From b3949340c8856383ec3696bfa838dd3ae27ebc14 Mon Sep 17 00:00:00 2001 From: Zhou Sheng Date: Tue, 20 Mar 2007 12:49:06 +0000 Subject: [PATCH] Simplify isHighOnes(). llvm-svn: 35211 --- llvm/lib/Transforms/Scalar/InstructionCombining.cpp | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) diff --git a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp index 287a0077ec6c..891868b98a6d 100644 --- a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp @@ -3491,15 +3491,7 @@ static bool isLowOnes(const ConstantInt *CI) { // isHighOnes - Return true if the constant is of the form 1+0+. // This is the same as lowones(~X). static bool isHighOnes(const ConstantInt *CI) { - if (CI->getValue() == 0) return false; // 0's does not match "1+" - - APInt V(~CI->getValue()); - - // There won't be bits set in parts that the type doesn't contain. - V &= APInt::getAllOnesValue(CI->getType()->getBitWidth()); - - APInt U(V+1); // If it is low ones, this should be a power of two. - return (U!=0) && (V!=0) && (U & V) == 0; + return (~CI->getValue() + 1).isPowerOf2(); } /// getICmpCode - Encode a icmp predicate into a three bit mask. These bits