[llvm] [NFC]Refactor static data splitter (PR #125758)
Mingming Liu via llvm-commits
llvm-commits at lists.llvm.org
Tue Feb 4 14:40:25 PST 2025
https://github.com/mingmingl-llvm updated https://github.com/llvm/llvm-project/pull/125758
>From 68765b3f37f0aafa018d9e47d6adc55cdf68461b Mon Sep 17 00:00:00 2001
From: mingmingl <mingmingl at google.com>
Date: Tue, 4 Feb 2025 11:28:09 -0800
Subject: [PATCH 1/2] [NFC]Refactor static data splitter
---
llvm/lib/CodeGen/StaticDataSplitter.cpp | 112 ++++++++++++------------
1 file changed, 58 insertions(+), 54 deletions(-)
diff --git a/llvm/lib/CodeGen/StaticDataSplitter.cpp b/llvm/lib/CodeGen/StaticDataSplitter.cpp
index e5bf0a5a3a255f..5d481c7d13e6c3 100644
--- a/llvm/lib/CodeGen/StaticDataSplitter.cpp
+++ b/llvm/lib/CodeGen/StaticDataSplitter.cpp
@@ -46,12 +46,12 @@ class StaticDataSplitter : public MachineFunctionPass {
const MachineBlockFrequencyInfo *MBFI = nullptr;
const ProfileSummaryInfo *PSI = nullptr;
- // Returns true iff any jump table is hot-cold categorized.
- bool splitJumpTables(MachineFunction &MF);
+ void updateStats(bool ProfileAvailable, const MachineJumpTableInfo *MJTI);
+ void updateJumpTableStats(bool ProfileAvailable,
+ const MachineJumpTableInfo &MJTI);
- // Same as above but works on functions with profile information.
- bool splitJumpTablesWithProfiles(const MachineFunction &MF,
- MachineJumpTableInfo &MJTI);
+ // Use profiles to partition static data.
+ bool partitionStaticDataWithProfiles(MachineFunction &MF);
public:
static char ID;
@@ -77,13 +77,22 @@ bool StaticDataSplitter::runOnMachineFunction(MachineFunction &MF) {
MBFI = &getAnalysis<MachineBlockFrequencyInfoWrapperPass>().getMBFI();
PSI = &getAnalysis<ProfileSummaryInfoWrapperPass>().getPSI();
- return splitJumpTables(MF);
+ const bool ProfileAvailable = PSI && PSI->hasProfileSummary() && MBFI &&
+ MF.getFunction().hasProfileData();
+ bool Changed = false;
+
+ if (ProfileAvailable)
+ Changed |= partitionStaticDataWithProfiles(MF);
+
+ updateStats(ProfileAvailable, MF.getJumpTableInfo());
+ return Changed;
}
-bool StaticDataSplitter::splitJumpTablesWithProfiles(
- const MachineFunction &MF, MachineJumpTableInfo &MJTI) {
+bool StaticDataSplitter::partitionStaticDataWithProfiles(MachineFunction &MF) {
int NumChangedJumpTables = 0;
+ MachineJumpTableInfo *MJTI = MF.getJumpTableInfo();
+
// Jump table could be used by either terminating instructions or
// non-terminating ones, so we walk all instructions and use
// `MachineOperand::isJTI()` to identify jump table operands.
@@ -92,63 +101,58 @@ bool StaticDataSplitter::splitJumpTablesWithProfiles(
for (const auto &MBB : MF) {
for (const MachineInstr &I : MBB) {
for (const MachineOperand &Op : I.operands()) {
- if (!Op.isJTI())
- continue;
- const int JTI = Op.getIndex();
- // This is not a source block of jump table.
- if (JTI == -1)
- continue;
-
- auto Hotness = MachineFunctionDataHotness::Hot;
-
- // Hotness is based on source basic block hotness.
- // TODO: PSI APIs are about instruction hotness. Introduce API for data
- // access hotness.
- if (PSI->isColdBlock(&MBB, MBFI))
- Hotness = MachineFunctionDataHotness::Cold;
-
- if (MJTI.updateJumpTableEntryHotness(JTI, Hotness))
- ++NumChangedJumpTables;
+ if (Op.isJTI()) {
+ assert(MJTI != nullptr && "Jump table info is not available.");
+ const int JTI = Op.getIndex();
+ // This is not a source block of jump table.
+ if (JTI == -1)
+ continue;
+
+ auto Hotness = MachineFunctionDataHotness::Hot;
+
+ // Hotness is based on source basic block hotness.
+ // TODO: PSI APIs are about instruction hotness. Introduce API for
+ // data access hotness.
+ if (PSI->isColdBlock(&MBB, MBFI))
+ Hotness = MachineFunctionDataHotness::Cold;
+
+ if (MJTI->updateJumpTableEntryHotness(JTI, Hotness))
+ ++NumChangedJumpTables;
+ }
}
}
}
return NumChangedJumpTables > 0;
}
-bool StaticDataSplitter::splitJumpTables(MachineFunction &MF) {
- MachineJumpTableInfo *MJTI = MF.getJumpTableInfo();
- if (!MJTI || MJTI->getJumpTables().empty())
- return false;
+void StaticDataSplitter::updateJumpTableStats(
+ bool ProfileAvailable, const MachineJumpTableInfo &MJTI) {
- const bool ProfileAvailable = PSI && PSI->hasProfileSummary() && MBFI &&
- MF.getFunction().hasProfileData();
- auto statOnExit = llvm::make_scope_exit([&] {
- if (!AreStatisticsEnabled())
- return;
-
- if (!ProfileAvailable) {
- NumUnknownJumpTables += MJTI->getJumpTables().size();
- return;
- }
+ if (!ProfileAvailable) {
+ NumUnknownJumpTables += MJTI.getJumpTables().size();
+ return;
+ }
- for (size_t JTI = 0; JTI < MJTI->getJumpTables().size(); JTI++) {
- auto Hotness = MJTI->getJumpTables()[JTI].Hotness;
- if (Hotness == MachineFunctionDataHotness::Hot) {
- ++NumHotJumpTables;
- } else {
- assert(Hotness == MachineFunctionDataHotness::Cold &&
- "A jump table is either hot or cold when profile information is "
- "available.");
- ++NumColdJumpTables;
- }
+ for (size_t JTI = 0; JTI < MJTI.getJumpTables().size(); JTI++) {
+ auto Hotness = MJTI.getJumpTables()[JTI].Hotness;
+ if (Hotness == MachineFunctionDataHotness::Hot) {
+ ++NumHotJumpTables;
+ } else {
+ assert(Hotness == MachineFunctionDataHotness::Cold &&
+ "A jump table is either hot or cold when profile information is "
+ "available.");
+ ++NumColdJumpTables;
}
- });
+ }
+}
- // Place jump tables according to block hotness if function has profile data.
- if (ProfileAvailable)
- return splitJumpTablesWithProfiles(MF, *MJTI);
+void StaticDataSplitter::updateStats(bool ProfileAvailable,
+ const MachineJumpTableInfo *MJTI) {
+ if (!AreStatisticsEnabled())
+ return;
- return true;
+ if (MJTI)
+ updateJumpTableStats(ProfileAvailable, *MJTI);
}
char StaticDataSplitter::ID = 0;
>From 079e7a61187a0f54fb93397dae08e4c595741f2c Mon Sep 17 00:00:00 2001
From: mingmingl <mingmingl at google.com>
Date: Tue, 4 Feb 2025 14:34:57 -0800
Subject: [PATCH 2/2] resolve comments
---
llvm/lib/CodeGen/StaticDataSplitter.cpp | 53 +++++++++++++------------
1 file changed, 27 insertions(+), 26 deletions(-)
diff --git a/llvm/lib/CodeGen/StaticDataSplitter.cpp b/llvm/lib/CodeGen/StaticDataSplitter.cpp
index 5d481c7d13e6c3..0965fe85acfc78 100644
--- a/llvm/lib/CodeGen/StaticDataSplitter.cpp
+++ b/llvm/lib/CodeGen/StaticDataSplitter.cpp
@@ -46,9 +46,10 @@ class StaticDataSplitter : public MachineFunctionPass {
const MachineBlockFrequencyInfo *MBFI = nullptr;
const ProfileSummaryInfo *PSI = nullptr;
- void updateStats(bool ProfileAvailable, const MachineJumpTableInfo *MJTI);
- void updateJumpTableStats(bool ProfileAvailable,
- const MachineJumpTableInfo &MJTI);
+ // Update LLVM statistics for a machine function without profiles.
+ void updateStatsWithoutProfiles(const MachineFunction &MF);
+ // Update LLVM statistics for a machine function with profiles.
+ void updateStatsWithProfiles(const MachineFunction &MF);
// Use profiles to partition static data.
bool partitionStaticDataWithProfiles(MachineFunction &MF);
@@ -79,12 +80,15 @@ bool StaticDataSplitter::runOnMachineFunction(MachineFunction &MF) {
const bool ProfileAvailable = PSI && PSI->hasProfileSummary() && MBFI &&
MF.getFunction().hasProfileData();
- bool Changed = false;
- if (ProfileAvailable)
- Changed |= partitionStaticDataWithProfiles(MF);
+ if (!ProfileAvailable) {
+ updateStatsWithoutProfiles(MF);
+ return false;
+ }
+
+ bool Changed = partitionStaticDataWithProfiles(MF);
- updateStats(ProfileAvailable, MF.getJumpTableInfo());
+ updateStatsWithProfiles(MF);
return Changed;
}
@@ -125,34 +129,31 @@ bool StaticDataSplitter::partitionStaticDataWithProfiles(MachineFunction &MF) {
return NumChangedJumpTables > 0;
}
-void StaticDataSplitter::updateJumpTableStats(
- bool ProfileAvailable, const MachineJumpTableInfo &MJTI) {
-
- if (!ProfileAvailable) {
- NumUnknownJumpTables += MJTI.getJumpTables().size();
+void StaticDataSplitter::updateStatsWithProfiles(const MachineFunction &MF) {
+ if (!AreStatisticsEnabled())
return;
- }
- for (size_t JTI = 0; JTI < MJTI.getJumpTables().size(); JTI++) {
- auto Hotness = MJTI.getJumpTables()[JTI].Hotness;
- if (Hotness == MachineFunctionDataHotness::Hot) {
- ++NumHotJumpTables;
- } else {
- assert(Hotness == MachineFunctionDataHotness::Cold &&
- "A jump table is either hot or cold when profile information is "
- "available.");
- ++NumColdJumpTables;
+ if (const MachineJumpTableInfo *MJTI = MF.getJumpTableInfo()) {
+ for (const auto &JumpTable : MJTI->getJumpTables()) {
+ if (JumpTable.Hotness == MachineFunctionDataHotness::Hot) {
+ ++NumHotJumpTables;
+ } else {
+ assert(JumpTable.Hotness == MachineFunctionDataHotness::Cold &&
+ "A jump table is either hot or cold when profile information is "
+ "available.");
+ ++NumColdJumpTables;
+ }
}
}
}
-void StaticDataSplitter::updateStats(bool ProfileAvailable,
- const MachineJumpTableInfo *MJTI) {
+void StaticDataSplitter::updateStatsWithoutProfiles(const MachineFunction &MF) {
if (!AreStatisticsEnabled())
return;
- if (MJTI)
- updateJumpTableStats(ProfileAvailable, *MJTI);
+ if (const MachineJumpTableInfo *MJTI = MF.getJumpTableInfo()) {
+ NumUnknownJumpTables += MJTI->getJumpTables().size();
+ }
}
char StaticDataSplitter::ID = 0;
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