Introduce print-memderefs to test isDereferenceablePointer

Since testing the function indirectly is tricky, introduce a direct
print-memderefs pass, in the same spirit as print-memdeps, which prints
dereferenceability information matched by FileCheck.

Differential Revision: http://reviews.llvm.org/D7075

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228369 91177308-0d34-0410-b5e6-96231b3b80d8

test/Analysis/ValueTracking/memory-dereferenceable.ll

@@ -0,0 +1,33 @@
+; RUN: opt -print-memderefs -analyze -S <%s | FileCheck %s
+
+; Uses the print-deref (+ analyze to print) pass to run
+; isDereferenceablePointer() on many load instruction operands
+
+declare zeroext i1 @return_i1()
+
+@globalstr = global [6 x i8] c"hello\00"
+
+define void @test(i32 addrspace(1)* byval %dparam) {
+; CHECK: The following are dereferenceable:
+; CHECK: %globalptr
+; CHECK: %alloca
+; CHECK: %dparam
+; We haven't yet taught it to look through relocations
+; CHECK-NOT: %relocate
+; CHECK-NOT: %nparam
+entry:
+    %globalptr = getelementptr inbounds [6 x i8]* @globalstr, i32 0, i32 0
+    %load1 = load i8* %globalptr
+    %alloca = alloca i1
+    %load2 = load i1* %alloca
+    %load3 = load i32 addrspace(1)* %dparam
+    %tok = tail call i32 (i1 ()*, i32, i32, ...)* @llvm.experimental.gc.statepoint.p0f_i1f(i1 ()* @return_i1, i32 0, i32 0, i32 0, i32 addrspace(1)* %dparam)
+    %relocate = call i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32 %tok, i32 4, i32 4)
+    %load4 = load i32 addrspace(1)* %relocate
+    %nparam = getelementptr i32 addrspace(1)* %dparam, i32 5
+    %load5 = load i32 addrspace(1)* %nparam
+    ret void
+}
+
+declare i32 @llvm.experimental.gc.statepoint.p0f_i1f(i1 ()*, i32, i32, ...)
+declare i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(i32, i32, i32)