[llvm] [TableGen] Add a maps from Write/ReadType to the parent WriteRes/ReadAdvance. NFC (PR #123876)
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Tue Jan 21 20:25:32 PST 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-backend-risc-v
Author: Craig Topper (topperc)
<details>
<summary>Changes</summary>
Use this to improve performance of SubtargetEmitter::findWriteResources
and SubtargetEmitter::findReadAdvance. Now we can do a map lookup
instead of a linear search through all WriteRes/ReadAdvance records.
This reduces the build time of RISCVGenSubtargetInfo.inc on my
machine from 43 seconds to 10 seconds.
Stacked on #<!-- -->123865
---
Full diff: https://github.com/llvm/llvm-project/pull/123876.diff
4 Files Affected:
- (modified) llvm/lib/Target/RISCV/RISCVSchedMIPSP8700.td (-1)
- (modified) llvm/utils/TableGen/Common/CodeGenSchedule.cpp (+16)
- (modified) llvm/utils/TableGen/Common/CodeGenSchedule.h (+6)
- (modified) llvm/utils/TableGen/SubtargetEmitter.cpp (+31-32)
``````````diff
diff --git a/llvm/lib/Target/RISCV/RISCVSchedMIPSP8700.td b/llvm/lib/Target/RISCV/RISCVSchedMIPSP8700.td
index 550f83a59b8b0e..ab6402dc96af10 100644
--- a/llvm/lib/Target/RISCV/RISCVSchedMIPSP8700.td
+++ b/llvm/lib/Target/RISCV/RISCVSchedMIPSP8700.td
@@ -125,7 +125,6 @@ def : WriteRes<WriteCSR, [p8700ALQ]>;
// Handle CTI Pipeline.
def : WriteRes<WriteJmp, [p8700IssueCTI]>;
-def : WriteRes<WriteJalr, [p8700IssueCTI]>;
let Latency = 2 in {
def : WriteRes<WriteJal, [p8700IssueCTI]>;
def : WriteRes<WriteJalr, [p8700IssueCTI]>;
diff --git a/llvm/utils/TableGen/Common/CodeGenSchedule.cpp b/llvm/utils/TableGen/Common/CodeGenSchedule.cpp
index 8eaba05e65ce92..2a42262f865cb9 100644
--- a/llvm/utils/TableGen/Common/CodeGenSchedule.cpp
+++ b/llvm/utils/TableGen/Common/CodeGenSchedule.cpp
@@ -2112,6 +2112,14 @@ void CodeGenSchedModels::addWriteRes(const Record *ProcWriteResDef,
return;
WRDefs.push_back(ProcWriteResDef);
+ if (ProcWriteResDef->isSubClassOf("WriteRes")) {
+ auto &WRMap = ProcModels[PIdx].WriteResMap;
+ const Record *WRDef = ProcWriteResDef->getValueAsDef("WriteType");
+ if (!WRMap.try_emplace(WRDef, ProcWriteResDef).second)
+ PrintFatalError(ProcWriteResDef->getLoc(),
+ "WriteType already used in another WriteRes");
+ }
+
// Visit ProcResourceKinds referenced by the newly discovered WriteRes.
for (const Record *ProcResDef :
ProcWriteResDef->getValueAsListOfDefs("ProcResources")) {
@@ -2135,6 +2143,14 @@ void CodeGenSchedModels::addReadAdvance(const Record *ProcReadAdvanceDef,
if (is_contained(RADefs, ProcReadAdvanceDef))
return;
RADefs.push_back(ProcReadAdvanceDef);
+
+ if (ProcReadAdvanceDef->isSubClassOf("ReadAdvance")) {
+ auto &RAMap = ProcModels[PIdx].ReadAdvanceMap;
+ const Record *RADef = ProcReadAdvanceDef->getValueAsDef("ReadType");
+ if (!RAMap.try_emplace(RADef, ProcReadAdvanceDef).second)
+ PrintFatalError(ProcReadAdvanceDef->getLoc(),
+ "ReadType already used in another ReadAdvance");
+ }
}
unsigned CodeGenProcModel::getProcResourceIdx(const Record *PRDef) const {
diff --git a/llvm/utils/TableGen/Common/CodeGenSchedule.h b/llvm/utils/TableGen/Common/CodeGenSchedule.h
index fed8b3e1ccb8a6..467b77e8acba31 100644
--- a/llvm/utils/TableGen/Common/CodeGenSchedule.h
+++ b/llvm/utils/TableGen/Common/CodeGenSchedule.h
@@ -244,6 +244,12 @@ struct CodeGenProcModel {
ConstRecVec WriteResDefs;
ConstRecVec ReadAdvanceDefs;
+ // Map from the WriteType field to the parent WriteRes record.
+ DenseMap<const Record *, const Record *> WriteResMap;
+
+ // Map from the ReadType field to the parent ReadAdvance record.
+ DenseMap<const Record *, const Record *> ReadAdvanceMap;
+
// Per-operand machine model resources associated with this processor.
ConstRecVec ProcResourceDefs;
diff --git a/llvm/utils/TableGen/SubtargetEmitter.cpp b/llvm/utils/TableGen/SubtargetEmitter.cpp
index 1120f06875c778..3db3ae65cc5557 100644
--- a/llvm/utils/TableGen/SubtargetEmitter.cpp
+++ b/llvm/utils/TableGen/SubtargetEmitter.cpp
@@ -943,24 +943,23 @@ SubtargetEmitter::findWriteResources(const CodeGenSchedRW &SchedWrite,
// Check this processor's list of write resources.
const Record *ResDef = nullptr;
- for (const Record *WR : ProcModel.WriteResDefs) {
- if (!WR->isSubClassOf("WriteRes"))
- continue;
- const Record *WRDef = WR->getValueAsDef("WriteType");
- if (AliasDef == WRDef || SchedWrite.TheDef == WRDef) {
- if (ResDef) {
- PrintFatalError(WR->getLoc(), "Resources are defined for both "
- "SchedWrite and its alias on processor " +
- ProcModel.ModelName);
- }
- ResDef = WR;
- // If there is no AliasDef and we find a match, we can early exit since
- // there is no need to verify whether there are resources defined for both
- // SchedWrite and its alias.
- if (!AliasDef)
- break;
+
+ auto I = ProcModel.WriteResMap.find(SchedWrite.TheDef);
+ if (I != ProcModel.WriteResMap.end())
+ ResDef = I->second;
+
+ if (AliasDef) {
+ I = ProcModel.WriteResMap.find(AliasDef);
+ if (I != ProcModel.WriteResMap.end()) {
+ if (ResDef)
+ PrintFatalError(I->second->getLoc(),
+ "Resources are defined for both SchedWrite and its "
+ "alias on processor " +
+ ProcModel.ModelName);
+ ResDef = I->second;
}
}
+
// TODO: If ProcModel has a base model (previous generation processor),
// then call FindWriteResources recursively with that model here.
if (!ResDef) {
@@ -1003,24 +1002,24 @@ SubtargetEmitter::findReadAdvance(const CodeGenSchedRW &SchedRead,
// Check this processor's ReadAdvanceList.
const Record *ResDef = nullptr;
- for (const Record *RA : ProcModel.ReadAdvanceDefs) {
- if (!RA->isSubClassOf("ReadAdvance"))
- continue;
- const Record *RADef = RA->getValueAsDef("ReadType");
- if (AliasDef == RADef || SchedRead.TheDef == RADef) {
- if (ResDef) {
- PrintFatalError(RA->getLoc(), "Resources are defined for both "
- "SchedRead and its alias on processor " +
- ProcModel.ModelName);
- }
- ResDef = RA;
- // If there is no AliasDef and we find a match, we can early exit since
- // there is no need to verify whether there are resources defined for both
- // SchedRead and its alias.
- if (!AliasDef)
- break;
+
+ auto I = ProcModel.ReadAdvanceMap.find(SchedRead.TheDef);
+ if (I != ProcModel.ReadAdvanceMap.end())
+ ResDef = I->second;
+
+ if (AliasDef) {
+ I = ProcModel.ReadAdvanceMap.find(AliasDef);
+ if (I != ProcModel.ReadAdvanceMap.end()) {
+ if (ResDef)
+ PrintFatalError(
+ I->second->getLoc(),
+ "Resources are defined for both SchedRead and its alias on "
+ "processor " +
+ ProcModel.ModelName);
+ ResDef = I->second;
}
}
+
// TODO: If ProcModel has a base model (previous generation processor),
// then call FindReadAdvance recursively with that model here.
if (!ResDef && SchedRead.TheDef->getName() != "ReadDefault") {
``````````
</details>
https://github.com/llvm/llvm-project/pull/123876
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