add an early out to ProcessBranchOnXOR to speed it up,

handle the case when we can infer an input to the xor
from all inputs that agree, instead of going into an
infinite loop.  Another part of PR6199


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94321 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 27 insertions, 0 deletions

diff --git a/test/Transforms/JumpThreading/crash.ll b/test/Transforms/JumpThreading/crash.ll
index c0ef078..ff980ff 100644
--- a/test/Transforms/JumpThreading/crash.ll
+++ b/test/Transforms/JumpThreading/crash.ll
@@ -259,3 +259,30 @@ for.cond:                                         ; preds = %for.body, %lor.end
 for.body:                                         ; preds = %for.cond
   br label %for.cond
 }
+
+; PR6119
+define i32 @test9(i32 %action) nounwind {
+entry:
+  switch i32 %action, label %lor.rhs [
+    i32 1, label %if.then
+    i32 0, label %lor.end
+  ]
+
+if.then:                                          ; preds = %for.cond, %lor.end, %entry
+  ret i32 undef
+
+lor.rhs:                                          ; preds = %entry
+  br label %lor.end
+
+lor.end:                                          ; preds = %lor.rhs, %entry
+  %0 = phi i1 [ undef, %lor.rhs ], [ true, %entry ] ; <i1> [#uses=1]
+  %cmp103 = xor i1 undef, %0                      ; <i1> [#uses=1]
+  br i1 %cmp103, label %for.cond, label %if.then
+
+for.cond:                                         ; preds = %for.body, %lor.end
+  br i1 undef, label %if.then, label %for.body
+
+for.body:                                         ; preds = %for.cond
+  br label %for.cond
+}
+