1 ; RUN: opt < %s -simplifycfg -instcombine -mem2reg -S | not grep alloca 2 ; 3 ; This tests to see if mem2reg can promote alloca instructions whose addresses 4 ; are used by PHI nodes that are immediately loaded. The LLVM C++ front-end 5 ; often generates code that looks like this (when it codegen's ?: exprs as 6 ; lvalues), so handling this simple extension is quite useful. 7 ; 8 ; This testcase is what the following program looks like when it reaches 9 ; instcombine: 10 ; 11 ; template<typename T> 12 ; const T& max(const T& a1, const T& a2) { return a1 < a2 ? a1 : a2; } 13 ; int main() { return max(0, 1); } 14 ; 15 ; This test checks to make sure the combination of instcombine and mem2reg 16 ; perform the transformation. 17 18 define i32 @main() { 19 entry: 20 %mem_tmp.0 = alloca i32 ; <i32*> [#uses=3] 21 %mem_tmp.1 = alloca i32 ; <i32*> [#uses=3] 22 store i32 0, i32* %mem_tmp.0 23 store i32 1, i32* %mem_tmp.1 24 %tmp.1.i = load i32, i32* %mem_tmp.1 ; <i32> [#uses=1] 25 %tmp.3.i = load i32, i32* %mem_tmp.0 ; <i32> [#uses=1] 26 %tmp.4.i = icmp sle i32 %tmp.1.i, %tmp.3.i ; <i1> [#uses=1] 27 br i1 %tmp.4.i, label %cond_true.i, label %cond_continue.i 28 cond_true.i: ; preds = %entry 29 br label %cond_continue.i 30 cond_continue.i: ; preds = %cond_true.i, %entry 31 %mem_tmp.i.0 = phi i32* [ %mem_tmp.1, %cond_true.i ], [ %mem_tmp.0, %entry ] ; <i32*> [#uses=1] 32 %tmp.3 = load i32, i32* %mem_tmp.i.0 ; <i32> [#uses=1] 33 ret i32 %tmp.3 34 } 35
