add a basic testcase.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50093 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/JumpThreading/basic.ll

@@ -0,0 +1,31 @@
+; RUN: llvm-as < %s | opt -jump-threading -simplifycfg -mem2reg | llvm-dis | grep {ret i32 %v1}
+; There should be no uncond branches left.
+; RUN: llvm-as < %s | opt -jump-threading -simplifycfg -mem2reg | llvm-dis | not grep {br label}
+
+declare i32 @f1()
+declare i32 @f2()
+declare void @f3()
+
+define i32 @test(i1 %cond) {
+	br i1 %cond, label %T1, label %F1
+
+T1:
+	%v1 = call i32 @f1()
+	br label %Merge
+
+F1:
+	%v2 = call i32 @f2()
+	br label %Merge
+
+Merge:
+	%A = phi i1 [true, %T1], [false, %F1]
+	%B = phi i32 [%v1, %T1], [%v2, %F1]
+	br i1 %A, label %T2, label %F2
+
+T2:
+	call void @f3()
+	ret i32 %B
+
+F2:
+	ret i32 %B
+}

test/Transforms/JumpThreading/dg.exp

@@ -0,0 +1,3 @@
+load_lib llvm.exp
+
+RunLLVMTests [lsort [glob -nocomplain $srcdir/$subdir/*.ll]]