[llvm] [RISCV] Add scheduling information for SiFive VCIX (PR #86093)
Michal Terepeta via llvm-commits
llvm-commits at lists.llvm.org
Wed Mar 20 23:28:48 PDT 2024
https://github.com/michalt created https://github.com/llvm/llvm-project/pull/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.
I don't have experience with this part of LLVM, so I might be doing a bunch of silly things. 😅 Let me know if there are any problems with this approach and how we could improve the patch!
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.
>From 3704b4bb62c91d34033c6cf6e8770dd1094ff60c Mon Sep 17 00:00:00 2001
From: Michal Terepeta <michalt at google.com>
Date: Wed, 20 Mar 2024 10:50:23 +0100
Subject: [PATCH] [RISCV] Add scheduling information for SiFive VCIX
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 #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.
---
llvm/lib/Target/RISCV/RISCVInstrInfoXSf.td | 24 ++++----
llvm/lib/Target/RISCV/RISCVSchedRocket.td | 1 +
llvm/lib/Target/RISCV/RISCVSchedSiFive7.td | 46 +++++++++++++++
llvm/lib/Target/RISCV/RISCVSchedSiFiveP400.td | 1 +
llvm/lib/Target/RISCV/RISCVSchedSiFiveP600.td | 1 +
.../Target/RISCV/RISCVSchedSyntacoreSCR1.td | 1 +
.../Target/RISCV/RISCVSchedXiangShanNanHu.td | 1 +
llvm/lib/Target/RISCV/RISCVSchedule.td | 1 +
llvm/lib/Target/RISCV/RISCVScheduleXSf.td | 59 +++++++++++++++++++
9 files changed, 123 insertions(+), 12 deletions(-)
create mode 100644 llvm/lib/Target/RISCV/RISCVScheduleXSf.td
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfoXSf.td b/llvm/lib/Target/RISCV/RISCVInstrInfoXSf.td
index 9a6818c99af206..20c69b1727e8f0 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfoXSf.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfoXSf.td
@@ -307,10 +307,10 @@ multiclass VPseudoVC_X<LMULInfo m, DAGOperand RS1Class,
Operand OpClass = payload2> {
let VLMul = m.value in {
let Defs = [VCIX_STATE], Uses = [VCIX_STATE] in {
- def "PseudoVC_" # NAME # "_SE_" # m.MX : VPseudoVC_X<OpClass, RS1Class>;
- def "PseudoVC_V_" # NAME # "_SE_" # m.MX : VPseudoVC_V_X<OpClass, m.vrclass, RS1Class>;
+ def "PseudoVC_" # NAME # "_SE_" # m.MX : VPseudoVC_X<OpClass, RS1Class>, Sched<[!cast<SchedWrite>("WriteVC_" # NAME # "_" # m.MX)]>;
+ def "PseudoVC_V_" # NAME # "_SE_" # m.MX : VPseudoVC_V_X<OpClass, m.vrclass, RS1Class>, Sched<[!cast<SchedWrite>("WriteVC_V_" # NAME # "_" # m.MX)]>;
}
- def "PseudoVC_V_" # NAME # "_" # m.MX : VPseudoVC_V_X<OpClass, m.vrclass, RS1Class>;
+ def "PseudoVC_V_" # NAME # "_" # m.MX : VPseudoVC_V_X<OpClass, m.vrclass, RS1Class>, Sched<[!cast<SchedWrite>("WriteVC_V_" # NAME # "_" # m.MX)]>;
}
}
@@ -318,10 +318,10 @@ multiclass VPseudoVC_XV<LMULInfo m, DAGOperand RS1Class,
Operand OpClass = payload2> {
let VLMul = m.value in {
let Defs = [VCIX_STATE], Uses = [VCIX_STATE] in {
- def "PseudoVC_" # NAME # "_SE_" # m.MX : VPseudoVC_XV<OpClass, m.vrclass, RS1Class>;
- def "PseudoVC_V_" # NAME # "_SE_" # m.MX : VPseudoVC_V_XV<OpClass, m.vrclass, m.vrclass, RS1Class>;
+ def "PseudoVC_" # NAME # "_SE_" # m.MX : VPseudoVC_XV<OpClass, m.vrclass, RS1Class>, Sched<[!cast<SchedWrite>("WriteVC_" # NAME # "_" # m.MX)]>;
+ def "PseudoVC_V_" # NAME # "_SE_" # m.MX : VPseudoVC_V_XV<OpClass, m.vrclass, m.vrclass, RS1Class>, Sched<[!cast<SchedWrite>("WriteVC_V_" # NAME # "_" # m.MX)]>;
}
- def "PseudoVC_V_" # NAME # "_" # m.MX : VPseudoVC_V_XV<OpClass, m.vrclass, m.vrclass, RS1Class>;
+ def "PseudoVC_V_" # NAME # "_" # m.MX : VPseudoVC_V_XV<OpClass, m.vrclass, m.vrclass, RS1Class>, Sched<[!cast<SchedWrite>("WriteVC_V_" # NAME # "_" # m.MX)]>;
}
}
@@ -329,10 +329,10 @@ multiclass VPseudoVC_XVV<LMULInfo m, DAGOperand RS1Class,
Operand OpClass = payload2> {
let VLMul = m.value in {
let Defs = [VCIX_STATE], Uses = [VCIX_STATE] in {
- def "PseudoVC_" # NAME # "_SE_" # m.MX : VPseudoVC_XVV<OpClass, m.vrclass, m.vrclass, RS1Class>;
- def "PseudoVC_V_" # NAME # "_SE_" # m.MX : VPseudoVC_V_XVV<OpClass, m.vrclass, m.vrclass, RS1Class>;
+ def "PseudoVC_" # NAME # "_SE_" # m.MX : VPseudoVC_XVV<OpClass, m.vrclass, m.vrclass, RS1Class>, Sched<[!cast<SchedWrite>("WriteVC_" # NAME # "_" # m.MX)]>;
+ def "PseudoVC_V_" # NAME # "_SE_" # m.MX : VPseudoVC_V_XVV<OpClass, m.vrclass, m.vrclass, RS1Class>, Sched<[!cast<SchedWrite>("WriteVC_V_" # NAME # "_" # m.MX)]>;
}
- def "PseudoVC_V_" # NAME # "_" # m.MX : VPseudoVC_V_XVV<OpClass, m.vrclass, m.vrclass, RS1Class>;
+ def "PseudoVC_V_" # NAME # "_" # m.MX : VPseudoVC_V_XVV<OpClass, m.vrclass, m.vrclass, RS1Class>, Sched<[!cast<SchedWrite>("WriteVC_V_" # NAME # "_" # m.MX)]>;
}
}
@@ -340,11 +340,11 @@ multiclass VPseudoVC_XVW<LMULInfo m, DAGOperand RS1Class,
Operand OpClass = payload2> {
let VLMul = m.value in {
let Defs = [VCIX_STATE], Uses = [VCIX_STATE] in
- def "PseudoVC_" # NAME # "_SE_" # m.MX : VPseudoVC_XVV<OpClass, m.wvrclass, m.vrclass, RS1Class>;
+ def "PseudoVC_" # NAME # "_SE_" # m.MX : VPseudoVC_XVV<OpClass, m.wvrclass, m.vrclass, RS1Class>, Sched<[!cast<SchedWrite>("WriteVC_" # NAME # "_" # m.MX)]>;
let Constraints = "@earlyclobber $rd, $rd = $rs3" in {
let Defs = [VCIX_STATE], Uses = [VCIX_STATE] in
- def "PseudoVC_V_" # NAME # "_SE_" # m.MX : VPseudoVC_V_XVV<OpClass, m.wvrclass, m.vrclass, RS1Class>;
- def "PseudoVC_V_" # NAME # "_" # m.MX : VPseudoVC_V_XVV<OpClass, m.wvrclass, m.vrclass, RS1Class>;
+ def "PseudoVC_V_" # NAME # "_SE_" # m.MX : VPseudoVC_V_XVV<OpClass, m.wvrclass, m.vrclass, RS1Class>, Sched<[!cast<SchedWrite>("WriteVC_V_" # NAME # "_" # m.MX)]>;
+ def "PseudoVC_V_" # NAME # "_" # m.MX : VPseudoVC_V_XVV<OpClass, m.wvrclass, m.vrclass, RS1Class>, Sched<[!cast<SchedWrite>("WriteVC_V_" # NAME # "_" # m.MX)]>;
}
}
}
diff --git a/llvm/lib/Target/RISCV/RISCVSchedRocket.td b/llvm/lib/Target/RISCV/RISCVSchedRocket.td
index e74c7aab7474da..65494e73758d63 100644
--- a/llvm/lib/Target/RISCV/RISCVSchedRocket.td
+++ b/llvm/lib/Target/RISCV/RISCVSchedRocket.td
@@ -261,4 +261,5 @@ defm : UnsupportedSchedZbkx;
defm : UnsupportedSchedZfa;
defm : UnsupportedSchedZfh;
defm : UnsupportedSchedSFB;
+defm : UnsupportedSchedXsfvcp;
}
diff --git a/llvm/lib/Target/RISCV/RISCVSchedSiFive7.td b/llvm/lib/Target/RISCV/RISCVSchedSiFive7.td
index 3586d235bdbbb9..9ba334cff4f6f1 100644
--- a/llvm/lib/Target/RISCV/RISCVSchedSiFive7.td
+++ b/llvm/lib/Target/RISCV/RISCVSchedSiFive7.td
@@ -944,6 +944,52 @@ let Latency = 3 in
def : InstRW<[WriteIALU], (instrs COPY)>;
+// VCIX
+//
+// In principle we don't know the latency of any VCIX instructions. But instead
+// of taking the default of 1, which can lead to issues [1], we assume that they
+// have a fairly high latency.
+//
+// [1] https://github.com/llvm/llvm-project/issues/83391
+foreach mx = SchedMxList in {
+ defvar Cycles = SiFive7GetCyclesDefault<mx>.c;
+ defvar IsWorstCase = SiFive7IsWorstCaseMX<mx, SchedMxList>.c;
+ let Latency = 20, AcquireAtCycles = [0, 1], ReleaseAtCycles = [1, !add(1, Cycles)] in {
+ defm "" : LMULWriteResMX<"WriteVC_V_I", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_V_X", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_V_IV", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_V_VV", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_V_XV", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_V_IVV", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_V_IVW", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_V_VVV", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_V_VVW", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_V_XVV", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_V_XVW", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ foreach f = ["FPR16", "FPR32", "FPR64"] in {
+ defm "" : LMULWriteResMX<"WriteVC_V_" # f # "V", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_V_" # f # "VV", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_V_" # f # "VW", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ }
+ defm "" : LMULWriteResMX<"WriteVC_I", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_X", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_IV", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_VV", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_XV", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_IVV", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_IVW", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_VVV", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_VVW", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_XVV", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_XVW", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ foreach f = ["FPR16", "FPR32", "FPR64"] in {
+ defm "" : LMULWriteResMX<"WriteVC_" # f # "V", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_" # f # "VV", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ defm "" : LMULWriteResMX<"WriteVC_" # f # "VW", [SiFive7VCQ, SiFive7VA], mx, IsWorstCase>;
+ }
+ }
+}
+
//===----------------------------------------------------------------------===//
// Bypass and advance
diff --git a/llvm/lib/Target/RISCV/RISCVSchedSiFiveP400.td b/llvm/lib/Target/RISCV/RISCVSchedSiFiveP400.td
index 8ec2e4ff885ebb..fccdd7e4f3ec2e 100644
--- a/llvm/lib/Target/RISCV/RISCVSchedSiFiveP400.td
+++ b/llvm/lib/Target/RISCV/RISCVSchedSiFiveP400.td
@@ -366,4 +366,5 @@ defm : UnsupportedSchedZbkx;
defm : UnsupportedSchedSFB;
defm : UnsupportedSchedZfa;
defm : UnsupportedSchedV;
+defm : UnsupportedSchedXsfvcp;
}
diff --git a/llvm/lib/Target/RISCV/RISCVSchedSiFiveP600.td b/llvm/lib/Target/RISCV/RISCVSchedSiFiveP600.td
index 54016959d348e3..70fb0ba9bde41a 100644
--- a/llvm/lib/Target/RISCV/RISCVSchedSiFiveP600.td
+++ b/llvm/lib/Target/RISCV/RISCVSchedSiFiveP600.td
@@ -1021,4 +1021,5 @@ defm : UnsupportedSchedZbkb;
defm : UnsupportedSchedZbkx;
defm : UnsupportedSchedSFB;
defm : UnsupportedSchedZfa;
+defm : UnsupportedSchedXsfvcp;
}
diff --git a/llvm/lib/Target/RISCV/RISCVSchedSyntacoreSCR1.td b/llvm/lib/Target/RISCV/RISCVSchedSyntacoreSCR1.td
index 9625d17e0b2600..0885e325f24e68 100644
--- a/llvm/lib/Target/RISCV/RISCVSchedSyntacoreSCR1.td
+++ b/llvm/lib/Target/RISCV/RISCVSchedSyntacoreSCR1.td
@@ -212,4 +212,5 @@ defm : UnsupportedSchedZbkb;
defm : UnsupportedSchedZbkx;
defm : UnsupportedSchedZfa;
defm : UnsupportedSchedZfh;
+defm : UnsupportedSchedXsfvcp;
}
diff --git a/llvm/lib/Target/RISCV/RISCVSchedXiangShanNanHu.td b/llvm/lib/Target/RISCV/RISCVSchedXiangShanNanHu.td
index 4fc7b0335af538..e0f1fab1d6b409 100644
--- a/llvm/lib/Target/RISCV/RISCVSchedXiangShanNanHu.td
+++ b/llvm/lib/Target/RISCV/RISCVSchedXiangShanNanHu.td
@@ -311,4 +311,5 @@ defm : UnsupportedSchedZfa;
defm : UnsupportedSchedZfh;
defm : UnsupportedSchedSFB;
defm : UnsupportedSchedZabha;
+defm : UnsupportedSchedXsfvcp;
}
diff --git a/llvm/lib/Target/RISCV/RISCVSchedule.td b/llvm/lib/Target/RISCV/RISCVSchedule.td
index 1d19624342d2bb..0086557a41fe7c 100644
--- a/llvm/lib/Target/RISCV/RISCVSchedule.td
+++ b/llvm/lib/Target/RISCV/RISCVSchedule.td
@@ -296,3 +296,4 @@ def : ReadAdvance<ReadAtomicHD, 0>;
// Include the scheduler resources for other instruction extensions.
include "RISCVScheduleZb.td"
include "RISCVScheduleV.td"
+include "RISCVScheduleXSf.td"
diff --git a/llvm/lib/Target/RISCV/RISCVScheduleXSf.td b/llvm/lib/Target/RISCV/RISCVScheduleXSf.td
new file mode 100644
index 00000000000000..58d508460f0190
--- /dev/null
+++ b/llvm/lib/Target/RISCV/RISCVScheduleXSf.td
@@ -0,0 +1,59 @@
+//===-- RISCVScheduleXSf.td - Scheduling Definitions XSf ---*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file describes the scheduling information for SiFive extensions.
+//
+//===----------------------------------------------------------------------===//
+
+multiclass LMULSchedWritesVCIX<string id>{
+defm "" : LMULSchedWrites<"WriteVC_" # id>;
+defm "" : LMULSchedWrites<"WriteVC_V_" # id>;
+}
+
+defm "" : LMULSchedWritesVCIX<"I">;
+defm "" : LMULSchedWritesVCIX<"X">;
+defm "" : LMULSchedWritesVCIX<"IV">;
+defm "" : LMULSchedWritesVCIX<"VV">;
+defm "" : LMULSchedWritesVCIX<"XV">;
+defm "" : LMULSchedWritesVCIX<"IVV">;
+defm "" : LMULSchedWritesVCIX<"IVW">;
+defm "" : LMULSchedWritesVCIX<"VVV">;
+defm "" : LMULSchedWritesVCIX<"VVW">;
+defm "" : LMULSchedWritesVCIX<"XVV">;
+defm "" : LMULSchedWritesVCIX<"XVW">;
+foreach f = ["FPR16", "FPR32", "FPR64"] in {
+ defm "" : LMULSchedWritesVCIX<f # "V">;
+ defm "" : LMULSchedWritesVCIX<f # "VV">;
+ defm "" : LMULSchedWritesVCIX<f # "VW">;
+}
+
+multiclass LMULWriteResVCIX<string id, list<ProcResourceKind> resources>{
+defm : LMULWriteRes<"WriteVC_" # id, resources>;
+defm : LMULWriteRes<"WriteVC_V_" # id, resources>;
+}
+
+multiclass UnsupportedSchedXsfvcp {
+let Unsupported = true in {
+defm : LMULWriteResVCIX<"I", []>;
+defm : LMULWriteResVCIX<"X", []>;
+defm : LMULWriteResVCIX<"IV", []>;
+defm : LMULWriteResVCIX<"VV", []>;
+defm : LMULWriteResVCIX<"XV", []>;
+defm : LMULWriteResVCIX<"IVV", []>;
+defm : LMULWriteResVCIX<"IVW", []>;
+defm : LMULWriteResVCIX<"VVV", []>;
+defm : LMULWriteResVCIX<"VVW", []>;
+defm : LMULWriteResVCIX<"XVV", []>;
+defm : LMULWriteResVCIX<"XVW", []>;
+foreach f = ["FPR16", "FPR32", "FPR64"] in {
+ defm : LMULWriteResVCIX<f # "V", []>;
+ defm : LMULWriteResVCIX<f # "VV", []>;
+ defm : LMULWriteResVCIX<f # "VW", []>;
+}
+}
+}
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