[llvm-commits] [llvm] r52839 - /llvm/trunk/include/llvm/Support/MathExtras.h

[Owen Anderson]

Author: resistor
Date: Fri Jun 27 16:48:21 2008
New Revision: 52839

URL: http://llvm.org/viewvc/llvm-project?rev=52839&view=rev
Log:
Add a NextPowerOf2 function to calculate the next power of two greater than a given integer.

Modified:
    llvm/trunk/include/llvm/Support/MathExtras.h

Modified: llvm/trunk/include/llvm/Support/MathExtras.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/MathExtras.h?rev=52839&r1=52838&r2=52839&view=diff

==============================================================================
--- llvm/trunk/include/llvm/Support/MathExtras.h (original)
+++ llvm/trunk/include/llvm/Support/MathExtras.h Fri Jun 27 16:48:21 2008
@@ -396,6 +396,18 @@
   // The largest power of 2 that divides both A and B.
   return (A | B) & -(A | B);
 }
+
+/// NextPowerOf2 - Returns the next power of two (in 64-bits)
+/// that is strictly greater than A.  Returns zero on overflow.
+static inline uint64_t NextPowerOf2(uint64_t A) {
+  A |= (A >> 1);
+  A |= (A >> 2);
+  A |= (A >> 4);
+  A |= (A >> 8);
+  A |= (A >> 16);
+  A |= (A >> 32);
+  return A + 1;
+}
   
 } // End llvm namespace