instcombine: Don't replace all uses for instructions with no uses

[oota-llvm.git] / lib / Transforms / IPO / DeadArgumentElimination.cpp

diff --git a/lib/Transforms/IPO/DeadArgumentElimination.cpp b/lib/Transforms/IPO/DeadArgumentElimination.cpp
index 29053a09e0513b2de94e520dc5224f64046c5255..4cfd0b235ab8a7aa61e55fc48a7888698f2c9820 100644 (file)
--- a/lib/Transforms/IPO/DeadArgumentElimination.cpp
+++ b/lib/Transforms/IPO/DeadArgumentElimination.cpp
@@ -32,6 +32,7 @@
 #include "llvm/Support/CallSite.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
+#include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/StringExtras.h"
@@ -129,7 +130,7 @@ namespace {
     // As the code generation for module is finished (and DIBuilder is
     // finalized) we assume that subprogram descriptors won't be changed, and
     // they are stored in map for short duration anyway.
-    typedef std::map<Function*, DISubprogram> FunctionDIMap;
+    typedef DenseMap<Function*, DISubprogram> FunctionDIMap;
     FunctionDIMap FunctionDIs;
 
   protected:
@@ -200,18 +201,20 @@ void DAE::CollectFunctionDIs(Module &M) {
   for (Module::named_metadata_iterator I = M.named_metadata_begin(),
        E = M.named_metadata_end(); I != E; ++I) {
     NamedMDNode &NMD = *I;
-    for (unsigned i = 0, n = NMD.getNumOperands(); i < n; ++i) {
-      MDNode *Node = NMD.getOperand(i);
-      if (DIDescriptor(Node).isCompileUnit()) {
-        DICompileUnit CU(Node);
-        const DIArray &SPs = CU.getSubprograms();
-        for (unsigned i = 0, n = SPs.getNumElements(); i < n; ++i) {
-          DISubprogram SP(SPs.getElement(i));
-          if (SP.Verify()) {
-            if (Function *F = SP.getFunction())
-              FunctionDIs[F] = SP;
-          }
-        }
+    for (unsigned MDIndex = 0, MDNum = NMD.getNumOperands();
+         MDIndex < MDNum; ++MDIndex) {
+      MDNode *Node = NMD.getOperand(MDIndex);
+      if (!DIDescriptor(Node).isCompileUnit())
+        continue;
+      DICompileUnit CU(Node);
+      const DIArray &SPs = CU.getSubprograms();
+      for (unsigned SPIndex = 0, SPNum = SPs.getNumElements();
+           SPIndex < SPNum; ++SPIndex) {
+        DISubprogram SP(SPs.getElement(SPIndex));
+        if (!SP.Verify())
+          continue;
+        if (Function *F = SP.getFunction())
+          FunctionDIs[F] = SP;
       }
     }
   }
@@ -273,9 +276,11 @@ bool DAE::DeleteDeadVarargs(Function &Fn) {
       SmallVector<AttributeWithIndex, 8> AttributesVec;
       for (unsigned i = 0; PAL.getSlot(i).Index <= NumArgs; ++i)
         AttributesVec.push_back(PAL.getSlot(i));
-      if (Attributes FnAttrs = PAL.getFnAttributes())
-        AttributesVec.push_back(AttributeWithIndex::get(~0, FnAttrs));
-      PAL = AttrListPtr::get(AttributesVec);
+      Attributes FnAttrs = PAL.getFnAttributes();
+      if (FnAttrs.hasAttributes())
+        AttributesVec.push_back(AttributeWithIndex::get(AttrListPtr::FunctionIndex,
+                                                        FnAttrs));
+      PAL = AttrListPtr::get(Fn.getContext(), AttributesVec);
     }
 
     Instruction *New;
@@ -759,13 +764,17 @@ bool DAE::RemoveDeadStuffFromFunction(Function *F) {
   // here. Currently, this should not be possible, but special handling might be
   // required when new return value attributes are added.
   if (NRetTy->isVoidTy())
-    RAttrs &= ~Attributes::typeIncompatible(NRetTy);
+    RAttrs =
+      Attributes::get(NRetTy->getContext(), AttrBuilder(RAttrs).
+                      removeAttributes(Attributes::typeIncompatible(NRetTy)));
   else
-    assert((RAttrs & Attributes::typeIncompatible(NRetTy)) == 0
-           && "Return attributes no longer compatible?");
+    assert(!AttrBuilder(RAttrs).
+             hasAttributes(Attributes::typeIncompatible(NRetTy)) &&
+           "Return attributes no longer compatible?");
 
-  if (RAttrs)
-    AttributesVec.push_back(AttributeWithIndex::get(0, RAttrs));
+  if (RAttrs.hasAttributes())
+    AttributesVec.push_back(AttributeWithIndex::get(AttrListPtr::ReturnIndex,
+                                                    RAttrs));
 
   // Remember which arguments are still alive.
   SmallVector<bool, 10> ArgAlive(FTy->getNumParams(), false);
@@ -782,7 +791,8 @@ bool DAE::RemoveDeadStuffFromFunction(Function *F) {
 
       // Get the original parameter attributes (skipping the first one, that is
       // for the return value.
-      if (Attributes Attrs = PAL.getParamAttributes(i + 1))
+      Attributes Attrs = PAL.getParamAttributes(i + 1);
+      if (Attrs.hasAttributes())
         AttributesVec.push_back(AttributeWithIndex::get(Params.size(), Attrs));
     } else {
       ++NumArgumentsEliminated;
@@ -792,10 +802,11 @@ bool DAE::RemoveDeadStuffFromFunction(Function *F) {
   }
 
   if (FnAttrs.hasAttributes())
-    AttributesVec.push_back(AttributeWithIndex::get(~0, FnAttrs));
+    AttributesVec.push_back(AttributeWithIndex::get(AttrListPtr::FunctionIndex,
+                                                    FnAttrs));
 
   // Reconstruct the AttributesList based on the vector we constructed.
-  AttrListPtr NewPAL = AttrListPtr::get(AttributesVec);
+  AttrListPtr NewPAL = AttrListPtr::get(F->getContext(), AttributesVec);
 
   // Create the new function type based on the recomputed parameters.
   FunctionType *NFTy = FunctionType::get(NRetTy, Params, FTy->isVarArg());
@@ -828,9 +839,12 @@ bool DAE::RemoveDeadStuffFromFunction(Function *F) {
     Attributes RAttrs = CallPAL.getRetAttributes();
     Attributes FnAttrs = CallPAL.getFnAttributes();
     // Adjust in case the function was changed to return void.
-    RAttrs &= ~Attributes::typeIncompatible(NF->getReturnType());
-    if (RAttrs)
-      AttributesVec.push_back(AttributeWithIndex::get(0, RAttrs));
+    RAttrs =
+      Attributes::get(NF->getContext(), AttrBuilder(RAttrs).
+           removeAttributes(Attributes::typeIncompatible(NF->getReturnType())));
+    if (RAttrs.hasAttributes())
+      AttributesVec.push_back(AttributeWithIndex::get(AttrListPtr::ReturnIndex,
+                                                      RAttrs));
 
     // Declare these outside of the loops, so we can reuse them for the second
     // loop, which loops the varargs.
@@ -842,22 +856,25 @@ bool DAE::RemoveDeadStuffFromFunction(Function *F) {
       if (ArgAlive[i]) {
         Args.push_back(*I);
         // Get original parameter attributes, but skip return attributes.
-        if (Attributes Attrs = CallPAL.getParamAttributes(i + 1))
+        Attributes Attrs = CallPAL.getParamAttributes(i + 1);
+        if (Attrs.hasAttributes())
           AttributesVec.push_back(AttributeWithIndex::get(Args.size(), Attrs));
       }
 
     // Push any varargs arguments on the list. Don't forget their attributes.
     for (CallSite::arg_iterator E = CS.arg_end(); I != E; ++I, ++i) {
       Args.push_back(*I);
-      if (Attributes Attrs = CallPAL.getParamAttributes(i + 1))
+      Attributes Attrs = CallPAL.getParamAttributes(i + 1);
+      if (Attrs.hasAttributes())
         AttributesVec.push_back(AttributeWithIndex::get(Args.size(), Attrs));
     }
 
     if (FnAttrs.hasAttributes())
-      AttributesVec.push_back(AttributeWithIndex::get(~0, FnAttrs));
+      AttributesVec.push_back(AttributeWithIndex::get(AttrListPtr::FunctionIndex,
+                                                      FnAttrs));
 
     // Reconstruct the AttributesList based on the vector we constructed.
-    AttrListPtr NewCallPAL = AttrListPtr::get(AttributesVec);
+    AttrListPtr NewCallPAL = AttrListPtr::get(F->getContext(), AttributesVec);
 
     Instruction *New;
     if (InvokeInst *II = dyn_cast<InvokeInst>(Call)) {