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| author | Shotaro Yamada <sinkuu@sinkuu.xyz> | 2017-12-03 17:38:56 +0900 |
|---|---|---|
| committer | Shotaro Yamada <sinkuu@sinkuu.xyz> | 2017-12-03 17:42:52 +0900 |
| commit | 17d6631c02a297b187d75817b4cfe4d2b3c6c9de (patch) | |
| tree | c0217ba883351bcf107bac78e310c1644d509449 /src | |
| parent | 7e251390c782d5b8d94c6e55c83572a3a7a26cb4 (diff) | |
| download | rust-17d6631c02a297b187d75817b4cfe4d2b3c6c9de.tar.gz rust-17d6631c02a297b187d75817b4cfe4d2b3c6c9de.zip | |
Fix MIR CopyPropagation regression
Diffstat (limited to 'src')
| -rw-r--r-- | src/librustc_mir/transform/copy_prop.rs | 11 | ||||
| -rw-r--r-- | src/test/mir-opt/copy_propagation_arg.rs | 76 |
2 files changed, 57 insertions, 30 deletions
diff --git a/src/librustc_mir/transform/copy_prop.rs b/src/librustc_mir/transform/copy_prop.rs index 6047b4e174a..95fe99a1bec 100644 --- a/src/librustc_mir/transform/copy_prop.rs +++ b/src/librustc_mir/transform/copy_prop.rs @@ -239,10 +239,13 @@ impl<'tcx> Action<'tcx> { // USE(SRC); let src_def_count = src_use_info.def_count_not_including_drop(); // allow function arguments to be propagated - if src_def_count > 1 || - (src_def_count == 0 && mir.local_kind(src_local) != LocalKind::Arg) { - debug!(" Can't copy-propagate local: {} defs of src", - src_use_info.def_count_not_including_drop()); + let is_arg = mir.local_kind(src_local) == LocalKind::Arg; + if (is_arg && src_def_count != 0) || (!is_arg && src_def_count != 1) { + debug!( + " Can't copy-propagate local: {} defs of src{}", + src_def_count, + if is_arg { " (argument)" } else { "" }, + ); return None } diff --git a/src/test/mir-opt/copy_propagation_arg.rs b/src/test/mir-opt/copy_propagation_arg.rs index 017fac6a6a1..35bb231df5a 100644 --- a/src/test/mir-opt/copy_propagation_arg.rs +++ b/src/test/mir-opt/copy_propagation_arg.rs @@ -30,42 +30,43 @@ fn baz(mut x: i32) { x = x; } +fn arg_src(mut x: i32) -> i32 { + let y = x; + x = 123; // Don't propagate this assignment to `y` + y +} + fn main() { // Make sure the function actually gets instantiated. foo(0); bar(0); baz(0); + arg_src(0); } // END RUST SOURCE // START rustc.foo.CopyPropagation.before.mir // bb0: { -// StorageLive(_2); -// StorageLive(_3); +// ... // _3 = _1; // _2 = const dummy(move _3) -> bb1; // } // bb1: { -// StorageDead(_3); +// ... // _1 = move _2; -// StorageDead(_2); -// _0 = (); -// return; +// ... // } // END rustc.foo.CopyPropagation.before.mir // START rustc.foo.CopyPropagation.after.mir // bb0: { -// StorageLive(_2); -// nop; -// nop; -// _2 = const dummy(move _1) -> bb1; +// ... +// _3 = _1; +// _2 = const dummy(move _3) -> bb1; // } // bb1: { -// nop; +// ... // _1 = move _2; -// StorageDead(_2); -// _0 = (); -// return; +// ... // } // END rustc.foo.CopyPropagation.after.mir // START rustc.bar.CopyPropagation.before.mir @@ -83,15 +84,14 @@ fn main() { // END rustc.bar.CopyPropagation.before.mir // START rustc.bar.CopyPropagation.after.mir // bb0: { -// nop; -// nop; -// _2 = const dummy(move _1) -> bb1; +// ... +// _3 = _1; +// _2 = const dummy(move _3) -> bb1; // } // bb1: { -// nop; +// ... // _1 = const 5u8; -// _0 = (); -// return; +// ... // } // END rustc.bar.CopyPropagation.after.mir // START rustc.baz.CopyPropagation.before.mir @@ -106,11 +106,35 @@ fn main() { // END rustc.baz.CopyPropagation.before.mir // START rustc.baz.CopyPropagation.after.mir // bb0: { -// nop; -// nop; -// nop; -// nop; -// _0 = (); -// return; +// ... +// _2 = _1; +// _1 = move _2; +// ... // } // END rustc.baz.CopyPropagation.after.mir +// START rustc.arg_src.CopyPropagation.before.mir +// bb0: { +// ... +// _3 = _1; +// _2 = move _3; +// ... +// _1 = const 123i32; +// ... +// _4 = _2; +// _0 = move _4; +// ... +// return; +// } +// END rustc.arg_src.CopyPropagation.before.mir +// START rustc.arg_src.CopyPropagation.after.mir +// bb0: { +// ... +// _3 = _1; +// ... +// _1 = const 123i32; +// ... +// _0 = move _3; +// ... +// return; +// } +// END rustc.arg_src.CopyPropagation.after.mir |