llvm-project/llvm/lib/Target/RISCV/RISCVSchedRocket.td
Michal Terepeta 6da1966bc5
[RISCV] Add scheduling information for SiFive VCIX (#86093)
This adds `RISCVScheduleXSf.td` with `SchedWrite` definitions for all
VCIX instructions and uses it in `RISCVSchedSiFive7.td` to set default
latencies for these instructions, helping with issue
https://github.com/llvm/llvm-project/issues/83391. Of course these
default latencies cannot be accurate (since each coprocessor will have
different latencies), but this seems to be enough to avoid some of the
problematic behavior described in the bug.

In any case, this seems to be enough to help with #83391 in our internal
testing.

A subsequent discussion is how to structure the code such that it's
easier for downstream consumers of this to use `SiFive7` scheduling
model with accurate VCIX latencies. But we can probably have a separate
issue to discuss that.
2024-04-16 13:55:45 +08:00

266 lines
8.9 KiB
TableGen

//==- RISCVSchedRocket.td - Rocket Scheduling Definitions ----*- tablegen -*-=//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// ===---------------------------------------------------------------------===//
// The following definitions describe the simpler per-operand machine model.
// This works with MachineScheduler. See MCSchedule.h for details.
// Rocket machine model for scheduling and other instruction cost heuristics.
def RocketModel : SchedMachineModel {
let MicroOpBufferSize = 0; // Rocket is in-order.
let IssueWidth = 1; // 1 micro-op is dispatched per cycle.
let LoadLatency = 3;
let MispredictPenalty = 3;
let CompleteModel = false;
let UnsupportedFeatures = [HasStdExtZbkb, HasStdExtZbkc, HasStdExtZbkx,
HasStdExtZcmt, HasStdExtZknd, HasStdExtZkne,
HasStdExtZknh, HasStdExtZksed, HasStdExtZksh,
HasStdExtZkr, HasVInstructions, HasVInstructionsI64];
}
//===----------------------------------------------------------------------===//
// Define each kind of processor resource and number available.
// Modeling each pipeline as a ProcResource using the BufferSize = 0 since
// Rocket is in-order.
let BufferSize = 0 in {
def RocketUnitALU : ProcResource<1>; // Int ALU
def RocketUnitIMul : ProcResource<1>; // Int Multiply
def RocketUnitMem : ProcResource<1>; // Load/Store
def RocketUnitB : ProcResource<1>; // Branch
def RocketUnitFPALU : ProcResource<1>; // FP ALU
}
let BufferSize = 1 in {
def RocketUnitIDiv : ProcResource<1>; // Int Division
def RocketUnitFPDivSqrt : ProcResource<1>; // FP Divide/Sqrt
}
//===----------------------------------------------------------------------===//
let SchedModel = RocketModel in {
// Branching
def : WriteRes<WriteJmp, [RocketUnitB]>;
def : WriteRes<WriteJal, [RocketUnitB]>;
def : WriteRes<WriteJalr, [RocketUnitB]>;
// Integer arithmetic and logic
def : WriteRes<WriteIALU32, [RocketUnitALU]>;
def : WriteRes<WriteIALU, [RocketUnitALU]>;
def : WriteRes<WriteShiftImm32, [RocketUnitALU]>;
def : WriteRes<WriteShiftImm, [RocketUnitALU]>;
def : WriteRes<WriteShiftReg32, [RocketUnitALU]>;
def : WriteRes<WriteShiftReg, [RocketUnitALU]>;
// Integer multiplication
let Latency = 4 in {
def : WriteRes<WriteIMul, [RocketUnitIMul]>;
def : WriteRes<WriteIMul32, [RocketUnitIMul]>;
}
// Integer division
// Worst case latency is used.
def : WriteRes<WriteIDiv32, [RocketUnitIDiv]> {
let Latency = 34;
let ReleaseAtCycles = [34];
}
def : WriteRes<WriteIDiv, [RocketUnitIDiv]> {
let Latency = 33;
let ReleaseAtCycles = [33];
}
// Integer remainder
def : WriteRes<WriteIRem32, [RocketUnitIDiv]> {
let Latency = 34;
let ReleaseAtCycles = [34];
}
def : WriteRes<WriteIRem, [RocketUnitIDiv]> {
let Latency = 33;
let ReleaseAtCycles = [33];
}
// Memory
def : WriteRes<WriteSTB, [RocketUnitMem]>;
def : WriteRes<WriteSTH, [RocketUnitMem]>;
def : WriteRes<WriteSTW, [RocketUnitMem]>;
def : WriteRes<WriteSTD, [RocketUnitMem]>;
def : WriteRes<WriteFST32, [RocketUnitMem]>;
def : WriteRes<WriteFST64, [RocketUnitMem]>;
let Latency = 3 in {
def : WriteRes<WriteLDB, [RocketUnitMem]>;
def : WriteRes<WriteLDH, [RocketUnitMem]>;
}
let Latency = 2 in {
def : WriteRes<WriteLDW, [RocketUnitMem]>;
def : WriteRes<WriteLDD, [RocketUnitMem]>;
def : WriteRes<WriteFLD32, [RocketUnitMem]>;
def : WriteRes<WriteFLD64, [RocketUnitMem]>;
// Atomic memory
def : WriteRes<WriteAtomicW, [RocketUnitMem]>;
def : WriteRes<WriteAtomicD, [RocketUnitMem]>;
def : WriteRes<WriteAtomicLDW, [RocketUnitMem]>;
def : WriteRes<WriteAtomicLDD, [RocketUnitMem]>;
}
def : WriteRes<WriteAtomicSTW, [RocketUnitMem]>;
def : WriteRes<WriteAtomicSTD, [RocketUnitMem]>;
// Single precision.
let Latency = 4 in {
def : WriteRes<WriteFAdd32, [RocketUnitFPALU]>;
def : WriteRes<WriteFSGNJ32, [RocketUnitFPALU]>;
def : WriteRes<WriteFMinMax32, [RocketUnitFPALU]>;
}
// Double precision
let Latency = 6 in {
def : WriteRes<WriteFAdd64, [RocketUnitFPALU]>;
def : WriteRes<WriteFSGNJ64, [RocketUnitFPALU]>;
def : WriteRes<WriteFMinMax64, [RocketUnitFPALU]>;
}
// Conversions
let Latency = 2 in {
def : WriteRes<WriteFCvtI32ToF32, [RocketUnitFPALU]>;
def : WriteRes<WriteFCvtI32ToF64, [RocketUnitFPALU]>;
def : WriteRes<WriteFCvtI64ToF32, [RocketUnitFPALU]>;
def : WriteRes<WriteFCvtI64ToF64, [RocketUnitFPALU]>;
def : WriteRes<WriteFCvtF32ToI32, [RocketUnitFPALU]>;
def : WriteRes<WriteFCvtF32ToI64, [RocketUnitFPALU]>;
def : WriteRes<WriteFCvtF64ToI32, [RocketUnitFPALU]>;
def : WriteRes<WriteFCvtF64ToI64, [RocketUnitFPALU]>;
def : WriteRes<WriteFCvtF32ToF64, [RocketUnitFPALU]>;
def : WriteRes<WriteFCvtF64ToF32, [RocketUnitFPALU]>;
def : WriteRes<WriteFClass32, [RocketUnitFPALU]>;
def : WriteRes<WriteFClass64, [RocketUnitFPALU]>;
def : WriteRes<WriteFCmp32, [RocketUnitFPALU]>;
def : WriteRes<WriteFCmp64, [RocketUnitFPALU]>;
def : WriteRes<WriteFMovF32ToI32, [RocketUnitFPALU]>;
def : WriteRes<WriteFMovI32ToF32, [RocketUnitFPALU]>;
def : WriteRes<WriteFMovF64ToI64, [RocketUnitFPALU]>;
def : WriteRes<WriteFMovI64ToF64, [RocketUnitFPALU]>;
}
// FP multiplication
let Latency = 5 in {
def : WriteRes<WriteFMul32, [RocketUnitFPALU]>;
def : WriteRes<WriteFMA32, [RocketUnitFPALU]>;
}
let Latency = 7 in {
def : WriteRes<WriteFMul64, [RocketUnitFPALU]>;
def : WriteRes<WriteFMA64, [RocketUnitFPALU]>;
}
// FP division
// FP division unit on Rocket is not pipelined, so set resource cycles to latency.
let Latency = 20, ReleaseAtCycles = [20] in {
def : WriteRes<WriteFDiv32, [RocketUnitFPDivSqrt]>;
def : WriteRes<WriteFDiv64, [RocketUnitFPDivSqrt]>;
}
// FP square root unit on Rocket is not pipelined, so set resource cycles to latency.
def : WriteRes<WriteFSqrt32, [RocketUnitFPDivSqrt]> { let Latency = 20;
let ReleaseAtCycles = [20]; }
def : WriteRes<WriteFSqrt64, [RocketUnitFPDivSqrt]> { let Latency = 25;
let ReleaseAtCycles = [25]; }
// Others
def : WriteRes<WriteCSR, []>;
def : WriteRes<WriteNop, []>;
def : InstRW<[WriteIALU], (instrs COPY)>;
//===----------------------------------------------------------------------===//
// Bypass and advance
def : ReadAdvance<ReadJmp, 0>;
def : ReadAdvance<ReadJalr, 0>;
def : ReadAdvance<ReadCSR, 0>;
def : ReadAdvance<ReadStoreData, 0>;
def : ReadAdvance<ReadMemBase, 0>;
def : ReadAdvance<ReadIALU, 0>;
def : ReadAdvance<ReadIALU32, 0>;
def : ReadAdvance<ReadShiftImm, 0>;
def : ReadAdvance<ReadShiftImm32, 0>;
def : ReadAdvance<ReadShiftReg, 0>;
def : ReadAdvance<ReadShiftReg32, 0>;
def : ReadAdvance<ReadIDiv, 0>;
def : ReadAdvance<ReadIDiv32, 0>;
def : ReadAdvance<ReadIRem, 0>;
def : ReadAdvance<ReadIRem32, 0>;
def : ReadAdvance<ReadIMul, 0>;
def : ReadAdvance<ReadIMul32, 0>;
def : ReadAdvance<ReadAtomicWA, 0>;
def : ReadAdvance<ReadAtomicWD, 0>;
def : ReadAdvance<ReadAtomicDA, 0>;
def : ReadAdvance<ReadAtomicDD, 0>;
def : ReadAdvance<ReadAtomicLDW, 0>;
def : ReadAdvance<ReadAtomicLDD, 0>;
def : ReadAdvance<ReadAtomicSTW, 0>;
def : ReadAdvance<ReadAtomicSTD, 0>;
def : ReadAdvance<ReadFStoreData, 0>;
def : ReadAdvance<ReadFMemBase, 0>;
def : ReadAdvance<ReadFAdd32, 0>;
def : ReadAdvance<ReadFAdd64, 0>;
def : ReadAdvance<ReadFMul32, 0>;
def : ReadAdvance<ReadFMul64, 0>;
def : ReadAdvance<ReadFMA32, 0>;
def : ReadAdvance<ReadFMA32Addend, 0>;
def : ReadAdvance<ReadFMA64, 0>;
def : ReadAdvance<ReadFMA64Addend, 0>;
def : ReadAdvance<ReadFDiv32, 0>;
def : ReadAdvance<ReadFDiv64, 0>;
def : ReadAdvance<ReadFSqrt32, 0>;
def : ReadAdvance<ReadFSqrt64, 0>;
def : ReadAdvance<ReadFCmp32, 0>;
def : ReadAdvance<ReadFCmp64, 0>;
def : ReadAdvance<ReadFSGNJ32, 0>;
def : ReadAdvance<ReadFSGNJ64, 0>;
def : ReadAdvance<ReadFMinMax32, 0>;
def : ReadAdvance<ReadFMinMax64, 0>;
def : ReadAdvance<ReadFCvtF32ToI32, 0>;
def : ReadAdvance<ReadFCvtF32ToI64, 0>;
def : ReadAdvance<ReadFCvtF64ToI32, 0>;
def : ReadAdvance<ReadFCvtF64ToI64, 0>;
def : ReadAdvance<ReadFCvtI32ToF32, 0>;
def : ReadAdvance<ReadFCvtI32ToF64, 0>;
def : ReadAdvance<ReadFCvtI64ToF32, 0>;
def : ReadAdvance<ReadFCvtI64ToF64, 0>;
def : ReadAdvance<ReadFCvtF32ToF64, 0>;
def : ReadAdvance<ReadFCvtF64ToF32, 0>;
def : ReadAdvance<ReadFMovF32ToI32, 0>;
def : ReadAdvance<ReadFMovI32ToF32, 0>;
def : ReadAdvance<ReadFMovF64ToI64, 0>;
def : ReadAdvance<ReadFMovI64ToF64, 0>;
def : ReadAdvance<ReadFClass32, 0>;
def : ReadAdvance<ReadFClass64, 0>;
//===----------------------------------------------------------------------===//
// Unsupported extensions
defm : UnsupportedSchedV;
defm : UnsupportedSchedZabha;
defm : UnsupportedSchedZba;
defm : UnsupportedSchedZbb;
defm : UnsupportedSchedZbc;
defm : UnsupportedSchedZbs;
defm : UnsupportedSchedZbkb;
defm : UnsupportedSchedZbkx;
defm : UnsupportedSchedZfa;
defm : UnsupportedSchedZfh;
defm : UnsupportedSchedSFB;
defm : UnsupportedSchedXsfvcp;
}