change simplifycfg to not duplicate 'unwind' instructions. Hopefully

this will increase the likelihood of common code getting sunk towards
the unwind.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83996 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 18 insertions, 3 deletions

diff --git a/test/Transforms/SimplifyCFG/invoke_unwind.ll b/test/Transforms/SimplifyCFG/invoke_unwind.ll
index da6e3db..bbd779b 100644
--- a/test/Transforms/SimplifyCFG/invoke_unwind.ll
+++ b/test/Transforms/SimplifyCFG/invoke_unwind.ll
@@ -1,10 +1,9 @@
-; This testcase checks to see if the simplifycfg pass is converting invoke
-; instructions to call instructions if the handler just rethrows the exception.
-
 ; RUN: opt < %s -simplifycfg -S | FileCheck %s
 
 declare void @bar()
 
+; This testcase checks to see if the simplifycfg pass is converting invoke
+; instructions to call instructions if the handler just rethrows the exception.
 define i32 @test1() {
 ; CHECK: @test1
 ; CHECK-NEXT: call void @bar()
@@ -16,3 +15,19 @@ Ok:             ; preds = %0
 Rethrow:                ; preds = %0
         unwind
 }
+
+
+; Verify that simplifycfg isn't duplicating 'unwind' instructions.  Doing this
+; is bad because it discourages commoning.
+define i32 @test2(i1 %c) {
+; CHECK: @test2
+; CHECK: T:
+; CHECK-NEXT: call void @bar()
+; CHECK-NEXT: br label %F
+  br i1 %c, label %T, label %F
+T:
+  call void @bar()
+  br label %F
+F:
+  unwind
+}