From d98a45d29a6047bd47d3a3cd83c13ac0dac851fb Mon Sep 17 00:00:00 2001 From: Owen Anderson Date: Fri, 27 Jun 2008 21:48:21 +0000 Subject: [PATCH] Add a NextPowerOf2 function to calculate the next power of two greater than a given integer. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52839 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Support/MathExtras.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/include/llvm/Support/MathExtras.h b/include/llvm/Support/MathExtras.h index f57beed0939..8a89d85cd58 100644 --- a/include/llvm/Support/MathExtras.h +++ b/include/llvm/Support/MathExtras.h @@ -396,6 +396,18 @@ static inline uint64_t MinAlign(uint64_t A, uint64_t B) { // 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