new testcase for serious code pessimization

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33770 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 43 insertions, 0 deletions

diff --git a/test/Transforms/InstCombine/2007-02-01-LoadSinkAlloca.ll b/test/Transforms/InstCombine/2007-02-01-LoadSinkAlloca.ll
new file mode 100644
index 0000000..d5e988f
--- /dev/null
+++ b/test/Transforms/InstCombine/2007-02-01-LoadSinkAlloca.ll
@@ -0,0 +1,43 @@
+; RUN: llvm-as < %s | opt -instcombine -mem2reg | llvm-dis | grep '%A = alloca' &&
+; RUN: llvm-as < %s | opt -instcombine -mem2reg | llvm-dis | not grep '%B = alloca'
+
+; Ensure that instcombine doesn't sink the loads in entry/cond_true into 
+; cond_next.  Doing so prevents mem2reg from promoting the B alloca.
+
+define i32 @test2(i32 %C) {
+entry:
+	%A = alloca i32
+	%B = alloca i32
+	%tmp = call i32 (...)* @bar( i32* %A )		; <i32> [#uses=0]
+	%T = load i32* %A		; <i32> [#uses=1]
+	%tmp = icmp eq i32 %C, 0		; <i1> [#uses=1]
+	br i1 %tmp, label %cond_next, label %cond_true
+
+cond_true:		; preds = %entry
+	store i32 123, i32* %B
+	call i32 @test2( i32 123 )		; <i32>:0 [#uses=0]
+	%T1 = load i32* %B		; <i32> [#uses=1]
+	br label %cond_next
+
+cond_next:		; preds = %cond_true, %entry
+	%tmp1.0 = phi i32 [ %T1, %cond_true ], [ %T, %entry ]		; <i32> [#uses=1]
+	%tmp7 = call i32 (...)* @baq( )		; <i32> [#uses=0]
+	%tmp8 = call i32 (...)* @baq( )		; <i32> [#uses=0]
+	%tmp9 = call i32 (...)* @baq( )		; <i32> [#uses=0]
+	%tmp10 = call i32 (...)* @baq( )		; <i32> [#uses=0]
+	%tmp11 = call i32 (...)* @baq( )		; <i32> [#uses=0]
+	%tmp12 = call i32 (...)* @baq( )		; <i32> [#uses=0]
+	%tmp13 = call i32 (...)* @baq( )		; <i32> [#uses=0]
+	%tmp14 = call i32 (...)* @baq( )		; <i32> [#uses=0]
+	%tmp15 = call i32 (...)* @baq( )		; <i32> [#uses=0]
+	%tmp16 = call i32 (...)* @baq( )		; <i32> [#uses=0]
+	%tmp17 = call i32 (...)* @baq( )		; <i32> [#uses=0]
+	%tmp18 = call i32 (...)* @baq( )		; <i32> [#uses=0]
+	%tmp19 = call i32 (...)* @baq( )		; <i32> [#uses=0]
+	%tmp20 = call i32 (...)* @baq( )		; <i32> [#uses=0]
+	ret i32 %tmp1.0
+}
+
+declare i32 @bar(...)
+
+declare i32 @baq(...)