From abf63457102b4a4e223c2f60f90886c225f1390a Mon Sep 17 00:00:00 2001 From: Evan Cheng Date: Thu, 26 Oct 2006 21:48:03 +0000 Subject: [PATCH] Speed up isCString() git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31206 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/VMCore/Constants.cpp | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/lib/VMCore/Constants.cpp b/lib/VMCore/Constants.cpp index ce29a21f86c..9c92b907783 100644 --- a/lib/VMCore/Constants.cpp +++ b/lib/VMCore/Constants.cpp @@ -1077,11 +1077,21 @@ bool ConstantArray::isString() const { /// isString) and it ends in a null byte \0 and does not contains any other /// null bytes except its terminator. bool ConstantArray::isCString() const { - if (!isString()) return false; - // This is safe because a ConstantArray cannot be a zero array. - for (unsigned i = 0, e = getNumOperands()-1; i != e; ++i) - if (cast(getOperand(i))->getZExtValue() == 0) + // Check the element type for sbyte or ubyte... + if (getType()->getElementType() != Type::UByteTy && + getType()->getElementType() != Type::SByteTy) + return false; + Constant *Zero = Constant::getNullValue(getOperand(0)->getType()); + // Last element must be a null. + if (getOperand(getNumOperands()-1) != Zero) + return false; + // Other elements must be non-null integers. + for (unsigned i = 0, e = getNumOperands()-1; i != e; ++i) { + if (!isa(getOperand(i))) return false; + if (getOperand(i) == Zero) + return false; + } return true; }