new testcases for PR557

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21782 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/Reassociate/basictest3.ll

@@ -0,0 +1,50 @@
+; RUN: llvm-as < %s | opt -reassociate -gcse | llvm-dis | grep add | wc -l | grep 6
+; Each of these functions should turn into two adds each.
+
+%e = external global int
+%a = external global int
+%b = external global int
+%c = external global int
+%f = external global int
+
+implementation
+
+void %test1() {
+        %A = load int* %a
+        %B = load int* %b
+        %C = load int* %c
+        %t1 = add int %A, %B
+	%t2 = add int %t1, %C
+        %t3 = add int %C, %A
+	%t4 = add int %t3, %B
+        store int %t2, int* %e  ; e = (a+b)+c;
+        store int %t4, int* %f  ; f = (a+c)+b
+        ret void
+}
+
+void %test2() {
+        %A = load int* %a
+        %B = load int* %b
+        %C = load int* %c
+	%t1 = add int %A, %B
+	%t2 = add int %t1, %C
+	%t3 = add int %C, %A
+	%t4 = add int %t3, %B
+        store int %t2, int* %e  ; e = c+(a+b)
+        store int %t4, int* %f  ; f = (c+a)+b
+        ret void
+}
+
+void %test3() {
+        %A = load int* %a
+        %B = load int* %b
+        %C = load int* %c
+	%t1 = add int %B, %A
+	%t2 = add int %t1, %C
+	%t3 = add int %C, %A
+	%t4 = add int %t3, %B
+        store int %t2, int* %e  ; e = c+(b+a)
+        store int %t4, int* %f  ; f = (c+a)+b
+        ret void
+}
+

test/Transforms/Reassociate/basictest4.ll

@@ -0,0 +1,20 @@
+; RUN: llvm-as < %s | opt -reassociate -gcse -instcombine | llvm-dis | not grep add
+
+%a = weak global int 0
+%b = weak global int 0
+%c = weak global int 0
+%d = weak global int 0
+
+implementation
+
+int %foo() {
+	%tmp.0 = load int* %a
+	%tmp.1 = load int* %b
+	%tmp.2 = add int %tmp.0, %tmp.1   ; (a+b)
+	%tmp.4 = load int* %c
+	%tmp.5 = add int %tmp.2, %tmp.4   ; (a+b)+c
+	%tmp.8 = add int %tmp.0, %tmp.4   ; (a+c)
+	%tmp.11 = add int %tmp.8, %tmp.1  ; (a+c)+b
+	%RV = xor int %tmp.5, %tmp.11     ; X ^ X = 0
+	ret int %RV
+}