Add an instruction deprecation feature to TableGen.

The 'Deprecated' class allows you to specify a SubtargetFeature that the
instruction is deprecated on.

The 'ComplexDeprecationPredicate' class allows you to define a custom
predicate that is called to check for deprecation.
For example:
  ComplexDeprecationPredicate<"MCR">

would mean you would have to define the following function:
  bool getMCRDeprecationInfo(MCInst &MI, MCSubtargetInfo &STI,
                             std::string &Info)

Which returns 'false' for not deprecated, and 'true' for deprecated
and store the warning message in 'Info'.

The MCTargetAsmParser constructor was chaned to take an extra argument of
the MCInstrInfo class, so out-of-tree targets will need to be changed.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190598 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 50 insertions, 0 deletions

diff --git a/utils/TableGen/AsmMatcherEmitter.cpp b/utils/TableGen/AsmMatcherEmitter.cpp
index 31c17fb3d6..c82752580e 100644
--- a/utils/TableGen/AsmMatcherEmitter.cpp
+++ b/utils/TableGen/AsmMatcherEmitter.cpp
@@ -430,6 +430,9 @@ struct MatchableInfo {
   /// function.
   std::string ConversionFnKind;
 
+  /// If this instruction is deprecated in some form.
+  bool HasDeprecation;
+
   MatchableInfo(const CodeGenInstruction &CGI)
     : AsmVariantID(0), TheDef(CGI.TheDef), DefRec(&CGI),
       AsmString(CGI.AsmString) {
@@ -779,6 +782,13 @@ void MatchableInfo::initialize(const AsmMatcherInfo &Info,
     if (Record *Reg = AsmOperands[i].SingletonReg)
       SingletonRegisters.insert(Reg);
   }
+
+  const RecordVal *DepMask = TheDef->getValue("DeprecatedFeatureMask");
+  if (!DepMask)
+    DepMask = TheDef->getValue("ComplexDeprecationPredicate");
+
+  HasDeprecation =
+      DepMask ? !DepMask->getValue()->getAsUnquotedString().empty() : false;
 }
 
 /// tokenizeAsmString - Tokenize a simplified assembly string.
@@ -2743,11 +2753,13 @@ void AsmMatcherEmitter::run(raw_ostream &OS) {
 
   size_t MaxNumOperands = 0;
   unsigned MaxMnemonicIndex = 0;
+  bool HasDeprecation = false;
   for (std::vector<MatchableInfo*>::const_iterator it =
          Info.Matchables.begin(), ie = Info.Matchables.end();
        it != ie; ++it) {
     MatchableInfo &II = **it;
     MaxNumOperands = std::max(MaxNumOperands, II.AsmOperands.size());
+    HasDeprecation |= II.HasDeprecation;
 
     // Store a pascal-style length byte in the mnemonic.
     std::string LenMnemonic = char(II.Mnemonic.size()) + II.Mnemonic.str();
@@ -3018,6 +3030,14 @@ void AsmMatcherEmitter::run(raw_ostream &OS) {
   if (!InsnCleanupFn.empty())
     OS << "    " << InsnCleanupFn << "(Inst);\n";
 
+  if (HasDeprecation) {
+    OS << "    std::string Info;\n";
+    OS << "    if (MII.get(Inst.getOpcode()).getDeprecatedInfo(Inst, STI, Info)) {\n";
+    OS << "      SMLoc Loc = ((" << Target.getName() << "Operand*)Operands[0])->getStartLoc();\n";
+    OS << "      Parser.Warning(Loc, Info, None);\n";
+    OS << "    }\n";
+  }
+
   OS << "    return Match_Success;\n";
   OS << "  }\n\n";
 
diff --git a/utils/TableGen/CodeGenInstruction.cpp b/utils/TableGen/CodeGenInstruction.cpp
index bf59d3afb5..576388b2ed 100644
--- a/utils/TableGen/CodeGenInstruction.cpp
+++ b/utils/TableGen/CodeGenInstruction.cpp
@@ -337,6 +337,20 @@ CodeGenInstruction::CodeGenInstruction(Record *R)
 
   // Parse the DisableEncoding field.
   Operands.ProcessDisableEncoding(R->getValueAsString("DisableEncoding"));
+
+  // First check for a ComplexDeprecationPredicate.
+  if (R->getValue("ComplexDeprecationPredicate")) {
+    HasComplexDeprecationPredicate = true;
+    DeprecatedReason = R->getValueAsString("ComplexDeprecationPredicate");
+  } else if (RecordVal *Dep = R->getValue("DeprecatedFeatureMask")) {
+    // Check if we have a Subtarget feature mask.
+    HasComplexDeprecationPredicate = false;
+    DeprecatedReason = Dep->getValue()->getAsString();
+  } else {
+    // This instruction isn't deprecated.
+    HasComplexDeprecationPredicate = false;
+    DeprecatedReason = "";
+  }
 }
 
 /// HasOneImplicitDefWithKnownVT - If the instruction has at least one
diff --git a/utils/TableGen/CodeGenInstruction.h b/utils/TableGen/CodeGenInstruction.h
index d1e1153554..6004f66792 100644
--- a/utils/TableGen/CodeGenInstruction.h
+++ b/utils/TableGen/CodeGenInstruction.h
@@ -248,6 +248,9 @@ namespace llvm {
     bool isCodeGenOnly;
     bool isPseudo;
 
+    std::string DeprecatedReason;
+    bool HasComplexDeprecationPredicate;
+
     /// Are there any undefined flags?
     bool hasUndefFlags() const {
       return mayLoad_Unset || mayStore_Unset || hasSideEffects_Unset;
diff --git a/utils/TableGen/InstrInfoEmitter.cpp b/utils/TableGen/InstrInfoEmitter.cpp
index 84bd4dee3a..af26353d01 100644
--- a/utils/TableGen/InstrInfoEmitter.cpp
+++ b/utils/TableGen/InstrInfoEmitter.cpp
@@ -514,6 +514,19 @@ void InstrInfoEmitter::emitRecord(const CodeGenInstruction &Inst, unsigned Num,
   else
     OS << "OperandInfo" << OpInfo.find(OperandInfo)->second;
 
+  CodeGenTarget &Target = CDP.getTargetInfo();
+  if (Inst.HasComplexDeprecationPredicate)
+    // Emit a function pointer to the complex predicate method.
+    OS << ",0"
+       << ",&get" << Inst.DeprecatedReason << "DeprecationInfo";
+  else if (!Inst.DeprecatedReason.empty())
+    // Emit the Subtarget feature.
+    OS << "," << Target.getInstNamespace() << "::" << Inst.DeprecatedReason
+       << ",0";
+  else
+    // Instruction isn't deprecated.
+    OS << ",0,0";
+
   OS << " },  // Inst #" << Num << " = " << Inst.TheDef->getName() << "\n";
 }