[llvm] [PassBuilder] Table-drive pass name printing (PR #202656)
David Zbarsky via llvm-commits
llvm-commits at lists.llvm.org
Thu Jun 11 10:48:01 PDT 2026
https://github.com/dzbarsky updated https://github.com/llvm/llvm-project/pull/202656
>From 35d4ce60cf4cdfbf22954d6a4dad7c70e6ea9f40 Mon Sep 17 00:00:00 2001
From: David Zbarsky <dzbarsky at gmail.com>
Date: Mon, 8 Jun 2026 23:39:29 -0400
Subject: [PATCH 1/2] [PassBuilder] Table-drive pass name printing
Replace the macro-expanded raw_ostream operations in PassBuilder::printPassNames with static pass-name arrays and two shared noinline printing loops. Preserve the generated category order and the exact spelling of parameterized pass names.
The change only executes when a client requests the pass-name listing; normal pipeline parsing and optimization do not access the new tables or helpers.
A stripped opt binary shrinks from 115,493,720 to 115,394,640 bytes, saving 99,080 bytes. The linked __TEXT section shrinks by 98,304 bytes.
Validate byte-identical opt --print-passes output, compile PassBuilder.cpp, and compare the linked stripped opt binaries. Normal optimization performance is unaffected because printPassNames is not called by optimization pipelines.
---
llvm/lib/Passes/PassBuilder.cpp | 111 +++++++++++++++++++++++++-------
1 file changed, 88 insertions(+), 23 deletions(-)
diff --git a/llvm/lib/Passes/PassBuilder.cpp b/llvm/lib/Passes/PassBuilder.cpp
index f7db63ef8bf74..ab4ed2f19e5e3 100644
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -2796,92 +2796,157 @@ PassBuilder::parseRegAllocFilter(StringRef FilterName) {
return std::nullopt;
}
-static void printPassName(StringRef PassName, raw_ostream &OS) {
- OS << " " << PassName << "\n";
+namespace {
+struct PassNameWithParams {
+ StringLiteral Name;
+ StringLiteral Params;
+};
+} // namespace
+
+LLVM_ATTRIBUTE_NOINLINE static void
+printPassNameList(ArrayRef<StringLiteral> PassNames, raw_ostream &OS) {
+ for (StringRef PassName : PassNames)
+ OS << " " << PassName << '\n';
}
-static void printPassName(StringRef PassName, StringRef Params,
- raw_ostream &OS) {
- OS << " " << PassName << "<" << Params << ">\n";
+
+LLVM_ATTRIBUTE_NOINLINE static void
+printPassNameList(ArrayRef<PassNameWithParams> PassNames, raw_ostream &OS) {
+ for (const PassNameWithParams &PassName : PassNames)
+ OS << " " << PassName.Name << "<" << PassName.Params << ">\n";
}
void PassBuilder::printPassNames(raw_ostream &OS) {
// TODO: print pass descriptions when they are available
OS << "Module passes:\n";
-#define MODULE_PASS(NAME, CREATE_PASS) printPassName(NAME, OS);
+ static constexpr StringLiteral ModulePassNames[] = {
+#define MODULE_PASS(NAME, CREATE_PASS) NAME,
#include "PassRegistry.def"
+ };
+ printPassNameList(ModulePassNames, OS);
OS << "Module passes with params:\n";
+ static constexpr PassNameWithParams ModulePassNamesWithParams[] = {
#define MODULE_PASS_WITH_PARAMS(NAME, CLASS, CREATE_PASS, PARSER, PARAMS) \
- printPassName(NAME, PARAMS, OS);
+ {NAME, PARAMS},
#include "PassRegistry.def"
+ };
+ printPassNameList(ModulePassNamesWithParams, OS);
OS << "Module analyses:\n";
-#define MODULE_ANALYSIS(NAME, CREATE_PASS) printPassName(NAME, OS);
+ static constexpr StringLiteral ModuleAnalysisNames[] = {
+#define MODULE_ANALYSIS(NAME, CREATE_PASS) NAME,
#include "PassRegistry.def"
+ };
+ printPassNameList(ModuleAnalysisNames, OS);
OS << "Module alias analyses:\n";
-#define MODULE_ALIAS_ANALYSIS(NAME, CREATE_PASS) printPassName(NAME, OS);
+ static constexpr StringLiteral ModuleAliasAnalysisNames[] = {
+#define MODULE_ALIAS_ANALYSIS(NAME, CREATE_PASS) NAME,
#include "PassRegistry.def"
+ };
+ printPassNameList(ModuleAliasAnalysisNames, OS);
OS << "CGSCC passes:\n";
-#define CGSCC_PASS(NAME, CREATE_PASS) printPassName(NAME, OS);
+ static constexpr StringLiteral CGSCCPassNames[] = {
+#define CGSCC_PASS(NAME, CREATE_PASS) NAME,
#include "PassRegistry.def"
+ };
+ printPassNameList(CGSCCPassNames, OS);
OS << "CGSCC passes with params:\n";
+ static constexpr PassNameWithParams CGSCCPassNamesWithParams[] = {
#define CGSCC_PASS_WITH_PARAMS(NAME, CLASS, CREATE_PASS, PARSER, PARAMS) \
- printPassName(NAME, PARAMS, OS);
+ {NAME, PARAMS},
#include "PassRegistry.def"
+ };
+ printPassNameList(CGSCCPassNamesWithParams, OS);
OS << "CGSCC analyses:\n";
-#define CGSCC_ANALYSIS(NAME, CREATE_PASS) printPassName(NAME, OS);
+ static constexpr StringLiteral CGSCCAnalysisNames[] = {
+#define CGSCC_ANALYSIS(NAME, CREATE_PASS) NAME,
#include "PassRegistry.def"
+ };
+ printPassNameList(CGSCCAnalysisNames, OS);
OS << "Function passes:\n";
-#define FUNCTION_PASS(NAME, CREATE_PASS) printPassName(NAME, OS);
+ static constexpr StringLiteral FunctionPassNames[] = {
+#define FUNCTION_PASS(NAME, CREATE_PASS) NAME,
#include "PassRegistry.def"
+ };
+ printPassNameList(FunctionPassNames, OS);
OS << "Function passes with params:\n";
+ static constexpr PassNameWithParams FunctionPassNamesWithParams[] = {
#define FUNCTION_PASS_WITH_PARAMS(NAME, CLASS, CREATE_PASS, PARSER, PARAMS) \
- printPassName(NAME, PARAMS, OS);
+ {NAME, PARAMS},
#include "PassRegistry.def"
+ };
+ printPassNameList(FunctionPassNamesWithParams, OS);
OS << "Function analyses:\n";
-#define FUNCTION_ANALYSIS(NAME, CREATE_PASS) printPassName(NAME, OS);
+ static constexpr StringLiteral FunctionAnalysisNames[] = {
+#define FUNCTION_ANALYSIS(NAME, CREATE_PASS) NAME,
#include "PassRegistry.def"
+ };
+ printPassNameList(FunctionAnalysisNames, OS);
OS << "Function alias analyses:\n";
-#define FUNCTION_ALIAS_ANALYSIS(NAME, CREATE_PASS) printPassName(NAME, OS);
+ static constexpr StringLiteral FunctionAliasAnalysisNames[] = {
+#define FUNCTION_ALIAS_ANALYSIS(NAME, CREATE_PASS) NAME,
#include "PassRegistry.def"
+ };
+ printPassNameList(FunctionAliasAnalysisNames, OS);
OS << "LoopNest passes:\n";
-#define LOOPNEST_PASS(NAME, CREATE_PASS) printPassName(NAME, OS);
+ static constexpr StringLiteral LoopNestPassNames[] = {
+#define LOOPNEST_PASS(NAME, CREATE_PASS) NAME,
#include "PassRegistry.def"
+ };
+ printPassNameList(LoopNestPassNames, OS);
OS << "Loop passes:\n";
-#define LOOP_PASS(NAME, CREATE_PASS) printPassName(NAME, OS);
+ static constexpr StringLiteral LoopPassNames[] = {
+#define LOOP_PASS(NAME, CREATE_PASS) NAME,
#include "PassRegistry.def"
+ };
+ printPassNameList(LoopPassNames, OS);
OS << "Loop passes with params:\n";
+ static constexpr PassNameWithParams LoopPassNamesWithParams[] = {
#define LOOP_PASS_WITH_PARAMS(NAME, CLASS, CREATE_PASS, PARSER, PARAMS) \
- printPassName(NAME, PARAMS, OS);
+ {NAME, PARAMS},
#include "PassRegistry.def"
+ };
+ printPassNameList(LoopPassNamesWithParams, OS);
OS << "Loop analyses:\n";
-#define LOOP_ANALYSIS(NAME, CREATE_PASS) printPassName(NAME, OS);
+ static constexpr StringLiteral LoopAnalysisNames[] = {
+#define LOOP_ANALYSIS(NAME, CREATE_PASS) NAME,
#include "PassRegistry.def"
+ };
+ printPassNameList(LoopAnalysisNames, OS);
OS << "Machine module passes (WIP):\n";
-#define MACHINE_MODULE_PASS(NAME, CREATE_PASS) printPassName(NAME, OS);
+ static constexpr StringLiteral MachineModulePassNames[] = {
+#define MACHINE_MODULE_PASS(NAME, CREATE_PASS) NAME,
#include "llvm/Passes/MachinePassRegistry.def"
+ ""};
+ printPassNameList(ArrayRef(MachineModulePassNames).drop_back(), OS);
OS << "Machine function passes (WIP):\n";
-#define MACHINE_FUNCTION_PASS(NAME, CREATE_PASS) printPassName(NAME, OS);
+ static constexpr StringLiteral MachineFunctionPassNames[] = {
+#define MACHINE_FUNCTION_PASS(NAME, CREATE_PASS) NAME,
#include "llvm/Passes/MachinePassRegistry.def"
+ };
+ printPassNameList(MachineFunctionPassNames, OS);
OS << "Machine function analyses (WIP):\n";
-#define MACHINE_FUNCTION_ANALYSIS(NAME, CREATE_PASS) printPassName(NAME, OS);
+ static constexpr StringLiteral MachineFunctionAnalysisNames[] = {
+#define MACHINE_FUNCTION_ANALYSIS(NAME, CREATE_PASS) NAME,
#include "llvm/Passes/MachinePassRegistry.def"
+ };
+ printPassNameList(MachineFunctionAnalysisNames, OS);
}
void PassBuilder::registerParseTopLevelPipelineCallback(
>From d909e47d114fb15212bacb8fec405c19a87909f2 Mon Sep 17 00:00:00 2001
From: David Zbarsky <dzbarsky at gmail.com>
Date: Thu, 11 Jun 2026 13:47:12 -0400
Subject: [PATCH 2/2] [PassBuilder] Table-drive pass name printing
Replace the address-bearing StringLiteral arrays with character blobs and local
StringTable views. Preserve the shared noinline printing loops, generated
category order, and exact parameterized pass-name spelling.
Relative to the StringLiteral array implementation, PassBuilder.cpp.o shrinks
by 5,032 bytes and 578 relocations. Linked opt runtime rebases decrease by 603,
restoring the pre-change fixup count. The fully stripped opt binary gives back
16,496 bytes but still shrinks by 99,072 bytes from the pre-change baseline;
the linked __TEXT segment still shrinks by 98,304 bytes.
Validate byte-identical opt --print-passes output, compile PassBuilder.cpp, and
compare matched linked opt binaries and fixups.
---
llvm/lib/Passes/PassBuilder.cpp | 139 ++++++++++++++++----------------
1 file changed, 71 insertions(+), 68 deletions(-)
diff --git a/llvm/lib/Passes/PassBuilder.cpp b/llvm/lib/Passes/PassBuilder.cpp
index 7a71b5d58ec05..0f288a2124b7b 100644
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -16,6 +16,7 @@
#include "llvm/Passes/PassBuilder.h"
#include "llvm/ADT/StringSwitch.h"
+#include "llvm/ADT/StringTable.h"
#include "llvm/Analysis/AliasAnalysisEvaluator.h"
#include "llvm/Analysis/AliasSetTracker.h"
#include "llvm/Analysis/AssumptionCache.h"
@@ -2850,157 +2851,159 @@ PassBuilder::parseRegAllocFilter(StringRef FilterName) {
return std::nullopt;
}
-namespace {
-struct PassNameWithParams {
- StringLiteral Name;
- StringLiteral Params;
-};
-} // namespace
-
-LLVM_ATTRIBUTE_NOINLINE static void
-printPassNameList(ArrayRef<StringLiteral> PassNames, raw_ostream &OS) {
- for (StringRef PassName : PassNames)
+LLVM_ATTRIBUTE_NOINLINE static void printPassNameList(StringTable PassNames,
+ raw_ostream &OS) {
+ for (StringRef PassName : drop_begin(PassNames))
OS << " " << PassName << '\n';
}
LLVM_ATTRIBUTE_NOINLINE static void
-printPassNameList(ArrayRef<PassNameWithParams> PassNames, raw_ostream &OS) {
- for (const PassNameWithParams &PassName : PassNames)
- OS << " " << PassName.Name << "<" << PassName.Params << ">\n";
+printPassNameListWithParams(StringTable PassNames, raw_ostream &OS) {
+ auto I = PassNames.begin();
+ auto End = PassNames.end();
+ ++I;
+ while (I != End) {
+ StringRef Name = *I;
+ ++I;
+ assert(I != End);
+ StringRef Params = *I;
+ ++I;
+ OS << " " << Name << '<' << Params << ">\n";
+ }
}
void PassBuilder::printPassNames(raw_ostream &OS) {
// TODO: print pass descriptions when they are available
OS << "Module passes:\n";
- static constexpr StringLiteral ModulePassNames[] = {
-#define MODULE_PASS(NAME, CREATE_PASS) NAME,
+ static constexpr char ModulePassNames[] = {"\0"
+#define MODULE_PASS(NAME, CREATE_PASS) NAME "\0"
#include "PassRegistry.def"
};
- printPassNameList(ModulePassNames, OS);
+ printPassNameList(StringTable(ModulePassNames), OS);
OS << "Module passes with params:\n";
- static constexpr PassNameWithParams ModulePassNamesWithParams[] = {
+ static constexpr char ModulePassNamesWithParams[] = {"\0"
#define MODULE_PASS_WITH_PARAMS(NAME, CLASS, CREATE_PASS, PARSER, PARAMS) \
- {NAME, PARAMS},
+ NAME "\0" PARAMS "\0"
#include "PassRegistry.def"
};
- printPassNameList(ModulePassNamesWithParams, OS);
+ printPassNameListWithParams(StringTable(ModulePassNamesWithParams), OS);
OS << "Module analyses:\n";
- static constexpr StringLiteral ModuleAnalysisNames[] = {
-#define MODULE_ANALYSIS(NAME, CREATE_PASS) NAME,
+ static constexpr char ModuleAnalysisNames[] = {"\0"
+#define MODULE_ANALYSIS(NAME, CREATE_PASS) NAME "\0"
#include "PassRegistry.def"
};
- printPassNameList(ModuleAnalysisNames, OS);
+ printPassNameList(StringTable(ModuleAnalysisNames), OS);
OS << "Module alias analyses:\n";
- static constexpr StringLiteral ModuleAliasAnalysisNames[] = {
-#define MODULE_ALIAS_ANALYSIS(NAME, CREATE_PASS) NAME,
+ static constexpr char ModuleAliasAnalysisNames[] = {"\0"
+#define MODULE_ALIAS_ANALYSIS(NAME, CREATE_PASS) NAME "\0"
#include "PassRegistry.def"
};
- printPassNameList(ModuleAliasAnalysisNames, OS);
+ printPassNameList(StringTable(ModuleAliasAnalysisNames), OS);
OS << "CGSCC passes:\n";
- static constexpr StringLiteral CGSCCPassNames[] = {
-#define CGSCC_PASS(NAME, CREATE_PASS) NAME,
+ static constexpr char CGSCCPassNames[] = {"\0"
+#define CGSCC_PASS(NAME, CREATE_PASS) NAME "\0"
#include "PassRegistry.def"
};
- printPassNameList(CGSCCPassNames, OS);
+ printPassNameList(StringTable(CGSCCPassNames), OS);
OS << "CGSCC passes with params:\n";
- static constexpr PassNameWithParams CGSCCPassNamesWithParams[] = {
+ static constexpr char CGSCCPassNamesWithParams[] = {"\0"
#define CGSCC_PASS_WITH_PARAMS(NAME, CLASS, CREATE_PASS, PARSER, PARAMS) \
- {NAME, PARAMS},
+ NAME "\0" PARAMS "\0"
#include "PassRegistry.def"
};
- printPassNameList(CGSCCPassNamesWithParams, OS);
+ printPassNameListWithParams(StringTable(CGSCCPassNamesWithParams), OS);
OS << "CGSCC analyses:\n";
- static constexpr StringLiteral CGSCCAnalysisNames[] = {
-#define CGSCC_ANALYSIS(NAME, CREATE_PASS) NAME,
+ static constexpr char CGSCCAnalysisNames[] = {"\0"
+#define CGSCC_ANALYSIS(NAME, CREATE_PASS) NAME "\0"
#include "PassRegistry.def"
};
- printPassNameList(CGSCCAnalysisNames, OS);
+ printPassNameList(StringTable(CGSCCAnalysisNames), OS);
OS << "Function passes:\n";
- static constexpr StringLiteral FunctionPassNames[] = {
-#define FUNCTION_PASS(NAME, CREATE_PASS) NAME,
+ static constexpr char FunctionPassNames[] = {"\0"
+#define FUNCTION_PASS(NAME, CREATE_PASS) NAME "\0"
#include "PassRegistry.def"
};
- printPassNameList(FunctionPassNames, OS);
+ printPassNameList(StringTable(FunctionPassNames), OS);
OS << "Function passes with params:\n";
- static constexpr PassNameWithParams FunctionPassNamesWithParams[] = {
+ static constexpr char FunctionPassNamesWithParams[] = {"\0"
#define FUNCTION_PASS_WITH_PARAMS(NAME, CLASS, CREATE_PASS, PARSER, PARAMS) \
- {NAME, PARAMS},
+ NAME "\0" PARAMS "\0"
#include "PassRegistry.def"
};
- printPassNameList(FunctionPassNamesWithParams, OS);
+ printPassNameListWithParams(StringTable(FunctionPassNamesWithParams), OS);
OS << "Function analyses:\n";
- static constexpr StringLiteral FunctionAnalysisNames[] = {
-#define FUNCTION_ANALYSIS(NAME, CREATE_PASS) NAME,
+ static constexpr char FunctionAnalysisNames[] = {"\0"
+#define FUNCTION_ANALYSIS(NAME, CREATE_PASS) NAME "\0"
#include "PassRegistry.def"
};
- printPassNameList(FunctionAnalysisNames, OS);
+ printPassNameList(StringTable(FunctionAnalysisNames), OS);
OS << "Function alias analyses:\n";
- static constexpr StringLiteral FunctionAliasAnalysisNames[] = {
-#define FUNCTION_ALIAS_ANALYSIS(NAME, CREATE_PASS) NAME,
+ static constexpr char FunctionAliasAnalysisNames[] = {"\0"
+#define FUNCTION_ALIAS_ANALYSIS(NAME, CREATE_PASS) NAME "\0"
#include "PassRegistry.def"
};
- printPassNameList(FunctionAliasAnalysisNames, OS);
+ printPassNameList(StringTable(FunctionAliasAnalysisNames), OS);
OS << "LoopNest passes:\n";
- static constexpr StringLiteral LoopNestPassNames[] = {
-#define LOOPNEST_PASS(NAME, CREATE_PASS) NAME,
+ static constexpr char LoopNestPassNames[] = {"\0"
+#define LOOPNEST_PASS(NAME, CREATE_PASS) NAME "\0"
#include "PassRegistry.def"
};
- printPassNameList(LoopNestPassNames, OS);
+ printPassNameList(StringTable(LoopNestPassNames), OS);
OS << "Loop passes:\n";
- static constexpr StringLiteral LoopPassNames[] = {
-#define LOOP_PASS(NAME, CREATE_PASS) NAME,
+ static constexpr char LoopPassNames[] = {"\0"
+#define LOOP_PASS(NAME, CREATE_PASS) NAME "\0"
#include "PassRegistry.def"
};
- printPassNameList(LoopPassNames, OS);
+ printPassNameList(StringTable(LoopPassNames), OS);
OS << "Loop passes with params:\n";
- static constexpr PassNameWithParams LoopPassNamesWithParams[] = {
+ static constexpr char LoopPassNamesWithParams[] = {"\0"
#define LOOP_PASS_WITH_PARAMS(NAME, CLASS, CREATE_PASS, PARSER, PARAMS) \
- {NAME, PARAMS},
+ NAME "\0" PARAMS "\0"
#include "PassRegistry.def"
};
- printPassNameList(LoopPassNamesWithParams, OS);
+ printPassNameListWithParams(StringTable(LoopPassNamesWithParams), OS);
OS << "Loop analyses:\n";
- static constexpr StringLiteral LoopAnalysisNames[] = {
-#define LOOP_ANALYSIS(NAME, CREATE_PASS) NAME,
+ static constexpr char LoopAnalysisNames[] = {"\0"
+#define LOOP_ANALYSIS(NAME, CREATE_PASS) NAME "\0"
#include "PassRegistry.def"
};
- printPassNameList(LoopAnalysisNames, OS);
+ printPassNameList(StringTable(LoopAnalysisNames), OS);
OS << "Machine module passes (WIP):\n";
- static constexpr StringLiteral MachineModulePassNames[] = {
-#define MACHINE_MODULE_PASS(NAME, CREATE_PASS) NAME,
+ static constexpr char MachineModulePassNames[] = {"\0"
+#define MACHINE_MODULE_PASS(NAME, CREATE_PASS) NAME "\0"
#include "llvm/Passes/MachinePassRegistry.def"
- ""};
- printPassNameList(ArrayRef(MachineModulePassNames).drop_back(), OS);
+ };
+ printPassNameList(StringTable(MachineModulePassNames), OS);
OS << "Machine function passes (WIP):\n";
- static constexpr StringLiteral MachineFunctionPassNames[] = {
-#define MACHINE_FUNCTION_PASS(NAME, CREATE_PASS) NAME,
+ static constexpr char MachineFunctionPassNames[] = {"\0"
+#define MACHINE_FUNCTION_PASS(NAME, CREATE_PASS) NAME "\0"
#include "llvm/Passes/MachinePassRegistry.def"
};
- printPassNameList(MachineFunctionPassNames, OS);
+ printPassNameList(StringTable(MachineFunctionPassNames), OS);
OS << "Machine function analyses (WIP):\n";
- static constexpr StringLiteral MachineFunctionAnalysisNames[] = {
-#define MACHINE_FUNCTION_ANALYSIS(NAME, CREATE_PASS) NAME,
+ static constexpr char MachineFunctionAnalysisNames[] = {"\0"
+#define MACHINE_FUNCTION_ANALYSIS(NAME, CREATE_PASS) NAME "\0"
#include "llvm/Passes/MachinePassRegistry.def"
};
- printPassNameList(MachineFunctionAnalysisNames, OS);
+ printPassNameList(StringTable(MachineFunctionAnalysisNames), OS);
}
void PassBuilder::registerParseTopLevelPipelineCallback(
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