[IR] Make getParamAttributes take argument numbers, not ArgNo+1

Add hasParamAttribute() and use it instead of hasAttribute(ArgNo+1,
Kind) everywhere.

The fact that the AttributeList index for an argument is ArgNo+1 should
be a hidden implementation detail.

NFC

llvm-svn: 300272

3 files changed, 14 insertions, 18 deletions

diff --git a/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp b/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
index 940c1ead096..a2c8a32dfe8 100644
--- a/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
+++ b/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
@@ -106,7 +106,7 @@ doPromotion(Function *F, SmallPtrSetImpl<Argument *> &ArgsToPromote,
   AttributeList PAL = F->getAttributes();
 
   // First, determine the new argument list
-  unsigned ArgIndex = 1;
+  unsigned ArgIndex = 0;
   for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E;
        ++I, ++ArgIndex) {
     if (ByValArgsToTransform.count(&*I)) {
diff --git a/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp b/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
index f0d987bfda7..375b74c494d 100644
--- a/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
+++ b/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
@@ -698,8 +698,8 @@ bool DeadArgumentEliminationPass::RemoveDeadStuffFromFunction(Function *F) {
     if (LiveValues.erase(Arg)) {
       Params.push_back(I->getType());
       ArgAlive[i] = true;
-      ArgAttrVec.push_back(PAL.getParamAttributes(i + 1));
-      HasLiveReturnedArg |= PAL.hasAttribute(i + 1, Attribute::Returned);
+      ArgAttrVec.push_back(PAL.getParamAttributes(i));
+      HasLiveReturnedArg |= PAL.hasParamAttribute(i, Attribute::Returned);
     } else {
       ++NumArgumentsEliminated;
       DEBUG(dbgs() << "DeadArgumentEliminationPass - Removing argument " << i
@@ -836,7 +836,7 @@ bool DeadArgumentEliminationPass::RemoveDeadStuffFromFunction(Function *F) {
       if (ArgAlive[i]) {
         Args.push_back(*I);
         // Get original parameter attributes, but skip return attributes.
-        AttributeSet Attrs = CallPAL.getParamAttributes(i + 1);
+        AttributeSet Attrs = CallPAL.getParamAttributes(i);
         if (NRetTy != RetTy && Attrs.hasAttribute(Attribute::Returned)) {
           // If the return type has changed, then get rid of 'returned' on the
           // call site. The alternative is to make all 'returned' attributes on
@@ -855,7 +855,7 @@ bool DeadArgumentEliminationPass::RemoveDeadStuffFromFunction(Function *F) {
     // 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);
-      ArgAttrVec.push_back(CallPAL.getParamAttributes(i + 1));
+      ArgAttrVec.push_back(CallPAL.getParamAttributes(i));
     }
 
     // Reconstruct the AttributesList based on the vector we constructed.
diff --git a/llvm/lib/Transforms/IPO/MergeFunctions.cpp b/llvm/lib/Transforms/IPO/MergeFunctions.cpp
index 4ce4de13c93..771770ddc06 100644
--- a/llvm/lib/Transforms/IPO/MergeFunctions.cpp
+++ b/llvm/lib/Transforms/IPO/MergeFunctions.cpp
@@ -432,19 +432,15 @@ void MergeFunctions::replaceDirectCallers(Function *Old, Function *New) {
       // Transferring other attributes may help other optimizations, but that
       // should be done uniformly and not in this ad-hoc way.
       auto &Context = New->getContext();
-      auto NewFuncAttrs = New->getAttributes();
-      auto CallSiteAttrs = CS.getAttributes();
-
-      CallSiteAttrs = CallSiteAttrs.addAttributes(
-          Context, AttributeList::ReturnIndex, NewFuncAttrs.getRetAttributes());
-
-      for (unsigned argIdx = 0; argIdx < CS.arg_size(); argIdx++) {
-        AttributeSet Attrs = NewFuncAttrs.getParamAttributes(argIdx);
-        if (Attrs.hasAttributes())
-          CallSiteAttrs = CallSiteAttrs.addAttributes(Context, argIdx, Attrs);
-      }
-
-      CS.setAttributes(CallSiteAttrs);
+      auto NewPAL = New->getAttributes();
+      SmallVector<AttributeSet, 4> NewArgAttrs;
+      for (unsigned argIdx = 0; argIdx < CS.arg_size(); argIdx++)
+        NewArgAttrs.push_back(NewPAL.getParamAttributes(argIdx));
+      // Don't transfer attributes from the function to the callee. Function
+      // attributes typically aren't relevant to the calling convention or ABI.
+      CS.setAttributes(AttributeList::get(Context, /*FnAttrs=*/AttributeSet(),
+                                          NewPAL.getRetAttributes(),
+                                          NewArgAttrs));
 
       remove(CS.getInstruction()->getParent()->getParent());
       U->set(BitcastNew);