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, 40 insertions, 5 deletions

diff --git a/include/llvm/CodeGen/AsmPrinter.h b/include/llvm/CodeGen/AsmPrinter.h
index 59d14cc..5462212 100644
--- a/include/llvm/CodeGen/AsmPrinter.h
+++ b/include/llvm/CodeGen/AsmPrinter.h
@@ -41,6 +41,7 @@ namespace llvm {
   class MCAsmInfo;
   class MCCFIInstruction;
   class MCContext;
+  class MCInstrInfo;
   class MCSection;
   class MCStreamer;
   class MCSymbol;
@@ -64,6 +65,7 @@ namespace llvm {
     ///
     const MCAsmInfo *MAI;
 
+    const MCInstrInfo *MII;
     /// OutContext - This is the context for the output file that we are
     /// streaming.  This owns all of the global MC-related objects for the
     /// generated translation unit.
diff --git a/include/llvm/MC/MCInstrDesc.h b/include/llvm/MC/MCInstrDesc.h
index 310f706..84d6380 100644
--- a/include/llvm/MC/MCInstrDesc.h
+++ b/include/llvm/MC/MCInstrDesc.h
@@ -17,6 +17,7 @@
 
 #include "llvm/MC/MCInst.h"
 #include "llvm/MC/MCRegisterInfo.h"
+#include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/Support/DataTypes.h"
 
 namespace llvm {
@@ -145,6 +146,10 @@ public:
   const uint16_t *ImplicitUses;  // Registers implicitly read by this instr
   const uint16_t *ImplicitDefs;  // Registers implicitly defined by this instr
   const MCOperandInfo *OpInfo;   // 'NumOperands' entries about operands
+  uint64_t DeprecatedFeatureMask;// Feature bits that this is deprecated on, if any
+  // A complex method to determine is a certain is deprecated or not, and return
+  // the reason for deprecation.
+  bool (*ComplexDeprecationInfo)(MCInst &, MCSubtargetInfo &, std::string &);
 
   /// \brief Returns the value of the specific constraint if
   /// it is set. Returns -1 if it is not set.
@@ -158,6 +163,20 @@ public:
     return -1;
   }
 
+  /// \brief Returns true if a certain instruction is deprecated and if so
+  /// returns the reason in \p Info.
+  bool getDeprecatedInfo(MCInst &MI, MCSubtargetInfo &STI,
+                         std::string &Info) const {
+    if (ComplexDeprecationInfo)
+      return ComplexDeprecationInfo(MI, STI, Info);
+    if (DeprecatedFeatureMask != 0) {
+      // FIXME: it would be nice to include the subtarget feature here.
+      Info = "deprecated";
+      return true;
+    }
+    return false;
+  }
+
   /// \brief Return the opcode number for this descriptor.
   unsigned getOpcode() const {
     return Opcode;
diff --git a/include/llvm/Support/TargetRegistry.h b/include/llvm/Support/TargetRegistry.h
index 9282853..05f7cf2 100644
--- a/include/llvm/Support/TargetRegistry.h
+++ b/include/llvm/Support/TargetRegistry.h
@@ -108,7 +108,8 @@ namespace llvm {
                                                 StringRef TT,
                                                 StringRef CPU);
     typedef MCTargetAsmParser *(*MCAsmParserCtorTy)(MCSubtargetInfo &STI,
-                                                    MCAsmParser &P);
+                                                    MCAsmParser &P,
+                                                    const MCInstrInfo &MII);
     typedef MCDisassembler *(*MCDisassemblerCtorTy)(const Target &T,
                                                     const MCSubtargetInfo &STI);
     typedef MCInstPrinter *(*MCInstPrinterCtorTy)(const Target &T,
@@ -386,10 +387,11 @@ namespace llvm {
     /// \param Parser The target independent parser implementation to use for
     /// parsing and lexing.
     MCTargetAsmParser *createMCAsmParser(MCSubtargetInfo &STI,
-                                         MCAsmParser &Parser) const {
+                                         MCAsmParser &Parser,
+                                         const MCInstrInfo &MII) const {
       if (!MCAsmParserCtorFn)
         return 0;
-      return MCAsmParserCtorFn(STI, Parser);
+      return MCAsmParserCtorFn(STI, Parser, MII);
     }
 
     /// createAsmPrinter - Create a target specific assembly printer pass.  This
@@ -1142,8 +1144,9 @@ namespace llvm {
     }
 
   private:
-    static MCTargetAsmParser *Allocator(MCSubtargetInfo &STI, MCAsmParser &P) {
-      return new MCAsmParserImpl(STI, P);
+    static MCTargetAsmParser *Allocator(MCSubtargetInfo &STI, MCAsmParser &P,
+                                        const MCInstrInfo &MII) {
+      return new MCAsmParserImpl(STI, P, MII);
     }
   };
 
diff --git a/include/llvm/Target/Target.td b/include/llvm/Target/Target.td
index b7f3693..c15a4ab 100644
--- a/include/llvm/Target/Target.td
+++ b/include/llvm/Target/Target.td
@@ -1010,6 +1010,17 @@ class SubtargetFeature<string n, string a,  string v, string d,
   list<SubtargetFeature> Implies = i;
 }
 
+/// Specifies a Subtarget feature that this instruction is deprecated on.
+class Deprecated<SubtargetFeature dep> {
+  SubtargetFeature DeprecatedFeatureMask = dep;
+}
+
+/// A custom predicate used to determine if an instruction is
+/// deprecated or not.
+class ComplexDeprecationPredicate<string dep> {
+  string ComplexDeprecationPredicate = dep;
+}
+
 //===----------------------------------------------------------------------===//
 // Processor chip sets - These values represent each of the chip sets supported
 // by the scheduler.  Each Processor definition requires corresponding