[llvm] TableGen: Use StringOffsetTable for RuntimeLibcall names (PR #148839)
Matt Arsenault via llvm-commits
llvm-commits at lists.llvm.org
Tue Jul 15 05:27:50 PDT 2025
https://github.com/arsenm created https://github.com/llvm/llvm-project/pull/148839
None
>From 471999cebda43bd8a0c27508c9c28bd5c534578e Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault at amd.com>
Date: Tue, 15 Jul 2025 17:27:36 +0900
Subject: [PATCH] TableGen: Use StringOffsetTable for RuntimeLibcall names
---
llvm/include/llvm/IR/RuntimeLibcalls.h | 13 ++++--
.../llvm/TableGen/StringToOffsetTable.h | 7 ++-
llvm/lib/IR/RuntimeLibcalls.cpp | 1 +
llvm/lib/TableGen/StringToOffsetTable.cpp | 10 ++---
llvm/test/TableGen/RuntimeLibcallEmitter.td | 45 ++++++++++++++-----
.../TableGen/Basic/RuntimeLibcallsEmitter.cpp | 27 ++++++-----
6 files changed, 72 insertions(+), 31 deletions(-)
diff --git a/llvm/include/llvm/IR/RuntimeLibcalls.h b/llvm/include/llvm/IR/RuntimeLibcalls.h
index 85db45e27e912..8058c8a4c5510 100644
--- a/llvm/include/llvm/IR/RuntimeLibcalls.h
+++ b/llvm/include/llvm/IR/RuntimeLibcalls.h
@@ -16,6 +16,7 @@
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/Sequence.h"
+#include "llvm/ADT/StringTable.h"
#include "llvm/IR/CallingConv.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/Support/AtomicOrdering.h"
@@ -77,12 +78,16 @@ struct RuntimeLibcallsInfo {
/// Get the libcall routine name for the specified libcall.
// FIXME: This should be removed. Only LibcallImpl should have a name.
const char *getLibcallName(RTLIB::Libcall Call) const {
- return LibCallImplNames[LibcallImpls[Call]];
+ return getLibcallImplName(LibcallImpls[Call]);
}
/// Get the libcall routine name for the specified libcall implementation.
+ // FIXME: Change to return StringRef
static const char *getLibcallImplName(RTLIB::LibcallImpl CallImpl) {
- return LibCallImplNames[CallImpl];
+ if (CallImpl == RTLIB::Unsupported)
+ return nullptr;
+ return RuntimeLibcallImplNameTable[RuntimeLibcallNameOffsetTable[CallImpl]]
+ .data();
}
/// Return the lowering's selection of implementation call for \p Call
@@ -144,7 +149,9 @@ struct RuntimeLibcallsInfo {
/// Names of concrete implementations of runtime calls. e.g. __ashlsi3 for
/// SHL_I32
- LLVM_ABI static const char *const LibCallImplNames[RTLIB::NumLibcallImpls];
+ LLVM_ABI static const char RuntimeLibcallImplNameTableStorage[];
+ LLVM_ABI static const StringTable RuntimeLibcallImplNameTable;
+ LLVM_ABI static const uint16_t RuntimeLibcallNameOffsetTable[];
/// Map from a concrete LibcallImpl implementation to its RTLIB::Libcall kind.
LLVM_ABI static const RTLIB::Libcall ImplToLibcall[RTLIB::NumLibcallImpls];
diff --git a/llvm/include/llvm/TableGen/StringToOffsetTable.h b/llvm/include/llvm/TableGen/StringToOffsetTable.h
index 1550515ce3d7b..154ded8e94d7f 100644
--- a/llvm/include/llvm/TableGen/StringToOffsetTable.h
+++ b/llvm/include/llvm/TableGen/StringToOffsetTable.h
@@ -23,10 +23,15 @@ namespace llvm {
class StringToOffsetTable {
StringMap<unsigned> StringOffset;
std::string AggregateString;
+
+ /// If this is to be a static class member, the prefix to use (i.e. class name
+ /// plus ::)
+ const StringRef ClassPrefix;
const bool AppendZero;
public:
- StringToOffsetTable(bool AppendZero = true) : AppendZero(AppendZero) {
+ StringToOffsetTable(bool AppendZero = true, StringRef ClassPrefix = "")
+ : ClassPrefix(ClassPrefix), AppendZero(AppendZero) {
// Ensure we always put the empty string at offset zero. That lets empty
// initialization also be zero initialization for offsets into the table.
GetOrAddStringOffset("");
diff --git a/llvm/lib/IR/RuntimeLibcalls.cpp b/llvm/lib/IR/RuntimeLibcalls.cpp
index 6624e24cc7cf5..b1864897dafa6 100644
--- a/llvm/lib/IR/RuntimeLibcalls.cpp
+++ b/llvm/lib/IR/RuntimeLibcalls.cpp
@@ -7,6 +7,7 @@
//===----------------------------------------------------------------------===//
#include "llvm/IR/RuntimeLibcalls.h"
+#include "llvm/ADT/StringTable.h"
using namespace llvm;
using namespace RTLIB;
diff --git a/llvm/lib/TableGen/StringToOffsetTable.cpp b/llvm/lib/TableGen/StringToOffsetTable.cpp
index 17e1e660c15ee..9fb41485db745 100644
--- a/llvm/lib/TableGen/StringToOffsetTable.cpp
+++ b/llvm/lib/TableGen/StringToOffsetTable.cpp
@@ -38,8 +38,8 @@ void StringToOffsetTable::EmitStringTableDef(raw_ostream &OS,
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Woverlength-strings"
#endif
-static constexpr char {}Storage[] = )",
- Name);
+{} constexpr char {}{}Storage[] = )",
+ ClassPrefix.empty() ? "static" : "", ClassPrefix, Name);
// MSVC silently miscompiles string literals longer than 64k in some
// circumstances. The build system sets EmitLongStrLiterals to false when it
@@ -83,10 +83,10 @@ static constexpr char {}Storage[] = )",
#pragma GCC diagnostic pop
#endif
-static constexpr llvm::StringTable
-{0} = {0}Storage;
+{1}constexpr llvm::StringTable
+{2}{0} = {0}Storage;
)",
- Name);
+ Name, ClassPrefix.empty() ? "static " : "", ClassPrefix);
}
void StringToOffsetTable::EmitString(raw_ostream &O) const {
diff --git a/llvm/test/TableGen/RuntimeLibcallEmitter.td b/llvm/test/TableGen/RuntimeLibcallEmitter.td
index a0061afab1db0..2a7da5dede3f6 100644
--- a/llvm/test/TableGen/RuntimeLibcallEmitter.td
+++ b/llvm/test/TableGen/RuntimeLibcallEmitter.td
@@ -116,19 +116,40 @@ def BlahLibrary : SystemRuntimeLibrary<isBlahArch, (add calloc, LibraryWithCondi
// CHECK-NEXT: RTLIB::Unsupported
// CHECK-NEXT: };
// CHECK-EMPTY:
-// CHECK-NEXT: const char *const llvm::RTLIB::RuntimeLibcallsInfo::LibCallImplNames[RTLIB::NumLibcallImpls] = {
-// CHECK-NEXT: nullptr, // RTLIB::Unsupported
-// CHECK-NEXT: "___memcpy", // RTLIB::___memcpy
-// CHECK-NEXT: "___memset", // RTLIB::___memset
-// CHECK-NEXT: "__ashlsi3", // RTLIB::__ashlsi3
-// CHECK-NEXT: "__lshrdi3", // RTLIB::__lshrdi3
-// CHECK-NEXT: "bzero", // RTLIB::bzero
-// CHECK-NEXT: "calloc", // RTLIB::calloc
-// CHECK-NEXT: "sqrtl", // RTLIB::sqrtl_f80
-// CHECK-NEXT: "sqrtl", // RTLIB::sqrtl_f128
+// CHECK-EMPTY:
+// CHECK-NEXT: #ifdef __GNUC__
+// CHECK-NEXT: #pragma GCC diagnostic push
+// CHECK-NEXT: #pragma GCC diagnostic ignored "-Woverlength-strings"
+// CHECK-NEXT: #endif
+// CHECK-NEXT: constexpr char RTLIB::RuntimeLibcallsInfo::RuntimeLibcallImplNameTableStorage[] =
+// CHECK-NEXT: "\0"
+// CHECK-NEXT: "___memcpy\0"
+// CHECK-NEXT: "___memset\0"
+// CHECK-NEXT: "__ashlsi3\0"
+// CHECK-NEXT: "__lshrdi3\0"
+// CHECK-NEXT: "bzero\0"
+// CHECK-NEXT: "calloc\0"
+// CHECK-NEXT: "sqrtl\0"
+// CHECK-NEXT: ;
+// CHECK-NEXT: #ifdef __GNUC__
+// CHECK-NEXT: #pragma GCC diagnostic pop
+// CHECK-NEXT: #endif
+// CHECK-EMPTY:
+// CHECK-NEXT: constexpr llvm::StringTable
+// CHECK-NEXT: RTLIB::RuntimeLibcallsInfo::RuntimeLibcallImplNameTable = RuntimeLibcallImplNameTableStorage;
+// CHECK-EMPTY:
+// CHECK-NEXT: const uint16_t RTLIB::RuntimeLibcallsInfo::RuntimeLibcallNameOffsetTable[] = {
+// CHECK-NEXT: 0, //
+// CHECK-NEXT: 1, // ___memcpy
+// CHECK-NEXT: 11, // ___memset
+// CHECK-NEXT: 21, // __ashlsi3
+// CHECK-NEXT: 31, // __lshrdi3
+// CHECK-NEXT: 41, // bzero
+// CHECK-NEXT: 47, // calloc
+// CHECK-NEXT: 54, // sqrtl
+// CHECK-NEXT: 54, // sqrtl
// CHECK-NEXT: };
-
-// CHECK: const RTLIB::Libcall llvm::RTLIB::RuntimeLibcallsInfo::ImplToLibcall[RTLIB::NumLibcallImpls] = {
+// CHECK-NEXT: const RTLIB::Libcall llvm::RTLIB::RuntimeLibcallsInfo::ImplToLibcall[RTLIB::NumLibcallImpls] = {
// CHECK-NEXT: RTLIB::UNKNOWN_LIBCALL, // RTLIB::Unsupported
// CHECK-NEXT: RTLIB::MEMCPY, // RTLIB::___memcpy
// CHECK-NEXT: RTLIB::MEMSET, // RTLIB::___memset
diff --git a/llvm/utils/TableGen/Basic/RuntimeLibcallsEmitter.cpp b/llvm/utils/TableGen/Basic/RuntimeLibcallsEmitter.cpp
index 68bd1b5c9cb21..652bea9dc7f65 100644
--- a/llvm/utils/TableGen/Basic/RuntimeLibcallsEmitter.cpp
+++ b/llvm/utils/TableGen/Basic/RuntimeLibcallsEmitter.cpp
@@ -8,10 +8,12 @@
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Debug.h"
+#include "llvm/Support/FormatVariadic.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/TableGen/Error.h"
#include "llvm/TableGen/Record.h"
#include "llvm/TableGen/SetTheory.h"
+#include "llvm/TableGen/StringToOffsetTable.h"
#include "llvm/TableGen/TableGenBackend.h"
using namespace llvm;
@@ -305,8 +307,6 @@ void RuntimeLibcallEmitter::emitGetRuntimeLibcallEnum(raw_ostream &OS) const {
void RuntimeLibcallEmitter::emitGetInitRuntimeLibcallNames(
raw_ostream &OS) const {
- // TODO: Emit libcall names as string offset table.
-
OS << "const RTLIB::LibcallImpl "
"llvm::RTLIB::RuntimeLibcallsInfo::"
"DefaultLibcallImpls[RTLIB::UNKNOWN_LIBCALL + 1] = {\n";
@@ -331,17 +331,24 @@ void RuntimeLibcallEmitter::emitGetInitRuntimeLibcallNames(
"};\n\n";
// Emit the implementation names
- OS << "const char *const llvm::RTLIB::RuntimeLibcallsInfo::"
- "LibCallImplNames[RTLIB::NumLibcallImpls] = {\n"
- " nullptr, // RTLIB::Unsupported\n";
+ StringToOffsetTable Table(/*AppendZero=*/true,
+ "RTLIB::RuntimeLibcallsInfo::");
+
+ for (const RuntimeLibcallImpl &LibCallImpl : RuntimeLibcallImplDefList)
+ Table.GetOrAddStringOffset(LibCallImpl.getLibcallFuncName());
+
+ Table.EmitStringTableDef(OS, "RuntimeLibcallImplNameTable");
+ OS << R"(
+const uint16_t RTLIB::RuntimeLibcallsInfo::RuntimeLibcallNameOffsetTable[] = {
+)";
+ OS << formatv(" {}, // {}\n", Table.GetStringOffset(""),
+ ""); // Unsupported entry
for (const RuntimeLibcallImpl &LibCallImpl : RuntimeLibcallImplDefList) {
- OS << " \"" << LibCallImpl.getLibcallFuncName() << "\", // ";
- LibCallImpl.emitEnumEntry(OS);
- OS << '\n';
+ StringRef ImplName = LibCallImpl.getLibcallFuncName();
+ OS << formatv(" {}, // {}\n", Table.GetStringOffset(ImplName), ImplName);
}
-
- OS << "};\n\n";
+ OS << "};\n";
// Emit the reverse mapping from implementation libraries to RTLIB::Libcall
OS << "const RTLIB::Libcall llvm::RTLIB::RuntimeLibcallsInfo::"
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