Add local PRE to GVN. This only operates in cases where it would not increase code size, namely when the instantiated expression

would only need to be created in one predecessor.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52471 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 18 insertions, 0 deletions

diff --git a/test/Transforms/GVN/local-pre.ll b/test/Transforms/GVN/local-pre.ll
new file mode 100644
index 0000000..7b6e833
--- /dev/null
+++ b/test/Transforms/GVN/local-pre.ll
@@ -0,0 +1,18 @@
+; RUN: llvm-as < %s | opt -gvn | llvm-dis | grep {b.pre}
+
+define i32 @main(i32 %p) {
+block1:
+  
+	br i1 true, label %block2, label %block3
+
+block2:
+ %a = add i32 %p, 1
+ br label %block4
+
+block3:
+  br label %block4
+
+block4:
+  %b = add i32 %p, 1
+  ret i32 %b
+}