new testcase for serious code pessimization

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

diff --git a/test/Transforms/InstCombine/2007-02-01-LoadSinkAlloca.ll b/test/Transforms/InstCombine/2007-02-01-LoadSinkAlloca.ll
new file mode 100644 (file)
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(...)