Mark s390x condition code register as clobbered in inline assembly by taiki-e · Pull Request #111331 · rust-lang/rust (original) (raw)

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rustbot added S-waiting-on-review

Status: Awaiting review from the assignee but also interested parties.

T-compiler

Relevant to the compiler team, which will review and decide on the PR/issue.

labels

May 8, 2023

Not directly related to this PR, but for clobber_abi support we'll probably need a way to mark the access registers as clobbered since they are volatile according to the calling convention.

📌 Commit e61bb88 has been approved by Amanieu

It is now in the queue for this repository.

bors added S-waiting-on-bors

Status: Waiting on bors to run and complete tests. Bors will change the label on completion.

and removed S-waiting-on-review

Status: Awaiting review from the assignee but also interested parties.

labels

May 8, 2023

This looks correct to me. Thanks for taking care of this!

bors added a commit to rust-lang-ci/rust that referenced this pull request

May 8, 2023

Rollup of 7 pull requests

Successful merges:

rust-lang#105354 (Add deployment-target --print flag for Apple targets)
rust-lang#110377 (Update max_atomic_width of armv7r and armv7_sony_vita targets to 64.)
rust-lang#110638 (STD support for PSVita)
rust-lang#111211 (Don't compute trait super bounds unless they're positive)
rust-lang#111315 (Remove identity_future from stdlib)
rust-lang#111331 (Mark s390x condition code register as clobbered in inline assembly)
rust-lang#111332 (Improve inline asm for LoongArch)

Failed merges:

r? @ghost @rustbot modify labels: rollup

GuillaumeGomez added a commit to GuillaumeGomez/rust that referenced this pull request

Oct 1, 2024

Support clobber_abi and vector/access registers (clobber-only) in s390x inline assembly

This supports clobber_abi which is one of the requirements of stabilization mentioned in rust-lang#93335.

This also supports vector registers (as vreg) and access registers (as areg) as clobber-only, which need to support clobbering of them to implement clobber_abi.

Refs:

"1.2.1.1. Register Preservation Rules" section in ELF Application Binary Interface s390x Supplement, Version 1.6.1 (lzsabi_s390x.pdf in https://github.com/IBM/s390x-abi/releases/tag/v1.6.1)
Register definition in LLVM:
- Vector registers https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/SystemZ/SystemZRegisterInfo.td#L249
- Access registers https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/SystemZ/SystemZRegisterInfo.td#L332

I have three questions:

ELF Application Binary Interface s390x Supplement says that cc (condition code, bits 18-19 of PSW) is "Volatile". However, we do not have a register class for cc and instead mark cc as clobbered unless preserves_flags is specified (rust-lang#111331). Therefore, in the current implementation, if both preserves_flags and clobber_abi are specified, cc is not marked as clobbered. Is this okay? Or even if preserves_flags is used, should cc be marked as clobbered if clobber_abi is used? UPDATE: resolved rust-lang#130630 (comment)
ELF Application Binary Interface s390x Supplement says that pm (program mask, bits 20-23 of PSW) is "Cleared". There does not appear to be any registers associated with this in either LLVM or GCC, so at this point I don't see any way other than to just ignore it. Is this okay as-is? UPDATE: resolved rust-lang#130630 (comment)
Is "areg" a good name for register class name for access registers? It may be a bit confusing between that and reg_addr, which uses the “a” constraint (rust-lang#119431)...

Note:

GCC seems to recognize only a0 and a1, and using a[2-15] causes errors. Given that cg_gcc has a similar problem with other architecture (rust-lang/rustc_codegen_gcc#485), I don't feel this is a blocker for this PR, but it is worth mentioning here.
vreg should be able to accept #[repr(simd)] types as input if the vector target feature added in rust-lang#127506 is enabled, but core_arch has no s390x vector type and both #[repr(simd)] and core::simd are unstable, so I have not implemented it in this PR. EDIT: And supporting it is probably more complex than doing the equivalent on other architectures... rust-lang#88245 (comment)

cc @uweigand

r? @Amanieu

@rustbot label +O-SystemZ

rust-timer added a commit to rust-lang-ci/rust that referenced this pull request

Oct 1, 2024

Rollup merge of rust-lang#130630 - taiki-e:s390x-clobber-abi, r=Amanieu

Support clobber_abi and vector/access registers (clobber-only) in s390x inline assembly

This supports clobber_abi which is one of the requirements of stabilization mentioned in rust-lang#93335.

This also supports vector registers (as vreg) and access registers (as areg) as clobber-only, which need to support clobbering of them to implement clobber_abi.

Refs:

"1.2.1.1. Register Preservation Rules" section in ELF Application Binary Interface s390x Supplement, Version 1.6.1 (lzsabi_s390x.pdf in https://github.com/IBM/s390x-abi/releases/tag/v1.6.1)
Register definition in LLVM:
- Vector registers https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/SystemZ/SystemZRegisterInfo.td#L249
- Access registers https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/SystemZ/SystemZRegisterInfo.td#L332

I have three questions:

ELF Application Binary Interface s390x Supplement says that cc (condition code, bits 18-19 of PSW) is "Volatile". However, we do not have a register class for cc and instead mark cc as clobbered unless preserves_flags is specified (rust-lang#111331). Therefore, in the current implementation, if both preserves_flags and clobber_abi are specified, cc is not marked as clobbered. Is this okay? Or even if preserves_flags is used, should cc be marked as clobbered if clobber_abi is used? UPDATE: resolved rust-lang#130630 (comment)
ELF Application Binary Interface s390x Supplement says that pm (program mask, bits 20-23 of PSW) is "Cleared". There does not appear to be any registers associated with this in either LLVM or GCC, so at this point I don't see any way other than to just ignore it. Is this okay as-is? UPDATE: resolved rust-lang#130630 (comment)
Is "areg" a good name for register class name for access registers? It may be a bit confusing between that and reg_addr, which uses the “a” constraint (rust-lang#119431)...

Note:

GCC seems to recognize only a0 and a1, and using a[2-15] causes errors. Given that cg_gcc has a similar problem with other architecture (rust-lang/rustc_codegen_gcc#485), I don't feel this is a blocker for this PR, but it is worth mentioning here.
vreg should be able to accept #[repr(simd)] types as input if the vector target feature added in rust-lang#127506 is enabled, but core_arch has no s390x vector type and both #[repr(simd)] and core::simd are unstable, so I have not implemented it in this PR. EDIT: And supporting it is probably more complex than doing the equivalent on other architectures... rust-lang#88245 (comment)

cc @uweigand

r? @Amanieu

@rustbot label +O-SystemZ

This was referenced

Oct 4, 2024

antoyo pushed a commit to rust-lang/rustc_codegen_gcc that referenced this pull request

Oct 9, 2024

Support clobber_abi and vector/access registers (clobber-only) in s390x inline assembly

This supports clobber_abi which is one of the requirements of stabilization mentioned in #93335.

This also supports vector registers (as vreg) and access registers (as areg) as clobber-only, which need to support clobbering of them to implement clobber_abi.

Refs:

"1.2.1.1. Register Preservation Rules" section in ELF Application Binary Interface s390x Supplement, Version 1.6.1 (lzsabi_s390x.pdf in https://github.com/IBM/s390x-abi/releases/tag/v1.6.1)
Register definition in LLVM:
- Vector registers https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/SystemZ/SystemZRegisterInfo.td#L249
- Access registers https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/SystemZ/SystemZRegisterInfo.td#L332

I have three questions:

ELF Application Binary Interface s390x Supplement says that cc (condition code, bits 18-19 of PSW) is "Volatile". However, we do not have a register class for cc and instead mark cc as clobbered unless preserves_flags is specified (rust-lang/rust#111331). Therefore, in the current implementation, if both preserves_flags and clobber_abi are specified, cc is not marked as clobbered. Is this okay? Or even if preserves_flags is used, should cc be marked as clobbered if clobber_abi is used? UPDATE: resolved rust-lang/rust#130630 (comment)
ELF Application Binary Interface s390x Supplement says that pm (program mask, bits 20-23 of PSW) is "Cleared". There does not appear to be any registers associated with this in either LLVM or GCC, so at this point I don't see any way other than to just ignore it. Is this okay as-is? UPDATE: resolved rust-lang/rust#130630 (comment)
Is "areg" a good name for register class name for access registers? It may be a bit confusing between that and reg_addr, which uses the “a” constraint (rust-lang/rust#119431)...

Note:

GCC seems to recognize only a0 and a1, and using a[2-15] causes errors. Given that cg_gcc has a similar problem with other architecture (#485), I don't feel this is a blocker for this PR, but it is worth mentioning here.
vreg should be able to accept #[repr(simd)] types as input if the vector target feature added in rust-lang/rust#127506 is enabled, but core_arch has no s390x vector type and both #[repr(simd)] and core::simd are unstable, so I have not implemented it in this PR. EDIT: And supporting it is probably more complex than doing the equivalent on other architectures... rust-lang/rust#88245 (comment)

cc @uweigand

r? @Amanieu

@rustbot label +O-SystemZ

matthiaskrgr added a commit to matthiaskrgr/rust that referenced this pull request

Nov 9, 2024

…nieu

Stabilize s390x inline assembly

This stabilizes inline assembly for s390x (SystemZ).

Corresponding reference PR: rust-lang/reference#1643

From the requirements of stabilization mentioned in rust-lang#93335

Each architecture needs to be reviewed before stabilization:

It must have clobber_abi.

Done in rust-lang#130630.

It must be possible to clobber every register that is normally clobbered by a function call.

Done in the PR that added support for clobber_abi.

Generally review that the exposed register classes make sense.

The followings can be used as input/output:

reg (r[0-10], r[12-14]): General-purpose register
reg_addr (r[1-10], r[12-14]): General-purpose register except r0 which is evaluated as zero in an address context

This class is needed because r0, which may be allocated when using the reg class, cannot be used as a register in certain contexts. This is identical to the a constraint in LLVM and GCC. See rust-lang#119431 for details.
freg (f[0-15]): Floating-point register

The followings are clobber-only:

vreg (v[0-31]): Vector register

Technically vreg should be able to accept #[repr(simd)] types as input/output if the unstable vector target feature added is enabled, but core::arch has no s390x vector type and both #[repr(simd)] and core::simd are unstable. Everything related is unstable, so the fact that this is currently a clobber-only should not be considered a stabilization blocker. (rust-lang#130869 tracks unstable stuff here)
areg (a[2-15]): Access register

All of the above register classes except reg_addr are needed for clobber_abi.

The followings cannot be used as operands for inline asm (see also getReservedRegs and SystemZELFRegisters in LLVM):

r11: frame pointer
r15: stack pointer
a0, a1: Reserved for system use
c[0-15] (control register) Reserved by the kernel

Although not listed in the above requirements, preserves_flags is implemented in rust-lang#111331.

cc @uweigand

r? @Amanieu

@rustbot label +O-SystemZ +A-inline-assembly

workingjubilee added a commit to workingjubilee/rustc that referenced this pull request

Nov 10, 2024

…nieu

Stabilize s390x inline assembly

This stabilizes inline assembly for s390x (SystemZ).

Corresponding reference PR: rust-lang/reference#1643

From the requirements of stabilization mentioned in rust-lang#93335

Each architecture needs to be reviewed before stabilization:

It must have clobber_abi.

Done in rust-lang#130630.

It must be possible to clobber every register that is normally clobbered by a function call.

Done in the PR that added support for clobber_abi.

Generally review that the exposed register classes make sense.

The followings can be used as input/output:

reg (r[0-10], r[12-14]): General-purpose register
reg_addr (r[1-10], r[12-14]): General-purpose register except r0 which is evaluated as zero in an address context

This class is needed because r0, which may be allocated when using the reg class, cannot be used as a register in certain contexts. This is identical to the a constraint in LLVM and GCC. See rust-lang#119431 for details.
freg (f[0-15]): Floating-point register

The followings are clobber-only:

vreg (v[0-31]): Vector register

Technically vreg should be able to accept #[repr(simd)] types as input/output if the unstable vector target feature added is enabled, but core::arch has no s390x vector type and both #[repr(simd)] and core::simd are unstable. Everything related is unstable, so the fact that this is currently a clobber-only should not be considered a stabilization blocker. (rust-lang#130869 tracks unstable stuff here)
areg (a[2-15]): Access register

All of the above register classes except reg_addr are needed for clobber_abi.

The followings cannot be used as operands for inline asm (see also getReservedRegs and SystemZELFRegisters in LLVM):

r11: frame pointer
r15: stack pointer
a0, a1: Reserved for system use
c[0-15] (control register) Reserved by the kernel

Although not listed in the above requirements, preserves_flags is implemented in rust-lang#111331.

cc @uweigand

r? @Amanieu

@rustbot label +O-SystemZ +A-inline-assembly

rust-timer added a commit to rust-lang-ci/rust that referenced this pull request

Nov 10, 2024

Rollup merge of rust-lang#131258 - taiki-e:s390x-stabilize-asm, r=Amanieu

Stabilize s390x inline assembly

This stabilizes inline assembly for s390x (SystemZ).

Corresponding reference PR: rust-lang/reference#1643

From the requirements of stabilization mentioned in rust-lang#93335

Each architecture needs to be reviewed before stabilization:

It must have clobber_abi.

Done in rust-lang#130630.

It must be possible to clobber every register that is normally clobbered by a function call.

Done in the PR that added support for clobber_abi.

Generally review that the exposed register classes make sense.

The followings can be used as input/output:

reg (r[0-10], r[12-14]): General-purpose register
reg_addr (r[1-10], r[12-14]): General-purpose register except r0 which is evaluated as zero in an address context

This class is needed because r0, which may be allocated when using the reg class, cannot be used as a register in certain contexts. This is identical to the a constraint in LLVM and GCC. See rust-lang#119431 for details.
freg (f[0-15]): Floating-point register

The followings are clobber-only:

vreg (v[0-31]): Vector register

Technically vreg should be able to accept #[repr(simd)] types as input/output if the unstable vector target feature added is enabled, but core::arch has no s390x vector type and both #[repr(simd)] and core::simd are unstable. Everything related is unstable, so the fact that this is currently a clobber-only should not be considered a stabilization blocker. (rust-lang#130869 tracks unstable stuff here)
areg (a[2-15]): Access register

All of the above register classes except reg_addr are needed for clobber_abi.

The followings cannot be used as operands for inline asm (see also getReservedRegs and SystemZELFRegisters in LLVM):

r11: frame pointer
r15: stack pointer
a0, a1: Reserved for system use
c[0-15] (control register) Reserved by the kernel

Although not listed in the above requirements, preserves_flags is implemented in rust-lang#111331.

cc @uweigand

r? @Amanieu

@rustbot label +O-SystemZ +A-inline-assembly

RalfJung pushed a commit to RalfJung/miri that referenced this pull request

Nov 10, 2024

Stabilize s390x inline assembly

This stabilizes inline assembly for s390x (SystemZ).

Corresponding reference PR: rust-lang/reference#1643

From the requirements of stabilization mentioned in rust-lang/rust#93335

Each architecture needs to be reviewed before stabilization:

It must have clobber_abi.

Done in rust-lang/rust#130630.

It must be possible to clobber every register that is normally clobbered by a function call.

Done in the PR that added support for clobber_abi.

Generally review that the exposed register classes make sense.

The followings can be used as input/output:

reg (r[0-10], r[12-14]): General-purpose register
reg_addr (r[1-10], r[12-14]): General-purpose register except r0 which is evaluated as zero in an address context

This class is needed because r0, which may be allocated when using the reg class, cannot be used as a register in certain contexts. This is identical to the a constraint in LLVM and GCC. See rust-lang/rust#119431 for details.
freg (f[0-15]): Floating-point register

The followings are clobber-only:

vreg (v[0-31]): Vector register

Technically vreg should be able to accept #[repr(simd)] types as input/output if the unstable vector target feature added is enabled, but core::arch has no s390x vector type and both #[repr(simd)] and core::simd are unstable. Everything related is unstable, so the fact that this is currently a clobber-only should not be considered a stabilization blocker. (rust-lang/rust#130869 tracks unstable stuff here)
areg (a[2-15]): Access register

All of the above register classes except reg_addr are needed for clobber_abi.

The followings cannot be used as operands for inline asm (see also getReservedRegs and SystemZELFRegisters in LLVM):

r11: frame pointer
r15: stack pointer
a0, a1: Reserved for system use
c[0-15] (control register) Reserved by the kernel

Although not listed in the above requirements, preserves_flags is implemented in rust-lang/rust#111331.

cc @uweigand

r? @Amanieu

@rustbot label +O-SystemZ +A-inline-assembly

mati865 pushed a commit to mati865/rust that referenced this pull request

Nov 12, 2024

…nieu

Stabilize s390x inline assembly

This stabilizes inline assembly for s390x (SystemZ).

Corresponding reference PR: rust-lang/reference#1643

From the requirements of stabilization mentioned in rust-lang#93335

Each architecture needs to be reviewed before stabilization:

It must have clobber_abi.

Done in rust-lang#130630.

It must be possible to clobber every register that is normally clobbered by a function call.

Done in the PR that added support for clobber_abi.

Generally review that the exposed register classes make sense.

The followings can be used as input/output:

reg (r[0-10], r[12-14]): General-purpose register
reg_addr (r[1-10], r[12-14]): General-purpose register except r0 which is evaluated as zero in an address context

This class is needed because r0, which may be allocated when using the reg class, cannot be used as a register in certain contexts. This is identical to the a constraint in LLVM and GCC. See rust-lang#119431 for details.
freg (f[0-15]): Floating-point register

The followings are clobber-only:

vreg (v[0-31]): Vector register

Technically vreg should be able to accept #[repr(simd)] types as input/output if the unstable vector target feature added is enabled, but core::arch has no s390x vector type and both #[repr(simd)] and core::simd are unstable. Everything related is unstable, so the fact that this is currently a clobber-only should not be considered a stabilization blocker. (rust-lang#130869 tracks unstable stuff here)
areg (a[2-15]): Access register

All of the above register classes except reg_addr are needed for clobber_abi.

The followings cannot be used as operands for inline asm (see also getReservedRegs and SystemZELFRegisters in LLVM):

r11: frame pointer
r15: stack pointer
a0, a1: Reserved for system use
c[0-15] (control register) Reserved by the kernel

Although not listed in the above requirements, preserves_flags is implemented in rust-lang#111331.

cc @uweigand

r? @Amanieu

@rustbot label +O-SystemZ +A-inline-assembly

Labels

A-inline-assembly

Area: Inline assembly (`asm!(…)`)

O-SystemZ

Target: SystemZ processors (s390x)

S-waiting-on-bors

Status: Waiting on bors to run and complete tests. Bors will change the label on completion.

T-compiler

Relevant to the compiler team, which will review and decide on the PR/issue.