Stream: git-wasmtime

Topic: wasmtime / issue #12087 Allow using TLSDESC TLS access fo...

Wasmtime GitHub notifications bot (Nov 25 2025 at 13:16):

bjorn3 opened issue #12087:

Feature

See title

Benefit

TLSDESC is a more efficient alternative to the traditional __tls_get_addr that is used for the global-dynamic tls model. TLSDESC is already mandatory on arm64. They were introduced relatively recently on x86 (2008, but with a glibc bugfix in 2024) and riscv (2024), so we should keep them optional for the time being.

Implementation

Add the required relocation types and adapt the TLS access binemit code as relevant.

Alternatives

Not support this and accept slower TLS accesses.

Wasmtime GitHub notifications bot (Nov 25 2025 at 13:16):

bjorn3 edited issue #12087:

Feature

See title

Benefit

TLSDESC is a more efficient alternative to the traditional __tls_get_addr that is used for the global-dynamic tls model. TLSDESC is already mandatory on arm64. They were introduced relatively recently on x86 (2008, but with a glibc bugfix in 2024) and riscv (2024), so we should keep them optional for the time being. https://github.com/riscv-non-isa/riscv-elf-psabi-doc/issues/94 links a bunch of useful documents.

Implementation

Add the required relocation types and adapt the TLS access binemit code as relevant.

Alternatives

Not support this and accept slower TLS accesses.

Wasmtime GitHub notifications bot (Nov 25 2025 at 13:18):

bjorn3 edited issue #12087:

Feature

See title

Benefit

TLSDESC is a more efficient alternative to the traditional __tls_get_addr that is used for the global-dynamic tls model. TLSDESC is already mandatory on arm64. They were introduced relatively recently on x86 (2008, but with a glibc bugfix in 2024) and riscv (2024), so we should keep them optional for the time being. https://github.com/riscv-non-isa/riscv-elf-psabi-doc/issues/94 links a bunch of useful documents. Also cc https://github.com/rust-lang/rust/pull/132480

Implementation

Add the required relocation types and adapt the TLS access binemit code as relevant.

Alternatives

Not support this and accept slower TLS accesses.

Wasmtime GitHub notifications bot (Dec 04 2025 at 17:38):

fitzgen added the cranelift:area:riscv64 label to Issue #12087.

Wasmtime GitHub notifications bot (Dec 04 2025 at 17:38):

fitzgen added the cranelift:area:x86 label to Issue #12087.

Wasmtime GitHub notifications bot (Dec 04 2025 at 17:38):

fitzgen added the cranelift label to Issue #12087.

Last updated: Dec 06 2025 at 07:03 UTC