Merging r257875:

[oota-llvm.git] / include / llvm / Transforms / Utils / Local.h

diff --git a/include/llvm/Transforms/Utils/Local.h b/include/llvm/Transforms/Utils/Local.h
index 911c6f14da0b98425d2d9972a3dd4bed831e1df2..3ae01657a2ecb54c29c2604e3c003a612af3280b 100644 (file)
--- a/include/llvm/Transforms/Utils/Local.h
+++ b/include/llvm/Transforms/Utils/Local.h
@@ -331,6 +331,25 @@ unsigned replaceDominatedUsesWith(Value *From, Value *To, DominatorTree &DT,
 /// during lowering by the GC infrastructure.
 bool callsGCLeafFunction(ImmutableCallSite CS);
 
+//===----------------------------------------------------------------------===//
+//  Intrinsic pattern matching
+//
+
+/// Try and match a bitreverse or bswap idiom.
+///
+/// If an idiom is matched, an intrinsic call is inserted before \c I. Any added
+/// instructions are returned in \c InsertedInsts. They will all have been added
+/// to a basic block.
+///
+/// A bitreverse idiom normally requires around 2*BW nodes to be searched (where
+/// BW is the bitwidth of the integer type). A bswap idiom requires anywhere up
+/// to BW / 4 nodes to be searched, so is significantly faster.
+///
+/// This function returns true on a successful match or false otherwise.
+bool recognizeBitReverseOrBSwapIdiom(
+    Instruction *I, bool MatchBSwaps, bool MatchBitReversals,
+    SmallVectorImpl<Instruction *> &InsertedInsts);
+
 } // End llvm namespace
 
 #endif