--- /dev/null
+; RUN: opt -S --passes="ipsccp<func-spec>" -force-function-specialization < %s | FileCheck %s
+
+@A = private constant [6 x i32] [i32 1, i32 2, i32 0, i32 0, i32 0, i32 0], align 16
+@B = external global ptr, align 8
+
+define i32 @caller() {
+entry:
+ %c1 = call fastcc i32 @func(ptr @f0, i32 0, ptr null)
+ %c2 = call fastcc i32 @func(ptr @f1, i32 1, ptr @A)
+ %c3 = call fastcc i32 @func(ptr @f2, i32 2, ptr @A)
+ %add = add i32 %c1, %c2
+ %sub = sub i32 %add, %c3
+ ret i32 %sub
+}
+
+define internal fastcc i32 @func(ptr %f, i32 %N, ptr %A) {
+entry:
+ switch i32 %N, label %sw.epilog [
+ i32 2, label %sw.bb
+ i32 1, label %sw.bb2
+ i32 0, label %sw.bb4
+ ]
+
+sw.bb: ; preds = %entry
+ %0 = getelementptr inbounds i32, ptr %A, i64 1
+ %1 = load i32, ptr %0, align 4
+ %2 = call i32 %f(i32 %1)
+ br label %sw.epilog
+
+sw.bb2: ; preds = %entry
+ %3 = load i32, ptr %A, align 4
+ %4 = zext i32 %3 to i64
+ %5 = call i32 %f(i64 %4)
+ br label %sw.epilog
+
+sw.bb4: ; preds = %entry
+ %6 = call i32 %f()
+ br label %sw.epilog
+
+sw.epilog: ; preds = %sw.bb, %sw.bb2, %sw.bb4, %entry
+ %7 = phi i32 [undef, %entry], [%2, %sw.bb], [%5, %sw.bb2], [%6, %sw.bb4]
+ ret i32 %7
+}
+
+define i32 @f0() {
+ %ld = load i32, ptr @B, align 4
+ ret i32 %ld
+}
+
+define i32 @f1(i64 %offset) {
+ %gep = getelementptr inbounds i32, ptr @B, i64 %offset
+ %ld = load i32, ptr %gep, align 4
+ ret i32 %ld
+}
+
+define i32 @f2(i32 %offset) {
+ %zext = zext i32 %offset to i64
+ %call = call i32 @f1(i64 %zext)
+ ret i32 %call
+}
+
+; Tests that `func` has been specialized and it didn't cause compiler crash.
+; CHECK-DAG: func.1
+; CHECK-DAG: func.2
+; CHECK-DAG: func.3
+