From b9ace0215d20e29a0e59de2917178ad5e308a835 Mon Sep 17 00:00:00 2001
From: Benjamin Kramer <benny.kra@googlemail.com>
Date: Wed, 29 Feb 2012 21:57:08 +0000
Subject: [PATCH] Emit the SubRegTable with the smallest possible integer type.

Doesn't help ARM with its massive register set, but halves the size on x86 and all other targets.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151760 91177308-0d34-0410-b5e6-96231b3b80d8
---
 utils/TableGen/AsmMatcherEmitter.cpp   | 9 ---------
 utils/TableGen/CodeGenTarget.cpp       | 8 ++++++++
 utils/TableGen/CodeGenTarget.h         | 4 ++++
 utils/TableGen/RegisterInfoEmitter.cpp | 4 ++--
 4 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/utils/TableGen/AsmMatcherEmitter.cpp b/utils/TableGen/AsmMatcherEmitter.cpp
index 80467ff3dc7..88e787cfd21 100644
--- a/utils/TableGen/AsmMatcherEmitter.cpp
+++ b/utils/TableGen/AsmMatcherEmitter.cpp
@@ -2008,15 +2008,6 @@ static bool EmitMnemonicAliases(raw_ostream &OS, const AsmMatcherInfo &Info) {
   return true;
 }
 
-static const char *getMinimalTypeForRange(uint64_t Range) {
-  assert(Range < 0xFFFFFFFFULL && "Enum too large");
-  if (Range > 0xFFFF)
-    return "uint32_t";
-  if (Range > 0xFF)
-    return "uint16_t";
-  return "uint8_t";
-}
-
 static void EmitCustomOperandParsing(raw_ostream &OS, CodeGenTarget &Target,
                               const AsmMatcherInfo &Info, StringRef ClassName) {
   // Emit the static custom operand parsing table;
diff --git a/utils/TableGen/CodeGenTarget.cpp b/utils/TableGen/CodeGenTarget.cpp
index cf6793570a2..1eb1a54e565 100644
--- a/utils/TableGen/CodeGenTarget.cpp
+++ b/utils/TableGen/CodeGenTarget.cpp
@@ -108,6 +108,14 @@ std::string llvm::getQualifiedName(const Record *R) {
   return Namespace + "::" + R->getName();
 }
 
+const char *llvm::getMinimalTypeForRange(uint64_t Range) {
+  assert(Range < 0xFFFFFFFFULL && "Enum too large");
+  if (Range > 0xFFFF)
+    return "uint32_t";
+  if (Range > 0xFF)
+    return "uint16_t";
+  return "uint8_t";
+}
 
 /// getTarget - Return the current instance of the Target class.
 ///
diff --git a/utils/TableGen/CodeGenTarget.h b/utils/TableGen/CodeGenTarget.h
index 85463da5973..a0df08bf954 100644
--- a/utils/TableGen/CodeGenTarget.h
+++ b/utils/TableGen/CodeGenTarget.h
@@ -58,6 +58,10 @@ std::string getEnumName(MVT::SimpleValueType T);
 /// namespace qualifier if the record contains one.
 std::string getQualifiedName(const Record *R);
 
+/// getMinimalTypeForRange - Helper method to get the minimum data type required
+/// to represent Range.
+const char *getMinimalTypeForRange(uint64_t Range);
+
 /// CodeGenTarget - This class corresponds to the Target class in the .td files.
 ///
 class CodeGenTarget {
diff --git a/utils/TableGen/RegisterInfoEmitter.cpp b/utils/TableGen/RegisterInfoEmitter.cpp
index 6aea4adb72c..899f5523e21 100644
--- a/utils/TableGen/RegisterInfoEmitter.cpp
+++ b/utils/TableGen/RegisterInfoEmitter.cpp
@@ -736,8 +736,8 @@ RegisterInfoEmitter::runTargetDesc(raw_ostream &OS, CodeGenTarget &Target,
 
   // Emit the data table for getSubReg().
   if (SubRegIndices.size()) {
-    OS << "static const unsigned short " << TargetName << "SubRegTable[]["
-      << SubRegIndices.size() << "] = {\n";
+    OS << "static const " << getMinimalTypeForRange(Regs.size()) << ' '
+       << TargetName << "SubRegTable[][" << SubRegIndices.size() << "] = {\n";
     for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
       const CodeGenRegister::SubRegMap &SRM = Regs[i]->getSubRegs();
       OS << "  /* " << Regs[i]->TheDef->getName() << " */\n";