Add basic support for performing whole-function RLE.

Note: This has not yet been thoroughly tested.  Use at your own risk.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40489 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 58 insertions, 0 deletions

diff --git a/test/Transforms/GVN/dominated.ll b/test/Transforms/GVN/dominated.ll
new file mode 100644
index 0000000..4a9e975
--- /dev/null
+++ b/test/Transforms/GVN/dominated.ll
@@ -0,0 +1,20 @@
+; RUN: llvm-as < %s | opt -gvn | llvm-dis | not grep DEAD
+
+define i32 @main(i32** %p) {
+block1:
+  %z = load i32** %p
+	br i1 true, label %block2, label %block3
+
+block2:
+ %a = load i32** %p
+ br label %block4
+
+block3:
+  %b = load i32** %p
+  br label %block4
+
+block4:
+  %DEAD = load i32** %p
+  %c = load i32* %DEAD
+  ret i32 %c
+}
\ No newline at end of file
diff --git a/test/Transforms/GVN/nonlocal.ll b/test/Transforms/GVN/nonlocal.ll
new file mode 100644
index 0000000..7e5ef91
--- /dev/null
+++ b/test/Transforms/GVN/nonlocal.ll
@@ -0,0 +1,19 @@
+; RUN: llvm-as < %s | opt -gvn | llvm-dis | not grep {DEAD =}
+
+define i32 @main(i32** %p) {
+block1:
+	br i1 true, label %block2, label %block3
+
+block2:
+ %a = load i32** %p
+ br label %block4
+
+block3:
+  %b = load i32** %p
+  br label %block4
+
+block4:
+  %DEAD = load i32** %p
+  %c = load i32* %DEAD
+  ret i32 %c
+}
\ No newline at end of file
diff --git a/test/Transforms/GVN/semidominated.ll b/test/Transforms/GVN/semidominated.ll
new file mode 100644
index 0000000..89eac46
--- /dev/null
+++ b/test/Transforms/GVN/semidominated.ll
@@ -0,0 +1,19 @@
+; RUN: llvm-as < %s | opt -gvn | llvm-dis | not grep {DEAD =}
+
+define i32 @main(i32* %p) {
+block1:
+  %z = load i32* %p
+	br i1 true, label %block2, label %block3
+
+block2:
+ br label %block4
+
+block3:
+  %b = bitcast i32 0 to i32
+  store i32 %b, i32* %p
+  br label %block4
+
+block4:
+  %DEAD = load i32* %p
+  ret i32 %DEAD
+}
\ No newline at end of file