; RUN: opt < %s -simplifycfg -instcombine -mem2reg -S | not grep alloca ; ; This tests to see if mem2reg can promote alloca instructions whose addresses ; are used by PHI nodes that are immediately loaded. The LLVM C++ front-end ; often generates code that looks like this (when it codegen's ?: exprs as ; lvalues), so handling this simple extension is quite useful. ; ; This testcase is what the following program looks like when it reaches ; instcombine: ; ; template<typename T> ; const T& max(const T& a1, const T& a2) { return a1 < a2 ? a1 : a2; } ; int main() { return max(0, 1); } ; ; This test checks to make sure the combination of instcombine and mem2reg ; perform the transformation. define i32 @main() { entry: %mem_tmp.0 = alloca i32 ; <i32*> [#uses=3] %mem_tmp.1 = alloca i32 ; <i32*> [#uses=3] store i32 0, i32* %mem_tmp.0 store i32 1, i32* %mem_tmp.1 %tmp.1.i = load i32* %mem_tmp.1 ; <i32> [#uses=1] %tmp.3.i = load i32* %mem_tmp.0 ; <i32> [#uses=1] %tmp.4.i = icmp sle i32 %tmp.1.i, %tmp.3.i ; <i1> [#uses=1] br i1 %tmp.4.i, label %cond_true.i, label %cond_continue.i cond_true.i: ; preds = %entry br label %cond_continue.i cond_continue.i: ; preds = %cond_true.i, %entry %mem_tmp.i.0 = phi i32* [ %mem_tmp.1, %cond_true.i ], [ %mem_tmp.0, %entry ] ; <i32*> [#uses=1] %tmp.3 = load i32* %mem_tmp.i.0 ; <i32> [#uses=1] ret i32 %tmp.3 }