This is the patch to provide clean intrinsic function overloading support in LLVM. It cleans up the intrinsic definitions and generally smooths the process for more complicated intrinsic writing. It will be used by the upcoming atomic intrinsics as well as vector and float intrinsics in the future.

This also changes the syntax for llvm.bswap, llvm.part.set, llvm.part.select, and llvm.ct* intrinsics. They are automatically upgraded by both the LLVM ASM reader and the bitcode reader. The test cases have been updated, with special tests added to ensure the automatic upgrading is supported.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40807 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 264 insertions, 66 deletions

diff --git a/lib/VMCore/AutoUpgrade.cpp b/lib/VMCore/AutoUpgrade.cpp
new file mode 100644
index 0000000..b56fe70
--- /dev/null
+++ b/lib/VMCore/AutoUpgrade.cpp
@@ -0,0 +1,197 @@
+//===-- AutoUpgrade.cpp - Implement auto-upgrade helper functions ---------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Chandler Carruth and is distributed under the 
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the auto-upgrade helper functions 
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/AutoUpgrade.h"
+#include "llvm/Function.h"
+#include "llvm/Module.h"
+#include "llvm/Instructions.h"
+#include "llvm/ParameterAttributes.h"
+#include "llvm/Intrinsics.h"
+using namespace llvm;
+
+
+Function* llvm::UpgradeIntrinsicFunction(Function *F) {
+  assert(F && "Illegal to upgrade a non-existent Function.");
+
+  // Get the Function's name.
+  const std::string& Name = F->getName();
+
+  // Convenience
+  const FunctionType *FTy = F->getFunctionType();
+
+  // Quickly eliminate it, if it's not a candidate.
+  if (Name.length() <= 8 || Name[0] != 'l' || Name[1] != 'l' || 
+      Name[2] != 'v' || Name[3] != 'm' || Name[4] != '.')
+    return 0;
+
+  Module *M = F->getParent();
+  switch (Name[5]) {
+  default: break;
+  case 'b':
+    //  This upgrades the name of the llvm.bswap intrinsic function to only use 
+    //  a single type name for overloading. We only care about the old format
+    //  'llvm.bswap.i*.i*', so check for 'bswap.' and then for there being 
+    //  a '.' after 'bswap.'
+    if (Name.compare(5,6,"bswap.",6) == 0) {
+      std::string::size_type delim = Name.find('.',11);
+      
+      if (delim != std::string::npos) {
+        //  Construct the new name as 'llvm.bswap' + '.i*'
+        F->setName(Name.substr(0,10)+Name.substr(delim));
+        return F;
+      }
+    }
+    break;
+
+  case 'c':
+    //  We only want to fix the 'llvm.ct*' intrinsics which do not have the 
+    //  correct return type, so we check for the name, and then check if the 
+    //  return type does not match the parameter type.
+    if ( (Name.compare(5,5,"ctpop",5) == 0 ||
+          Name.compare(5,4,"ctlz",4) == 0 ||
+          Name.compare(5,4,"cttz",4) == 0) &&
+        FTy->getReturnType() != FTy->getParamType(0)) {
+      //  We first need to change the name of the old (bad) intrinsic, because 
+      //  its type is incorrect, but we cannot overload that name. We 
+      //  arbitrarily unique it here allowing us to construct a correctly named 
+      //  and typed function below.
+      F->setName("");
+
+      //  Now construct the new intrinsic with the correct name and type. We 
+      //  leave the old function around in order to query its type, whatever it 
+      //  may be, and correctly convert up to the new type.
+      return cast<Function>(M->getOrInsertFunction(Name, 
+                                                   FTy->getParamType(0),
+                                                   FTy->getParamType(0),
+                                                   (Type *)0));
+    }
+    break;
+
+  case 'p':
+    //  This upgrades the llvm.part.select overloaded intrinsic names to only 
+    //  use one type specifier in the name. We only care about the old format
+    //  'llvm.part.select.i*.i*', and solve as above with bswap.
+    if (Name.compare(5,12,"part.select.",12) == 0) {
+      std::string::size_type delim = Name.find('.',17);
+      
+      if (delim != std::string::npos) {
+        //  Construct a new name as 'llvm.part.select' + '.i*'
+        F->setName(Name.substr(0,16)+Name.substr(delim));
+        return F;
+      }
+      break;
+    }
+
+    //  This upgrades the llvm.part.set intrinsics similarly as above, however 
+    //  we care about 'llvm.part.set.i*.i*.i*', but only the first two types 
+    //  must match. There is an additional type specifier after these two 
+    //  matching types that we must retain when upgrading.  Thus, we require 
+    //  finding 2 periods, not just one, after the intrinsic name.
+    if (Name.compare(5,9,"part.set.",9) == 0) {
+      std::string::size_type delim = Name.find('.',14);
+
+      if (delim != std::string::npos &&
+          Name.find('.',delim+1) != std::string::npos) {
+        //  Construct a new name as 'llvm.part.select' + '.i*.i*'
+        F->setName(Name.substr(0,13)+Name.substr(delim));
+        return F;
+      }
+      break;
+    }
+
+    break;
+  }
+
+  //  This may not belong here. This function is effectively being overloaded 
+  //  to both detect an intrinsic which needs upgrading, and to provide the 
+  //  upgraded form of the intrinsic. We should perhaps have two separate 
+  //  functions for this.
+  return 0;
+}
+
+// UpgradeIntrinsicCall - Upgrade a call to an old intrinsic to be a call the 
+// upgraded intrinsic. All argument and return casting must be provided in 
+// order to seamlessly integrate with existing context.
+void llvm::UpgradeIntrinsicCall(CallInst *CI, Function *NewFn) {
+  assert(NewFn && "Cannot upgrade an intrinsic call without a new function.");
+
+  Function *F = CI->getCalledFunction();
+  assert(F && "CallInst has no function associated with it.");
+
+  const FunctionType *FTy = F->getFunctionType();
+  const FunctionType *NewFnTy = NewFn->getFunctionType();
+  
+  switch(NewFn->getIntrinsicID()) {
+  default:  assert(0 && "Unknown function for CallInst upgrade.");
+  case Intrinsic::ctlz:
+  case Intrinsic::ctpop:
+  case Intrinsic::cttz:
+    //  Build a small vector of the 1..(N-1) operands, which are the 
+    //  parameters.
+    SmallVector<Value*, 8>   Operands(CI->op_begin()+1, CI->op_end());
+
+    //  Construct a new CallInst
+    CallInst *NewCI = new CallInst(NewFn, Operands.begin(), Operands.end(), 
+                                   "upgraded."+CI->getName(), CI);
+    NewCI->setTailCall(CI->isTailCall());
+    NewCI->setCallingConv(CI->getCallingConv());
+
+    //  Handle any uses of the old CallInst.
+    if (!CI->use_empty()) {
+      //  Check for sign extend parameter attributes on the return values.
+      bool SrcSExt = NewFnTy->getParamAttrs() &&
+                     NewFnTy->getParamAttrs()->paramHasAttr(0,ParamAttr::SExt);
+      bool DestSExt = FTy->getParamAttrs() &&
+                      FTy->getParamAttrs()->paramHasAttr(0,ParamAttr::SExt);
+      
+      //  Construct an appropriate cast from the new return type to the old.
+      CastInst *RetCast = CastInst::create(
+                            CastInst::getCastOpcode(NewCI, SrcSExt,
+                                                    F->getReturnType(),
+                                                    DestSExt),
+                            NewCI, F->getReturnType(),
+                            NewCI->getName(), CI);
+      NewCI->moveBefore(RetCast);
+
+      //  Replace all uses of the old call with the new cast which has the 
+      //  correct type.
+      CI->replaceAllUsesWith(RetCast);
+    }
+
+    //  Clean up the old call now that it has been completely upgraded.
+    CI->eraseFromParent();
+    break;
+  }
+}
+
+// This tests each Function to determine if it needs upgrading. When we find 
+// one we are interested in, we then upgrade all calls to reflect the new 
+// function.
+void llvm::UpgradeCallsToIntrinsic(Function* F) {
+  assert(F && "Illegal attempt to upgrade a non-existent intrinsic.");
+
+  // Upgrade the function and check if it is a totaly new function.
+  if (Function* NewFn = UpgradeIntrinsicFunction(F)) {
+    if (NewFn != F) {
+      // Replace all uses to the old function with the new one if necessary.
+      for (Value::use_iterator UI = F->use_begin(), UE = F->use_end();
+           UI != UE; ) {
+        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
+          UpgradeIntrinsicCall(CI, NewFn);
+      }
+      // Remove old function, no longer used, from the module.
+      F->eraseFromParent();
+    }
+  }
+}
+
diff --git a/lib/VMCore/Verifier.cpp b/lib/VMCore/Verifier.cpp
index 6d4aa98..86a72c4 100644
--- a/lib/VMCore/Verifier.cpp
+++ b/lib/VMCore/Verifier.cpp
@@ -53,6 +53,7 @@
 #include "llvm/Intrinsics.h"
 #include "llvm/PassManager.h"
 #include "llvm/Analysis/Dominators.h"
+#include "llvm/CodeGen/ValueTypes.h"
 #include "llvm/Support/CFG.h"
 #include "llvm/Support/InstVisitor.h"
 #include "llvm/Support/Streams.h"
@@ -225,7 +226,8 @@ namespace {  // Anonymous namespace for class
     void visitUserOp2(Instruction &I) { visitUserOp1(I); }
     void visitIntrinsicFunctionCall(Intrinsic::ID ID, CallInst &CI);
 
-    void VerifyIntrinsicPrototype(Intrinsic::ID ID, Function *F, ...);
+    void VerifyIntrinsicPrototype(Intrinsic::ID ID, Function *F,
+                                  unsigned Count, ...);
 
     void WriteValue(const Value *V) {
       if (!V) return;
@@ -1075,9 +1077,11 @@ void Verifier::visitIntrinsicFunctionCall(Intrinsic::ID ID, CallInst &CI) {
 /// VerifyIntrinsicPrototype - TableGen emits calls to this function into
 /// Intrinsics.gen.  This implements a little state machine that verifies the
 /// prototype of intrinsics.
-void Verifier::VerifyIntrinsicPrototype(Intrinsic::ID ID, Function *F, ...) {
+void Verifier::VerifyIntrinsicPrototype(Intrinsic::ID ID,
+                                        Function *F,
+                                        unsigned Count, ...) {
   va_list VA;
-  va_start(VA, F);
+  va_start(VA, Count);
   
   const FunctionType *FTy = F->getFunctionType();
   
@@ -1086,97 +1090,94 @@ void Verifier::VerifyIntrinsicPrototype(Intrinsic::ID ID, Function *F, ...) {
   // suffix, to be checked at the end.
   std::string Suffix;
 
-  // Note that "arg#0" is the return type.
-  for (unsigned ArgNo = 0; 1; ++ArgNo) {
-    int TypeID = va_arg(VA, int);
+  if (FTy->getNumParams() + FTy->isVarArg() != Count - 1) {
+    CheckFailed("Intrinsic prototype has incorrect number of arguments!", F);
+    return;
+  }
 
-    if (TypeID == -2) {
-      break;
-    }
+  // Note that "arg#0" is the return type.
+  for (unsigned ArgNo = 0; ArgNo < Count; ++ArgNo) {
+    MVT::ValueType VT = va_arg(VA, MVT::ValueType);
 
-    if (TypeID == -1) {
-      if (ArgNo != FTy->getNumParams()+1)
-        CheckFailed("Intrinsic prototype has too many arguments!", F);
+    if (VT == MVT::isVoid && ArgNo > 0) {
+      if (!FTy->isVarArg())
+        CheckFailed("Intrinsic prototype has no '...'!", F);
       break;
     }
 
-    if (ArgNo == FTy->getNumParams()+1) {
-      CheckFailed("Intrinsic prototype has too few arguments!", F);
-      break;
-    }
-    
     const Type *Ty;
     if (ArgNo == 0)
       Ty = FTy->getReturnType();
     else
       Ty = FTy->getParamType(ArgNo-1);
-    
-    if (TypeID != Ty->getTypeID()) {
-      if (ArgNo == 0)
-        CheckFailed("Intrinsic prototype has incorrect result type!", F);
-      else
-        CheckFailed("Intrinsic parameter #" + utostr(ArgNo-1) + " is wrong!",F);
-      break;
-    }
 
-    if (TypeID == Type::IntegerTyID) {
-      unsigned ExpectedBits = (unsigned) va_arg(VA, int);
-      unsigned GotBits = cast<IntegerType>(Ty)->getBitWidth();
-      if (ExpectedBits == 0) {
-        Suffix += ".i" + utostr(GotBits);
-      } else if (GotBits != ExpectedBits) {
-        std::string bitmsg = " Expected " + utostr(ExpectedBits) + " but got "+
-                             utostr(GotBits) + " bits.";
-        if (ArgNo == 0)
-          CheckFailed("Intrinsic prototype has incorrect integer result width!"
-                      + bitmsg, F);
-        else
-          CheckFailed("Intrinsic parameter #" + utostr(ArgNo-1) + " has "
-                      "incorrect integer width!" + bitmsg, F);
-        break;
+    unsigned NumElts = 0;
+    const Type *EltTy = Ty;
+    if (const VectorType *VTy = dyn_cast<VectorType>(Ty)) {
+      EltTy = VTy->getElementType();
+      NumElts = VTy->getNumElements();
+    }
+    
+    if ((int)VT < 0) {
+      int Match = ~VT;
+      if (Match == 0) {
+        if (Ty != FTy->getReturnType()) {
+          CheckFailed("Intrinsic parameter #" + utostr(ArgNo-1) + " does not "
+                      "match return type.", F);
+          break;
+        }
+      } else {
+        if (Ty != FTy->getParamType(Match-1)) {
+          CheckFailed("Intrinsic parameter #" + utostr(ArgNo-1) + " does not "
+                      "match parameter %" + utostr(Match-1) + ".", F);
+          break;
+        }
       }
+    } else if (VT == MVT::iAny) {
+      unsigned GotBits = cast<IntegerType>(EltTy)->getBitWidth();
+      Suffix += ".";
+      if (EltTy != Ty)
+        Suffix += "v" + utostr(NumElts);
+      Suffix += "i" + utostr(GotBits);;
       // Check some constraints on various intrinsics.
       switch (ID) {
         default: break; // Not everything needs to be checked.
         case Intrinsic::bswap:
           if (GotBits < 16 || GotBits % 16 != 0)
             CheckFailed("Intrinsic requires even byte width argument", F);
-          /* FALL THROUGH */
-        case Intrinsic::part_set:
-        case Intrinsic::part_select:
-          if (ArgNo == 1) {
-            unsigned ResultBits = 
-              cast<IntegerType>(FTy->getReturnType())->getBitWidth();
-            if (GotBits != ResultBits)
-              CheckFailed("Intrinsic requires the bit widths of the first "
-                          "parameter and the result to match", F);
-          }
           break;
       }
-    } else if (TypeID == Type::VectorTyID) {
+    } else if (VT == MVT::iPTR) {
+      if (!isa<PointerType>(Ty)) {
+        CheckFailed("Intrinsic parameter #" + utostr(ArgNo-1) + " is not a "
+                    "pointer and a pointer is required.", F);
+        break;
+      }
+    } else if (MVT::isVector(VT)) {
       // If this is a vector argument, verify the number and type of elements.
-      const VectorType *PTy = cast<VectorType>(Ty);
-      int ElemTy = va_arg(VA, int);
-      if (ElemTy != PTy->getElementType()->getTypeID()) {
+      if (MVT::getVectorElementType(VT) != MVT::getValueType(EltTy)) {
         CheckFailed("Intrinsic prototype has incorrect vector element type!",
                     F);
         break;
       }
-      if (ElemTy == Type::IntegerTyID) {
-        unsigned NumBits = (unsigned)va_arg(VA, int);
-        unsigned ExpectedBits = 
-          cast<IntegerType>(PTy->getElementType())->getBitWidth();
-        if (NumBits != ExpectedBits) {
-          CheckFailed("Intrinsic prototype has incorrect vector element type!",
-                      F);
-          break;
-        }
-      }
-      if ((unsigned)va_arg(VA, int) != PTy->getNumElements()) {
+      if (MVT::getVectorNumElements(VT) != NumElts) {
         CheckFailed("Intrinsic prototype has incorrect number of "
                     "vector elements!",F);
-          break;
+        break;
       }
+    } else if (MVT::getTypeForValueType(VT) != EltTy) {
+      if (ArgNo == 0)
+        CheckFailed("Intrinsic prototype has incorrect result type!", F);
+      else
+        CheckFailed("Intrinsic parameter #" + utostr(ArgNo-1) + " is wrong!",F);
+      break;
+    } else if (EltTy != Ty) {
+      if (ArgNo == 0)
+        CheckFailed("Intrinsic result type is vector "
+                    "and a scalar is required.", F);
+      else
+        CheckFailed("Intrinsic parameter #" + utostr(ArgNo-1) + " is vector "
+                    "and a scalar is required.", F);
     }
   }