new testcase for PR590

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22317 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 51 insertions, 0 deletions

diff --git a/test/Transforms/Mem2Reg/2005-06-30-ReadBeforeWrite.ll b/test/Transforms/Mem2Reg/2005-06-30-ReadBeforeWrite.ll
new file mode 100644
index 0000000..a6d4696
--- /dev/null
+++ b/test/Transforms/Mem2Reg/2005-06-30-ReadBeforeWrite.ll
@@ -0,0 +1,51 @@
+; RUN: llvm-as < %s | opt -mem2reg -instcombine | llvm-dis | grep store
+; PR590
+
+void %zero(sbyte* %p, int %n) {
+entry:
+	%p_addr = alloca sbyte*		; <sbyte**> [#uses=2]
+	%n_addr = alloca int		; <int*> [#uses=2]
+	%i = alloca int		; <int*> [#uses=6]
+	%out = alloca int		; <int*> [#uses=2]
+	%undef = alloca int		; <int*> [#uses=2]
+	store sbyte* %p, sbyte** %p_addr
+	store int %n, int* %n_addr
+	store int 0, int* %i
+	br label %loopentry
+
+loopentry:		; preds = %endif, %entry
+	%tmp.0 = load int* %n_addr		; <int> [#uses=1]
+	%tmp.1 = add int %tmp.0, 1		; <int> [#uses=1]
+	%tmp.2 = load int* %i		; <int> [#uses=1]
+	%tmp.3 = setgt int %tmp.1, %tmp.2		; <bool> [#uses=2]
+	%tmp.4 = cast bool %tmp.3 to int		; <int> [#uses=0]
+	br bool %tmp.3, label %no_exit, label %return
+
+no_exit:		; preds = %loopentry
+	%tmp.5 = load int* %undef		; <int> [#uses=1]
+	store int %tmp.5, int* %out
+	store int 0, int* %undef
+	%tmp.6 = load int* %i		; <int> [#uses=1]
+	%tmp.7 = setgt int %tmp.6, 0		; <bool> [#uses=2]
+	%tmp.8 = cast bool %tmp.7 to int		; <int> [#uses=0]
+	br bool %tmp.7, label %then, label %endif
+
+then:		; preds = %no_exit
+	%tmp.9 = load sbyte** %p_addr		; <sbyte*> [#uses=1]
+	%tmp.10 = load int* %i		; <int> [#uses=1]
+	%tmp.11 = sub int %tmp.10, 1		; <int> [#uses=1]
+	%tmp.12 = getelementptr sbyte* %tmp.9, int %tmp.11		; <sbyte*> [#uses=1]
+	%tmp.13 = load int* %out		; <int> [#uses=1]
+	%tmp.14 = cast int %tmp.13 to sbyte		; <sbyte> [#uses=1]
+	store sbyte %tmp.14, sbyte* %tmp.12
+	br label %endif
+
+endif:		; preds = %then, %no_exit
+	%tmp.15 = load int* %i		; <int> [#uses=1]
+	%inc = add int %tmp.15, 1		; <int> [#uses=1]
+	store int %inc, int* %i
+	br label %loopentry
+
+return:		; preds = %loopentry
+	ret void
+}