Allow "exhaustive" trip count evaluation on phi nodes with all

constant operands.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106537 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 19 insertions, 0 deletions

diff --git a/test/Analysis/ScalarEvolution/trip-count10.ll b/test/Analysis/ScalarEvolution/trip-count10.ll
index 2386cf4..546e1dc 100644
--- a/test/Analysis/ScalarEvolution/trip-count10.ll
+++ b/test/Analysis/ScalarEvolution/trip-count10.ll
@@ -105,3 +105,22 @@ bb2:
 retbb:
   ret void
 }
+
+; PHI nodes with all constant operands.
+
+; CHECK: Determining loop execution counts for: @constant_phi_operands
+; CHECK: Loop %loop: backedge-taken count is 1
+; CHECK: Loop %loop: max backedge-taken count is 1
+
+define void @constant_phi_operands() nounwind {
+entry:
+  br label %loop
+
+loop:
+  %i = phi i64 [ 1, %loop ], [ 0, %entry ]
+  %exitcond = icmp eq i64 %i, 1
+  br i1 %exitcond, label %return, label %loop
+
+return:
+  ret void
+}