Add support for alternative register names, useful for instructions whose operands are logically equivalent to existing registers, but happen to be printed specially. For example, an instruciton that prints d0[0] instead of s0.

Patch by Jim Grosbach.

llvm-svn: 133940

1 files changed, 90 insertions, 26 deletions

diff --git a/llvm/utils/TableGen/AsmWriterEmitter.cpp b/llvm/utils/TableGen/AsmWriterEmitter.cpp
index 066e03d8c71..53df7dd71a0 100644
--- a/llvm/utils/TableGen/AsmWriterEmitter.cpp
+++ b/llvm/utils/TableGen/AsmWriterEmitter.cpp
@@ -18,6 +18,7 @@
 #include "CodeGenTarget.h"
 #include "Record.h"
 #include "StringToOffsetTable.h"
+#include "llvm/ADT/Twine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/MathExtras.h"
 #include <algorithm>
@@ -458,6 +459,58 @@ void AsmWriterEmitter::EmitPrintInstruction(raw_ostream &O) {
   O << "}\n";
 }
 
+static void
+emitRegisterNameString(raw_ostream &O, StringRef AltName,
+  const std::vector<CodeGenRegister*> &Registers) {
+  StringToOffsetTable StringTable;
+  O << "  static const unsigned RegAsmOffset" << AltName << "[] = {\n    ";
+  for (unsigned i = 0, e = Registers.size(); i != e; ++i) {
+    const CodeGenRegister &Reg = *Registers[i];
+
+    StringRef AsmName;
+    // "NoRegAltName" is special. We don't need to do a lookup for that,
+    // as it's just a reference to the default register name.
+    if (AltName == "" || AltName == "NoRegAltName") {
+      AsmName = Reg.TheDef->getValueAsString("AsmName");
+      if (AsmName.empty())
+        AsmName = Reg.getName();
+    } else {
+      // Make sure the register has an alternate name for this index.
+      std::vector<Record*> AltNameList =
+        Reg.TheDef->getValueAsListOfDefs("RegAltNameIndices");
+      unsigned Idx = 0, e;
+      for (e = AltNameList.size();
+           Idx < e && (AltNameList[Idx]->getName() != AltName);
+           ++Idx)
+        ;
+      // If the register has an alternate name for this index, use it.
+      // Otherwise, leave it empty as an error flag.
+      if (Idx < e) {
+        std::vector<std::string> AltNames =
+          Reg.TheDef->getValueAsListOfStrings("AltNames");
+        if (AltNames.size() <= Idx)
+          throw TGError(Reg.TheDef->getLoc(),
+                        (Twine("Register definition missing alt name for '") +
+                        AltName + "'.").str());
+        AsmName = AltNames[Idx];
+      }
+    }
+
+    O << StringTable.GetOrAddStringOffset(AsmName);
+    if (((i + 1) % 14) == 0)
+      O << ",\n    ";
+    else
+      O << ", ";
+
+  }
+  O << "0\n"
+    << "  };\n"
+    << "\n";
+
+  O << "  const char *AsmStrs" << AltName << " =\n";
+  StringTable.EmitString(O);
+  O << ";\n";
+}
 
 void AsmWriterEmitter::EmitGetRegisterName(raw_ostream &O) {
   CodeGenTarget Target(Records);
@@ -465,40 +518,48 @@ void AsmWriterEmitter::EmitGetRegisterName(raw_ostream &O) {
   std::string ClassName = AsmWriter->getValueAsString("AsmWriterClassName");
   const std::vector<CodeGenRegister*> &Registers =
     Target.getRegBank().getRegisters();
+  std::vector<Record*> AltNameIndices = Target.getRegAltNameIndices();
+  bool hasAltNames = AltNameIndices.size() > 1;
 
-  StringToOffsetTable StringTable;
   O <<
   "\n\n/// getRegisterName - This method is automatically generated by tblgen\n"
   "/// from the register set description.  This returns the assembler name\n"
   "/// for the specified register.\n"
-  "const char *" << Target.getName() << ClassName
-  << "::getRegisterName(unsigned RegNo) {\n"
-  << "  assert(RegNo && RegNo < " << (Registers.size()+1)
-  << " && \"Invalid register number!\");\n"
-  << "\n"
-  << "  static const unsigned RegAsmOffset[] = {";
-  for (unsigned i = 0, e = Registers.size(); i != e; ++i) {
-    const CodeGenRegister &Reg = *Registers[i];
-
-    std::string AsmName = Reg.TheDef->getValueAsString("AsmName");
-    if (AsmName.empty())
-      AsmName = Reg.getName();
-
-
-    if ((i % 14) == 0)
-      O << "\n    ";
-
-    O << StringTable.GetOrAddStringOffset(AsmName) << ", ";
-  }
-  O << "0\n"
-    << "  };\n"
+  "const char *" << Target.getName() << ClassName << "::";
+  if (hasAltNames)
+    O << "\ngetRegisterName(unsigned RegNo, unsigned AltIdx) {\n";
+  else
+    O << "getRegisterName(unsigned RegNo) {\n";
+  O << "  assert(RegNo && RegNo < " << (Registers.size()+1)
+    << " && \"Invalid register number!\");\n"
     << "\n";
 
-  O << "  const char *AsmStrs =\n";
-  StringTable.EmitString(O);
-  O << ";\n";
+  if (hasAltNames) {
+    for (unsigned i = 0, e = AltNameIndices.size(); i < e; ++i)
+      emitRegisterNameString(O, AltNameIndices[i]->getName(), Registers);
+  } else
+    emitRegisterNameString(O, "", Registers);
+
+  if (hasAltNames) {
+    O << "  const unsigned *RegAsmOffset;\n"
+      << "  const char *AsmStrs;\n"
+      << "  switch(AltIdx) {\n"
+      << "  default: assert(0 && \"Invalid register alt name index!\");\n";
+    for (unsigned i = 0, e = AltNameIndices.size(); i < e; ++i) {
+      StringRef Namespace = AltNameIndices[1]->getValueAsString("Namespace");
+      StringRef AltName(AltNameIndices[i]->getName());
+      O << "  case " << Namespace << "::" << AltName
+        << ":\n"
+        << "    AsmStrs = AsmStrs" << AltName  << ";\n"
+        << "    RegAsmOffset = RegAsmOffset" << AltName << ";\n"
+        << "    break;\n";
+    }
+    O << "}\n";
+  }
 
-  O << "  return AsmStrs+RegAsmOffset[RegNo-1];\n"
+  O << "  assert (*(AsmStrs+RegAsmOffset[RegNo-1]) &&\n"
+    << "          \"Invalid alt name index for register!\");\n"
+    << "  return AsmStrs+RegAsmOffset[RegNo-1];\n"
     << "}\n";
 }
 
@@ -936,6 +997,9 @@ void AsmWriterEmitter::EmitPrintAliasInstruction(raw_ostream &O) {
           const Record *Rec = RO.getRecord();
           StringRef ROName = RO.getName();
 
+
+          if (Rec->isSubClassOf("RegisterOperand"))
+            Rec = Rec->getValueAsDef("RegClass");
           if (Rec->isSubClassOf("RegisterClass")) {
             Cond = std::string("MI->getOperand(")+llvm::utostr(i)+").isReg()";
             IAP->addCond(Cond);