new testcases for the stackrestore instcombine optimizations

llvm-svn: 25297

1 files changed, 20 insertions, 0 deletions

diff --git a/llvm/test/Regression/Transforms/InstCombine/stacksaverestore.ll b/llvm/test/Regression/Transforms/InstCombine/stacksaverestore.ll
new file mode 100644
index 00000000000..c41a1b1e7fc
--- /dev/null
+++ b/llvm/test/Regression/Transforms/InstCombine/stacksaverestore.ll
@@ -0,0 +1,20 @@
+; RUN: llvm-as < %s | opt -instcombine -disable-output &&
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep call
+
+;; Test that llvm.stackrestore is removed when possible.
+
+int* %test1(uint %P) {
+        %tmp = call sbyte* %llvm.stacksave()
+        call void %llvm.stackrestore(sbyte* %tmp) ;; not restoring anything
+	%A = alloca int, uint %P
+        ret int* %A
+}
+
+void %test2(sbyte* %X) {
+	call void %llvm.stackrestore(sbyte* %X)  ;; no allocas before return.
+	ret void
+}
+
+declare sbyte* %llvm.stacksave()
+
+declare void %llvm.stackrestore(sbyte*)