diff options
| author | Ed Schouten <ed@FreeBSD.org> | 2009-06-02 17:52:33 +0000 |
|---|---|---|
| committer | Ed Schouten <ed@FreeBSD.org> | 2009-06-02 17:52:33 +0000 |
| commit | 009b1c42aa6266385f2c37e227516b24077e6dd7 (patch) | |
| tree | 64ba909838c23261cace781ece27d106134ea451 /test/Transforms/SimplifyCFG/switch_thread.ll | |
Diffstat (limited to 'test/Transforms/SimplifyCFG/switch_thread.ll')
| -rw-r--r-- | test/Transforms/SimplifyCFG/switch_thread.ll | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/test/Transforms/SimplifyCFG/switch_thread.ll b/test/Transforms/SimplifyCFG/switch_thread.ll new file mode 100644 index 0000000000000..a92528a3331f2 --- /dev/null +++ b/test/Transforms/SimplifyCFG/switch_thread.ll @@ -0,0 +1,79 @@ +; RUN: llvm-as < %s | opt -simplifycfg | llvm-dis | \ +; RUN: not grep {call void @DEAD} + +; Test that we can thread a simple known condition through switch statements. + +declare void @foo1() + +declare void @foo2() + +declare void @DEAD() + +define void @test1(i32 %V) { + switch i32 %V, label %A [ + i32 4, label %T + i32 17, label %Done + i32 1234, label %A + ] +;; V == 4 if we get here. +T: ; preds = %0 + call void @foo1( ) + ;; This switch is always statically determined. + switch i32 %V, label %A2 [ + i32 4, label %B + i32 17, label %C + i32 42, label %C + ] +A2: ; preds = %T + call void @DEAD( ) + call void @DEAD( ) + ;; always true + %cond2 = icmp eq i32 %V, 4 ; <i1> [#uses=1] + br i1 %cond2, label %Done, label %C +A: ; preds = %0, %0 + call void @foo1( ) + ;; always true + %cond = icmp ne i32 %V, 4 ; <i1> [#uses=1] + br i1 %cond, label %Done, label %C +Done: ; preds = %B, %A, %A2, %0 + ret void +B: ; preds = %T + call void @foo2( ) + ;; always true + %cond3 = icmp eq i32 %V, 4 ; <i1> [#uses=1] + br i1 %cond3, label %Done, label %C +C: ; preds = %B, %A, %A2, %T, %T + call void @DEAD( ) + ret void +} + +define void @test2(i32 %V) { + switch i32 %V, label %A [ + i32 4, label %T + i32 17, label %D + i32 1234, label %E + ] +;; V != 4, 17, 1234 here. +A: ; preds = %0 + call void @foo1( ) + ;; This switch is always statically determined. + switch i32 %V, label %E [ + i32 4, label %C + i32 17, label %C + i32 42, label %D + ] +;; unreacahble. +C: ; preds = %A, %A + call void @DEAD( ) + ret void +T: ; preds = %0 + call void @foo1( ) + call void @foo1( ) + ret void +D: ; preds = %A, %0 + call void @foo1( ) + ret void +E: ; preds = %A, %0 + ret void +} + |