Simplify IntrinsicLowering and clarify that it is only for use by the

CBE and interpreter.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31755 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/IntrinsicLowering.h

@@ -9,24 +9,7 @@
 //
 // This file defines the IntrinsicLowering interface.  This interface allows
 // addition of domain-specific or front-end specific intrinsics to LLVM without
-// having to modify all of the code generators to support the new intrinsic.
+// having to modify all of the C backend or interpreter.
-// Later, as desired, targets can incrementally add support for particular
-// intrinsic functions, as desired, to generate better code.
-//
-// If a code generator cannot handle or does not know about an intrinsic
-// function, it will use the intrinsic lowering interface to change an intrinsic
-// function name into a concrete function name which can be used to implement
-// the functionality of the intrinsic.  For example, llvm.memcpy can be
-// implemented as a call to the math library 'memcpy' function if the target
-// doesn't have hardware support for the intrinsic, or if it has not yet been
-// implemented yet.
-//
-// Another use for this interface is the addition of domain-specific intrinsics.
-// The default implementation of this interface would then lower the intrinsics
-// to noop calls, allowing the direct execution of programs with instrumentation
-// or other hooks placed in them.  When a specific tool or flag is used, a
-// different implementation of these interfaces may be used, which activates the
-// intrinsics in some way.
 //
 //===----------------------------------------------------------------------===//
 
@@ -42,12 +25,11 @@ namespace llvm {
   class IntrinsicLowering {
   public:
     IntrinsicLowering() {}
-    virtual ~IntrinsicLowering() {}
 
     /// AddPrototypes - This method, if called, causes all of the prototypes
     /// that might be needed by an intrinsic lowering implementation to be
     /// inserted into the module specified.
-    virtual void AddPrototypes(Module &M) = 0;
+    void AddPrototypes(Module &M);
 
     /// LowerIntrinsicCall - This method returns the LLVM function which should
     /// be used to implement the specified intrinsic function call.  If an
@@ -59,16 +41,7 @@ namespace llvm {
     /// _after_ the call instruction and the call is deleted.  The caller must
     /// be capable of handling this kind of change.
     ///
-    virtual void LowerIntrinsicCall(CallInst *CI) = 0;
+    void LowerIntrinsicCall(CallInst *CI);
-  };
-
-  /// DefaultIntrinsicLower - This is the default intrinsic lowering pass which
-  /// is used if no other one is specified.  Custom intrinsic lowering
-  /// implementations should pass any unhandled intrinsics to this
-  /// implementation to allow for future extensibility.
-  struct DefaultIntrinsicLowering : public IntrinsicLowering {
-    virtual void AddPrototypes(Module &M);
-    virtual void LowerIntrinsicCall(CallInst *CI);
   };
 }
 

lib/CodeGen/IntrinsicLowering.cpp

@@ -7,7 +7,7 @@
 //
 //===----------------------------------------------------------------------===//
 //
-// This file implements the default intrinsic lowering implementation.
+// This file implements the IntrinsicLowering class.
 //
 //===----------------------------------------------------------------------===//
 
@@ -82,7 +82,7 @@ static CallInst *ReplaceCallWith(const char *NewFn, CallInst *CI,
   return NewCI;
 }
 
-void DefaultIntrinsicLowering::AddPrototypes(Module &M) {
+void IntrinsicLowering::AddPrototypes(Module &M) {
   for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
     if (I->isExternal() && !I->use_empty())
       switch (I->getIntrinsicID()) {
@@ -263,7 +263,7 @@ static Value *LowerCTLZ(Value *V, Instruction *IP) {
 
 
 
-void DefaultIntrinsicLowering::LowerIntrinsicCall(CallInst *CI) {
+void IntrinsicLowering::LowerIntrinsicCall(CallInst *CI) {
   Function *Callee = CI->getCalledFunction();
   assert(Callee && "Cannot lower an indirect call!");
 

lib/ExecutionEngine/Interpreter/Interpreter.cpp

@@ -67,7 +67,7 @@ Interpreter::Interpreter(Module *M) : ExecutionEngine(M), TD(M) {
   initializeExternalFunctions();
   emitGlobals();
 
-  IL = new DefaultIntrinsicLowering();
+  IL = new IntrinsicLowering();
 }
 
 Interpreter::~Interpreter() {

lib/Target/CBackend/CBackend.cpp

@@ -69,7 +69,7 @@ namespace {
   /// module to a C translation unit.
   class CWriter : public FunctionPass, public InstVisitor<CWriter> {
     std::ostream &Out;
-    DefaultIntrinsicLowering IL;
+    IntrinsicLowering IL;
     Mangler *Mang;
     LoopInfo *LI;
     const Module *TheModule;

lib/Target/CBackend/Writer.cpp

@@ -69,7 +69,7 @@ namespace {
   /// module to a C translation unit.
   class CWriter : public FunctionPass, public InstVisitor<CWriter> {
     std::ostream &Out;
-    DefaultIntrinsicLowering IL;
+    IntrinsicLowering IL;
     Mangler *Mang;
     LoopInfo *LI;
     const Module *TheModule;