Wasm funclet RA

[AndyAyersMS]

Implement register allocation for funclets, along with some funclet codegen.

[AndyAyersMS]

FYI @dotnet/jit-contrib

Still a work in progress, but figured I'd ask for some feedback before getting too much further. Things I know of that are still to do:

• We may need to handle case where an allocatable local is not live across a funclet boundary and ends up in different registers in different regions. Currently for STORE_LCL_VAR we always take the reg from the lcl var.
• ABI classifier type support for funclet params?
• Check if typeless catch won't actually get an ex obj from runtime (I suppose we can pass nullptr if necessary)
• Codegen is still off -- there is a bogus block before funclet start, and no return
• This won't validate (I'm pretty sure) until the jit host extracts the funclets into separate functions.

@SingleAccretion this may be more complex than what you had envisioned.

[Copilot]

Pull request overview

This PR extends the WASM JIT backend to support funclets by introducing per-funclet (region) register allocation state, per-funclet locals declarations, and basic funclet prolog codegen so EH regions can be code-generated with their own Wasm-local layouts.

Changes:

• Add per-funclet RA state (SP/FP/EX + reference tracking) and resolve/register publish logic per region.
• Teach codegen/emitter to use per-funclet SP/FP and emit per-funclet local declarations / funclet prologs.
• Update internal-register tracking to be per-funclet on targets without a fixed register set (WASM).

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 10 comments.

Show a summary per file

File	Description
src/coreclr/jit/regallocwasm.h	Introduces per-region RA state (SP/FP/EX + ref tracking) and new catch-arg collection hook.
src/coreclr/jit/regallocwasm.cpp	Implements per-funclet allocation, catch-arg rewriting, per-funclet internal-reg tables, and per-funclet locals decl generation/publishing.
src/coreclr/jit/lclvars.cpp	Adjusts frame-location dumping to use region-0 SP/FP on non-fixed-reg targets.
src/coreclr/jit/emitwasm.cpp	Extends wasm arg-count computation to support funclet signatures.
src/coreclr/jit/codegenwasm.cpp	Uses per-funclet SP/FP accessors and implements funclet prolog local signature emission.
src/coreclr/jit/codegeninterface.h	Makes SP/FP storage and internal-reg tracking per-funclet for non-fixed-reg targets; makes locals decls per-funclet.
src/coreclr/jit/codegencommon.cpp	Implements non-fixed-reg per-funclet NodeInternalRegisters tables and initializes per-funclet SP/FP/locals storage.

[SingleAccretion]

Looks a lot like what I was thinking about too.

Left some high-level feedback.

[AndyAyersMS]

@SingleAccretion90066eb should cover most of your feedback except internal regs.

[dotnet-policy-service]

Tagging subscribers to 'arch-wasm': @lewing, @pavelsavara
See info in area-owners.md if you want to be subscribed.

[SingleAccretion]

Mostly small comments left from me. But we also need to be a bit more careful with lvRegNum mutations.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 5 comments.

[AndyAyersMS]

Hopefully closer now...

@SingleAccretion in the future maybe just point out one instance of a recurring pattern? Otherwise stuff may get overlooked.

[AndyAyersMS]

There's still an issue where a node can be collected twice, eg if it both needs a register and also has internal registers, and double processing a collected node is not good.

We could have the collector mark nodes perhaps, use this to avoid a double collection, and unmark them when we process them later.

Also RequestInternalRegister can be called multiple times for the same node.

[AndyAyersMS]

Ok, one more batch of updates:

• rely on allocator's m_currentFunclet to track what assignments the lcl var dscs hold. If we think they're already correct, verify that they are, in debug.
• remove need for LIR flag by remembering the last collected node
• add node on why we don't need a debug live range update like LSRA has

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 5 comments.

[SingleAccretion]

Looking pretty good, just a few comments!

There is also #126445 (comment) which looks valid but is pre-existing and can be addressed separately.

[AndyAyersMS]

@dotnet/jit-contrib PTAL

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 2 comments.

[kg]

LGTM but I don't understand all of it.

[AndyAyersMS]

/ba-g infrastructure issues

[AndyAyersMS]

Implement register allocation for funclets, along with some funclet codegen.

[AndyAyersMS]

FYI @dotnet/jit-contrib

Still a work in progress, but figured I'd ask for some feedback before getting too much further. Things I know of that are still to do:

• We may need to handle case where an allocatable local is not live across a funclet boundary and ends up in different registers in different regions. Currently for STORE_LCL_VAR we always take the reg from the lcl var.
• ABI classifier type support for funclet params?
• Check if typeless catch won't actually get an ex obj from runtime (I suppose we can pass nullptr if necessary)
• Codegen is still off -- there is a bogus block before funclet start, and no return
• This won't validate (I'm pretty sure) until the jit host extracts the funclets into separate functions.

@SingleAccretion this may be more complex than what you had envisioned.

[Copilot]

Pull request overview

This PR extends the WASM JIT backend to support funclets by introducing per-funclet (region) register allocation state, per-funclet locals declarations, and basic funclet prolog codegen so EH regions can be code-generated with their own Wasm-local layouts.

Changes:

• Add per-funclet RA state (SP/FP/EX + reference tracking) and resolve/register publish logic per region.
• Teach codegen/emitter to use per-funclet SP/FP and emit per-funclet local declarations / funclet prologs.
• Update internal-register tracking to be per-funclet on targets without a fixed register set (WASM).

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 10 comments.

Show a summary per file

File	Description
src/coreclr/jit/regallocwasm.h	Introduces per-region RA state (SP/FP/EX + ref tracking) and new catch-arg collection hook.
src/coreclr/jit/regallocwasm.cpp	Implements per-funclet allocation, catch-arg rewriting, per-funclet internal-reg tables, and per-funclet locals decl generation/publishing.
src/coreclr/jit/lclvars.cpp	Adjusts frame-location dumping to use region-0 SP/FP on non-fixed-reg targets.
src/coreclr/jit/emitwasm.cpp	Extends wasm arg-count computation to support funclet signatures.
src/coreclr/jit/codegenwasm.cpp	Uses per-funclet SP/FP accessors and implements funclet prolog local signature emission.
src/coreclr/jit/codegeninterface.h	Makes SP/FP storage and internal-reg tracking per-funclet for non-fixed-reg targets; makes locals decls per-funclet.
src/coreclr/jit/codegencommon.cpp	Implements non-fixed-reg per-funclet NodeInternalRegisters tables and initializes per-funclet SP/FP/locals storage.

[SingleAccretion]

Looks a lot like what I was thinking about too.

Left some high-level feedback.

[AndyAyersMS]

@SingleAccretion90066eb should cover most of your feedback except internal regs.

[dotnet-policy-service]

Tagging subscribers to 'arch-wasm': @lewing, @pavelsavara
See info in area-owners.md if you want to be subscribed.

[SingleAccretion]

Mostly small comments left from me. But we also need to be a bit more careful with lvRegNum mutations.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 5 comments.

[AndyAyersMS]

Hopefully closer now...

@SingleAccretion in the future maybe just point out one instance of a recurring pattern? Otherwise stuff may get overlooked.

[AndyAyersMS]

There's still an issue where a node can be collected twice, eg if it both needs a register and also has internal registers, and double processing a collected node is not good.

We could have the collector mark nodes perhaps, use this to avoid a double collection, and unmark them when we process them later.

Also RequestInternalRegister can be called multiple times for the same node.

[AndyAyersMS]

Ok, one more batch of updates:

• rely on allocator's m_currentFunclet to track what assignments the lcl var dscs hold. If we think they're already correct, verify that they are, in debug.
• remove need for LIR flag by remembering the last collected node
• add node on why we don't need a debug live range update like LSRA has

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 5 comments.

[SingleAccretion]

Looking pretty good, just a few comments!

There is also #126445 (comment) which looks valid but is pre-existing and can be addressed separately.

[AndyAyersMS]

@dotnet/jit-contrib PTAL

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 2 comments.

[kg]

LGTM but I don't understand all of it.

[AndyAyersMS]

/ba-g infrastructure issues

[AndyAyersMS]

Implement register allocation for funclets, along with some funclet codegen.

[AndyAyersMS]

FYI @dotnet/jit-contrib

Still a work in progress, but figured I'd ask for some feedback before getting too much further. Things I know of that are still to do:

• We may need to handle case where an allocatable local is not live across a funclet boundary and ends up in different registers in different regions. Currently for STORE_LCL_VAR we always take the reg from the lcl var.
• ABI classifier type support for funclet params?
• Check if typeless catch won't actually get an ex obj from runtime (I suppose we can pass nullptr if necessary)
• Codegen is still off -- there is a bogus block before funclet start, and no return
• This won't validate (I'm pretty sure) until the jit host extracts the funclets into separate functions.

@SingleAccretion this may be more complex than what you had envisioned.

[Copilot]

Pull request overview

This PR extends the WASM JIT backend to support funclets by introducing per-funclet (region) register allocation state, per-funclet locals declarations, and basic funclet prolog codegen so EH regions can be code-generated with their own Wasm-local layouts.

Changes:

• Add per-funclet RA state (SP/FP/EX + reference tracking) and resolve/register publish logic per region.
• Teach codegen/emitter to use per-funclet SP/FP and emit per-funclet local declarations / funclet prologs.
• Update internal-register tracking to be per-funclet on targets without a fixed register set (WASM).

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 10 comments.

Show a summary per file

File	Description
src/coreclr/jit/regallocwasm.h	Introduces per-region RA state (SP/FP/EX + ref tracking) and new catch-arg collection hook.
src/coreclr/jit/regallocwasm.cpp	Implements per-funclet allocation, catch-arg rewriting, per-funclet internal-reg tables, and per-funclet locals decl generation/publishing.
src/coreclr/jit/lclvars.cpp	Adjusts frame-location dumping to use region-0 SP/FP on non-fixed-reg targets.
src/coreclr/jit/emitwasm.cpp	Extends wasm arg-count computation to support funclet signatures.
src/coreclr/jit/codegenwasm.cpp	Uses per-funclet SP/FP accessors and implements funclet prolog local signature emission.
src/coreclr/jit/codegeninterface.h	Makes SP/FP storage and internal-reg tracking per-funclet for non-fixed-reg targets; makes locals decls per-funclet.
src/coreclr/jit/codegencommon.cpp	Implements non-fixed-reg per-funclet NodeInternalRegisters tables and initializes per-funclet SP/FP/locals storage.

[SingleAccretion]

Looks a lot like what I was thinking about too.

Left some high-level feedback.

[AndyAyersMS]

@SingleAccretion90066eb should cover most of your feedback except internal regs.

[dotnet-policy-service]

Tagging subscribers to 'arch-wasm': @lewing, @pavelsavara
See info in area-owners.md if you want to be subscribed.

[SingleAccretion]

Mostly small comments left from me. But we also need to be a bit more careful with lvRegNum mutations.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 5 comments.

[AndyAyersMS]

Hopefully closer now...

@SingleAccretion in the future maybe just point out one instance of a recurring pattern? Otherwise stuff may get overlooked.

[AndyAyersMS]

There's still an issue where a node can be collected twice, eg if it both needs a register and also has internal registers, and double processing a collected node is not good.

We could have the collector mark nodes perhaps, use this to avoid a double collection, and unmark them when we process them later.

Also RequestInternalRegister can be called multiple times for the same node.

[AndyAyersMS]

Ok, one more batch of updates:

• rely on allocator's m_currentFunclet to track what assignments the lcl var dscs hold. If we think they're already correct, verify that they are, in debug.
• remove need for LIR flag by remembering the last collected node
• add node on why we don't need a debug live range update like LSRA has

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 5 comments.

[SingleAccretion]

Looking pretty good, just a few comments!

There is also #126445 (comment) which looks valid but is pre-existing and can be addressed separately.

[AndyAyersMS]

@dotnet/jit-contrib PTAL

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 2 comments.

[kg]

LGTM but I don't understand all of it.

[AndyAyersMS]

/ba-g infrastructure issues

[AndyAyersMS]

Implement register allocation for funclets, along with some funclet codegen.

[AndyAyersMS]

FYI @dotnet/jit-contrib

Still a work in progress, but figured I'd ask for some feedback before getting too much further. Things I know of that are still to do:

• We may need to handle case where an allocatable local is not live across a funclet boundary and ends up in different registers in different regions. Currently for STORE_LCL_VAR we always take the reg from the lcl var.
• ABI classifier type support for funclet params?
• Check if typeless catch won't actually get an ex obj from runtime (I suppose we can pass nullptr if necessary)
• Codegen is still off -- there is a bogus block before funclet start, and no return
• This won't validate (I'm pretty sure) until the jit host extracts the funclets into separate functions.

@SingleAccretion this may be more complex than what you had envisioned.

[Copilot]

Pull request overview

This PR extends the WASM JIT backend to support funclets by introducing per-funclet (region) register allocation state, per-funclet locals declarations, and basic funclet prolog codegen so EH regions can be code-generated with their own Wasm-local layouts.

Changes:

• Add per-funclet RA state (SP/FP/EX + reference tracking) and resolve/register publish logic per region.
• Teach codegen/emitter to use per-funclet SP/FP and emit per-funclet local declarations / funclet prologs.
• Update internal-register tracking to be per-funclet on targets without a fixed register set (WASM).

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 10 comments.

Show a summary per file

File	Description
src/coreclr/jit/regallocwasm.h	Introduces per-region RA state (SP/FP/EX + ref tracking) and new catch-arg collection hook.
src/coreclr/jit/regallocwasm.cpp	Implements per-funclet allocation, catch-arg rewriting, per-funclet internal-reg tables, and per-funclet locals decl generation/publishing.
src/coreclr/jit/lclvars.cpp	Adjusts frame-location dumping to use region-0 SP/FP on non-fixed-reg targets.
src/coreclr/jit/emitwasm.cpp	Extends wasm arg-count computation to support funclet signatures.
src/coreclr/jit/codegenwasm.cpp	Uses per-funclet SP/FP accessors and implements funclet prolog local signature emission.
src/coreclr/jit/codegeninterface.h	Makes SP/FP storage and internal-reg tracking per-funclet for non-fixed-reg targets; makes locals decls per-funclet.
src/coreclr/jit/codegencommon.cpp	Implements non-fixed-reg per-funclet NodeInternalRegisters tables and initializes per-funclet SP/FP/locals storage.

[SingleAccretion]

Looks a lot like what I was thinking about too.

Left some high-level feedback.

[AndyAyersMS]

@SingleAccretion90066eb should cover most of your feedback except internal regs.

[dotnet-policy-service]

Tagging subscribers to 'arch-wasm': @lewing, @pavelsavara
See info in area-owners.md if you want to be subscribed.

[SingleAccretion]

Mostly small comments left from me. But we also need to be a bit more careful with lvRegNum mutations.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 5 comments.

[AndyAyersMS]

Hopefully closer now...

@SingleAccretion in the future maybe just point out one instance of a recurring pattern? Otherwise stuff may get overlooked.

[AndyAyersMS]

There's still an issue where a node can be collected twice, eg if it both needs a register and also has internal registers, and double processing a collected node is not good.

We could have the collector mark nodes perhaps, use this to avoid a double collection, and unmark them when we process them later.

Also RequestInternalRegister can be called multiple times for the same node.

[AndyAyersMS]

Ok, one more batch of updates:

• rely on allocator's m_currentFunclet to track what assignments the lcl var dscs hold. If we think they're already correct, verify that they are, in debug.
• remove need for LIR flag by remembering the last collected node
• add node on why we don't need a debug live range update like LSRA has

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 5 comments.

[SingleAccretion]

Looking pretty good, just a few comments!

There is also #126445 (comment) which looks valid but is pre-existing and can be addressed separately.

[AndyAyersMS]

@dotnet/jit-contrib PTAL

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 2 comments.

[kg]

LGTM but I don't understand all of it.

[AndyAyersMS]

/ba-g infrastructure issues

[AndyAyersMS]

Implement register allocation for funclets, along with some funclet codegen.

[AndyAyersMS]

FYI @dotnet/jit-contrib

Still a work in progress, but figured I'd ask for some feedback before getting too much further. Things I know of that are still to do:

• We may need to handle case where an allocatable local is not live across a funclet boundary and ends up in different registers in different regions. Currently for STORE_LCL_VAR we always take the reg from the lcl var.
• ABI classifier type support for funclet params?
• Check if typeless catch won't actually get an ex obj from runtime (I suppose we can pass nullptr if necessary)
• Codegen is still off -- there is a bogus block before funclet start, and no return
• This won't validate (I'm pretty sure) until the jit host extracts the funclets into separate functions.

@SingleAccretion this may be more complex than what you had envisioned.

[Copilot]

Pull request overview

This PR extends the WASM JIT backend to support funclets by introducing per-funclet (region) register allocation state, per-funclet locals declarations, and basic funclet prolog codegen so EH regions can be code-generated with their own Wasm-local layouts.

Changes:

• Add per-funclet RA state (SP/FP/EX + reference tracking) and resolve/register publish logic per region.
• Teach codegen/emitter to use per-funclet SP/FP and emit per-funclet local declarations / funclet prologs.
• Update internal-register tracking to be per-funclet on targets without a fixed register set (WASM).

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 10 comments.

Show a summary per file

File	Description
src/coreclr/jit/regallocwasm.h	Introduces per-region RA state (SP/FP/EX + ref tracking) and new catch-arg collection hook.
src/coreclr/jit/regallocwasm.cpp	Implements per-funclet allocation, catch-arg rewriting, per-funclet internal-reg tables, and per-funclet locals decl generation/publishing.
src/coreclr/jit/lclvars.cpp	Adjusts frame-location dumping to use region-0 SP/FP on non-fixed-reg targets.
src/coreclr/jit/emitwasm.cpp	Extends wasm arg-count computation to support funclet signatures.
src/coreclr/jit/codegenwasm.cpp	Uses per-funclet SP/FP accessors and implements funclet prolog local signature emission.
src/coreclr/jit/codegeninterface.h	Makes SP/FP storage and internal-reg tracking per-funclet for non-fixed-reg targets; makes locals decls per-funclet.
src/coreclr/jit/codegencommon.cpp	Implements non-fixed-reg per-funclet NodeInternalRegisters tables and initializes per-funclet SP/FP/locals storage.

[SingleAccretion]

Looks a lot like what I was thinking about too.

Left some high-level feedback.

[AndyAyersMS]

@SingleAccretion90066eb should cover most of your feedback except internal regs.

[dotnet-policy-service]

Tagging subscribers to 'arch-wasm': @lewing, @pavelsavara
See info in area-owners.md if you want to be subscribed.

[SingleAccretion]

Mostly small comments left from me. But we also need to be a bit more careful with lvRegNum mutations.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 5 comments.

[AndyAyersMS]

Hopefully closer now...

@SingleAccretion in the future maybe just point out one instance of a recurring pattern? Otherwise stuff may get overlooked.

[AndyAyersMS]

There's still an issue where a node can be collected twice, eg if it both needs a register and also has internal registers, and double processing a collected node is not good.

We could have the collector mark nodes perhaps, use this to avoid a double collection, and unmark them when we process them later.

Also RequestInternalRegister can be called multiple times for the same node.

[AndyAyersMS]

Ok, one more batch of updates:

• rely on allocator's m_currentFunclet to track what assignments the lcl var dscs hold. If we think they're already correct, verify that they are, in debug.
• remove need for LIR flag by remembering the last collected node
• add node on why we don't need a debug live range update like LSRA has

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 5 comments.

[SingleAccretion]

Looking pretty good, just a few comments!

There is also #126445 (comment) which looks valid but is pre-existing and can be addressed separately.

[AndyAyersMS]

@dotnet/jit-contrib PTAL

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 2 comments.

[kg]

LGTM but I don't understand all of it.

[AndyAyersMS]

/ba-g infrastructure issues

[AndyAyersMS]

Implement register allocation for funclets, along with some funclet codegen.

[AndyAyersMS]

FYI @dotnet/jit-contrib

Still a work in progress, but figured I'd ask for some feedback before getting too much further. Things I know of that are still to do:

• We may need to handle case where an allocatable local is not live across a funclet boundary and ends up in different registers in different regions. Currently for STORE_LCL_VAR we always take the reg from the lcl var.
• ABI classifier type support for funclet params?
• Check if typeless catch won't actually get an ex obj from runtime (I suppose we can pass nullptr if necessary)
• Codegen is still off -- there is a bogus block before funclet start, and no return
• This won't validate (I'm pretty sure) until the jit host extracts the funclets into separate functions.

@SingleAccretion this may be more complex than what you had envisioned.

[Copilot]

Pull request overview

This PR extends the WASM JIT backend to support funclets by introducing per-funclet (region) register allocation state, per-funclet locals declarations, and basic funclet prolog codegen so EH regions can be code-generated with their own Wasm-local layouts.

Changes:

• Add per-funclet RA state (SP/FP/EX + reference tracking) and resolve/register publish logic per region.
• Teach codegen/emitter to use per-funclet SP/FP and emit per-funclet local declarations / funclet prologs.
• Update internal-register tracking to be per-funclet on targets without a fixed register set (WASM).

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 10 comments.

Show a summary per file

File	Description
src/coreclr/jit/regallocwasm.h	Introduces per-region RA state (SP/FP/EX + ref tracking) and new catch-arg collection hook.
src/coreclr/jit/regallocwasm.cpp	Implements per-funclet allocation, catch-arg rewriting, per-funclet internal-reg tables, and per-funclet locals decl generation/publishing.
src/coreclr/jit/lclvars.cpp	Adjusts frame-location dumping to use region-0 SP/FP on non-fixed-reg targets.
src/coreclr/jit/emitwasm.cpp	Extends wasm arg-count computation to support funclet signatures.
src/coreclr/jit/codegenwasm.cpp	Uses per-funclet SP/FP accessors and implements funclet prolog local signature emission.
src/coreclr/jit/codegeninterface.h	Makes SP/FP storage and internal-reg tracking per-funclet for non-fixed-reg targets; makes locals decls per-funclet.
src/coreclr/jit/codegencommon.cpp	Implements non-fixed-reg per-funclet NodeInternalRegisters tables and initializes per-funclet SP/FP/locals storage.

[SingleAccretion]

Looks a lot like what I was thinking about too.

Left some high-level feedback.

[AndyAyersMS]

@SingleAccretion90066eb should cover most of your feedback except internal regs.

[dotnet-policy-service]

Tagging subscribers to 'arch-wasm': @lewing, @pavelsavara
See info in area-owners.md if you want to be subscribed.

[SingleAccretion]

Mostly small comments left from me. But we also need to be a bit more careful with lvRegNum mutations.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 5 comments.

[AndyAyersMS]

Hopefully closer now...

@SingleAccretion in the future maybe just point out one instance of a recurring pattern? Otherwise stuff may get overlooked.

[AndyAyersMS]

There's still an issue where a node can be collected twice, eg if it both needs a register and also has internal registers, and double processing a collected node is not good.

We could have the collector mark nodes perhaps, use this to avoid a double collection, and unmark them when we process them later.

Also RequestInternalRegister can be called multiple times for the same node.

[AndyAyersMS]

Ok, one more batch of updates:

• rely on allocator's m_currentFunclet to track what assignments the lcl var dscs hold. If we think they're already correct, verify that they are, in debug.
• remove need for LIR flag by remembering the last collected node
• add node on why we don't need a debug live range update like LSRA has

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 5 comments.

[SingleAccretion]

Looking pretty good, just a few comments!

There is also #126445 (comment) which looks valid but is pre-existing and can be addressed separately.

[AndyAyersMS]

@dotnet/jit-contrib PTAL

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 2 comments.

[kg]

LGTM but I don't understand all of it.

[AndyAyersMS]

/ba-g infrastructure issues

[AndyAyersMS]

Implement register allocation for funclets, along with some funclet codegen.

[AndyAyersMS]

FYI @dotnet/jit-contrib

Still a work in progress, but figured I'd ask for some feedback before getting too much further. Things I know of that are still to do:

• We may need to handle case where an allocatable local is not live across a funclet boundary and ends up in different registers in different regions. Currently for STORE_LCL_VAR we always take the reg from the lcl var.
• ABI classifier type support for funclet params?
• Check if typeless catch won't actually get an ex obj from runtime (I suppose we can pass nullptr if necessary)
• Codegen is still off -- there is a bogus block before funclet start, and no return
• This won't validate (I'm pretty sure) until the jit host extracts the funclets into separate functions.

@SingleAccretion this may be more complex than what you had envisioned.

[Copilot]

Pull request overview

This PR extends the WASM JIT backend to support funclets by introducing per-funclet (region) register allocation state, per-funclet locals declarations, and basic funclet prolog codegen so EH regions can be code-generated with their own Wasm-local layouts.

Changes:

• Add per-funclet RA state (SP/FP/EX + reference tracking) and resolve/register publish logic per region.
• Teach codegen/emitter to use per-funclet SP/FP and emit per-funclet local declarations / funclet prologs.
• Update internal-register tracking to be per-funclet on targets without a fixed register set (WASM).

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 10 comments.

Show a summary per file

File	Description
src/coreclr/jit/regallocwasm.h	Introduces per-region RA state (SP/FP/EX + ref tracking) and new catch-arg collection hook.
src/coreclr/jit/regallocwasm.cpp	Implements per-funclet allocation, catch-arg rewriting, per-funclet internal-reg tables, and per-funclet locals decl generation/publishing.
src/coreclr/jit/lclvars.cpp	Adjusts frame-location dumping to use region-0 SP/FP on non-fixed-reg targets.
src/coreclr/jit/emitwasm.cpp	Extends wasm arg-count computation to support funclet signatures.
src/coreclr/jit/codegenwasm.cpp	Uses per-funclet SP/FP accessors and implements funclet prolog local signature emission.
src/coreclr/jit/codegeninterface.h	Makes SP/FP storage and internal-reg tracking per-funclet for non-fixed-reg targets; makes locals decls per-funclet.
src/coreclr/jit/codegencommon.cpp	Implements non-fixed-reg per-funclet NodeInternalRegisters tables and initializes per-funclet SP/FP/locals storage.

[SingleAccretion]

Looks a lot like what I was thinking about too.

Left some high-level feedback.

[AndyAyersMS]

@SingleAccretion90066eb should cover most of your feedback except internal regs.

[dotnet-policy-service]

Tagging subscribers to 'arch-wasm': @lewing, @pavelsavara
See info in area-owners.md if you want to be subscribed.

[SingleAccretion]

Mostly small comments left from me. But we also need to be a bit more careful with lvRegNum mutations.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 5 comments.

[AndyAyersMS]

Hopefully closer now...

@SingleAccretion in the future maybe just point out one instance of a recurring pattern? Otherwise stuff may get overlooked.

[AndyAyersMS]

There's still an issue where a node can be collected twice, eg if it both needs a register and also has internal registers, and double processing a collected node is not good.

We could have the collector mark nodes perhaps, use this to avoid a double collection, and unmark them when we process them later.

Also RequestInternalRegister can be called multiple times for the same node.

[AndyAyersMS]

Ok, one more batch of updates:

• rely on allocator's m_currentFunclet to track what assignments the lcl var dscs hold. If we think they're already correct, verify that they are, in debug.
• remove need for LIR flag by remembering the last collected node
• add node on why we don't need a debug live range update like LSRA has

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 5 comments.

[SingleAccretion]

Looking pretty good, just a few comments!

There is also #126445 (comment) which looks valid but is pre-existing and can be addressed separately.

[AndyAyersMS]

@dotnet/jit-contrib PTAL

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 2 comments.

[kg]

LGTM but I don't understand all of it.

[AndyAyersMS]

/ba-g infrastructure issues

[AndyAyersMS]

Implement register allocation for funclets, along with some funclet codegen.

[AndyAyersMS]

FYI @dotnet/jit-contrib

Still a work in progress, but figured I'd ask for some feedback before getting too much further. Things I know of that are still to do:

• We may need to handle case where an allocatable local is not live across a funclet boundary and ends up in different registers in different regions. Currently for STORE_LCL_VAR we always take the reg from the lcl var.
• ABI classifier type support for funclet params?
• Check if typeless catch won't actually get an ex obj from runtime (I suppose we can pass nullptr if necessary)
• Codegen is still off -- there is a bogus block before funclet start, and no return
• This won't validate (I'm pretty sure) until the jit host extracts the funclets into separate functions.

@SingleAccretion this may be more complex than what you had envisioned.

[Copilot]

Pull request overview

This PR extends the WASM JIT backend to support funclets by introducing per-funclet (region) register allocation state, per-funclet locals declarations, and basic funclet prolog codegen so EH regions can be code-generated with their own Wasm-local layouts.

Changes:

• Add per-funclet RA state (SP/FP/EX + reference tracking) and resolve/register publish logic per region.
• Teach codegen/emitter to use per-funclet SP/FP and emit per-funclet local declarations / funclet prologs.
• Update internal-register tracking to be per-funclet on targets without a fixed register set (WASM).

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 10 comments.

Show a summary per file

File	Description
src/coreclr/jit/regallocwasm.h	Introduces per-region RA state (SP/FP/EX + ref tracking) and new catch-arg collection hook.
src/coreclr/jit/regallocwasm.cpp	Implements per-funclet allocation, catch-arg rewriting, per-funclet internal-reg tables, and per-funclet locals decl generation/publishing.
src/coreclr/jit/lclvars.cpp	Adjusts frame-location dumping to use region-0 SP/FP on non-fixed-reg targets.
src/coreclr/jit/emitwasm.cpp	Extends wasm arg-count computation to support funclet signatures.
src/coreclr/jit/codegenwasm.cpp	Uses per-funclet SP/FP accessors and implements funclet prolog local signature emission.
src/coreclr/jit/codegeninterface.h	Makes SP/FP storage and internal-reg tracking per-funclet for non-fixed-reg targets; makes locals decls per-funclet.
src/coreclr/jit/codegencommon.cpp	Implements non-fixed-reg per-funclet NodeInternalRegisters tables and initializes per-funclet SP/FP/locals storage.

[SingleAccretion]

Looks a lot like what I was thinking about too.

Left some high-level feedback.

[AndyAyersMS]

@SingleAccretion90066eb should cover most of your feedback except internal regs.

[dotnet-policy-service]

Tagging subscribers to 'arch-wasm': @lewing, @pavelsavara
See info in area-owners.md if you want to be subscribed.

[SingleAccretion]

Mostly small comments left from me. But we also need to be a bit more careful with lvRegNum mutations.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 5 comments.

[AndyAyersMS]

Hopefully closer now...

@SingleAccretion in the future maybe just point out one instance of a recurring pattern? Otherwise stuff may get overlooked.

[AndyAyersMS]

There's still an issue where a node can be collected twice, eg if it both needs a register and also has internal registers, and double processing a collected node is not good.

We could have the collector mark nodes perhaps, use this to avoid a double collection, and unmark them when we process them later.

Also RequestInternalRegister can be called multiple times for the same node.

[AndyAyersMS]

Ok, one more batch of updates:

• rely on allocator's m_currentFunclet to track what assignments the lcl var dscs hold. If we think they're already correct, verify that they are, in debug.
• remove need for LIR flag by remembering the last collected node
• add node on why we don't need a debug live range update like LSRA has

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 5 comments.

[SingleAccretion]

Looking pretty good, just a few comments!

There is also #126445 (comment) which looks valid but is pre-existing and can be addressed separately.

[AndyAyersMS]

@dotnet/jit-contrib PTAL

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 2 comments.

[kg]

LGTM but I don't understand all of it.

[AndyAyersMS]

/ba-g infrastructure issues