| ; RUN: llvm-as < %s | opt -instcombine -mem2reg | llvm-dis | 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. |
| |
| int %main() { |
| entry: |
| %mem_tmp.0 = alloca int |
| %mem_tmp.1 = alloca int |
| store int 0, int* %mem_tmp.0 |
| store int 1, int* %mem_tmp.1 |
| %tmp.1.i = load int* %mem_tmp.1 |
| %tmp.3.i = load int* %mem_tmp.0 |
| %tmp.4.i = setle int %tmp.1.i, %tmp.3.i |
| br bool %tmp.4.i, label %cond_true.i, label %cond_continue.i |
| |
| cond_true.i: |
| br label %cond_continue.i |
| |
| cond_continue.i: |
| %mem_tmp.i.0 = phi int* [ %mem_tmp.1, %cond_true.i ], [ %mem_tmp.0, %entry ] |
| %tmp.3 = load int* %mem_tmp.i.0 |
| ret int %tmp.3 |
| } |
| |