Upstream ARC-V RMX-100 #171
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MichielDerhaeg
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MichielDerhaeg
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Oct 2, 2025
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| -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
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Oct 2, 2025
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| /* Implement one boolean function for each of the values of the | ||
| arcv_mpy_option enum, for the needs of rhx100.md. */ |
MichielDerhaeg
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Oct 2, 2025
| (define_automaton "arcv_rmx100") | ||
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| (define_cpu_unit "arcv_rmx100_ALU" "arcv_rmx100") | ||
| ;(define_cpu_unit "arcv_rmx100_CSR" "arcv_rmx100") |
MichielDerhaeg
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Oct 2, 2025
gcc/config/riscv/arcv-rmx100.md
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| ;;(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") |
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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 <artemiy@synopsys.com>
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 <artemiy@synopsys.com>
This patch adds latencies related to FPU instructions to arcv-rmx100.md. The specific values used correspond to the 'fast' config, except fdiv where the latency was reduced to 10 cycles. In the future, FP latencies for RMX-100 should be made dependent on an external (-mfpu-like) option. Signed-off-by: Artemiy Volkov <artemiy@synopsys.com>
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The purpose of the PR is solely to review the patch set that will be submitted to upstream.