restriction wouldn't prevent most of
use cases. This CL errors out with a clear messsage for this case.
Reviewed By: dschuff, kripken
Differential Revision: https://reviews.llvm.org/D118286
When we create an invoke wrapper call, if the original call instruction
has a `noreturn` attribute, we shouldn't copy it, because we expect
invoke wrapper calls to return. This generated incorrect `free` call
before an invoke wrapper call that calls `__cxa_throw`, because
`__cxa_throw` has `noreturn` attribute.
Reviewed By: dschuff
Differential Revision: https://reviews.llvm.org/D118274
In D117610 we treated `__cxa_end_catch` longjmpable even though it was
not to make unwind destination relationships correct. But we only need
to do this in Wasm SjLj, and doing this in Emscripten SjLj does not make
the code incorrect but add unnecessary invokes. This CL treats
`__cxa_end_catch` longjmpable only in Wasm SjLj.
Reviewed By: dschuff
Differential Revision: https://reviews.llvm.org/D117943
This is the unsigned variant of D111976, where we convert a clamped
fptoui to a fptoui.sat. Because we are unsigned, the condition this time
is only UMIN of UINT_MAX. Similarly to D111976 it handles ISD::UMIN,
ISD::SETCC/ISD::SELECT, ISD::VSELECT or ISD::SELECT_CC nodes.
This especially helps on ARM/AArch64 where the vcvt instructions
naturally saturate the result.
Differential Revision: https://reviews.llvm.org/D114964
D108960 added support for SjLj using Wasm EH instructions, which we call
Wasm SjLj going forward. (We call the old SjLj Emscripten SjLj) But it
did not support using Wasm EH and Wasm SjLj together. So far users of
Wasm EH had to use Wasm EH with Emscripten SjLj, which had a certain
limitation and it suffered from bigger code size increases as well.
This enables using Wasm EH and Wasm SjLj together.
1. This redirects `catchswitch` and `cleanupret` that unwind to caller
to `catch.dispatch.longjmp` BB, which is a `catchswitch` BB that
handles longjmps.
2. D108960 converted all longjmpable `call`s to `invokes` that unwind to
`catch.dispatch.longjmp`. This CL checks if the `call` is embedded
within another `catchpad`, and if so, makes it unwind to its nearest
parent's unwind destination, rather than `catch.dispatch.longjmp`.
This is necessary to preserve the scoping structure.
Reviewed By: dschuff
Differential Revision: https://reviews.llvm.org/D117610
Implement support for matching an index from a WebAssembly CALL
instruction. Add test.
Reviewed By: tlively
Differential Revision: https://reviews.llvm.org/D115327
This uses `changeToCall` and `changeToInvokeAndSplitBasicBlock` from
`lib/Transforms/Utils`, replacing the custom logic. One difference of
those functions from our previous logic is they delete the original
`CallInst`/`InvokeInst`, which makes them tricky to use while iterating
through instructions/BBs. So this CL gathers the candidate calls first
and run them through `changeToInvokeAndSplitBasicBlock` later.
Also this renames some variables.
Reviewed By: dschuff
Differential Revision: https://reviews.llvm.org/D116620
D107530 did a small optimization that, if a function contains `setjmp`
calls but not other calls that can `longjmp`, we don't do SjLj
transformation on those `setjmp` calls, because they don't have
possibilities of returning from `longjmp`.
But we should remove those `setjmp` calls even in that case, because
Emscripten doesn't provide that function, assuming it is lowered away by
SjLj transformation. `setjmp` always returns 0 when called directly, so
this CL replaces them with `i32 0`.
Fixes https://github.com/emscripten-core/emscripten/issues/15679.
Reviewed By: dschuff
Differential Revision: https://reviews.llvm.org/D116619
When possible, optimize TRUNCATE to generate Wasm SIMD narrow
instructions (i16x8.narrow_i32x4_u, i8x16.narrow_i16x8_u), rather than generate
lots of extract_lane and replace_lane.
Closes#50350.
This patch implements a fix to recognize global symbols that represent
WebAssembly appropriately and generate the necessary .tabletype
directives.
Reviewed By: sbc100
Differential Revision: https://reviews.llvm.org/D115511
This patch fixes an issue during SelectionDAG construction. When the
target is unable to lower the function's return value, a hidden sret
parameter is created. It is initialized and copied to a stored variable
(DemoteRegister) with CopyToReg and is later fetched with
CopyFromReg. The bug is that the chains used for each copy are
inconsistent, and thus in rare cases the scheduler may issue them out of
order.
The fix is to ensure that the CopyFromReg uses the DAG root which is set
as the chain corresponding to the initial CopyToReg.
Fixes https://llvm.org/PR52475
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D114795
This patch implements the intrinsic for ref.null.
In the process of implementing int_wasm_ref_null_func() and
int_wasm_ref_null_extern() intrinsics, it removes the redundant
HeapType.
This also causes the textual assembler syntax for ref.null to
change. Instead of receiving an argument: `func` or `extern`, the
instruction mnemonic is either ref.null_func or ref.null_extern,
without the need for a further operand.
Reviewed By: tlively
Differential Revision: https://reviews.llvm.org/D114979
As an extension to D111976, this converts clamp fptosi, clamped between
0 and (2^n)-1 to a fptoui.sat. This can greatly help on targets with
conversions that naturally saturate, such as Arm.
X86 disables the transform as some of the test cases increases in size.
A fptoui.sat necessitates a fp clamp without native support, so there is
little use in converting if the instruction is just going to be
expanded.
Differential Revision: https://reviews.llvm.org/D112428
This adds a fold in DAGCombine to create fptosi_sat from sequences for
smin(smax(fptosi(x))) nodes, where the min/max saturate the output of
the fp convert to a specific bitwidth (say INT_MIN and INT_MAX). Because
it is dealing with smin(/smax) in DAG they may currently be ISD::SMIN,
ISD::SETCC/ISD::SELECT, ISD::VSELECT or ISD::SELECT_CC nodes which need
to be handled similarly.
A shouldConvertFpToSat method was added to control when converting may
be profitable. The original fptosi will have a less strict semantics
than the fptosisat, with less values that need to produce defined
behaviour.
This especially helps on ARM/AArch64 where the vcvt instructions
naturally saturate the result.
Differential Revision: https://reviews.llvm.org/D111976
It causes builds to fail with this assert:
llvm/include/llvm/ADT/APInt.h:990:
bool llvm::APInt::operator==(const llvm::APInt &) const:
Assertion `BitWidth == RHS.BitWidth && "Comparison requires equal bit widths"' failed.
See comment on the code review.
> This adds a fold in DAGCombine to create fptosi_sat from sequences for
> smin(smax(fptosi(x))) nodes, where the min/max saturate the output of
> the fp convert to a specific bitwidth (say INT_MIN and INT_MAX). Because
> it is dealing with smin(/smax) in DAG they may currently be ISD::SMIN,
> ISD::SETCC/ISD::SELECT, ISD::VSELECT or ISD::SELECT_CC nodes which need
> to be handled similarly.
>
> A shouldConvertFpToSat method was added to control when converting may
> be profitable. The original fptosi will have a less strict semantics
> than the fptosisat, with less values that need to produce defined
> behaviour.
>
> This especially helps on ARM/AArch64 where the vcvt instructions
> naturally saturate the result.
>
> Differential Revision: https://reviews.llvm.org/D111976
This reverts commit 52ff3b009388f1bef4854f1b6470b4ec19d10b0e.
This adds a fold in DAGCombine to create fptosi_sat from sequences for
smin(smax(fptosi(x))) nodes, where the min/max saturate the output of
the fp convert to a specific bitwidth (say INT_MIN and INT_MAX). Because
it is dealing with smin(/smax) in DAG they may currently be ISD::SMIN,
ISD::SETCC/ISD::SELECT, ISD::VSELECT or ISD::SELECT_CC nodes which need
to be handled similarly.
A shouldConvertFpToSat method was added to control when converting may
be profitable. The original fptosi will have a less strict semantics
than the fptosisat, with less values that need to produce defined
behaviour.
This especially helps on ARM/AArch64 where the vcvt instructions
naturally saturate the result.
Differential Revision: https://reviews.llvm.org/D111976
Add i32x4.relaxed_trunc_f32x4_s, i32x4.relaxed_trunc_f32x4_u,
i32x4.relaxed_trunc_f64x2_s_zero, i32x4.relaxed_trunc_f64x2_u_zero.
These are only exposed as builtins, and require user opt-in.
Differential Revision: https://reviews.llvm.org/D112186
Add relaxed. f32x4.min, f32x4.max, f64x2.min, f64x2.max. These are only
exposed as builtins, and require user opt-in.
Differential Revision: https://reviews.llvm.org/D112146
Our fallback expansion for CTLZ/CTTZ relies on CTPOP. If CTPOP
isn't legal or custom for a vector type we would scalarize the
CTLZ/CTTZ. This is different than CTPOP itself which would use a
vector expansion.
This patch teaches expandCTLZ/CTTZ to rely on the vector CTPOP
expansion instead of scalarizing. To do this I had to add additional
checks to make sure the operations used by CTPOP expansions are all
supported. Some of the operations were already needed for the CTLZ/CTTZ
expansion.
This is a huge improvement to the RISCV which doesn't have a scalar
ctlz or cttz in the base ISA.
For WebAssembly, I've added Custom lowering to keep the scalarizing
behavior. I've also extended the scalarizing to CTPOP.
Differential Revision: https://reviews.llvm.org/D111919
This change implements new DAG nodes TABLE_GET/TABLE_SET, and lowering
methods for load and stores of reference types from IR arrays. These
global LLVM IR arrays represent tables at the Wasm level.
Differential Revision: https://reviews.llvm.org/D111154
Add i8x16 relaxed_swizzle instructions. These are only
exposed as builtins, and require user opt-in.
Differential Revision: https://reviews.llvm.org/D112022
This makes Wasm EH work with dynamic linking. So far we were only able
to handle destructors, which do not use any tags or LSDA info.
1. This uses `TargetExternalSymbol` for `GCC_except_tableN` symbols,
which points to the address of per-function LSDA info. It is more
convenient to use than `MCSymbol` because it can take additional
target flags.
2. When lowering `wasm_lsda` intrinsic, if PIC is enabled, make the
symbol relative to `__memory_base` and generate the `add` node. If
PIC is disabled, continue to use the absolute address.
3. Make tag symbols (`__cpp_exception` and `__c_longjmp`) undefined in
the backend, because it is hard to make it work with dynamic
linking's loading order. Instead, we make all tag symbols undefined
in the LLVM backend and import it from JS.
4. Add support for undefined tags to the linker.
Companion patches:
- https://github.com/WebAssembly/binaryen/pull/4223
- https://github.com/emscripten-core/emscripten/pull/15266
Reviewed By: sbc100
Differential Revision: https://reviews.llvm.org/D111388
The currently implementation of funcrefs is broken since it is putting
the funcref itself on the stack before the call_indirect. Instead what
should be on the stack is the constant 0, which is the index at which
we store the funcref in __funcref_call_table.
Reviewed By: tlively
Differential Revision: https://reviews.llvm.org/D111152
This reverts commit b7b4ebbcfa463a7fae61dca7cec30c5b747bdec8.
Reason: This breaks several code-size tests in Emscripten test suite
because this exports `emscripten_longjmp` for programs that didn't do it
before.
We previously had a limitation that TLS variables could not
be exported (and therefore could also not be imported). This
change removed that limitation.
Differential Revision: https://reviews.llvm.org/D108877
This is a fix on top of D106525's Case 2. In D106525, in
`runEHOnFunction` which handles Emscripten EH, We rethrow `longjmp` only
when the module has any usage of `setjmp` or `longjmp`. But now Wasm
object files are linked using wasm-ld, the module this pass sees is not
the whole program, and even if this module does not contain any
`longjmp`, another file can contain it and can be linked with the
current module. This enables the rethrowing of longjmp whenever
Emscripten SjLj is enabled, regardless of whether it is used in this
module or not.
Reviewed By: dschuff
Differential Revision: https://reviews.llvm.org/D109670
Currently, opaque pointers are supported in two forms: The
-force-opaque-pointers mode, where all pointers are opaque and
typed pointers do not exist. And as a simple ptr type that can
coexist with typed pointers.
This patch removes support for the mixed mode. You either get
typed pointers, or you get opaque pointers, but not both. In the
(current) default mode, using ptr is forbidden. In -opaque-pointers
mode, all pointers are opaque.
The motivation here is that the mixed mode introduces additional
issues that don't exist in fully opaque mode. D105155 is an example
of a design problem. Looking at D109259, it would probably need
additional work to support mixed mode (e.g. to generate GEPs for
typed base but opaque result). Mixed mode will also end up
inserting many casts between i8* and ptr, which would require
significant additional work to consistently avoid.
I don't think the mixed mode is particularly valuable, as it
doesn't align with our end goal. The only thing I've found it to
be moderately useful for is adding some opaque pointer tests in
between typed pointer tests, but I think we can live without that.
Differential Revision: https://reviews.llvm.org/D109290
Both Wasm & Emscripten SjLj handling has a restriction that `setjmp`
cannot be called indirectly. I thought we have been erroring out on
indirect uses of `setjmp`, but some recent CL disrupted the logic and
we are not erroring out anymore.
We currently
1. Collect functions that contain `setjmp` calls in `SetjmpUsers`. This
only counts direct calls:
8f77dc459e/llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp (L869-L878)
2. Run `runSjLjOnFunction` only on those `SetjmpUsers`. Within
`runSjLjOnFunction`, if we see an indirect use of `setjmp`, we error
out:
8f77dc459e/llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp (L1218-L1221)
So if there are only indirect setjmp calls within the module,
`SetjmpUsers` will be empty, and `runSjLjOnFunction` is not even entered
once. And the indirect `setjmp` call will error out at link time. So in
this CL we check for the indirect uses of `setjmp` upfront before we
enter `runSjLjOnFunction`.
Also this currently errors out on `invoke @setjmp`, which can only occur
when using Wasm EH + Wasm SjLj within a function. We recently added Wasm
SjLj support but we don't support using Wasm EH + Wasm SjLj in the same
function yet. We plan to add this support very soon, so I don't think
it's worth creating another test file just for this. (This is an error
test so it needs its own file)
Reviewed By: dschuff
Differential Revision: https://reviews.llvm.org/D109375
The change here is basically the same as in D108880: Rather than
looking at bitcasts, look at calls and their function type. We
still need to look through bitcasts to find those calls.
The change in llvm/test/CodeGen/WebAssembly/add-prototypes-conflict.ll
is due to different visitation order. add-prototypes-opaque-ptrs.ll
is a copy of add-prototypes.ll with -force-opaque-pointers.
Differential Revision: https://reviews.llvm.org/D109256
This add support for SjLj using Wasm exception handling instructions:
https://github.com/WebAssembly/exception-handling/blob/master/proposals/exception-handling/Exceptions.md
This does not yet support the mixed use of EH and SjLj within a
function. It will be added in a follow-up CL.
This currently passes all SjLj Emscripten tests for wasm0/1/2/3/s,
except for the below:
- `test_longjmp_standalone`: Uses Node
- `test_dlfcn_longjmp`: Uses NodeRAWFS
- `test_longjmp_throw`: Mixes EH and SjLj
- `test_exceptions_longjmp1`: Mixes EH and SjLj
- `test_exceptions_longjmp2`: Mixes EH and SjLj
- `test_exceptions_longjmp3`: Mixes EH and SjLj
Reviewed By: dschuff, tlively
Differential Revision: https://reviews.llvm.org/D108960
With opaque pointers, no actual bitcasts will be present. Instead,
there will be a mismatch between the call FunctionType and the
function ValueType. Change the code to collect CallBases
specifically (rather than general Uses) and compare these types.
RAUW is no longer performed, as there would no longer be any
bitcasts that can be RAUWd.
Differential Revision: https://reviews.llvm.org/D108880
Previously extra wide v4f32 to v4f64 extending loads would be legalized to v2f32
to v2f64 extending loads, which would then be scalarized by legalization. (v2f32
to v2f64 extending loads not produced by legalization were already being emitted
correctly.) Instead, mark v2f32 to v2f64 extending loads as legal and explicitly
lower them using promote_low. This regresses the addressing modes supported for
the extloads not produced by legalization, but that's a fine trade off for now.
Differential Revision: https://reviews.llvm.org/D108496
This is an improvement over D107852. We don't need to enumerate specific
function names; we can just check for `noreturn` attribute. This also
requires us to make sure `__resumeExeption` and `emscripten_longjmp`
have `noreturn` attribute too; one of them is a JS function and the
other calls a JS function so Clang does not have a way to deduce they
don't return.
This is effectively NFC, because I'm not sure if there is an additional
case this case covers; if we add a custom function call that has
`noreturn` attribute, it will be processed within the SjLj handling and
turned into `__invoke` call. So this really applies to some special
functions like `emscripten_longjmp`.
Reviewed By: dschuff
Differential Revision: https://reviews.llvm.org/D108955
There are three kinds of "rethrowing" BBs in this pass:
1. In Emscripten SjLj, after a possibly longjmping function call, we
check if the thrown longjmp corresponds to one of setjmps within the
current function. If not, we rethrow the longjmp by calling
`emscripten_longjmp`.
2. In Emscripten EH, after a possibly throwing function call, we check
if the thrown exception corresponds to the current `catch` clauses.
If not, we rethrow the exception by calling `__resumeException`.
3. When both Emscripten EH and SjLj are used, when we check for an
exception after a possibly throwing function call, it is possible
that we get not an exception but a longjmp. In this case, we
shouldn't swallow it; we should rethrow the longjmp by calling
`emscripten_longjmp`.
4. When both Emscripten EH and SjLj are used, when we check for a
longjmp after a possibly longjmping function call, it is possible
that we get not a longjmp but an exception. In this case, we
shouldn't swallot it; we should rethrow the exception by calling
`__resumeException`.
Case 1 is in Emscripten SjLj, 2 is in Emscripten EH, and 3 and 4 are
relevant when both Emscripten EH and SjLj are used. 3 and 4 were first
implemented in D106525.
We create BBs for 1, 3, and 4 in this pass. We create those BBs for
every throwing/longjmping function call, along with other BBs that
contain condition checks. What this CL does is to create a single BB
within a function for each of 1, 3, and 4 cases. These BBs are exiting
BBs in the function and thus don't have successors, so easy to be shared
between calls.
The names of BBs created are:
Case 1: `call.em.longjmp`
Case 3: `rethrow.exn`
Case 4: `rethrow.longjmp`
For the case 2 we don't currently create BBs; we only replace the
existing `resume` instruction with `call @__resumeException`. And Clang
already creates only a single `resume` BB per function and reuses it,
so we don't need to optimize this case.
Not sure what are good benchmarks for EH/SjLj, but this decreases the
size of the object file for `grfmt_jpeg.bc` (presumably from opencv) we
got from one of our users by 8.9%. Even after running `wasm-opt -O4` on
them, there is still 4.8% improvement.
Reviewed By: dschuff
Differential Revision: https://reviews.llvm.org/D108945
If the icmp is in a different block, then the register for the icmp
operand may not be initialized, as it nominally does not have
cross-block uses. Add a check that the icmp is in the same block
as the branch, which should be the common case.
This matches what X86 FastISel does:
5b6b090cf2/llvm/lib/Target/X86/X86FastISel.cpp (L1648)
The "not" transform that could have a similar issue is dropped
entirely, because it is currently dead: The incoming value is
a branch or select condition of type i1, but this code requires
an i32 to trigger.
Fixes https://bugs.llvm.org/show_bug.cgi?id=51651.
Differential Revision: https://reviews.llvm.org/D108840
When doing Emscritpen EH, if SjLj is also enabled and used and if the
thrown exception has a possiblity being a longjmp instead of an
exception, we shouldn't swallow it; we should rethrow, or relay it. It
was done in D106525 and the code is here:
8441a8eea8/llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp (L858-L898)
Here is the pseudocode of that part: (copied from comments)
```
if (%__THREW__.val == 0 || %__THREW__.val == 1)
goto %tail
else
goto %longjmp.rethrow
longjmp.rethrow: ;; This is longjmp. Rethrow it
%__threwValue.val = __threwValue
emscripten_longjmp(%__THREW__.val, %__threwValue.val);
tail: ;; Nothing happened or an exception is thrown
... Continue exception handling ...
```
If the current BB (where the `invoke` is created) has successors that
has the current BB as its PHI incoming node, now that has to change to
`tail` in the pseudocode, because `tail` is the latest BB that is
connected with the next BB, but this was missing.
Reviewed By: tlively
Differential Revision: https://reviews.llvm.org/D108785
