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| author | Thomas Lively <tlively@google.com> | 2022-12-09 17:56:10 -0600 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2022-12-09 23:56:10 +0000 |
| commit | 082dbe25b7377809b1b3dc429cb334fc80fac286 (patch) | |
| tree | 62478deb4383c8f78ca648fd6ea8629494a9a113 /src/wasm/wasm-stack.cpp | |
| parent | 48959ab5a74d849e9782f54b3535c6fca69d51d7 (diff) | |
| download | binaryen-082dbe25b7377809b1b3dc429cb334fc80fac286.tar.gz binaryen-082dbe25b7377809b1b3dc429cb334fc80fac286.tar.bz2 binaryen-082dbe25b7377809b1b3dc429cb334fc80fac286.zip | |
Use non-nullable ref.cast for non-nullable input (#5335)
We switched from emitting the legacy `ref.cast_static` instruction to emitting
`ref.cast null` in #5331, but that wasn't quite correct. The legacy instruction
had polymorphic typing so that its output type was nullable if and only if its
input type was nullable. In contrast, `ref.cast null` always has a a nullable
output type.
Fix our output by instead emitting non-nullable `ref.cast` if the output should
be non-nullable. Parse `ref.cast` in binary and text forms as well. Since the IR
can only represent the legacy polymorphic semantics, disallow unsupported casts
from nullable to non-nullable references or vice versa for now.
Diffstat (limited to 'src/wasm/wasm-stack.cpp')
| -rw-r--r-- | src/wasm/wasm-stack.cpp | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/src/wasm/wasm-stack.cpp b/src/wasm/wasm-stack.cpp index c4b9598c7..db40a5980 100644 --- a/src/wasm/wasm-stack.cpp +++ b/src/wasm/wasm-stack.cpp @@ -2033,10 +2033,16 @@ void BinaryInstWriter::visitRefCast(RefCast* curr) { o << int8_t(BinaryConsts::GCPrefix); if (curr->safety == RefCast::Unsafe) { o << U32LEB(BinaryConsts::RefCastNop); + parent.writeIndexedHeapType(curr->intendedType); } else { - o << U32LEB(BinaryConsts::RefCastNull); + // Emulate legacy polymorphic behavior for now. + if (curr->ref->type.isNullable()) { + o << U32LEB(BinaryConsts::RefCastNull); + } else { + o << U32LEB(BinaryConsts::RefCast); + } + parent.writeHeapType(curr->intendedType); } - parent.writeHeapType(curr->intendedType); } void BinaryInstWriter::visitBrOn(BrOn* curr) { |