From 1fc08f5e9ef733ef1ce6f363fecedc2260e78974 Mon Sep 17 00:00:00 2001 From: dim Date: Sat, 14 Apr 2012 13:54:10 +0000 Subject: Vendor import of llvm trunk r154661: http://llvm.org/svn/llvm-project/llvm/trunk@r154661 --- lib/Analysis/AliasAnalysis.cpp | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'lib/Analysis/AliasAnalysis.cpp') diff --git a/lib/Analysis/AliasAnalysis.cpp b/lib/Analysis/AliasAnalysis.cpp index bd132c0..95c834b 100644 --- a/lib/Analysis/AliasAnalysis.cpp +++ b/lib/Analysis/AliasAnalysis.cpp @@ -440,3 +440,19 @@ bool llvm::isIdentifiedObject(const Value *V) { return A->hasNoAliasAttr() || A->hasByValAttr(); return false; } + +/// isKnownNonNull - Return true if we know that the specified value is never +/// null. +bool llvm::isKnownNonNull(const Value *V) { + // Alloca never returns null, malloc might. + if (isa(V)) return true; + + // A byval argument is never null. + if (const Argument *A = dyn_cast(V)) + return A->hasByValAttr(); + + // Global values are not null unless extern weak. + if (const GlobalValue *GV = dyn_cast(V)) + return !GV->hasExternalWeakLinkage(); + return false; +} -- cgit v1.1