[llvm] r259251 - AttributeSetNode: Summarize existing attributes in a bitset.

[Matthias Braun via llvm-commits]

Author: matze
Date: Fri Jan 29 16:25:13 2016
New Revision: 259251

URL: http://llvm.org/viewvc/llvm-project?rev=259251&view=rev
Log:
AttributeSetNode: Summarize existing attributes in a bitset.

The majority of queries just checks for the existince of an enum
attribute.  We only have 48 of those and can summaryiz them in an
uint64_t bitfield so we can avoid searching the list. This improves
"opt" compile time by 1-4% in my measurements.

Differential Revision: http://reviews.llvm.org/D16617

Modified:
    llvm/trunk/lib/IR/AttributeImpl.h
    llvm/trunk/lib/IR/Attributes.cpp

Modified: llvm/trunk/lib/IR/AttributeImpl.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/AttributeImpl.h?rev=259251&r1=259250&r2=259251&view=diff
==============================================================================
--- llvm/trunk/lib/IR/AttributeImpl.h (original)
+++ llvm/trunk/lib/IR/AttributeImpl.h Fri Jan 29 16:25:13 2016
@@ -148,10 +148,21 @@ class AttributeSetNode final
   friend TrailingObjects;
 
   unsigned NumAttrs; ///< Number of attributes in this node.
+  /// Bitset with a bit for each available attribute Attribute::AttrKind.
+  uint64_t AvailableAttrs;
+  static_assert(Attribute::EndAttrKinds <= sizeof(AvailableAttrs)*CHAR_BIT,
+                "Too many attributes for AvailableAttrs");
 
-  AttributeSetNode(ArrayRef<Attribute> Attrs) : NumAttrs(Attrs.size()) {
+  AttributeSetNode(ArrayRef<Attribute> Attrs)
+    : NumAttrs(Attrs.size()), AvailableAttrs(0) {
     // There's memory after the node where we can store the entries in.
     std::copy(Attrs.begin(), Attrs.end(), getTrailingObjects<Attribute>());
+
+    for (iterator I = begin(), E = end(); I != E; ++I) {
+      if (!I->isStringAttribute()) {
+        AvailableAttrs |= ((uint64_t)1) << I->getKindAsEnum();
+      }
+    }
   }
 
   // AttributesSetNode is uniqued, these should not be publicly available.
@@ -160,7 +171,9 @@ class AttributeSetNode final
 public:
   static AttributeSetNode *get(LLVMContext &C, ArrayRef<Attribute> Attrs);
 
-  bool hasAttribute(Attribute::AttrKind Kind) const;
+  bool hasAttribute(Attribute::AttrKind Kind) const {
+    return AvailableAttrs & ((uint64_t)1) << Kind;
+  }
   bool hasAttribute(StringRef Kind) const;
   bool hasAttributes() const { return NumAttrs != 0; }
 

Modified: llvm/trunk/lib/IR/Attributes.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Attributes.cpp?rev=259251&r1=259250&r2=259251&view=diff
==============================================================================
--- llvm/trunk/lib/IR/Attributes.cpp (original)
+++ llvm/trunk/lib/IR/Attributes.cpp Fri Jan 29 16:25:13 2016
@@ -498,13 +498,6 @@ AttributeSetNode *AttributeSetNode::get(
   return PA;
 }
 
-bool AttributeSetNode::hasAttribute(Attribute::AttrKind Kind) const {
-  for (iterator I = begin(), E = end(); I != E; ++I)
-    if (I->hasAttribute(Kind))
-      return true;
-  return false;
-}
-
 bool AttributeSetNode::hasAttribute(StringRef Kind) const {
   for (iterator I = begin(), E = end(); I != E; ++I)
     if (I->hasAttribute(Kind))
@@ -513,9 +506,11 @@ bool AttributeSetNode::hasAttribute(Stri
 }
 
 Attribute AttributeSetNode::getAttribute(Attribute::AttrKind Kind) const {
-  for (iterator I = begin(), E = end(); I != E; ++I)
-    if (I->hasAttribute(Kind))
-      return *I;
+  if (hasAttribute(Kind)) {
+    for (iterator I = begin(), E = end(); I != E; ++I)
+      if (I->hasAttribute(Kind))
+        return *I;
+  }
   return Attribute();
 }