Fix PR7328: when turning a tail recursion into a loop, need to preserve

the returned value after the tail call if it differs from other return
values.  The optimal thing to do would be to introduce a phi node for
the return value, but for the moment just fix the miscompile.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106947 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/TailCallElim/2010-06-26-MultipleReturnValues.ll

@@ -0,0 +1,17 @@
+; RUN: opt < %s -tailcallelim -S | FileCheck %s
+; PR7328
+define i32 @foo(i32 %x) {
+; CHECK: define i32 @foo
+entry:
+  %cond = icmp ugt i32 %x, 0                      ; <i1> [#uses=1]
+  br i1 %cond, label %return, label %body
+
+body:                                             ; preds = %entry
+  %y = add i32 %x, 1                              ; <i32> [#uses=1]
+  %tmp = call i32 @foo(i32 %y)                    ; <i32> [#uses=0]
+  ret i32 0
+; CHECK: ret i32 0
+
+return:                                           ; preds = %entry
+  ret i32 1
+}