isKnownNonNull needs to consider globals in non-zero address spaces.
Globals in address spaces other than one may have 0 as a valid address,
so we should not assume that they can be null.
Reviewed by Philip Reames.
llvm-svn: 246137
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 9b930d7..352b0fb 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -3226,9 +3226,12 @@
if (const Argument *A = dyn_cast<Argument>(V))
return A->hasByValOrInAllocaAttr() || A->hasNonNullAttr();
- // Global values are not null unless extern weak.
+ // A global variable in address space 0 is non null unless extern weak.
+ // Other address spaces may have null as a valid address for a global,
+ // so we can't assume anything.
if (const GlobalValue *GV = dyn_cast<GlobalValue>(V))
- return !GV->hasExternalWeakLinkage();
+ return !GV->hasExternalWeakLinkage() &&
+ GV->getType()->getAddressSpace() == 0;
// A Load tagged w/nonnull metadata is never null.
if (const LoadInst *LI = dyn_cast<LoadInst>(V))
diff --git a/llvm/test/Transforms/InstCombine/nonnull-attribute.ll b/llvm/test/Transforms/InstCombine/nonnull-attribute.ll
new file mode 100644
index 0000000..74fb091
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/nonnull-attribute.ll
@@ -0,0 +1,19 @@
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+; This test makes sure that we do not assume globals in address spaces other
+; than 0 are able to be null.
+
+@as0 = external global i32
+@as1 = external addrspace(1) global i32
+
+declare void @addrspace0(i32*)
+declare void @addrspace1(i32 addrspace(1)*)
+
+; CHECK: call void @addrspace0(i32* nonnull @as0)
+; CHECK: call void @addrspace1(i32 addrspace(1)* @as1)
+
+define void @test() {
+ call void @addrspace0(i32* @as0)
+ call void @addrspace1(i32 addrspace(1)* @as1)
+ ret void
+}