Tracking Issue for asm_experimental_reg

@rustbot

This tracks support for additional registers in architectures where inline assembly is already stable.
The feature gate for the issue is #![feature(asm_experimental_reg)].

About tracking issues

Tracking issues are used to record the overall progress of implementation.
They are also used as hubs connecting to other relevant issues, e.g., bugs or open design questions.
A tracking issue is however not meant for large scale discussion, questions, or bug reports about a feature.
Instead, open a dedicated issue for the specific matter and add the relevant feature gate label.
Discussion comments will get marked as off-topic or deleted.
Repeated discussions on the tracking issue may lead to the tracking issue getting locked.

Steps

Implementation (see implementation history below)
Stabilization PR (see instructions on rustc-dev-guide)

Unresolved Questions

Implementation history

s390x vreg input/output (related LLVM code)
- Implementation Support input/output in vector registers of s390x inline assembly (under asm_experimental_reg feature) #131664
- Stabilization PR stabilize s390x vector registers #154184
RISC-V reg_pair
- Implementation Support GPR pair in RISC-V inline assembly #150973
x86 {xyz}mm_reg {i,u}128 input/output (related LLVM code)
- Implementation x86: support passing u128/i128 to inline assembly #151059
- Stabilization PR Stabilize passing 128-bit integers via vector registers with asm! on x86 #159525
aarch64 vreg {i,u}128 input/output (related LLVM code)
- Implementation support passing i128 to assembly on aarch64 #154342
loongarch vreg/xreg (related LLVM code)
- Implementation rustc_target/asm: add LoongArch LSX/LASX inline asm register support #158364

Other candidates:

powerpc vreg/vsreg {i,u}128 input/output (related LLVM code) https://www.ibm.com/docs/en/openxl-c-and-cpp-aix/17.1.4?topic=functions-vec-add-u128
GPR pair on Arm and s390x
AArch64 SVE types
RISC-V RVV types

@rustbot label +A-inline-assembly +O-SystemZ +O-riscv +O-x86_32 +O-x86_64 +O-loongarch

Rollup merge of rust-lang#131664 - taiki-e:s390x-asm-vreg-inout, r=Am…

Unrolled build for rust-lang#131664

Rollup merge of #131664 - taiki-e:s390x-asm-vreg-inout, r=Amanieu

Error: Unknown labels: O-x86

Please file an issue on GitHub at triagebot if there's a problem with this bot, or reach out on #triagebot on Zulip.

Rollup merge of #131664 - taiki-e:s390x-asm-vreg-inout, r=Amanieu

Rollup merge of rust-lang#151059 - folkertdev:x86-u128-reg, r=Amanieu

Rollup merge of rust-lang#159525 - folkertdev:stabilize-x86-i128-asm,…

Unrolled build for #159525

Rollup merge of #159525 - folkertdev:stabilize-x86-i128-asm, r=Amanieu

Rollup merge of rust-lang#161865 - heiher:inline-asm-i128, r=folkertdev

Unrolled build for #161865 in rollup 161959

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Tracking Issue for asm_experimental_reg #133416

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Tracking Issue for asm_experimental_reg #133416

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rustbot commented on Jan 13, 2026

8 remaining items

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