Reimplement the parameter attributes support, phase #1. hilights:

1. There is now a "PAListPtr" class, which is a smart pointer around
   the underlying uniqued parameter attribute list object, and manages
   its refcount.  It is now impossible to mess up the refcount.
2. PAListPtr is now the main interface to the underlying object, and
   the underlying object is now completely opaque.
3. Implementation details like SmallVector and FoldingSet are now no
   longer part of the interface.
4. You can create a PAListPtr with an arbitrary sequence of
   ParamAttrsWithIndex's, no need to make a SmallVector of a specific 
   size (you can just use an array or scalar or vector if you wish).
5. All the client code that had to check for a null pointer before
   dereferencing the pointer is simplified to just access the 
   PAListPtr directly.
6. The interfaces for adding attrs to a list and removing them is a
   bit simpler.

Phase #2 will rename some stuff (e.g. PAListPtr) and do other less 
invasive changes.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48289 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 20 insertions, 24 deletions

diff --git a/lib/Transforms/IPO/StructRetPromotion.cpp b/lib/Transforms/IPO/StructRetPromotion.cpp
index c6b561dfd3..1e51cb96c9 100644
--- a/lib/Transforms/IPO/StructRetPromotion.cpp
+++ b/lib/Transforms/IPO/StructRetPromotion.cpp
@@ -17,7 +17,6 @@
 #include "llvm/Module.h"
 #include "llvm/CallGraphSCCPass.h"
 #include "llvm/Instructions.h"
-#include "llvm/ParamAttrsList.h"
 #include "llvm/Analysis/CallGraph.h"
 #include "llvm/Support/CallSite.h"
 #include "llvm/Support/CFG.h"
@@ -117,7 +116,8 @@ bool SRETPromotion::PromoteReturn(CallGraphNode *CGN) {
           SmallVector<Value*, 2> GEPIdx;
           GEPIdx.push_back(ConstantInt::get(Type::Int32Ty, 0));
           GEPIdx.push_back(ConstantInt::get(Type::Int32Ty, idx));
-          Value *NGEPI = new GetElementPtrInst(TheAlloca, GEPIdx.begin(), GEPIdx.end(),
+          Value *NGEPI = new GetElementPtrInst(TheAlloca, GEPIdx.begin(),
+                                               GEPIdx.end(),
                                                "mrv.gep", I);
           Value *NV = new LoadInst(NGEPI, "mrv.ld", I);
           RetVals.push_back(NV);
@@ -200,11 +200,11 @@ Function *SRETPromotion::cloneFunctionBody(Function *F,
   std::vector<const Type*> Params;
 
   // ParamAttrs - Keep track of the parameter attributes for the arguments.
-  ParamAttrsVector ParamAttrsVec;
-  const ParamAttrsList *PAL = F->getParamAttrs();
+  SmallVector<ParamAttrsWithIndex, 8> ParamAttrsVec;
+  const PAListPtr &PAL = F->getParamAttrs();
 
   // Add any return attributes.
-  if (ParameterAttributes attrs = PAL ? PAL->getParamAttrs(0) : ParamAttr::None)
+  if (ParameterAttributes attrs = PAL.getParamAttrs(0))
     ParamAttrsVec.push_back(ParamAttrsWithIndex::get(0, attrs));
 
   // Skip first argument.
@@ -215,12 +215,8 @@ Function *SRETPromotion::cloneFunctionBody(Function *F,
   unsigned ParamIndex = 2; 
   while (I != E) {
     Params.push_back(I->getType());
-    if (PAL) {
-      ParameterAttributes Attrs = PAL->getParamAttrs(ParamIndex);
-      if (Attrs != ParamAttr::None)
-        ParamAttrsVec.push_back(ParamAttrsWithIndex::get(ParamIndex - 1,
-                                                         Attrs));
-    }
+    if (ParameterAttributes Attrs = PAL.getParamAttrs(ParamIndex))
+      ParamAttrsVec.push_back(ParamAttrsWithIndex::get(ParamIndex - 1, Attrs));
     ++I;
     ++ParamIndex;
   }
@@ -228,7 +224,7 @@ Function *SRETPromotion::cloneFunctionBody(Function *F,
   FunctionType *NFTy = FunctionType::get(STy, Params, FTy->isVarArg());
   Function *NF = new Function(NFTy, F->getLinkage(), F->getName());
   NF->setCallingConv(F->getCallingConv());
-  NF->setParamAttrs(ParamAttrsList::get(ParamAttrsVec));
+  NF->setParamAttrs(PAListPtr::get(ParamAttrsVec.begin(), ParamAttrsVec.end()));
   F->getParent()->getFunctionList().insert(F, NF);
   NF->getBasicBlockList().splice(NF->begin(), F->getBasicBlockList());
 
@@ -253,16 +249,17 @@ void SRETPromotion::updateCallSites(Function *F, Function *NF) {
   SmallVector<Value*, 16> Args;
 
   // ParamAttrs - Keep track of the parameter attributes for the arguments.
-  ParamAttrsVector ArgAttrsVec;
+  SmallVector<ParamAttrsWithIndex, 8> ArgAttrsVec;
 
-  for (Value::use_iterator FUI = F->use_begin(), FUE = F->use_end(); FUI != FUE;) {
+  for (Value::use_iterator FUI = F->use_begin(), FUE = F->use_end();
+       FUI != FUE;) {
     CallSite CS = CallSite::get(*FUI);
     ++FUI;
     Instruction *Call = CS.getInstruction();
 
-    const ParamAttrsList *PAL = F->getParamAttrs();
+    const PAListPtr &PAL = F->getParamAttrs();
     // Add any return attributes.
-    if (ParameterAttributes attrs = PAL ? PAL->getParamAttrs(0) : ParamAttr::None)
+    if (ParameterAttributes attrs = PAL.getParamAttrs(0))
       ArgAttrsVec.push_back(ParamAttrsWithIndex::get(0, attrs));
 
     // Copy arguments, however skip first one.
@@ -274,27 +271,26 @@ void SRETPromotion::updateCallSites(Function *F, Function *NF) {
     unsigned ParamIndex = 2; 
     while (AI != AE) {
       Args.push_back(*AI); 
-      if (PAL) {
-        ParameterAttributes Attrs = PAL->getParamAttrs(ParamIndex);
-        if (Attrs != ParamAttr::None)
-          ArgAttrsVec.push_back(ParamAttrsWithIndex::get(ParamIndex - 1, 
-                                                         Attrs));
-      }
+      if (ParameterAttributes Attrs = PAL.getParamAttrs(ParamIndex))
+        ArgAttrsVec.push_back(ParamAttrsWithIndex::get(ParamIndex - 1, Attrs));
       ++ParamIndex;
       ++AI;
     }
 
+    
+    PAListPtr NewPAL = PAListPtr::get(ArgAttrsVec.begin(), ArgAttrsVec.end());
+    
     // Build new call instruction.
     Instruction *New;
     if (InvokeInst *II = dyn_cast<InvokeInst>(Call)) {
       New = new InvokeInst(NF, II->getNormalDest(), II->getUnwindDest(),
                            Args.begin(), Args.end(), "", Call);
       cast<InvokeInst>(New)->setCallingConv(CS.getCallingConv());
-      cast<InvokeInst>(New)->setParamAttrs(ParamAttrsList::get(ArgAttrsVec));
+      cast<InvokeInst>(New)->setParamAttrs(NewPAL);
     } else {
       New = new CallInst(NF, Args.begin(), Args.end(), "", Call);
       cast<CallInst>(New)->setCallingConv(CS.getCallingConv());
-      cast<CallInst>(New)->setParamAttrs(ParamAttrsList::get(ArgAttrsVec));
+      cast<CallInst>(New)->setParamAttrs(NewPAL);
       if (cast<CallInst>(Call)->isTailCall())
         cast<CallInst>(New)->setTailCall();
     }