[StrTable] Switch Clang builtins to use string tables

This both reapplies #118734, the initial attempt at this, and updates it
significantly.

First, it uses the newly added `StringTable` abstraction for string
tables, and simplifies the construction to build the string table and
info arrays separately. This should reduce any `constexpr` compile time
memory or CPU cost of the original PR while significantly improving the
APIs throughout.

It also restructures the builtins to support sharding across several
independent tables. This accomplishes two improvements from the
original PR:

1) It improves the APIs used significantly.

2) When builtins are defined from different sources (like SVE vs MVE in
   AArch64), this allows each of them to build their own string table
   independently rather than having to merge the string tables and info
   structures.

3) It allows each shard to factor out a common prefix, often cutting the
   size of the strings needed for the builtins by a factor two.

The second point is important both to allow different mechanisms of
construction (for example a `.def` file and a tablegen'ed `.inc` file,
or different tablegen'ed `.inc files), it also simply reduces the sizes
of these tables which is valuable given how large they are in some
cases. The third builds on that size reduction.

Initially, we use this new sharding rather than merging tables in
AArch64, LoongArch, RISCV, and X86. Mostly this helps ensure the system
works, as without further changes these still push scaling limits.
Subsequent commits will more deeply leverage the new structure,
including using the prefix capabilities which cannot be easily factored
out here and requires deep changes to the targets.

1 files changed, 17 insertions, 9 deletions

diff --git a/clang/lib/Basic/Targets/AMDGPU.cpp b/clang/lib/Basic/Targets/AMDGPU.cpp
index 0d308cb..228f967 100644
--- a/clang/lib/Basic/Targets/AMDGPU.cpp
+++ b/clang/lib/Basic/Targets/AMDGPU.cpp
@@ -89,13 +89,21 @@ const LangASMap AMDGPUTargetInfo::AMDGPUDefIsPrivMap = {
 } // namespace targets
 } // namespace clang
 
-static constexpr Builtin::Info BuiltinInfo[] = {
-#define BUILTIN(ID, TYPE, ATTRS)                                               \
-  {#ID, TYPE, ATTRS, nullptr, HeaderDesc::NO_HEADER, ALL_LANGUAGES},
-#define TARGET_BUILTIN(ID, TYPE, ATTRS, FEATURE)                               \
-  {#ID, TYPE, ATTRS, FEATURE, HeaderDesc::NO_HEADER, ALL_LANGUAGES},
+static constexpr int NumBuiltins =
+    clang::AMDGPU::LastTSBuiltin - Builtin::FirstTSBuiltin;
+
+static constexpr llvm::StringTable BuiltinStrings =
+    CLANG_BUILTIN_STR_TABLE_START
+#define BUILTIN CLANG_BUILTIN_STR_TABLE
+#define TARGET_BUILTIN CLANG_TARGET_BUILTIN_STR_TABLE
 #include "clang/Basic/BuiltinsAMDGPU.def"
-};
+    ;
+
+static constexpr auto BuiltinInfos = Builtin::MakeInfos<NumBuiltins>({
+#define BUILTIN CLANG_BUILTIN_ENTRY
+#define TARGET_BUILTIN CLANG_TARGET_BUILTIN_ENTRY
+#include "clang/Basic/BuiltinsAMDGPU.def"
+});
 
 const char *const AMDGPUTargetInfo::GCCRegNames[] = {
   "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v8",
@@ -267,9 +275,9 @@ void AMDGPUTargetInfo::adjust(DiagnosticsEngine &Diags, LangOptions &Opts) {
                      !isAMDGCN(getTriple()));
 }
 
-ArrayRef<Builtin::Info> AMDGPUTargetInfo::getTargetBuiltins() const {
-  return llvm::ArrayRef(BuiltinInfo,
-                        clang::AMDGPU::LastTSBuiltin - Builtin::FirstTSBuiltin);
+llvm::SmallVector<Builtin::InfosShard>
+AMDGPUTargetInfo::getTargetBuiltins() const {
+  return {{&BuiltinStrings, BuiltinInfos}};
 }
 
 void AMDGPUTargetInfo::getTargetDefines(const LangOptions &Opts,