different trace related actions happen at the same time

[senlinhe]

According to trace specification,

Can one instruction cause turn-on and turn-off and trace-notify at the same time?

[senlinhe]

Another question is

program order:

#1 add

#2 sub - turn on trace

#3 load

#4 store - turn off trace

if the above four instructions retired at the same cycle, according to the spec, does it mean the TRACE should trace all four instrucitons.

[IainCRobertson]

Yes -please refer to section 4.2.4 in the latest E-trace spec accessible from here<https://lf-riscv.atlassian.net/wiki/spaces/HOME/pages/16154769/RISC-V+Technical+Specifications>. Iain From: hahahah ***@***.***> Sent: 04 August 2025 11:04 To: riscv-non-isa/riscv-trace-spec ***@***.***> Cc: Subscribed ***@***.***> Subject: Re: [riscv-non-isa/riscv-trace-spec] different trace related actions happen at the same time (Issue #246) [https://avatars.githubusercontent.com/u/102632519?s=20&v=4]senlinhe left a comment (riscv-non-isa/riscv-trace-spec#246)<#246 (comment)> image.png (view on web)<https://github.com/user-attachments/assets/4b6ebaad-ce52-4131-a64f-d74afcf33221> program order: #1<#1> add #2<#2> sub - turn on trace #3<#3> load #4<#4> store - turn off trace if the above four instructions retired at the same cycle, according to the spec, does it mean the TRACE should trace all four instrucitons. - Reply to this email directly, view it on GitHub<#246 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ALQOPSUPYAUE4KMV5FP2D5L3L4VY7AVCNFSM6AAAAACDBQ5HN6VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTCNBZHEYTSMJQGI>. You are receiving this because you are subscribed to this thread.Message ID: ***@***.******@***.***>>

[senlinhe]

To be specific,

1.In the first scenario, if the tracing is enabled but trace-on occurs on the cycle before trace-off, will the tracing be closed? or if one instruction has trace-on and trace-off trigger simultaneously when tracing is enable, will the tracing be closed or stay on?

2.In the second scenario, do we need to turn tracing on or off if trigger events occur sequentially when tracing is disabled，just like the first scenario.

[IainCRobertson]

Sorry for the delayed response.

Regarding point 1. A trace on trigger when trace is already on has no effect. So tracing will stop after the trace-off.

Regarding point 2, I'm afraid I don't understand what you're asking. Please can you re-phrase with more detail.