From d802347a2ec410b491a0aef3dd0336b10baf078a Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Thu, 24 Feb 2005 06:15:27 +0000 Subject: [PATCH] new testcase for a simple optimization that simplifycfg is about to do. All CFG edges to DEAD should be eliminated. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20299 91177308-0d34-0410-b5e6-96231b3b80d8 --- test/Transforms/SimplifyCFG/switch_thread.ll | 78 ++++++++++++++++++++ 1 file changed, 78 insertions(+) create mode 100644 test/Transforms/SimplifyCFG/switch_thread.ll diff --git a/test/Transforms/SimplifyCFG/switch_thread.ll b/test/Transforms/SimplifyCFG/switch_thread.ll new file mode 100644 index 00000000000..5eee2c7a7ae --- /dev/null +++ b/test/Transforms/SimplifyCFG/switch_thread.ll @@ -0,0 +1,78 @@ +; RUN: llvm-as < %s | opt -simplifycfg | llvm-dis | 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() + +void %test1(uint %V) { + switch uint %V, label %A [ + uint 4, label %T + uint 17, label %Done + uint 1234, label %A + ] + +T: ;; V == 4 if we get here. + call void %foo1() + ;; This switch is always statically determined. + switch uint %V, label %A2 [ + uint 4, label %B + uint 17, label %C + uint 42, label %C + ] +A2: + call void %DEAD() + call void %DEAD() + %cond2 = seteq uint %V, 4 ;; always false + br bool %cond2, label %Done, label %C + +A: + call void %foo1() + %cond = setne uint %V, 4 ;; always true + br bool %cond, label %Done, label %C + + +Done: + ret void + +B: + call void %foo2() + %cond3 = seteq uint %V, 4 ;; always true + br bool %cond3, label %Done, label %C +C: + call void %DEAD() + ret void +} + +void %test2(uint %V) { + switch uint %V, label %A [ + uint 4, label %T + uint 17, label %D + uint 1234, label %E + ] + +A: ;; V != 4, 17, 1234 here. + call void %foo1() + ;; This switch is always statically determined. + switch uint %V, label %E [ + uint 4, label %C + uint 17, label %C + uint 42, label %D + ] +C: + call void %DEAD() ;; unreacahble. + ret void +T: + call void %foo1() + call void %foo1() + ret void + +D: + call void %foo1() + ret void + +E: + ret void +} +