[llvm-branch-commits] [llvm] [AsmPrinter][ELF] Support profile-guided section prefix for jump tables' (read-only) data sections (PR #122215)
https://github.com/williamweixiao edited https://github.com/llvm/llvm-project/pull/122215 ___ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
[llvm-branch-commits] [llvm] [AsmPrinter][ELF] Support profile-guided section prefix for jump tables' (read-only) data sections (PR #122215)
https://github.com/williamweixiao commented: Looks good. Just some trivial comments. https://github.com/llvm/llvm-project/pull/122215 ___ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
[llvm-branch-commits] [llvm] [AsmPrinter][ELF] Support profile-guided section prefix for jump tables' (read-only) data sections (PR #122215)
@@ -3,21 +3,53 @@ ; Stop after 'finalize-isel' for simpler MIR, and lower the minimum number of ; jump table entries so 'switch' needs fewer cases to generate a jump table. -; RUN: llc -stop-after=finalize-isel -min-jump-table-entries=2 %s -o %t.mir -; RUN: llc --run-pass=static-data-splitter -stats -x mir %t.mir -o - 2>&1 | FileCheck %s --check-prefix=STAT +; RUN: llc -mtriple=x86_64-unknown-linux-gnu -stop-after=finalize-isel -min-jump-table-entries=2 %s -o %t.mir +; RUN: llc -mtriple=x86_64-unknown-linux-gnu --run-pass=static-data-splitter -stats -x mir %t.mir -o - 2>&1 | FileCheck %s --check-prefix=STAT -; Tests stat messages are expected. -; TODO: Update test to verify section suffixes when target-lowering and assembler changes are implemented. -; TODO: Also run static-data-splitter pass with -static-data-default-hotness=cold and check data section suffix. - + ; Tests stat messages are expected. ; STAT-DAG: 2 static-data-splitter - Number of cold jump tables seen ; STAT-DAG: 2 static-data-splitter - Number of hot jump tables seen ; STAT-DAG: 1 static-data-splitter - Number of jump tables with unknown hotness -; In function @foo, the 2 switch instructions to jt0.* and jt2.* get lowered to hot jump tables, -; and the 2 switch instructions to jt1.* and jt3.* get lowered to cold jump tables. - -; @func_without_profile doesn't have profiles. It's jump table hotness is unknown. +; When 'partition-static-data-sections' is enabled, static data splitter pass will +; categorize jump tables and assembly printer will place hot jump tables in the +; `.rodata.hot`-prefixed section, and cold ones in the `.rodata.unlikely`-prefixed section. +; Section names will optionally have `.` if -function-sections is enabled. +; RUN: llc -mtriple=x86_64-unknown-linux-gnu -enable-split-machine-functions -partition-static-data-sections=true -function-sections=true -min-jump-table-entries=2 -unique-section-names=false %s -o - 2>&1 | FileCheck %s --check-prefixes=LINEAR,JT +; RUN: llc -mtriple=x86_64-unknown-linux-gnu -enable-split-machine-functions -partition-static-data-sections=true -function-sections=true -min-jump-table-entries=2 %s -o - 2>&1 | FileCheck %s --check-prefixes=FUNC,JT,DEFAULTHOT +; RUN: llc -mtriple=x86_64-unknown-linux-gnu -enable-split-machine-functions -partition-static-data-sections=true -function-sections=false -min-jump-table-entries=2 %s -o - 2>&1 | FileCheck %s --check-prefixes=FUNCLESS,JT --implicit-check-not=unique + +; Tests that `-static-data-default-hotness` can override hotness for data with +; unknown hotness. +; RUN: llc -mtriple=x86_64-unknown-linux-gnu -enable-split-machine-functions -partition-static-data-sections=true -min-jump-table-entries=2 -static-data-default-hotness=cold -function-sections=true %s -o - 2>&1 | FileCheck %s --check-prefixes=FUNC,JT,DEFAULTCOLD + +; LINEAR:.section .rodata.hot,"a",@progbits,unique,2 +; FUNC: .section .rodata.hot.foo,"a",@progbits +; FUNCLESS: .section .rodata.hot,"a",@progbits +; JT: .LJTI0_0: +; JT: .LJTI0_2: +; LINEAR: .section.rodata.unlikely,"a",@progbits,unique,3 +; FUNC: .section .rodata.unlikely.foo,"a",@progbits +; FUNCLESS: .section .rodata.unlikely,"a",@progbits +; JT: .LJTI0_1: +; JT: .LJTI0_3: +; DEFAULTHOT: .section .rodata.hot.func_without_entry_count,"a",@progbits williamweixiao wrote: According referenced function is inside ".section .text.func_without_entry_count" but its data in ".section .rodata.hot.func_without_entry_count". There seems to be some inconsistency here. https://github.com/llvm/llvm-project/pull/122215 ___ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
[llvm-branch-commits] [llvm] [AsmPrinter][ELF] Support profile-guided section prefix for jump tables' (read-only) data sections (PR #122215)
@@ -1261,9 +1261,9 @@ void TargetPassConfig::addMachinePasses() {
"performance.\n";
}
}
-addPass(createMachineFunctionSplitterPass());
-if (SplitStaticData)
+if (SplitStaticData || TM->Options.EnableStaticDataPartitioning)
addPass(createStaticDataSplitterPass());
+addPass(createMachineFunctionSplitterPass());
williamweixiao wrote:
Any specific reason to reorder "createStaticDataSplitterPass" before
"createMachineFunctionSplitterPass"?
https://github.com/llvm/llvm-project/pull/122215
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[llvm-branch-commits] [llvm] [AArch64AsmPrinter]Place jump tables into hot/unlikely-prefixed data sections for aarch64 (PR #126018)
https://github.com/williamweixiao approved this pull request. https://github.com/llvm/llvm-project/pull/126018 ___ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
[llvm-branch-commits] [llvm] [CodeGen][StaticDataSplitter]Support constant pool partitioning (PR #129781)
@@ -112,21 +117,52 @@ bool
StaticDataSplitter::runOnMachineFunction(MachineFunction &MF) {
return Changed;
}
+const Constant *
+StaticDataSplitter::getConstant(const MachineOperand &Op,
+const TargetMachine &TM,
+const MachineConstantPool *MCP) {
+ if (!Op.isGlobal() && !Op.isCPI())
+return nullptr;
+
+ if (Op.isGlobal()) {
+// Find global variables with local linkage.
+const GlobalVariable *GV = getLocalLinkageGlobalVariable(Op.getGlobal());
+// Skip 'special' global variables conservatively because they are
+// often handled specially, and skip those not in static data
+// sections.
+if (!GV || GV->getName().starts_with("llvm.") ||
+!inStaticDataSection(GV, TM))
+ return nullptr;
+return GV;
williamweixiao wrote:
What's the motivation to handle "GlobalVariable" here? Any test to cover it?
https://github.com/llvm/llvm-project/pull/129781
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[llvm-branch-commits] [llvm] [CodeGen][StaticDataSplitter]Support constant pool partitioning (PR #129781)
@@ -112,21 +117,52 @@ bool
StaticDataSplitter::runOnMachineFunction(MachineFunction &MF) {
return Changed;
}
+const Constant *
+StaticDataSplitter::getConstant(const MachineOperand &Op,
+const TargetMachine &TM,
+const MachineConstantPool *MCP) {
+ if (!Op.isGlobal() && !Op.isCPI())
+return nullptr;
+
+ if (Op.isGlobal()) {
+// Find global variables with local linkage.
+const GlobalVariable *GV = getLocalLinkageGlobalVariable(Op.getGlobal());
+// Skip 'special' global variables conservatively because they are
+// often handled specially, and skip those not in static data
+// sections.
+if (!GV || GV->getName().starts_with("llvm.") ||
+!inStaticDataSection(GV, TM))
+ return nullptr;
+return GV;
+ }
+ assert(Op.isCPI() && "Op must be constant pool index in this branch");
+ int CPI = Op.getIndex();
+ if (CPI == -1)
+return nullptr;
+
+ assert(MCP != nullptr && "Constant pool info is not available.");
+ const MachineConstantPoolEntry &CPE = MCP->getConstants()[CPI];
+
+ if (CPE.isMachineConstantPoolEntry())
+return nullptr;
+
+ return CPE.Val.ConstVal;
+}
+
bool StaticDataSplitter::partitionStaticDataWithProfiles(MachineFunction &MF) {
int NumChangedJumpTables = 0;
- const TargetMachine &TM = MF.getTarget();
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.
- // Similarly, `MachineOperand::isCPI()` can identify constant pool usages
- // in the same loop.
+ // Similarly, `MachineOperand::isCPI()` is used to identify constant pool
+ // usages in the same loop.
for (const auto &MBB : MF) {
for (const MachineInstr &I : MBB) {
for (const MachineOperand &Op : I.operands()) {
-if (!Op.isJTI() && !Op.isGlobal())
+if (!Op.isJTI() && !Op.isGlobal() && !Op.isCPI())
continue;
std::optional Count = MBFI->getBlockProfileCount(&MBB);
williamweixiao wrote:
line 168 can be hoisted out to the outmost loop (i.e line 163).
https://github.com/llvm/llvm-project/pull/129781
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[llvm-branch-commits] [llvm] [CodeGen][StaticDataSplitter]Support constant pool partitioning (PR #129781)
@@ -148,17 +184,9 @@ bool
StaticDataSplitter::partitionStaticDataWithProfiles(MachineFunction &MF) {
if (MJTI->updateJumpTableEntryHotness(JTI, Hotness))
++NumChangedJumpTables;
-} else {
- // Find global variables with local linkage.
- const GlobalVariable *GV =
- getLocalLinkageGlobalVariable(Op.getGlobal());
- // Skip 'special' global variables conservatively because they are
- // often handled specially, and skip those not in static data
- // sections.
- if (!GV || GV->getName().starts_with("llvm.") ||
- !inStaticDataSection(GV, TM))
-continue;
- SDPI->addConstantProfileCount(GV, Count);
+} else if (const Constant *C =
+ getConstant(Op, MF.getTarget(), MF.getConstantPool())) {
+ SDPI->addConstantProfileCount(C, Count);
williamweixiao wrote:
yes, we don't need to update "NumChangedJumpTables" here. but why do we need to
return "true" or "false" for this function?
https://github.com/llvm/llvm-project/pull/129781
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[llvm-branch-commits] [llvm] [CodeGen][StaticDataSplitter]Support constant pool partitioning (PR #129781)
https://github.com/williamweixiao approved this pull request. https://github.com/llvm/llvm-project/pull/129781 ___ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
