[Loads] Fix crash in is isDereferenceableAndAlignedPointer()

Summary:
We were trying to add APInt values with different bit sizes after
visiting an addrspacecast instruction which changed the bit width
of the pointer.

Reviewers: majnemer, hfinkel

Subscribers: hfinkel, wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D24774

llvm-svn: 285407

1 files changed, 21 insertions, 0 deletions

diff --git a/llvm/test/Analysis/ValueTracking/dereferenceable-and-aligned.ll b/llvm/test/Analysis/ValueTracking/dereferenceable-and-aligned.ll
new file mode 100644
index 00000000000..8af0548db11
--- /dev/null
+++ b/llvm/test/Analysis/ValueTracking/dereferenceable-and-aligned.ll
@@ -0,0 +1,21 @@
+; RUN: opt < %s -licm -S | FileCheck %s
+
+target datalayout = "e-p:32:32-p1:64:64-p4:64:64"
+
+; Make sure isDereferenceableAndAlignePointer() doesn't crash when looking
+; walking pointer defs with an addrspacecast that changes pointer size.
+; CHECK-LABEL: @addrspacecast_crash
+define void @addrspacecast_crash() {
+bb:
+  %tmp = alloca [256 x i32]
+  br label %bb1
+
+bb1:
+  %tmp2 = getelementptr inbounds [256 x i32], [256 x i32]* %tmp, i32 0, i32 36
+  %tmp3 = bitcast i32* %tmp2 to <4 x i32>*
+  %tmp4 = addrspacecast <4 x i32>* %tmp3 to <4 x i32> addrspace(4)*
+  %tmp5 = load <4 x i32>, <4 x i32> addrspace(4)* %tmp4
+  %tmp6 = xor <4 x i32> %tmp5, undef
+  store <4 x i32> %tmp6, <4 x i32> addrspace(1)* undef
+  br label %bb1
+}