Upstream ARC-V RMX-100 #171
Draft
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This commit introduces a new -mtune=rmx100 tuning option together with relevant scheduler definitions. Instruction latencies and costs are based on the "RMX-100 Technical Reference Manual" document (revision 0.4, 13 September 2023) and are subject to change. The changes have been verified by running the Dhrystone and Coremark benchmarks and observing expected (small) improvements compared to the -mtune=generic results. Signed-off-by: Artemiy Volkov <[email protected]>
This commit adds the new arcv-mpy-option compilation parameter with the valid (string) values of 1c, 2c, and 10c. This corresponds to different versions of the MPY/DIV unit of the RMX100 core, each of which has different latencies for imul/idiv instructions. Internally, this option is propagated to the pipeline description information in rmx100.md with the use of new helper functions defined in riscv.cc. Signed-off-by: Artemiy Volkov <[email protected]>
Since it is critical to scheduling for the RMX-100 core, allow setting load latency via a newly create target-specific arcv-ld-cycles parameter. The worst case latency is 3, and so is the parameter's default value. Signed-off-by: Artemiy Volkov <[email protected]>
MichielDerhaeg
force-pushed
the
michiel/upstream_rmx100
branch
from
0efc8b2 to
2fa36eb
Compare
MichielDerhaeg
commented
Oct 2, 2025
|
|
||
| -param=arcv-mpy-option= | ||
| Target RejectNegative Joined Enum(arcv_mpy_option) Var(arcv_mpy_option) Init(ARCV_MPY_OPTION_2C) | ||
| The type of MPY unit used by the RMX-100 core (to be used in combination with -mtune=rmx100) (default: 2c). |
MichielDerhaeg
commented
Oct 2, 2025
| } | ||
|
|
||
| /* Implement one boolean function for each of the values of the | ||
| arcv_mpy_option enum, for the needs of rhx100.md. */ |
MichielDerhaeg
commented
Oct 2, 2025
| (define_automaton "arcv_rmx100") | ||
|
|
||
| (define_cpu_unit "arcv_rmx100_ALU" "arcv_rmx100") | ||
| ;(define_cpu_unit "arcv_rmx100_CSR" "arcv_rmx100") |
MichielDerhaeg
commented
Oct 2, 2025
Comment on lines
+80
to
+82
| ;;(define_insn_reservation "core" 1 | ||
| ;; (eq_attr "type" "block, brk, dmb, flag, lr, sr, sync") | ||
| ;; "arcv_rmx100_ALU0 + arcv_rmx100_ALU1 + arcv_rmx100_DMP + arcv_rmx100_MPY + arcv_rmx100_MPY64 + arcv_rmx100_DIV") |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The purpose of the PR is solely to review the patch set that will be submitted to upstream.