Index: lib/Analysis/BasicAliasAnalysis.cpp
===================================================================
--- lib/Analysis/BasicAliasAnalysis.cpp
+++ lib/Analysis/BasicAliasAnalysis.cpp
@@ -1077,8 +1077,8 @@
   // of GetLinearExpression decomposition. In the example above, if Var0
   // is zext(%x + 1) we should get V1 == %x and V1Offset == 1.
 
-  APInt V0Scale(Width, 0), V0Offset(Width, 0), V1Scale(Width, 1),
-      V1Offset(Width, 1);
+  APInt V0Scale(Width, 0), V0Offset(Width, 0), V1Scale(Width, 0),
+      V1Offset(Width, 0);
   bool NSW = true, NUW = true;
   unsigned V0ZExtBits = 0, V0SExtBits = 0, V1ZExtBits = 0, V1SExtBits = 0;
   const Value *V0 = GetLinearExpression(Var0.V, V0Scale, V0Offset, V0ZExtBits,
Index: test/Analysis/BasicAA/bug.23540.ll
===================================================================
--- /dev/null
+++ test/Analysis/BasicAA/bug.23540.ll
@@ -0,0 +1,23 @@
+; RUN: opt < %s -basicaa -licm -S 2>&1 | FileCheck %s
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@c = external global i32
+
+; CHECK-LABEL: @f
+; CHECK: br label %for.body
+; CHECK: br label %for.body
+define void @f() {
+entry:
+  br label %for.body
+
+for.body:
+  %idxprom = zext i32 undef to i64
+  %arrayidx = getelementptr inbounds i32, i32* @c, i64 %idxprom
+  %0 = load i32, i32* %arrayidx
+  %add4 = add i32 0, 1
+  %idxprom5 = zext i32 %add4 to i64
+  %arrayidx6 = getelementptr inbounds i32, i32* @c, i64 %idxprom5
+  %1 = load i32, i32* %arrayidx6
+  br label %for.body
+}
\ No newline at end of file