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, 5 insertions, 12 deletions

diff --git a/lib/Transforms/IPO/GlobalOpt.cpp b/lib/Transforms/IPO/GlobalOpt.cpp
index 7bfed8afc6..5bb7494cd1 100644
--- a/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/lib/Transforms/IPO/GlobalOpt.cpp
@@ -21,7 +21,6 @@
 #include "llvm/Instructions.h"
 #include "llvm/IntrinsicInst.h"
 #include "llvm/Module.h"
-#include "llvm/ParamAttrsList.h"
 #include "llvm/Pass.h"
 #include "llvm/Analysis/ConstantFolding.h"
 #include "llvm/Target/TargetData.h"
@@ -1592,18 +1591,13 @@ static void ChangeCalleesToFastCall(Function *F) {
   }
 }
 
-static const ParamAttrsList *StripNest(const ParamAttrsList *Attrs) {
-  if (!Attrs)
-    return NULL;
-
-  for (unsigned i = 0, e = Attrs->size(); i != e; ++i) {
-    if ((Attrs->getParamAttrsAtIndex(i) & ParamAttr::Nest) == 0)
+static PAListPtr StripNest(const PAListPtr &Attrs) {
+  for (unsigned i = 0, e = Attrs.getNumSlots(); i != e; ++i) {
+    if ((Attrs.getSlot(i).Attrs & ParamAttr::Nest) == 0)
       continue;
 
-    Attrs = ParamAttrsList::excludeAttrs(Attrs, Attrs->getParamIndex(i),
-                                         ParamAttr::Nest);
     // There can be only one.
-    break;
+    return Attrs.removeAttr(Attrs.getSlot(i).Index, ParamAttr::Nest);
   }
 
   return Attrs;
@@ -1640,8 +1634,7 @@ bool GlobalOpt::OptimizeFunctions(Module &M) {
         Changed = true;
       }
 
-      if (F->getParamAttrs() &&
-          F->getParamAttrs()->hasAttrSomewhere(ParamAttr::Nest) &&
+      if (F->getParamAttrs().hasAttrSomewhere(ParamAttr::Nest) &&
           OnlyCalledDirectly(F)) {
         // The function is not used by a trampoline intrinsic, so it is safe
         // to remove the 'nest' attribute.