Fix PR2967 by not deleting volatile load/stores that occur before unreachable.

I don't really see this as being needed, but there is little harm from doing
it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58385 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 19 insertions, 0 deletions

diff --git a/test/Transforms/SimplifyCFG/trapping-load-unreachable.ll b/test/Transforms/SimplifyCFG/trapping-load-unreachable.ll
new file mode 100644
index 0000000..a73a82b
--- /dev/null
+++ b/test/Transforms/SimplifyCFG/trapping-load-unreachable.ll
@@ -0,0 +1,19 @@
+; RUN: llvm-as < %s | opt -simplifycfg | llvm-dis | grep {volatile load}
+; PR2967
+
+target datalayout =
+"e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32"
+target triple = "i386-pc-linux-gnu"
+
+define void @foo(i32 %x) nounwind {
+entry:
+        %0 = icmp eq i32 %x, 0          ; <i1> [#uses=1]
+        br i1 %0, label %bb, label %return
+
+bb:             ; preds = %entry
+        %1 = volatile load i32* null            ; <i32> [#uses=0]
+        unreachable
+        br label %return
+return:         ; preds = %entry
+        ret void
+}