[Safepoint Verifier] Add a false positive test.

Author: Serguei Katkov

llvm/test/SafepointIRVerifier/hidden-constant-base.ll

@@ -0,0 +1,39 @@
+; RUN: opt -safepoint-ir-verifier-print-only -verify-safepoint-ir -S %s 2>&1 | FileCheck %s
+
+; This is a false positive case. Actually base of %tmp5 is null but verifier does not see that.
+; As a result it states that %tmp5 can have a unrelocated value of %tmp.
+; Relocation of %tmp is expected to be after the call to @widget but it is not required
+; due to %tmp is always null as well.
+
+; CHECK-LABEL: Verifying gc pointers in function: test
+; CHECK: Illegal use of unrelocated value found!
+define i8 addrspace(1)* @test(i1 %arg) gc "statepoint-example" {
+bb:
+  br label %bb2
+
+bb2:                                              ; preds = %bb8, %bb
+  %tmp = phi i8 addrspace(1)* [ %tmp5.relocated, %bb8 ], [ null, %bb ]
+  %statepoint_token = call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 2882400000, i32 0, void ()* elementtype(void ()) @widget, i32 0, i32 0, i32 0, i32 0) [ "deopt"() ]
+  br label %bb4
+
+bb4:                                              ; preds = %bb8, %bb2
+  %tmp5 = phi i8 addrspace(1)* [ %tmp5.relocated, %bb8 ], [ %tmp, %bb2 ]
+  %statepoint_token1 = call token (i64, i32, i1 ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_i1f(i64 2882400000, i32 0, i1 ()* elementtype(i1 ()) @baz, i32 0, i32 0, i32 0, i32 0) [ "deopt"(i8 addrspace(1)* %tmp5), "gc-live"(i8 addrspace(1)* %tmp5) ]
+  %tmp62 = call i1 @llvm.experimental.gc.result.i1(token %statepoint_token1)
+  %tmp5.relocated = call coldcc i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token %statepoint_token1, i32 0, i32 0) ; (%tmp5, %tmp5)
+  br i1 %tmp62, label %bb8, label %bb6
+
+bb6:                                              ; preds = %bb4
+  ret i8 addrspace(1)* null
+
+bb8:                                              ; preds = %bb4
+  br i1 %arg, label %bb4, label %bb2
+}
+
+declare void @widget()
+declare i1 @baz()
+
+declare token @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 immarg, i32 immarg, void ()*, i32 immarg, i32 immarg, ...)
+declare token @llvm.experimental.gc.statepoint.p0f_i1f(i64 immarg, i32 immarg, i1 ()*, i32 immarg, i32 immarg, ...)
+declare i1 @llvm.experimental.gc.result.i1(token)
+declare i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token, i32 immarg, i32 immarg)