Summary:
D72308 incorrectly assumed `resume` cannot exist without a `landingpad`,
which is not true. This sets `Changed` to true whenever we make changes
to a function, including creating a call to `__resumeException` within a
function without a landing pad.
Reviewers: tlively
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73308
Summary:
WebAssembly is unique among upstream targets in that it does not at
any point use physical registers to store values. Instead, it uses
virtual registers to model positions in its value stack. This means
that some target-independent lowering activities that would use
physical registers need to use virtual registers instead for
WebAssembly and similar downstream targets. This CL generalizes the
existing `usesPhysRegsForPEI` lowering hook to
`usesPhysRegsForValues` in preparation for using it in more places.
One such place is in InstrEmitter for instructions that have variadic
defs. On register machines, it only makes sense for these defs to be
physical registers, but for WebAssembly they must be virtual registers
like any other values. This CL changes InstrEmitter to check the new
target lowering hook to determine whether variadic defs should be
physical or virtual registers.
These changes are necessary to support a generalized CALL instruction
for WebAssembly that is capable of returning an arbitrary number of
arguments. Fully implementing that instruction will require additional
changes that are described in comments here but left for a follow up
commit.
Reviewers: aheejin, dschuff, qcolombet
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71484
This change has 2 components:
Target-independent: add a method getDwarfFrameBase to TargetFrameLowering. It
describes how the Dwarf frame base will be encoded. That can be a register (the
default), the CFA (which replaces NVPTX-specific logic in DwarfCompileUnit), or
a DW_OP_WASM_location descriptr.
WebAssembly: Allow WebAssemblyFunctionInfo::getFrameRegister to return the
correct virtual register instead of FP32/SP32 after WebAssemblyReplacePhysRegs
has run. Make WebAssemblyExplicitLocals store the local it allocates for the
frame register. Use this local information to implement getDwarfFrameBase
The result is that the DW_AT_frame_base attribute is correctly encoded for each
subprogram, and each param and local variable has a correct DW_AT_location that
uses DW_OP_fbreg to refer to the frame base.
This is a reland of rG3a05c3969c18 with fixes for the expensive-checks
and Windows builds
Differential Revision: https://reviews.llvm.org/D71681
This change has 2 components:
Target-independent: add a method getDwarfFrameBase to TargetFrameLowering. It
describes how the Dwarf frame base will be encoded. That can be a register (the
default), the CFA (which replaces NVPTX-specific logic in DwarfCompileUnit), or
a DW_OP_WASM_location descriptr.
WebAssembly: Allow WebAssemblyFunctionInfo::getFrameRegister to return the
correct virtual register instead of FP32/SP32 after WebAssemblyReplacePhysRegs
has run. Make WebAssemblyExplicitLocals store the local it allocates for the
frame register. Use this local information to implement getDwarfFrameBase
The result is that the DW_AT_frame_base attribute is correctly encoded for each
subprogram, and each param and local variable has a correct DW_AT_location that
uses DW_OP_fbreg to refer to the frame base.
Differential Revision: https://reviews.llvm.org/D71681
Summary:
This patch could be treated as a rebase of D33960. It also fixes PR35547.
A fix for `llvm/test/Other/close-stderr.ll` is proposed in D68164. Seems
the consensus is that the test is passing by chance and I'm not
sure how important it is for us. So it is removed like in D33960 for now.
The rest of the test fixes are just adding `--crash` flag to `not` tool.
** The reason it fixes PR35547 is
`exit` does cleanup including calling class destructor whereas `abort`
does not do any cleanup. In multithreading environment such as ThinLTO or JIT,
threads may share states which mostly are ManagedStatic<>. If faulting thread
tearing down a class when another thread is using it, there are chances of
memory corruption. This is bad 1. It will stop error reporting like pretty
stack printer; 2. The memory corruption is distracting and nondeterministic in
terms of error message, and corruption type (depending one the timing, it
could be double free, heap free after use, etc.).
Reviewers: rnk, chandlerc, zturner, sepavloff, MaskRay, espindola
Reviewed By: rnk, MaskRay
Subscribers: wuzish, jholewinski, qcolombet, dschuff, jyknight, emaste, sdardis, nemanjai, jvesely, nhaehnle, sbc100, arichardson, jgravelle-google, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, lenary, s.egerton, pzheng, cfe-commits, MaskRay, filcab, davide, MatzeB, mehdi_amini, hiraditya, steven_wu, dexonsmith, rupprecht, seiya, llvm-commits
Tags: #llvm, #clang
Differential Revision: https://reviews.llvm.org/D67847
Append this to the existing target-features attribute on the function.
Some flags ignore existing attributes, and some overwrite them. Move
towards consistently respecting existing attributes if present. Since
target features act as a state machine on their own, append to the
function attribute. The backend default added feature list, function
attributes, and -mattr will all be appended together, and the later
features can individually toggle the earlier settings.
Summary:
Previously we didn't set `Changed` to true when there are only landing
pads but not invokes. This fixes it and we set `Changed` to true
whenever we have landing pads. (There can't be invokes without landing
pads, so that case is covered too)
The test case for this has to be a separate file because this pass is a
`ModulePass` and `Changed` is computed based on the whole module.
Reviewers: tlively
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72308
This patch attempts to peek through vectors based on the demanded bits/elt of a particular ISD::EXTRACT_VECTOR_ELT node, allowing us to avoid dependencies on ops that have no impact on the extract.
In particular this helps remove some unnecessary scalar->vector->scalar patterns.
The wasm shift patterns are annoying - @tlively has indicated that the wasm vector shift codegen are to be refactored in the near-term and isn't considered a major issue.
Reapplied after reversion at rL368660 due to PR42982 which was fixed at rGca7fdd41bda0.
Differential Revision: https://reviews.llvm.org/D65887
Summary:
The vector pattern `(a + b + 1) / 2` was previously selected to an
avgr_u instruction regardless of nuw flags, but this is incorrect in
the case where either addition may have an unsigned wrap. This CL
changes the existing pattern to require both adds to have nuw flags
and adds builtin functions and intrinsics for the avgr_u instructions
because the corrected pattern is not representable in C.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D71648
Summary:
These instructions were added to the spec proposal in
https://github.com/WebAssembly/simd/pull/126. Their semantics are
equivalent to `(a + b + 1) / 2`. The opcode for the experimental
i32x4.dot_i16x8_s is also bumped due to a collision with the
i8x16.avgr_u opcode.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71628
Summary:
The instructions were originally implemented via builtins and
intrinsics so users would have to explicitly opt-in to using
them. This was useful while were validating whether these instructions
should have been merged into the spec proposal. Now that they have
been, we can use normal codegen patterns, so the intrinsics and
builtins are no longer useful.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D71500
This is equivalent to the existing `import_name` and `import_module`
attributes which control the import names in the final wasm binary
produced by lld.
This maps the existing
This attribute currently requires a string rather than using the
symbol name for a couple of reasons:
1. Avoid confusion with static and dynamic linking which is
based on symbol name. Exporting a function from a wasm module using
this directive is orthogonal to both static and dynamic linking.
2. Avoids name mangling.
Differential Revision: https://reviews.llvm.org/D70520
Summary:
This instruction is not merged to the spec proposal, but we need it to
be implemented in the toolchain to experiment with it. It is available
only on an opt-in basis through a clang builtin.
Defined in https://github.com/WebAssembly/simd/pull/127.
Depends on D69696.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D69697
This reverts commit e5cae5692b, which
reverted 11850a6305. The original revert
was done because of breakage that was actually in a separate commit,
2ab1b8c1ec, which was also reverted and
has since been fixed and relanded.
Summary:
Introduces a clang builtins and LLVM intrinsics representing integer
min/max instructions. These instructions have not been merged to the
SIMD spec proposal yet, so they are currently opt-in only via builtins
and not produced by general pattern matching. If these instructions
are accepted into the spec proposal the builtins and intrinsics will
be replaced with normal pattern matching.
Defined in https://github.com/WebAssembly/simd/pull/27.
Reviewers: aheejin
Reviewed By: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D69696
This reverts commit 2ab1b8c1ec, it is
causing build failures on numerous bots, including
sanitizer-x86_64-linux-bootstrap-ubsan. My previous revert was for the
wrong commit.
Summary:
Fixes an ISel failure when a splatted load is used more than once. The
failure was due to the hacks we were doing in ISel lowering to
preserve the original load as the operand of a LOAD_SPLAT node. The
fix is to properly lower the splatted use of the load to a separate
LOAD_SPLAT node.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69640
Summary:
The SIMD spec does not include i64x2 comparisons, so they need to be
expanded. Using setOperationAction to expand them also causes f64x2
comparisons to be expanded, so setCondCodeAction needs to be used
instead. But since there are no legal condition codes, the legalizer
does not know how to expand the comparisons. We therefore manually
unroll the operation, taking care to fill each lane with -1 or 0
rather than 1 or 0 for consistency with the other vector comparisons.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69604
Similar to:
rG4c47617627fb
This makes the DAG behavior consistent with IR's insertelement.
https://bugs.llvm.org/show_bug.cgi?id=42689
I've tried to maintain test intent for AArch64 and WebAssembly
by replacing undef index operands with something else.
This makes the DAG behavior consistent with IR's extractelement after:
rGb32e4664a715
https://bugs.llvm.org/show_bug.cgi?id=42689
I've tried to maintain test intent for WebAssembly.
The AMDGPU test is trying to test for crashing or other bad behavior,
but I'm not sure if that's possible after this change.
Summary:
Also changes the wasm YAML format to reflect the possibility of having
multiple return types and to put the returns after the params for
consistency with the binary encoding.
Reviewers: aheejin, sbc100
Subscribers: dschuff, jgravelle-google, hiraditya, sunfish, arphaman, rupprecht, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69156
llvm-svn: 375283
Summary:
Renames `ExprType` to the more apt `BlockType` and adds a variant for
multivalue blocks. Currently non-void blocks are only generated at the
end of functions where the block return type needs to agree with the
function return type, and that remains true for multivalue
blocks. That invariant means that the actual signature does not need
to be stored in the block signature `MachineOperand` because it can be
inferred by `WebAssemblyMCInstLower` from the return type of the
parent function. `WebAssemblyMCInstLower` continues to lower block
signature operands to immediates when possible but lowers multivalue
signatures to function type symbols. The AsmParser and Disassembler
are updated to handle multivalue block types as well.
Reviewers: aheejin, dschuff, aardappel
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68889
llvm-svn: 374933
Summary:
The WebAssembly backend lowers fptoint instructions to a code sequence
that checks for overflow to avoid traps because fptoint is supposed to
be speculatable. These new builtins and intrinsics give users a way to
depend on the trapping semantics of the underlying instructions and
avoid the extra code generated normally.
Patch by coffee and tlively.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D68902
llvm-svn: 374856
Summary:
This is necessary and sufficient to get simple cases of multiple
return working with multivalue enabled. More complex cases will
require block and loop signatures to be generalized to potentially be
type indices as well.
Reviewers: aheejin, dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68684
llvm-svn: 374235
Summary:
This clang builtin and corresponding LLVM intrinsic are necessary to
expose the exact semantics of the underlying WebAssembly instruction
to users. LLVM produces a poison value if the dynamic swizzle indices
are greater than the vector size, but the WebAssembly instruction sets
the corresponding output lane to zero. Users who depend on this
behavior can safely use this builtin.
Depends on D68527.
Reviewers: aheejin, dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D68531
llvm-svn: 374189
Summary:
Adds the new v8x16.swizzle SIMD instruction as specified at
https://github.com/WebAssembly/simd/blob/master/proposals/simd/SIMD.md#swizzling-using-variable-indices.
In addition to adding swizzles as a candidate lowering in
LowerBUILD_VECTOR, also rewrites and simplifies the lowering to
minimize the number of replace_lanes necessary rather than trying to
minimize code size. This leads to more uses of v128.const instead of
splats, which is expected to increase performance.
The new code will be easier to tune once V8 implements all the vector
construction operations, and it will also be easier to add new
candidate instructions in the future if necessary.
Reviewers: aheejin, dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68527
llvm-svn: 374188
Summary:
When searching for local expression tree created by stackified
registers, for 'block' placement, we start the search from the previous
instruction of a BB's terminator. But in 'try''s case, we should start
from the previous instruction of a call that can throw, or a EH_LABEL
that precedes the call, because the return values of the call's previous
instructions can be stackified and consumed by the throwing call.
For example,
```
i32.call @foo
call @bar ; may throw
br $label0
```
In this case, if we start the search from the previous instruction of
the terminator (`br` here), we end up stopping at `call @bar` and place
a 'try' between `i32.call @foo` and `call @bar`, because `call @bar`
does not have a return value so it is not a local expression tree of
`br`.
But in this case, unlike when placing 'block's, we should start the
search from `call @bar`, because the return value of `i32.call @foo` is
stackified and used by `call @bar`.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68619
llvm-svn: 374073
Summary:
There was a bug when computing the number of unwind destination
mismatches in CFGStackify. When there are many mismatched calls that
share the same (original) destination BB, they have to be counted
separately.
This also fixes a typo and runs `fixUnwindMismatches` only when the wasm
exception handling is enabled. This is to prevent unnecessary
computations and does not change behavior.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68552
llvm-svn: 373975
Summary:
Previously, `WebAssembly::mayThrow()` assumed all inputs are global
addresses. But when intrinsics, such as `memcpy`, `memmove`, or `memset`
are lowered to external symbols in instruction selection and later
emitted as library calls. And these functions don't throw.
This patch adds handling to those memory intrinsics to `mayThrow`
function. But while most of libcalls don't throw, we can't guarantee all
of them don't throw, so currently we conservatively return true for all
other external symbols.
I think a better way to solve this problem is to embed 'nounwind' info
in `TargetLowering::CallLoweringInfo`, so that we can access the info
from the backend. This will also enable transferring 'nounwind'
properties of LLVM IR instructions. Currently we don't transfer that
info and we can only access properties of callee functions, if the
callees are within the module. Other targets don't need this info in the
backend because they do all the processing before isel, but it will help
us because that info will reduce code size increase in fixing unwind
destination mismatches in CFGStackify.
But for now we return false for these memory intrinsics and true for all
other libcalls conservatively.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68553
llvm-svn: 373967
Summary:
64-bit WebAssembly (wasm64) is not specified and not supported in the
WebAssembly backend. We do have support for it in clang, however, and
we would like to keep that support because we expect wasm64 to be
specified and supported in the future. For now add an error when
trying to use wasm64 from the backend to minimize user confusion from
unexplained crashes.
Reviewers: aheejin, dschuff, sunfish
Subscribers: sbc100, jgravelle-google, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68254
llvm-svn: 373493
Summary:
In CFGSort, we try to make EH pads have higher priorities as soon as
they are ready to be sorted, to prevent creation of unwind destination
mismatches in CFGStackify. We did that by making priority queues'
comparison function prefer EH pads, but it was possible for an EH pad
to be popped from `Preferred` queue and then not sorted immediately and
enter `Ready` queue instead in a certain condition. This patch makes
sure that special condition does not consider EH pads as its candidates.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68229
llvm-svn: 373302
Summary:
Fixing unwind mismatches for exception handling can result in splicing
existing BBs and moving some of instructions to new BBs. In this case
some of stackified def registers in the original BB can be used in the
split BB. For example, we have this BB and suppose %r0 is a stackified
register.
```
bb.1:
%r0 = call @foo
... use %r0 ...
```
After fixing unwind mismatches in CFGStackify, `bb.1` can be split and
some instructions can be moved to a newly created BB:
```
bb.1:
%r0 = call @foo
bb.split (new):
... use %r0 ...
```
In this case we should make %r0 un-stackified, because its use is now in
another BB.
When spliting a BB, this CL unstackifies all def registers that have
uses in the new split BB.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68218
llvm-svn: 373301
Summary:
Adds the new load_splat instructions as specified at
https://github.com/WebAssembly/simd/blob/master/proposals/simd/SIMD.md#load-and-splat.
DAGISel does not allow matching multiple copies of the same load in a
single pattern, so we use a new node in WebAssemblyISD to wrap loads
that should be splatted.
Depends on D67783.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67784
llvm-svn: 372655
Summary:
Large slowdowns were observed in Rust due to many small, constant
sized copies in conjunction with poorly-optimized memory.copy
implementations. Since memory.copy cannot be expected to be inlined
efficiently by engines at this time, stop using it for the smallest
copies. We continue to lower all memcpy intrinsics to memory.copy,
though.
Reviewers: aheejin, alexcrichton
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, JDevlieghere, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67639
llvm-svn: 372275
Summary:
This removes all string constants for function names and compares
functions by string directly when needed. Many of these constants are
used only once or twice so the benefit of defining them separately is
not very clear, and this actually fixes a bug.
When we already have a `malloc` declaration which is an alias to
something else within the module,
```
@malloc = weak hidden alias i8* (i32), i8* (i32)* @dlmalloc
```
(this happens compiling with emscripten with `-s WASM_OBJECT_FILES=0`
because all bc files are merged before being fed into `wasm-ld` which
runs the backend optimizations as LTO)
`Module::getFunction("malloc")` in `canLongjmp` returns `nullptr`
because `Module::getFunction` dyncasts pointer into `Function`, but the
alias is a `GlobalValue` but not a `Function`. This makes `canLongjmp`
return false for `malloc` in this case, and we end up adding a lot of
longjmp handling code around malloc. This is not only a code size
increase but actually a bug because `malloc` is used in the entry block
when preparing for setjmp tables for emscripten sjlj handling, and this
makes initial setjmp preparation, which has to happen in the entry
block, move to another split block, and this interferes with SSA update
later.
This also adds two more functions, `getTempRet0` and `setTempRet0`, in
the list of not longjmp-able functions.
Fixes https://github.com/emscripten-core/emscripten/issues/8935.
Reviewers: sbc100
Subscribers: mehdi_amini, jgravelle-google, hiraditya, sunfish, dexonsmith, dschuff, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67129
llvm-svn: 370828
Summary:
Adds clang builtins and LLVM intrinsics for these experimental
instructions. They are not implemented in engines yet, but that is ok
because the user must opt into using them by calling the builtins.
Reviewers: aheejin, dschuff
Reviewed By: aheejin
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D67020
llvm-svn: 370556
When the number of return values exceeds the number of registers available,
SelectionDAGBuilder::visitRet transforms a function's return to use a
pointer to a buffer to hold return values. When the returned value is an
operator such as extractvalue, the value may have a non-zero result number.
Add that number to the indexing when obtaining the values to store.
This fixes https://bugs.llvm.org/show_bug.cgi?id=43132.
Differential Revision: https://reviews.llvm.org/D66978
llvm-svn: 370430
Summary:
Previously we skipped uses within the same BB as a def when rebuilding
SSA after SjLj transformation. For example, before transformation,
```
for.cond:
%0 = phi i32 [ %var, %for.inc ] ...
%var = ...
br label %for.inc
for.inc: ; preds = %for.cond
call i32 @setjmp(...)
br %for.cond
```
In this BB, %var should be defined in all paths from %for.inc to make %0
valid. In the input it was true; %for.inc's only predecessor was
%for.cond. But after SjLj transformation, it is possible that %for.inc
has other predecessors that are reachable without reaching %for.cond.
```
entry.split:
...
br i1 %a, label %bb.1, label %for.inc
for.cond:
%0 = phi i32 [ %var, %for.inc ] ... ; Not valid!
%var = ...
br label %for.inc
for.inc: ; preds = %for.cond, %entry.split
call i32 @setjmp(...)
...
br %for.cond
```
In this case, we can't use %var in the `phi` instruction in %for.cond,
because %var is not defined in all paths through %for.inc (If the
control flow is %entry -> %entry.split -> %for.inc -> %for.cond, %var
has not been defined until we reach the `phi`). But the previous code
excluded users within the same BB, skipping instructions within the same
BB so they are not rewritten properly. User instructions within the same
BB also should be candidates for rewriting if they are _before_ the
original definition.
Fixes PR43097.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66729
llvm-svn: 369978
Summary:
Combine a test in lower-em-sjlj-longjmp-only.ll into lower-em-sjlj.ll,
because the test command is the same and I don't see any reason it
should be a separate file. Also converted tabs into spaces and fixed
indentations in lower-em-sjlj-sret.ll. (lower-em-sjlj.ll uses a
different test command (llc), so it couldn't be combined)
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66728
llvm-svn: 369974
This introduced a false positive MemorySanitizer warning about use of
uninitialized memory in a vectorized crc function in Chromium. That suggests
maybe something is not right with this transformation. See
https://crbug.com/992853#c7 for a reproducer.
This also reverts the follow-up commits r368307 and r368308 which
depended on this.
> This patch attempts to peek through vectors based on the demanded bits/elt of a particular ISD::EXTRACT_VECTOR_ELT node, allowing us to avoid dependencies on ops that have no impact on the extract.
>
> In particular this helps remove some unnecessary scalar->vector->scalar patterns.
>
> The wasm shift patterns are annoying - @tlively has indicated that the wasm vector shift codegen are to be refactored in the near-term and isn't considered a major issue.
>
> Differential Revision: https://reviews.llvm.org/D65887
llvm-svn: 368660
Summary:
When exceptions are repeatedly thrown in the middle of handling another
exception, we call `__clang_call_terminate` with the exception pointer
(i32) as an argument. But in case of foreign exceptions, we don't have
the pointer, so we call the function with 0. (This requires
`__clang_call_terminate` can deal with 0 argument, which will be done
later)
But previously the 0 argument was not added as a `i32.const 0` but an
immediate by mistake, causing the `call` instruction to take not an i32
but rather an exnref, because an `exnref` is left on top of the value
stack if `br_on_exn` is not taken.
```
block i32
br_on_exn 0, __cpp_exception
;; exnref is on top of stack now
i32.const 0 ;; This was missing!
call __clang_call_terminate
unreachable
end
call __clang_call_terminate ;; This takes i32 extracted by br_on_exn
```
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65475
llvm-svn: 368527
This patch attempts to peek through vectors based on the demanded bits/elt of a particular ISD::EXTRACT_VECTOR_ELT node, allowing us to avoid dependencies on ops that have no impact on the extract.
In particular this helps remove some unnecessary scalar->vector->scalar patterns.
The wasm shift patterns are annoying - @tlively has indicated that the wasm vector shift codegen are to be refactored in the near-term and isn't considered a major issue.
Differential Revision: https://reviews.llvm.org/D65887
llvm-svn: 368276
Summary:
When the WebAssembly backend encounters a return type that doesn't
fit within i32, SelectionDAG performs sret demotion, adding an
additional argument to the start of the function that contains
a pointer to an sret buffer to use instead. However, this conflicts
with the emscripten sjlj lowering pass. There we translate calls like:
```
call {i32, i32} @foo()
```
into (in pseudo-llvm)
```
%addr = @foo
call {i32, i32} @__invoke_{i32,i32}(%addr)
```
i.e. we perform an indirect call through an extra function.
However, the sret transform now transforms this into
the equivalent of
```
%addr = @foo
%sret = alloca {i32, i32}
call {i32, i32} @__invoke_{i32,i32}(%sret, %addr)
```
(while simultaneously translation the implementation of @foo as well).
Unfortunately, this doesn't work out. The __invoke_ ABI expected
the function address to be the first argument, causing crashes.
There is several possible ways to fix this:
1. Implementing the sret rewrite at the IR level as well and performing
it as part of lowering to __invoke
2. Fixing the wasm backend to recognize that __invoke has a special ABI
3. A change to the binaryen/emscripten ABI to recognize this situation
This revision implements the middle option, teaching the backend to
treat __invoke_ functions specially in sret lowering. This is achieved
by
1) Introducing a new CallingConv ID for invoke functions
2) When this CallingConv ID is seen in the backend and the first argument
is marked as sret (a function pointer would never be marked as sret),
swapping the first two arguments.
Reviewed By: tlively, aheejin
Differential Revision: https://reviews.llvm.org/D65463
llvm-svn: 367935
I managed to use the update_llc_test_checks script for this, but had to set -asm-verbose=true and then manually tweak the result (PR42882)
llvm-svn: 367787
Summary:
The allocsize attribute refers to call parameters by index.
Thus, when we add the extra parameter in sjlj lowering, we
need to increment the referenced paramater in the allocsize
attribute to avoid angering the Verifier.
Reviewed By: aheejin
Differential Revision: https://reviews.llvm.org/D65470
llvm-svn: 367765
A TYPE_INDEX operand (as used by call_indirect) used to be represented
by the InstPrinter as a symbol (e.g. .Ltype_index0@TYPE_INDEX) which
was a bit of a mismatch with the WasmObjectWriter which expects an
unnamed symbol, to receive the signature from and then turn into a
reloc.
There was really no good way to round-trip this information. An earlier
version of this patch tried to attach the signature information using
a .functype, but that ran into trouble when the symbol was re-emitted
without a name. Removing the name was a giant hack also.
The current version changes the assembly syntax to have an inline
signature spec for TYPEINDEX operands that is always unnamed, which
is much more elegant both in syntax and in implementation (as now the
assembler is able to follow the same path as the regular backend)
Reviewers: sbc100, dschuff, aheejin, jgravelle-google, sunfish, tlively
Subscribers: arphaman, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64758
llvm-svn: 367590
Summary:
return_call and return_call_indirect are only valid if the return
types of the callee and caller match. We were previously not enforcing
that, which was producing invalid modules.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65246
llvm-svn: 367339
Summary:
Add immutable WASM global `__tls_align` which stores the alignment
requirements of the TLS segment.
Add `__builtin_wasm_tls_align()` intrinsic to get this alignment in Clang.
The expected usage has now changed to:
__wasm_init_tls(memalign(__builtin_wasm_tls_align(),
__builtin_wasm_tls_size()));
Reviewers: tlively, aheejin, sbc100, sunfish, alexcrichton
Reviewed By: tlively
Subscribers: dschuff, jgravelle-google, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D65028
llvm-svn: 366624
Summary:
Add `__builtin_wasm_tls_base` so that LeakSanitizer can find the thread-local
block and scan through it for memory leaks.
Reviewers: tlively, aheejin, sbc100
Subscribers: dschuff, jgravelle-google, hiraditya, sunfish, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D64900
llvm-svn: 366475
Summary:
Currently, on Emscripten, dynamic linking is not supported with threads.
This means that if thread-local storage is used, it must be used in a
statically-linked executable. Hence, local-exec is the only possible model.
This diff compiles all TLS variables to use local-exec on Emscripten as a
temporary measure until dynamic linking is supported with threads.
The goal for this is to allow C++ types with constructors to be thread-local.
Currently, when `clang` compiles a `thread_local` variable with a constructor,
it generates `__tls_guard` variable:
@__tls_guard = internal thread_local global i8 0, align 1
As no TLS model is specified, this is treated as general-dynamic, which we do
not support (and cannot support without implementing dynamic linking support
with threads in Emscripten). As a result, any C++ constructor in `thread_local`
variables would not compile.
By compiling all `thread_local` as local-exec, `__tls_guard` will compile and
we can support C++ constructors with TLS without implementing dynamic linking
with threads.
Depends on D64537
Reviewers: tlively, aheejin, sbc100
Reviewed By: aheejin
Subscribers: dschuff, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64776
llvm-svn: 366275
Summary:
Thread local variables are placed inside a `.tdata` segment. Their symbols are
offsets from the start of the segment. The address of a thread local variable
is computed as `__tls_base` + the offset from the start of the segment.
`.tdata` segment is a passive segment and `memory.init` is used once per thread
to initialize the thread local storage.
`__tls_base` is a wasm global. Since each thread has its own wasm instance,
it is effectively thread local. Currently, `__tls_base` must be initialized
at thread startup, and so cannot be used with dynamic libraries.
`__tls_base` is to be initialized with a new linker-synthesized function,
`__wasm_init_tls`, which takes as an argument a block of memory to use as the
storage for thread locals. It then initializes the block of memory and sets
`__tls_base`. As `__wasm_init_tls` will handle the memory initialization,
the memory does not have to be zeroed.
To help allocating memory for thread-local storage, a new compiler intrinsic
is introduced: `__builtin_wasm_tls_size()`. This instrinsic function returns
the size of the thread-local storage for the current function.
The expected usage is to run something like the following upon thread startup:
__wasm_init_tls(malloc(__builtin_wasm_tls_size()));
Reviewers: tlively, aheejin, kripken, sbc100
Subscribers: dschuff, jgravelle-google, hiraditya, sunfish, jfb, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D64537
llvm-svn: 366272
Summary:
This adds missing utility methods and copy instruction handling for
`exnref` type and also adds tests.
`tee` instruction tests are missing because `isTee` is currently only
used in ExplicitLocals pass and testing that pass in mir requires
serialization of stackified registers in mir files, which is a bit
nontrivial because `MachineFunctionInfo` only has info of vreg numbers
(which are large integers) but not the mir's register numbers. But this
change is quite trivial anyway.
Reviewers: tlively
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64705
llvm-svn: 366149
Summary:
We agreed to rename `except_ref` to `exnref` for consistency with other
reference types in
https://github.com/WebAssembly/exception-handling/issues/79. This also
renames WebAssemblyInstrExceptRef.td to WebAssemblyInstrRef.td in order
to use the file for other reference types in future.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64703
llvm-svn: 366145
Summary:
This deletes the ll templates from the functions because they don't need
them (mir files need ll templates only when they have function calls or
BB names that are not numbers).
This also renames the filename to `reg-copy.mir`, because I'm planning
to add some more `reg-*.mir` soon.
Reviewers: tlively
Subscribers: dschuff, sbc100, jgravelle-google, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64704
llvm-svn: 366140
Summary:
Wasm does not currently support `llvm.clear_cache` intrinsic, and this
prints a proper error message instead of segfault.
Reviewers: dschuff, sbc100, sunfish
Subscribers: jgravelle-google, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64322
llvm-svn: 365731
Summary:
Even with functions with `no-prototype` attribute, there can be an
argument `sret` (structure return) attribute, which is an optimization
when a function return type is a struct. Fixes PR42420.
Reviewers: sbc100
Subscribers: dschuff, jgravelle-google, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64318
llvm-svn: 365426
Wasm doesn't have a direct way to lower indirectbr, so hook up the
IndirectBrExpandPass to lower indirectbr into a switch.
Fixes PR42498
Reviewers: aheejin
Differential Revision: https://reviews.llvm.org/D64161
llvm-svn: 365096
Summary:
Per feedback in D64115, simplify the test.
`hidden` is left in though, because every test in the file has it.
Reviewers: aheejin, tlively
Subscribers: dschuff, sbc100, jgravelle-google, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64117
llvm-svn: 365089
Summary:
Before, inline assembly gets mangled by the SjLj transformation.
For example, in a function with setjmp/longjmp, this LLVM IR code
call void asm sideeffect "", ""()
would be transformed into
call void @__invoke_void(void ()* asm sideeffect "", "")
This is invalid, and results in the error:
Cannot take the address of an inline asm!
In this diff, we skip the transformation for inline assembly.
Reviewers: aheejin, tlively
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64115
llvm-svn: 364985
The SDAGBuilder behavior stems from the days when we didn't have fast
math flags available in SDAG. We do now and doing the transformation in
the legalizer has the advantage that it also works for vector types.
llvm-svn: 364743
Summary:
Since the WebAssembly SIMD shift instructions take i32 operands, we
truncate the i64 operand to <2 x i64> shifts during ISel. When the i64
operand is sign extended from i32, this CL makes it so the sign
extension is dropped instead of a wrap instruction added.
Reviewers: dschuff, aheejin
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63615
llvm-svn: 364446
Summary:
Implements direct and indirect tail calls enabled by the 'tail-call'
feature in both DAG ISel and FastISel. Updates existing call tests and
adds new tests including a binary encoding test.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62877
llvm-svn: 364445
Summary:
Converting the result *.{all,any}_true to a bool at the source level
generates LLVM IR that compares the result to 0. This check is
redundant since these instructions already return either 0 or 1 and
therefore conform to the BooleanContents setting for WebAssembly. This
CL adds patterns to detect and remove such redundant operations on the
result of Boolean reductions.
Reviewers: dschuff, aheejin
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63529
llvm-svn: 363756
The current PIC support currently only works with Emscripten, so
disable it for other targets.
This is the PIC portion of https://reviews.llvm.org/D62542.
Reviewed By: dschuff, sbc100
llvm-svn: 362638
Summary:
Adjusts the index and adds a bitcast around the vector operand of
EXTRACT_VECTOR_ELT so that its lane type matches the source type of
its parent sext_inreg. Without this bitcast the ISel patterns do not
match and ISel fails.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62646
llvm-svn: 362547
Summary:
This adds support for translation of LLVM IR fence instruction. We
convert a singlethread fence to a pseudo compiler barrier which becomes
0 instructions in final binary, and a thread fence to an idempotent
atomicrmw instruction to a memory address.
Reviewers: dschuff, jfb, sunfish, tlively
Subscribers: sbc100, jgravelle-google, llvm-commits
Differential Revision: https://reviews.llvm.org/D50277
llvm-svn: 361884
Summary:
These features will both be implemented soon, so I thought I would
save time by adding the boilerplate for both of them at the same time.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D62047
llvm-svn: 361516
Summary:
In this patch, `ISD::RETURNADDR` is lowered on the emscripten target
to the new Emscripten runtime function `emscripten_return_address`, which
implements the functionality.
Patch by Guanzhong Chen
Reviewers: tlively, aheejin
Reviewed By: tlively
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62210
llvm-svn: 361454
r360889 added new llround builtin functions. This patch adds their
signatures for the WebAssembly backend.
It also adds wasm32 support to utils/update_llc_test_checks.py, since
that's the script other targets are using for their testcases for this
feature.
Differential Revision: https://reviews.llvm.org/D62207
llvm-svn: 361327
Usually this will abort fast-isel at the instruction using the
non-legal result, but if the only use is in a different basic block,
we'll incorrectly assume that the zext/sext is to i32 (rather than
i128 in this case).
Differential Revision: https://reviews.llvm.org/D61823
llvm-svn: 360616
The current PIC model for WebAssembly is more like ELF in that it
allows symbol interposition.
This means that more functions end up being addressed via the GOT
and fewer directly added to the wasm table.
One effect is a reduction in the number of wasm table entries similar
to the previous attempt in https://reviews.llvm.org/D61539 which was
reverted.
Differential Revision: https://reviews.llvm.org/D61772
llvm-svn: 360402
Add support for f16 libcalls in WebAssembly. This entails adding signatures
for the remaining F16 libcalls, and renaming gnu_f2h_ieee/gnu_h2f_ieee to
truncsfhf2/extendhfsf2 for consistency between f32 and f64/f128 (compiler-rt
already supports this).
Differential Revision: https://reviews.llvm.org/D61287
Reviewer: dschuff
llvm-svn: 359600
The WebAssembly backend needs to know the signatures of all runtime
libcall functions. This adds the signature for __stack_chk_fail which was
previously missing.
Also, make the error message for a missing libcall include the name of
the function.
Differential Revision: https://reviews.llvm.org/D59521
Reviewed By: sbc100
llvm-svn: 359505
Summary:
Extract the logic for doing reassociations
from DAGCombiner::reassociateOps into a helper
function DAGCombiner::reassociateOpsCommutative,
and use that helper to trigger reassociation
on the original operand order, or the commuted
operand order.
Codegen is not identical since the operand order will
be different when doing the reassociations for the
commuted case. That causes some unfortunate churn in
some test cases. Apart from that this should be NFC.
Reviewers: spatel, craig.topper, tstellar
Reviewed By: spatel
Subscribers: dmgreen, dschuff, jvesely, nhaehnle, javed.absar, sbc100, jgravelle-google, hiraditya, aheejin, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61199
llvm-svn: 359476
Summary:
Targets like ARM, MSP430, PPC, and SystemZ have complex behavior when
printing the address of a MachineOperand::MO_GlobalAddress. Move that
handling into a new overriden method in each base class. A virtual
method was added to the base class for handling the generic case.
Refactors a few subclasses to support the target independent %a, %c, and
%n.
The patch also contains small cleanups for AVRAsmPrinter and
SystemZAsmPrinter.
It seems that NVPTXTargetLowering is possibly missing some logic to
transform GlobalAddressSDNodes for
TargetLowering::LowerAsmOperandForConstraint to handle with "i" extended
inline assembly asm constraints.
Fixes:
- https://bugs.llvm.org/show_bug.cgi?id=41402
- https://github.com/ClangBuiltLinux/linux/issues/449
Reviewers: echristo, void
Reviewed By: void
Subscribers: void, craig.topper, jholewinski, dschuff, jyknight, dylanmckay, sdardis, nemanjai, javed.absar, sbc100, jgravelle-google, eraman, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, jrtc27, atanasyan, jsji, llvm-commits, kees, tpimh, nathanchance, peter.smith, srhines
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60887
llvm-svn: 359337
Summary:
Always convert switches to br_tables unless there is only one case,
which is equivalent to a simple branch. This reduces code size for wasm,
and we defer possible jump table optimizations to the VM.
Addresses PR41502.
Reviewers: kripken, sunfish
Subscribers: dschuff, sbc100, jgravelle-google, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60966
llvm-svn: 359038
Summary:
This way we can change the order of tests or delete some of them without
affecting tests for other functions.
Reviewers: tlively
Subscribers: sunfish, dschuff, sbc100, jgravelle-google, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60929
llvm-svn: 359036
My understanding is that once BuildMI has been called we can't fallback
to SelectionDAG.
This change moves the fallback for when getRegForValue() fails for
that target of an indirect call. This was failing in -fPIC mode when
the callee is GlobalValue.
Add a test case that tickles this.
Differential Revision: https://reviews.llvm.org/D60908
llvm-svn: 358793
Summary: This brings the backend in line with Clang.
Reviewers: aheejin, dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60594
llvm-svn: 358310
Summary:
Linearing the control flow by placing `try`/`end_try` markers can create
mismatches in unwind destinations. This patch resolves these mismatches
by wrapping those instructions with an incorrect unwind destination with
a nested `try`/`catch`/`end_try` and branching to the right destination
within the new catch block.
Reviewers: dschuff
Subscribers: sunfish, sbc100, jgravelle-google, chrib, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D48345
llvm-svn: 357343
Summary:
While this does not change any final output, this will greatly simplify
ixing unwind destination mismatches in CFGStackify (D48345), because we
have to create some new registers there.
Reviewers: dschuff
Subscribers: sunfish, sbc100, jgravelle-google, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59652
llvm-svn: 357342
Summary:
Currently we create a routing block to the dispatch block for every
predecessor of every entry. So the total number of routing blocks
created will be (# of preds) * (# of entries). But we don't need to do
this: we need at most 2 routing blocks per loop entry, one for when the
predecessor is inside the loop and one for it is outside the loop. (We
can't merge these into one because this will creates another loop cycle
between blocks inside and blocks outside) This patch fixes this and
creates at most 2 routing blocks per entry.
This also renames variable `Split` to `Routing`, which I think is a bit
clearer.
Reviewers: kripken
Subscribers: sunfish, dschuff, sbc100, jgravelle-google, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59462
llvm-svn: 357337
Summary:
This feature is not actually used for anything in the WebAssembly
backend, but adding it allows users to get it into the target features
sections of their objects, which makes these objects
future-compatible.
Reviewers: aheejin, dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, jdoerfert, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D60013
llvm-svn: 357321
Summary:
This fixes crashes when a BB in which an END_LOOP is to be placed is
unreachable and does not have any predecessors. Fixes PR41307.
Reviewers: dschuff
Subscribers: yurydelendik, sbc100, jgravelle-google, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60004
llvm-svn: 357303
Summary:
It does not currently make sense to use WebAssembly features in some functions
but not others, so this CL adds an IR pass that takes the union of all used
feature sets and applies it to each function in the module. This allows us to
prevent atomics from being lowered away if some function has opted in to using
them. When atomics is not enabled anywhere, we detect whether there exists any
atomic operations or thread local storage that would be stripped and disallow
linking with objects that contain atomics if and only if atomics or tls are
stripped. When atomics is enabled, mark it as used but do not require it of
other objects in the link. These changes allow libraries that do not use atomics
to be built once and linked into both single-threaded and multithreaded
binaries.
Reviewers: aheejin, sbc100, dschuff
Subscribers: jgravelle-google, hiraditya, sunfish, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59625
llvm-svn: 357226
This change implements lowering of references global symbols in PIC
mode.
This change implements lowering of global references in PIC mode using a
new @GOT reference type. @GOT references can be used with function or
data symbol names combined with the get_global instruction. In this case
the linker will insert the wasm global that stores the address of the
symbol (either in memory for data symbols or in the wasm table for
function symbols).
For now I'm continuing to use the R_WASM_GLOBAL_INDEX_LEB relocation
type for this type of reference which means that this relocation type
can refer to either a global or a function or data symbol. We could
choose to introduce specific relocation types for GOT entries in the
future. See the current dynamic linking proposal:
https://github.com/WebAssembly/tool-conventions/blob/master/DynamicLinking.md
Differential Revision: https://reviews.llvm.org/D54647
llvm-svn: 357022
Summary:
`WebAssembly::analyzeBranch` now does not analyze anything if the
function is CFG stackified. We were previously doing similar things by
checking if a branch's operand is whether an integer or an MBB, but this
failed to bail out when a BB did not have any terminators.
Consider this case:
```
bb0:
try $label0
call @foo // unwinds to %ehpad
bb1:
...
br $label0 // jumps to %cont. can be deleted
ehpad:
catch
...
cont:
end_try
```
Here `br $label0` will be deleted in CFGStackify's
`removeUnnecessaryInstrs` function, because we jump to the %cont block
even without the branch. But in this case, MachineVerifier fails to
verify this, because `ehpad` is not a successor of `bb1` even if `bb1`
does not have any terminators. MachineVerifier incorrectly thinks `bb1`
falls through to the next block.
This pass now consistently rejects all analysis after CFGStackify
whether a BB has terminators or not, also making the MachineVerifier
work. (MachineVerifier does not try to verify relationships between BBs
if `analyzeBranch` fails, the behavior we want after CFGStackify.)
This also adds a new option `-wasm-disable-ehpad-sort` for testing. This
option helps create the sorted order we want to test, and without the
fix in this patch, the tests in cfg-stackify-eh.ll fail at
MachineVerifier with `-wasm-disable-ehpad-sort`.
Reviewers: dschuff
Subscribers: sunfish, sbc100, jgravelle-google, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59740
llvm-svn: 357015
Summary:
This adds `CFGStackified` field and its serialization to
WebAssemblyFunctionInfo.
Reviewers: dschuff
Subscribers: sunfish, sbc100, jgravelle-google, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59747
llvm-svn: 357011
Summary:
The framework for supporting target-specific MachineFunctionInfo was
added in r356215. This adds serialization support for
WebAssemblyFunctionInfo on top of that. This patch only adds the
framework and does not actually serialize anything at this point; we
have to add YAML mapping later for the fields in WebAssemblyFunctionInfo
we want to serialize if necessary.
Reviewers: dschuff, arsenm
Subscribers: sunfish, wdng, sbc100, jgravelle-google, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59737
llvm-svn: 357009
Summary:
When TRY and LOOP markers are in the same BB and END_TRY and END_LOOP
markers are in the same BB, END_TRY should be _before_ END_LOOP, because
LOOP is always before TRY if they are in the same BB. (TRY is placed in
the latest possible position, whereas LOOP is in the earliest possible
position.)
Reviewers: dschuff
Subscribers: sunfish, sbc100, jgravelle-google, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59751
llvm-svn: 357008
Summary:
Before we placed all TRY/END_TRY markers before placing BLOCK/END_BLOCK
markers. This couldn't handle this case:
```
bb0:
br bb2
bb1: // nearest common dominator of bb3 and bb4
br_if ... bb3
br bb4
bb2:
...
bb3:
call @foo // unwinds to ehpad
bb4:
call @bar // unwinds to ehpad
ehpad:
catch
...
```
When we placed TRY markers, we placed it in bb1 because it is the
nearest common dominator of bb3 and bb4. But because bb0 jumps to bb2,
when we placed block markers, we ended up with interleaved scopes like
```
block
try
end_block
catch
end_try
```
which was not correct.
This patch fixes the bug by placing BLOCK and TRY markers in one pass
while iterating BBs in a function. This also adds some more routines to
`placeTryMarkers`, because we now have to assume that there can be
previously placed BLOCK and END_BLOCK.
Reviewers: dschuff
Subscribers: sunfish, sbc100, jgravelle-google, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59739
llvm-svn: 357007
Summary:
Implements a new target features section in assembly and object files
that records what features are used, required, and disallowed in
WebAssembly objects. The linker uses this information to ensure that
all objects participating in a link are feature-compatible and records
the set of used features in the output binary for use by optimizers
and other tools later in the toolchain.
The "atomics" feature is always required or disallowed to prevent
linking code with stripped atomics into multithreaded binaries. Other
features are marked used if they are enabled globally or on any
function in a module.
Future CLs will add linker flags for ignoring feature compatibility
checks and for specifying the set of allowed features, implement using
the presence of the "atomics" feature to control the type of memory
and segments in the linked binary, and add front-end flags for
relaxing the linkage policy for atomics.
Reviewers: aheejin, sbc100, dschuff
Subscribers: jgravelle-google, hiraditya, sunfish, mgrang, jfb, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59173
llvm-svn: 356610
Summary:
This adds `preds` comment lines to BB names for readability, while also
fixes some of existing incorrect comment lines. Also deletes a few
unnecessary attributes. Autogenerated by `opt`.
Reviewers: kripken
Subscribers: dschuff, sbc100, jgravelle-google, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59456
llvm-svn: 356439
Summary:
After r355981, intrinsic arguments that are immediate values should be
marked as `ImmArg`.
Reviewers: dschuff, tlively
Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59447
llvm-svn: 356437
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
llvm-svn: 356316
Summary:
Rewrite WebAssemblyFixIrreducibleControlFlow to a simpler and cleaner
design, which directly computes reachability and other properties
itself. This avoids previous complexity and bugs. (The new graph
analyses are very similar to how the Relooper algorithm would find loop
entries and so forth.)
This fixes a few bugs, including where we had a false positive and
thought fannkuch was irreducible when it was not, which made us much
larger and slower there, and a reverse bug where we missed
irreducibility. On fannkuch, we used to be 44% slower than asm2wasm and
are now 4% faster.
Reviewers: aheejin
Subscribers: jdoerfert, mgrang, dschuff, sbc100, jgravelle-google, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D58919
Patch by Alon Zakai (kripken)
llvm-svn: 356313
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
llvm-svn: 355996
Summary:
Uses the named operands tablegen feature to look up the indices of
offset, address, and p2align operands for all load and store
instructions. This replaces brittle, incorrect logic for identifying
loads and store when eliminating frame indices, which previously
crashed on bulk-memory ops. It also cleans up the SetP2Alignment pass.
Reviewers: aheejin, dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59007
llvm-svn: 355770
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
llvm-svn: 355296
Summary:
This prevents crashes in instruction selection when these operations
are used. The tests check that the scalar version of the instruction
is used where applicable, although some expansions do not use the
scalar version.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58859
llvm-svn: 355261
Summary:
In the clang UI, replaces -mthread-model posix with -matomics as the
source of truth on threading. In the backend, replaces
-thread-model=posix with the atomics target feature, which is now
collected on the WebAssemblyTargetMachine along with all other used
features. These collected features will also be used to emit the
target features section in the future.
The default configuration for the backend is thread-model=posix and no
atomics, which was previously an invalid configuration. This change
makes the default valid because the thread model is ignored.
A side effect of this change is that objects are never emitted with
passive segments. It will instead be up to the linker to decide
whether sections should be active or passive based on whether atomics
are used in the final link.
Reviewers: aheejin, sbc100, dschuff
Subscribers: mehdi_amini, jgravelle-google, hiraditya, sunfish, steven_wu, dexonsmith, rupprecht, jfb, jdoerfert, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D58742
llvm-svn: 355112
Summary:
When creating `ScopeTops` info for `try` ~ `catch` ~ `end_try`, we
should create not only `end_try` -> `try` mapping but also `catch` ->
`try` mapping as well. If this is not created, `block` and `end_block`
markers later added may span across an existing `catch`, resulting in
the incorrect code like:
```
try
block --| (X)
catch |
end_block --|
end_try
```
Reviewers: dschuff
Subscribers: sunfish, sbc100, jgravelle-google, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58605
llvm-svn: 354945
Summary:
This removes unnecessary instructions after TRY marker placement. There
are two cases:
- `end`/`end_block` can be removed if they overlap with `try`/`end_try`
and they have the same return types.
- `br` right before `catch` that branches to after `end_try` can be
deleted.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58591
llvm-svn: 354939
For outgoing varargs arguments, it's necessary to check the OrigAlign field
of the corresponding OutputArg entry to determine argument alignment, rather
than just computing an alignment from the argument value type. This is
because types like fp128 are split into multiple argument values, with
narrower types that don't reflect the ABI alignment of the full fp128.
This fixes the printf("printfL: %4.*Lf\n", 2, lval); testcase.
Differential Revision: https://reviews.llvm.org/D58656
llvm-svn: 354846
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
llvm-svn: 354844
Summary:
- Indent check lines to easily figure out try-catch-end structure
- Add the original C++ code the tests were genereated from
- Add a few more lines to make the structure more readable
- Rename a couple function / structures
- Add label and branch annotations to cfg-stackify-eh.ll
- Temporarily delete check lines for `test1` in `cfg-stackify-eh.ll`
because it will be updated in a later CL soon and there's no point of
making it look better here
Reviewers: dschuff
Subscribers: sunfish, sbc100, jgravelle-google, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58562
llvm-svn: 354842
Fixes https://bugs.llvm.org/show_bug.cgi?id=40805 introduced by
patterns added in D53676.
I'm removing the patterns entirely here, as they are not correct
in the general case. If necessary something more specific can be
added in the future.
Differential Revision: https://reviews.llvm.org/D58575
llvm-svn: 354733
Previously if we couldn't derive a prototype for a "no-prototype"
function from C we would leave it as is:
void foo(...)
With this change we instead give is an empty signature and remove
the "no-prototype" attribute.
This fixes the current wasm waterfall test failure.
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58488
llvm-svn: 354544
When we can't determine with certainty the signature of a function
import we pick the fist signature we find rather than error'ing out.
The resulting program might not do what is expected since we might pick
the wrong signature. However since undefined behavior in C to use the
same function with different signatures this seems better than refusing
to compile such programs.
Fixes PR40472
Differential Revision: https://reviews.llvm.org/D58304
llvm-svn: 354523
Summary:
Rename MemoryIndex to InitFlags and implement logic for determining
data segment layout in ObjectYAML and MC. Also adds a "passive" flag
for the .section assembler directive although this cannot be assembled
yet because the assembler does not support data sections.
Reviewers: sbc100, aardappel, aheejin, dschuff
Subscribers: jgravelle-google, hiraditya, sunfish, rupprecht, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D57938
llvm-svn: 354397
Summary:
The custom lowering introduced in rL352592 creates build_vector nodes
with negative i32 operands, but these operands did not meet the value
range constraints necessary to match build_vector nodes. This CL fixes
the issue by removing the unnecessary constraints.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish
Differential Revision: https://reviews.llvm.org/D57481
llvm-svn: 352813
Summary:
Fixes PR40267, in which the removed assertion was triggering on
perfectly valid IR. As far as I can tell, constant out of bounds
indices should be allowed when splitting extract_vector_elt, since
they will simply be propagated as out of bounds indices in the
resulting split vector and handled appropriately elsewhere.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya
Differential Revision: https://reviews.llvm.org/D57471
llvm-svn: 352702
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
llvm-svn: 352681
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
llvm-svn: 352598
Summary:
Implements custom lowering logic that finds the optimal value for the
initial splat of the vector and either uses it or uses v128.const if
it is available and if it would produce smaller code. This logic
replaces large TableGen ISEL patterns that would lower all non-splat
BUILD_VECTORs into a splat followed by a fixed number of replace_lane
instructions. This CL fixes PR39685.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D56633
llvm-svn: 352592
Re-enable the code to rewrite main-function signatures into
"int main(int argc, char *argv[])", but limited to only handling
the case of "int main(void)", so that it doesn't silently strip
an argument in the "int main(int argc, char *argv[], char *envp[])"
case.
This allows main to be called by C startup code, since WebAssembly
requires caller and callee signatures to match, so it can't rely
on passing main a different number of arguments than it expects.
Differential Revision: https://reviews.llvm.org/D57323
llvm-svn: 352479
Previously we were only handling bitcast operations, however
prototypeless functions can also appear in other places such as
comparisons and as function params.
Switch to using replaceAllUsesWith() to replace the prototype-less
function uses. This new approach results in some redundant bitcasting
but is much simpler and handles all cases.
Differential Revision: https://reviews.llvm.org/D56938
llvm-svn: 352445
Heejin Ahn