lib/Analysis/LibCallSemantics.cpp

   1 //===- LibCallSemantics.cpp - Describe library semantics ------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file implements interfaces that can be used to describe language
  11 // specific runtime library interfaces (e.g. libc, libm, etc) to LLVM
  12 // optimizers.
  13 //
  14 //===----------------------------------------------------------------------===//
  15
  16 #include "llvm/Analysis/LibCallSemantics.h"
  17 #include "llvm/ADT/StringMap.h"
  18 #include "llvm/Function.h"
  19 using namespace llvm;
  20
  21 /// getMap - This impl pointer in ~LibCallInfo is actually a StringMap.  This
  22 /// helper does the cast.
  23 static StringMap<const LibCallFunctionInfo*> *getMap(void *Ptr) {
  24   return static_cast<StringMap<const LibCallFunctionInfo*> *>(Ptr);
  25 }
  26
  27 LibCallInfo::~LibCallInfo() {
  28   delete getMap(Impl);
  29 }
  30
  31 const LibCallLocationInfo &LibCallInfo::getLocationInfo(unsigned LocID) const {
  32   // Get location info on the first call.
  33   if (NumLocations == 0)
  34     NumLocations = getLocationInfo(Locations);
  35
  36   assert(LocID < NumLocations && "Invalid location ID!");
  37   return Locations[LocID];
  38 }
  39
  40
  41 /// getFunctionInfo - Return the LibCallFunctionInfo object corresponding to
  42 /// the specified function if we have it.  If not, return null.
  43 const LibCallFunctionInfo *LibCallInfo::getFunctionInfo(Function *F) const {
  44   StringMap<const LibCallFunctionInfo*> *Map = getMap(Impl);
  45
  46   /// If this is the first time we are querying for this info, lazily construct
  47   /// the StringMap to index it.
  48   if (Map == 0) {
  49     Impl = Map = new StringMap<const LibCallFunctionInfo*>();
  50
  51     const LibCallFunctionInfo *Array = getFunctionInfoArray();
  52     if (Array == 0) return 0;
  53
  54     // We now have the array of entries.  Populate the StringMap.
  55     for (unsigned i = 0; Array[i].Name; ++i)
  56       (*Map)[Array[i].Name] = Array+i;
  57   }
  58
  59   // Look up this function in the string map.
  60   return Map->lookup(F->getName());
  61 }
  62