| 1 | use std::collections::BTreeSet; |
| 2 | use std::path::PathBuf; |
| 3 | |
| 4 | use armfortas::driver::OptLevel; |
| 5 | use armfortas::testing::{capture_from_path, CaptureRequest, CapturedStage, Stage}; |
| 6 | |
| 7 | fn fixture(name: &str) -> PathBuf { |
| 8 | let path = PathBuf::from("test_programs").join(name); |
| 9 | assert!(path.exists(), "missing test fixture {}", path.display()); |
| 10 | path |
| 11 | } |
| 12 | |
| 13 | fn capture_text(request: CaptureRequest, stage: Stage) -> String { |
| 14 | let result = capture_from_path(&request).expect("capture should succeed"); |
| 15 | match result.get(stage) { |
| 16 | Some(CapturedStage::Text(text)) => text.clone(), |
| 17 | Some(CapturedStage::Run(_)) => panic!("expected text stage for {}", stage.as_str()), |
| 18 | None => panic!("missing requested stage {}", stage.as_str()), |
| 19 | } |
| 20 | } |
| 21 | |
| 22 | fn function_section<'a>(ir: &'a str, name: &str) -> &'a str { |
| 23 | let header = format!(" func @{}", name); |
| 24 | let start = ir |
| 25 | .find(&header) |
| 26 | .unwrap_or_else(|| panic!("missing function section for {}", name)); |
| 27 | let rest = &ir[start..]; |
| 28 | let end = rest |
| 29 | .find("\n }\n") |
| 30 | .unwrap_or_else(|| panic!("unterminated function section for {}", name)); |
| 31 | &rest[..end + "\n }".len()] |
| 32 | } |
| 33 | |
| 34 | fn param_count(func_section: &str) -> usize { |
| 35 | let header = func_section.lines().next().expect("function header"); |
| 36 | let inside = header |
| 37 | .split_once('(') |
| 38 | .and_then(|(_, tail)| tail.split_once(") ->")) |
| 39 | .map(|(params, _)| params.trim()) |
| 40 | .expect("function header params"); |
| 41 | if inside.is_empty() { |
| 42 | 0 |
| 43 | } else { |
| 44 | inside.split(", ").count() |
| 45 | } |
| 46 | } |
| 47 | |
| 48 | fn call_arg_counts_for(func_section: &str, callee_marker: &str) -> Vec<usize> { |
| 49 | func_section |
| 50 | .lines() |
| 51 | .filter_map(|line| { |
| 52 | let line = line.trim(); |
| 53 | let call = line.find(&format!("call {}", callee_marker))?; |
| 54 | let inside = line[call..].split_once('(')?.1.split_once(')')?.0.trim(); |
| 55 | Some(if inside.is_empty() { |
| 56 | 0 |
| 57 | } else { |
| 58 | inside.split(", ").count() |
| 59 | }) |
| 60 | }) |
| 61 | .collect() |
| 62 | } |
| 63 | |
| 64 | #[test] |
| 65 | fn o2_elides_dead_dummy_arg_from_recursive_internal_helper() { |
| 66 | let source = fixture("ipo_dead_arg.f90"); |
| 67 | |
| 68 | let raw_ir = capture_text( |
| 69 | CaptureRequest { |
| 70 | input: source.clone(), |
| 71 | requested: BTreeSet::from([Stage::Ir]), |
| 72 | opt_level: OptLevel::O0, |
| 73 | }, |
| 74 | Stage::Ir, |
| 75 | ); |
| 76 | let opt_ir = capture_text( |
| 77 | CaptureRequest { |
| 78 | input: source, |
| 79 | requested: BTreeSet::from([Stage::OptIr]), |
| 80 | opt_level: OptLevel::O2, |
| 81 | }, |
| 82 | Stage::OptIr, |
| 83 | ); |
| 84 | |
| 85 | let raw_main = function_section(&raw_ir, "__prog_ipo_dead_arg"); |
| 86 | let raw_helper = function_section(&raw_ir, "helper"); |
| 87 | let opt_main = function_section(&opt_ir, "__prog_ipo_dead_arg"); |
| 88 | let opt_helper = function_section(&opt_ir, "helper"); |
| 89 | |
| 90 | assert_eq!( |
| 91 | param_count(raw_helper), |
| 92 | 3, |
| 93 | "raw helper should keep all dummy args:\n{}", |
| 94 | raw_helper |
| 95 | ); |
| 96 | assert_eq!( |
| 97 | param_count(opt_helper), |
| 98 | 2, |
| 99 | "optimized helper should drop the dead dummy arg:\n{}", |
| 100 | opt_helper |
| 101 | ); |
| 102 | |
| 103 | let raw_call_counts = [ |
| 104 | call_arg_counts_for(raw_main, "@helper"), |
| 105 | call_arg_counts_for(raw_helper, "@helper"), |
| 106 | ] |
| 107 | .concat(); |
| 108 | // dead-arg-elim rewrites @helper in-place (no clone, no rename) |
| 109 | // so the optimized IR still calls @helper — with one fewer |
| 110 | // argument per site. |
| 111 | let opt_call_counts = [ |
| 112 | call_arg_counts_for(opt_main, "@helper"), |
| 113 | call_arg_counts_for(opt_helper, "@helper"), |
| 114 | ] |
| 115 | .concat(); |
| 116 | |
| 117 | assert_eq!( |
| 118 | raw_call_counts, |
| 119 | vec![3, 3], |
| 120 | "raw IR should pass all three args at both call sites" |
| 121 | ); |
| 122 | assert_eq!( |
| 123 | opt_call_counts, |
| 124 | vec![2, 2], |
| 125 | "optimized IR should trim the dead arg at both call sites" |
| 126 | ); |
| 127 | } |
| 128 |