Add a GVN-PRE basic regression test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37549 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/GVNPRE/basic.ll

@@ -0,0 +1,38 @@
+; RUN: llvm-as | opt -gvnpre | llvm-dis | not grep {%t3 =}
+; RUN: llvm-as | opt -gvnpre | llvm-dis | not grep {%t9 =}
+
+define i32 @main() {
+block1:
+	%t1 = bitcast i32 0 to i32		; <i32> [#uses=5]
+	br label %block2
+
+block2:		; preds = %block6, %block1
+	%t2 = phi i32 [ %t1, %block1 ], [ %t3, %block6 ]		; <i32> [#uses=3]
+	%t3 = add i32 %t2, 1		; <i32> [#uses=5]
+	br i1 false, label %block3, label %block7
+
+block3:		; preds = %block2
+	br i1 true, label %block4, label %block5
+
+block4:		; preds = %block3
+	%t4 = add i32 %t2, %t3		; <i32> [#uses=1]
+	%t5 = bitcast i32 %t4 to i32		; <i32> [#uses=1]
+	%t6 = add i32 %t1, %t5		; <i32> [#uses=0]
+	br label %block6
+
+block5:		; preds = %block3
+	%t7 = add i32 %t3, 1		; <i32> [#uses=1]
+	br label %block6
+
+block6:		; preds = %block5, %block4
+	%t8 = phi i32 [ %t1, %block4 ], [ %t7, %block5 ]		; <i32> [#uses=1]
+	%t9 = add i32 %t2, %t3		; <i32> [#uses=2]
+	%t10 = add i32 %t9, %t8		; <i32> [#uses=0]
+	%t11 = bitcast i32 12 to i32		; <i32> [#uses=1]
+	%t12 = add i32 %t9, %t11		; <i32> [#uses=1]
+	%t13 = add i32 %t12, %t3		; <i32> [#uses=0]
+	br label %block2
+
+block7:		; preds = %block2
+	ret i32 %t1
+}

test/Transforms/GVNPRE/dg.exp

@@ -0,0 +1,3 @@
+load_lib llvm.exp
+
+RunLLVMTests [lsort [glob -nocomplain $srcdir/$subdir/*.{ll,llx,c,cpp,tr}]]