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mir-opt: a sub-BB of a cleanup BB must also be a cleanup BB

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DianQK 2024-09-24 22:51:36 +08:00
parent 7a0b78da91
commit 15fa788cc3
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4 changed files with 322 additions and 1 deletions
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3
compiler/rustc_mir_transform/src/early_otherwise_branch.rs
View file

@ -179,7 +179,7 @@ impl<'tcx> crate::MirPass<'tcx> for EarlyOtherwiseBranch {
let eq_targets = SwitchTargets::new(eq_new_targets, parent_targets.otherwise());
// Create `bbEq` in example above
let eq_switch = BasicBlockData::new(Some(Terminator {
let mut eq_switch = BasicBlockData::new(Some(Terminator {
source_info: bbs[parent].terminator().source_info,
kind: TerminatorKind::SwitchInt {
// switch on the first discriminant, so we can mark the second one as dead
@ -187,6 +187,7 @@ impl<'tcx> crate::MirPass<'tcx> for EarlyOtherwiseBranch {
targets: eq_targets,
},
}));
eq_switch.is_cleanup = bbs[parent].is_cleanup;
let eq_bb = patch.new_block(eq_switch);

142
tests/mir-opt/early_otherwise_branch_unwind.poll.EarlyOtherwiseBranch.diff Normal file
View file

@ -0,0 +1,142 @@
- // MIR for `poll` before EarlyOtherwiseBranch
+ // MIR for `poll` after EarlyOtherwiseBranch
fn poll(_1: Poll<Result<Option<Vec<u8>>, u8>>) -> () {
debug val => _1;
let mut _0: ();
let mut _2: isize;
let mut _3: isize;
let mut _4: isize;
let _5: std::vec::Vec<u8>;
let _6: u8;
let mut _7: bool;
let mut _8: bool;
let mut _9: isize;
+ let mut _10: bool;
scope 1 {
debug _trailers => _5;
}
scope 2 {
debug _err => _6;
}
bb0: {
_7 = const false;
_8 = const false;
_7 = const true;
_8 = const true;
_4 = discriminant(_1);
switchInt(copy _4) -> [0: bb2, 1: bb4, otherwise: bb1];
}
bb1: {
unreachable;
}
bb2: {
_3 = discriminant(((_1 as Ready).0: std::result::Result<std::option::Option<std::vec::Vec<u8>>, u8>));
switchInt(copy _3) -> [0: bb3, 1: bb6, otherwise: bb1];
}
bb3: {
_2 = discriminant(((((_1 as Ready).0: std::result::Result<std::option::Option<std::vec::Vec<u8>>, u8>) as Ok).0: std::option::Option<std::vec::Vec<u8>>));
switchInt(copy _2) -> [0: bb5, 1: bb7, otherwise: bb1];
}
bb4: {
_0 = const ();
- goto -> bb17;
+ goto -> bb15;
}
bb5: {
_0 = const ();
- goto -> bb17;
+ goto -> bb15;
}
bb6: {
StorageLive(_6);
_6 = copy ((((_1 as Ready).0: std::result::Result<std::option::Option<std::vec::Vec<u8>>, u8>) as Err).0: u8);
_0 = const ();
StorageDead(_6);
- goto -> bb17;
+ goto -> bb15;
}
bb7: {
StorageLive(_5);
_5 = move ((((((_1 as Ready).0: std::result::Result<std::option::Option<std::vec::Vec<u8>>, u8>) as Ok).0: std::option::Option<std::vec::Vec<u8>>) as Some).0: std::vec::Vec<u8>);
_0 = const ();
- drop(_5) -> [return: bb8, unwind: bb20];
+ drop(_5) -> [return: bb8, unwind: bb16];
}
bb8: {
StorageDead(_5);
- goto -> bb17;
+ goto -> bb15;
}
bb9 (cleanup): {
+ StorageDead(_10);
resume;
}
bb10: {
return;
}
bb11: {
- switchInt(copy _7) -> [0: bb12, otherwise: bb16];
+ switchInt(copy _7) -> [0: bb12, otherwise: bb14];
}
bb12: {
_7 = const false;
goto -> bb10;
}
bb13: {
- switchInt(copy _8) -> [0: bb14, otherwise: bb15];
- }
-
- bb14: {
_8 = const false;
goto -> bb12;
}
- bb15: {
- goto -> bb14;
- }
-
- bb16: {
+ bb14: {
_9 = discriminant(((_1 as Ready).0: std::result::Result<std::option::Option<std::vec::Vec<u8>>, u8>));
switchInt(move _9) -> [0: bb13, otherwise: bb12];
}
- bb17: {
+ bb15: {
switchInt(copy _4) -> [0: bb11, otherwise: bb10];
}
- bb18 (cleanup): {
- switchInt(copy _3) -> [0: bb19, otherwise: bb9];
+ bb16 (cleanup): {
+ StorageLive(_10);
+ _10 = Ne(copy _4, copy _3);
+ switchInt(move _10) -> [0: bb17, otherwise: bb9];
}
- bb19 (cleanup): {
+ bb17 (cleanup): {
+ StorageDead(_10);
goto -> bb9;
- }
-
- bb20 (cleanup): {
- switchInt(copy _4) -> [0: bb18, otherwise: bb9];
}
}

43
tests/mir-opt/early_otherwise_branch_unwind.rs Normal file
View file

@ -0,0 +1,43 @@
//@ test-mir-pass: EarlyOtherwiseBranch
//@ compile-flags: -Zmir-enable-passes=+GVN,+SimplifyLocals-after-value-numbering
//@ needs-unwind
use std::task::Poll;
// We find a matching pattern in the unwind path,
// and we need to create a cleanup BB for this case to meet the unwind invariants rule.
// EMIT_MIR early_otherwise_branch_unwind.unwind.EarlyOtherwiseBranch.diff
fn unwind<T>(val: Option<Option<Option<T>>>) {
// CHECK-LABEL: fn unwind(
// CHECK: drop({{.*}}) -> [return: bb{{.*}}, unwind: [[PARENT_UNWIND_BB:bb.*]]];
// CHECK: [[PARENT_UNWIND_BB]] (cleanup): {
// CHECK-NEXT: StorageLive
// CHECK-NEXT: [[CMP_LOCAL:_.*]] = Ne
// CHECK-NEXT: switchInt(move [[CMP_LOCAL]]) -> [0: [[NEW_UNWIND_BB:bb.*]], otherwise
// CHECK: [[NEW_UNWIND_BB]] (cleanup): {
match val {
Some(Some(Some(_v))) => {}
Some(Some(None)) => {}
Some(None) => {}
None => {}
}
}
// From https://github.com/rust-lang/rust/issues/130769#issuecomment-2370443086.
// EMIT_MIR early_otherwise_branch_unwind.poll.EarlyOtherwiseBranch.diff
pub fn poll(val: Poll<Result<Option<Vec<u8>>, u8>>) {
// CHECK-LABEL: fn poll(
// CHECK: drop({{.*}}) -> [return: bb{{.*}}, unwind: [[PARENT_UNWIND_BB:bb.*]]];
// CHECK: [[PARENT_UNWIND_BB]] (cleanup): {
// CHECK-NEXT: StorageLive
// CHECK-NEXT: [[CMP_LOCAL:_.*]] = Ne
// CHECK-NEXT: switchInt(move [[CMP_LOCAL]]) -> [0: [[NEW_UNWIND_BB:bb.*]], otherwise
// CHECK: [[NEW_UNWIND_BB]] (cleanup): {
match val {
Poll::Ready(Ok(Some(_trailers))) => {}
Poll::Ready(Err(_err)) => {}
Poll::Ready(Ok(None)) => {}
Poll::Pending => {}
}
}

135
tests/mir-opt/early_otherwise_branch_unwind.unwind.EarlyOtherwiseBranch.diff Normal file
View file

@ -0,0 +1,135 @@
- // MIR for `unwind` before EarlyOtherwiseBranch
+ // MIR for `unwind` after EarlyOtherwiseBranch
fn unwind(_1: Option<Option<Option<T>>>) -> () {
debug val => _1;
let mut _0: ();
let mut _2: isize;
let mut _3: isize;
let mut _4: isize;
let _5: T;
let mut _6: bool;
let mut _7: bool;
let mut _8: isize;
+ let mut _9: bool;
scope 1 {
debug _v => _5;
}
bb0: {
_6 = const false;
_7 = const false;
_6 = const true;
_7 = const true;
_4 = discriminant(_1);
switchInt(copy _4) -> [0: bb4, 1: bb2, otherwise: bb1];
}
bb1: {
unreachable;
}
bb2: {
_3 = discriminant(((_1 as Some).0: std::option::Option<std::option::Option<T>>));
switchInt(copy _3) -> [0: bb5, 1: bb3, otherwise: bb1];
}
bb3: {
_2 = discriminant(((((_1 as Some).0: std::option::Option<std::option::Option<T>>) as Some).0: std::option::Option<T>));
switchInt(copy _2) -> [0: bb6, 1: bb7, otherwise: bb1];
}
bb4: {
_0 = const ();
- goto -> bb17;
+ goto -> bb15;
}
bb5: {
_0 = const ();
- goto -> bb17;
+ goto -> bb15;
}
bb6: {
_0 = const ();
- goto -> bb17;
+ goto -> bb15;
}
bb7: {
StorageLive(_5);
_5 = move ((((((_1 as Some).0: std::option::Option<std::option::Option<T>>) as Some).0: std::option::Option<T>) as Some).0: T);
_0 = const ();
- drop(_5) -> [return: bb8, unwind: bb20];
+ drop(_5) -> [return: bb8, unwind: bb16];
}
bb8: {
StorageDead(_5);
- goto -> bb17;
+ goto -> bb15;
}
bb9 (cleanup): {
+ StorageDead(_9);
resume;
}
bb10: {
return;
}
bb11: {
- switchInt(copy _6) -> [0: bb12, otherwise: bb16];
+ switchInt(copy _6) -> [0: bb12, otherwise: bb14];
}
bb12: {
_6 = const false;
goto -> bb10;
}
bb13: {
- switchInt(copy _7) -> [0: bb14, otherwise: bb15];
- }
-
- bb14: {
_7 = const false;
goto -> bb12;
}
- bb15: {
- goto -> bb14;
- }
-
- bb16: {
+ bb14: {
_8 = discriminant(((_1 as Some).0: std::option::Option<std::option::Option<T>>));
switchInt(move _8) -> [1: bb13, otherwise: bb12];
}
- bb17: {
+ bb15: {
switchInt(copy _4) -> [1: bb11, otherwise: bb10];
}
- bb18 (cleanup): {
- switchInt(copy _3) -> [1: bb19, otherwise: bb9];
+ bb16 (cleanup): {
+ StorageLive(_9);
+ _9 = Ne(copy _4, copy _3);
+ switchInt(move _9) -> [0: bb17, otherwise: bb9];
}
- bb19 (cleanup): {
+ bb17 (cleanup): {
+ StorageDead(_9);
goto -> bb9;
- }
-
- bb20 (cleanup): {
- switchInt(copy _4) -> [1: bb18, otherwise: bb9];
}
}