new testcase: instcombine should remove all the casts.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34869 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/Transforms/InstCombine/cast2.ll b/test/Transforms/InstCombine/cast2.ll
new file mode 100644 (file)
index 0000000..5151f84
--- /dev/null
+++ b/test/Transforms/InstCombine/cast2.ll
@@ -0,0 +1,24 @@
+; Tests to make sure elimination of casts is working correctly
+; RUN: llvm-as < %s | opt -instcombine -disable-output &&
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | notcast
+
+define i16 @test1(i16 %a) {
+        %tmp = zext i16 %a to i32               ; <i32> [#uses=2]
+        %tmp21 = lshr i32 %tmp, 8               ; <i32> [#uses=1]
+        %tmp5 = shl i32 %tmp, 8         ; <i32> [#uses=1]
+        %tmp.upgrd.32 = or i32 %tmp21, %tmp5            ; <i32> [#uses=1]
+        %tmp.upgrd.3 = trunc i32 %tmp.upgrd.32 to i16           ; <i16> [#uses=1]
+        ret i16 %tmp.upgrd.3
+}
+
+define i16 @test2(i16 %a) {
+        %tmp = zext i16 %a to i32               ; <i32> [#uses=2]
+        %tmp21 = lshr i32 %tmp, 9               ; <i32> [#uses=1]
+        %tmp5 = shl i32 %tmp, 8         ; <i32> [#uses=1]
+        %tmp.upgrd.32 = or i32 %tmp21, %tmp5            ; <i32> [#uses=1]
+        %tmp.upgrd.3 = trunc i32 %tmp.upgrd.32 to i16           ; <i16> [#uses=1]
+        ret i16 %tmp.upgrd.3
+}
+
+
+