Make LoopDeletion work on loops with multiple edges, as long as the incoming

values from all of the loop's exiting blocks are equal. Patch by Andrew Clinton.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126253 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/LoopDeletion/multiple-exits.ll

@@ -0,0 +1,26 @@
+; RUN: opt < %s -loop-deletion -S | FileCheck %s
+
+; Checks whether dead loops with multiple exits can be eliminated
+
+; CHECK:      entry:
+; CHECK-NEXT:   br label %return
+
+; CHECK:      return:
+; CHECK-NEXT:   ret void
+
+define void @foo(i64 %n, i64 %m) nounwind {
+entry:
+  br label %bb
+
+bb:
+  %x.0 = phi i64 [ 0, %entry ], [ %t0, %bb2 ]
+  %t0 = add i64 %x.0, 1
+  %t1 = icmp slt i64 %x.0, %n
+  br i1 %t1, label %bb2, label %return
+bb2:
+  %t2 = icmp slt i64 %x.0, %m
+  br i1 %t1, label %bb, label %return
+
+return:
+  ret void
+}