| //@ test-mir-pass: JumpThreading |
| //@ compile-flags: -Zmir-enable-passes=+Inline |
| // EMIT_MIR_FOR_EACH_PANIC_STRATEGY |
| |
| #![feature(try_trait_v2)] |
| #![feature(custom_mir, core_intrinsics, rustc_attrs)] |
| |
| use std::intrinsics::mir::*; |
| use std::ops::ControlFlow; |
| |
| fn too_complex(x: Result<i32, usize>) -> Option<i32> { |
| // CHECK-LABEL: fn too_complex( |
| // CHECK: bb0: { |
| // CHECK: switchInt(move {{_.*}}) -> [0: bb3, 1: bb2, otherwise: bb1]; |
| // CHECK: bb1: { |
| // CHECK: unreachable; |
| // CHECK: bb2: { |
| // CHECK: [[controlflow:_.*]] = ControlFlow::<usize, i32>::Break( |
| // CHECK: goto -> bb8; |
| // CHECK: bb3: { |
| // CHECK: [[controlflow]] = ControlFlow::<usize, i32>::Continue( |
| // CHECK: goto -> bb4; |
| // CHECK: bb4: { |
| // CHECK: goto -> bb6; |
| // CHECK: bb5: { |
| // CHECK: {{_.*}} = copy (([[controlflow]] as Break).0: usize); |
| // CHECK: _0 = Option::<i32>::None; |
| // CHECK: goto -> bb7; |
| // CHECK: bb6: { |
| // CHECK: {{_.*}} = copy (([[controlflow]] as Continue).0: i32); |
| // CHECK: _0 = Option::<i32>::Some( |
| // CHECK: goto -> bb7; |
| // CHECK: bb7: { |
| // CHECK: return; |
| // CHECK: bb8: { |
| // CHECK: goto -> bb5; |
| match { |
| match x { |
| Ok(v) => ControlFlow::Continue(v), |
| Err(r) => ControlFlow::Break(r), |
| } |
| } { |
| ControlFlow::Continue(v) => Some(v), |
| ControlFlow::Break(r) => None, |
| } |
| } |
| |
| fn identity(x: Result<i32, i32>) -> Result<i32, i32> { |
| // CHECK-LABEL: fn identity( |
| // CHECK: bb0: { |
| // CHECK: [[x:_.*]] = copy _1; |
| // CHECK: switchInt(move {{_.*}}) -> [0: bb7, 1: bb6, otherwise: bb1]; |
| // CHECK: bb1: { |
| // CHECK: unreachable; |
| // CHECK: bb2: { |
| // CHECK: {{_.*}} = copy (([[controlflow:_.*]] as Continue).0: i32); |
| // CHECK: _0 = Result::<i32, i32>::Ok( |
| // CHECK: goto -> bb4; |
| // CHECK: bb3: { |
| // CHECK: {{_.*}} = copy (([[controlflow]] as Break).0: std::result::Result<std::convert::Infallible, i32>); |
| // CHECK: _0 = Result::<i32, i32>::Err( |
| // CHECK: goto -> bb4; |
| // CHECK: bb4: { |
| // CHECK: return; |
| // CHECK: bb5: { |
| // CHECK: goto -> bb2; |
| // CHECK: bb6: { |
| // CHECK: {{_.*}} = move (([[x]] as Err).0: i32); |
| // CHECK: [[controlflow]] = ControlFlow::<Result<Infallible, i32>, i32>::Break( |
| // CHECK: goto -> bb8; |
| // CHECK: bb7: { |
| // CHECK: {{_.*}} = move (([[x]] as Ok).0: i32); |
| // CHECK: [[controlflow]] = ControlFlow::<Result<Infallible, i32>, i32>::Continue( |
| // CHECK: goto -> bb5; |
| // CHECK: bb8: { |
| // CHECK: goto -> bb3; |
| Ok(x?) |
| } |
| |
| enum DFA { |
| A, |
| B, |
| C, |
| D, |
| } |
| |
| /// Check that we do not thread through a loop header, |
| /// to avoid creating an irreducible CFG. |
| fn dfa() { |
| // CHECK-LABEL: fn dfa( |
| // CHECK: bb0: { |
| // CHECK: {{_.*}} = DFA::A; |
| // CHECK: goto -> bb1; |
| // CHECK: bb1: { |
| // CHECK: switchInt({{.*}}) -> [0: bb6, 1: bb5, 2: bb4, 3: bb3, otherwise: bb2]; |
| // CHECK: bb2: { |
| // CHECK: unreachable; |
| // CHECK: bb3: { |
| // CHECK: return; |
| // CHECK: bb4: { |
| // CHECK: {{_.*}} = DFA::D; |
| // CHECK: goto -> bb1; |
| // CHECK: bb5: { |
| // CHECK: {{_.*}} = DFA::C; |
| // CHECK: goto -> bb1; |
| // CHECK: bb6: { |
| // CHECK: {{_.*}} = DFA::B; |
| // CHECK: goto -> bb1; |
| let mut state = DFA::A; |
| loop { |
| match state { |
| DFA::A => state = DFA::B, |
| DFA::B => state = DFA::C, |
| DFA::C => state = DFA::D, |
| DFA::D => return, |
| } |
| } |
| } |
| |
| #[repr(u8)] |
| enum CustomDiscr { |
| A = 35, |
| B = 73, |
| C = 99, |
| } |
| |
| /// Verify that we correctly match the discriminant value, and not its index. |
| fn custom_discr(x: bool) -> u8 { |
| // CHECK-LABEL: fn custom_discr( |
| // CHECK: bb0: { |
| // CHECK: switchInt({{.*}}) -> [0: bb2, otherwise: bb1]; |
| // CHECK: bb1: { |
| // CHECK: {{_.*}} = CustomDiscr::A; |
| // CHECK: goto -> bb7; |
| // CHECK: bb2: { |
| // CHECK: {{_.*}} = CustomDiscr::B; |
| // CHECK: goto -> bb3; |
| // CHECK: bb3: { |
| // CHECK: goto -> bb4; |
| // CHECK: bb4: { |
| // CHECK: _0 = const 13_u8; |
| // CHECK: goto -> bb6; |
| // CHECK: bb5: { |
| // CHECK: _0 = const 5_u8; |
| // CHECK: goto -> bb6; |
| // CHECK: bb6: { |
| // CHECK: return; |
| // CHECK: bb7: { |
| // CHECK: goto -> bb5; |
| match if x { CustomDiscr::A } else { CustomDiscr::B } { |
| CustomDiscr::A => 5, |
| _ => 13, |
| } |
| } |
| |
| #[custom_mir(dialect = "runtime", phase = "post-cleanup")] |
| fn multiple_match(x: u8) -> u8 { |
| // CHECK-LABEL: fn multiple_match( |
| mir! { |
| { |
| // CHECK: bb0: { |
| // CHECK: switchInt(copy [[x:_.*]]) -> [3: bb1, otherwise: bb2]; |
| match x { 3 => bb1, _ => bb2 } |
| } |
| bb1 = { |
| // We know `x == 3`, so we can take `bb3`. |
| // CHECK: bb1: { |
| // CHECK: {{_.*}} = copy [[x]]; |
| // CHECK: goto -> bb3; |
| let y = x; |
| match y { 3 => bb3, _ => bb4 } |
| } |
| bb2 = { |
| // We know `x != 3`, so we can take `bb6`. |
| // CHECK: bb2: { |
| // CHECK: [[z:_.*]] = copy [[x]]; |
| // CHECK: goto -> bb6; |
| let z = x; |
| match z { 3 => bb5, _ => bb6 } |
| } |
| bb3 = { |
| // CHECK: bb3: { |
| // CHECK: _0 = const 5_u8; |
| // CHECK: return; |
| RET = 5; |
| Return() |
| } |
| bb4 = { |
| // CHECK: bb4: { |
| // CHECK: _0 = const 7_u8; |
| // CHECK: return; |
| RET = 7; |
| Return() |
| } |
| bb5 = { |
| // CHECK: bb5: { |
| // CHECK: _0 = const 9_u8; |
| // CHECK: return; |
| RET = 9; |
| Return() |
| } |
| bb6 = { |
| // We know `z != 3`, so we CANNOT take `bb7`. |
| // CHECK: bb6: { |
| // CHECK: switchInt(copy [[z]]) -> [1: bb7, otherwise: bb8]; |
| match z { 1 => bb7, _ => bb8 } |
| } |
| bb7 = { |
| // CHECK: bb7: { |
| // CHECK: _0 = const 9_u8; |
| // CHECK: return; |
| RET = 9; |
| Return() |
| } |
| bb8 = { |
| // CHECK: bb8: { |
| // CHECK: _0 = const 11_u8; |
| // CHECK: return; |
| RET = 11; |
| Return() |
| } |
| } |
| } |
| |
| /// Both 1-3-4 and 2-3-4 are threadable. As 1 and 2 are the only predecessors of 3, |
| /// verify that we only thread the 3-4 part. |
| #[custom_mir(dialect = "runtime", phase = "post-cleanup")] |
| fn duplicate_chain(x: bool) -> u8 { |
| // CHECK-LABEL: fn duplicate_chain( |
| mir! { |
| let a: u8; |
| { |
| // CHECK: bb0: { |
| // CHECK: switchInt({{.*}}) -> [1: bb1, otherwise: bb2]; |
| match x { true => bb1, _ => bb2 } |
| } |
| bb1 = { |
| // CHECK: bb1: { |
| // CHECK: [[a:_.*]] = const 5_u8; |
| // CHECK: goto -> bb3; |
| a = 5; |
| Goto(bb3) |
| } |
| bb2 = { |
| // CHECK: bb2: { |
| // CHECK: [[a]] = const 5_u8; |
| // CHECK: goto -> bb3; |
| a = 5; |
| Goto(bb3) |
| } |
| bb3 = { |
| // CHECK: bb3: { |
| // CHECK: {{_.*}} = const 13_i32; |
| // CHECK: goto -> bb4; |
| let b = 13; |
| Goto(bb4) |
| } |
| bb4 = { |
| // CHECK: bb4: { |
| // CHECK: {{_.*}} = const 15_i32; |
| // CHECK-NOT: switchInt( |
| // CHECK: goto -> bb5; |
| let c = 15; |
| match a { 5 => bb5, _ => bb6 } |
| } |
| bb5 = { |
| // CHECK: bb5: { |
| // CHECK: _0 = const 7_u8; |
| // CHECK: return; |
| RET = 7; |
| Return() |
| } |
| bb6 = { |
| // CHECK: bb6: { |
| // CHECK: _0 = const 9_u8; |
| // CHECK: return; |
| RET = 9; |
| Return() |
| } |
| } |
| } |
| |
| #[rustc_layout_scalar_valid_range_start(1)] |
| #[rustc_nonnull_optimization_guaranteed] |
| struct NonZeroUsize(usize); |
| |
| /// Verify that we correctly discard threads that may mutate a discriminant by aliasing. |
| #[custom_mir(dialect = "runtime", phase = "post-cleanup")] |
| fn mutate_discriminant() -> u8 { |
| // CHECK-LABEL: fn mutate_discriminant( |
| // CHECK-NOT: goto -> {{bb.*}}; |
| // CHECK: switchInt( |
| // CHECK-NOT: goto -> {{bb.*}}; |
| mir! { |
| let x: Option<NonZeroUsize>; |
| { |
| SetDiscriminant(x, 1); |
| // This assignment overwrites the niche in which the discriminant is stored. |
| place!(Field(Field(Variant(x, 1), 0), 0)) = 0_usize; |
| // So we cannot know the value of this discriminant. |
| let a = Discriminant(x); |
| match a { |
| 0 => bb1, |
| _ => bad, |
| } |
| } |
| bb1 = { |
| RET = 1; |
| Return() |
| } |
| bad = { |
| RET = 2; |
| Unreachable() |
| } |
| } |
| } |
| |
| /// Verify that we do not try to reason when there are mutable pointers involved. |
| fn mutable_ref() -> bool { |
| // CHECK-LABEL: fn mutable_ref( |
| // CHECK-NOT: goto -> {{bb.*}}; |
| // CHECK: switchInt( |
| // CHECK: goto -> [[bbret:bb.*]]; |
| // CHECK: goto -> [[bbret]]; |
| // CHECK: [[bbret]]: { |
| // CHECK-NOT: {{bb.*}}: { |
| // CHECK: return; |
| let mut x = 5; |
| let a = std::ptr::addr_of_mut!(x); |
| x = 7; |
| unsafe { *a = 8 }; |
| if x == 7 { true } else { false } |
| } |
| |
| /// This function has 2 TOs: 1-3-4 and 0-1-3-4-6. |
| /// We verify that the second TO does not modify 3 once the first has been applied. |
| #[custom_mir(dialect = "runtime", phase = "post-cleanup")] |
| fn renumbered_bb(x: bool) -> u8 { |
| // CHECK-LABEL: fn renumbered_bb( |
| mir! { |
| let a: bool; |
| let b: bool; |
| { |
| // CHECK: bb0: { |
| // CHECK: switchInt({{.*}}) -> [1: bb1, otherwise: bb2]; |
| b = false; |
| match x { true => bb1, _ => bb2 } |
| } |
| bb1 = { |
| // CHECK: bb1: { |
| // CHECK: goto -> bb8; |
| a = false; |
| Goto(bb3) |
| } |
| bb2 = { |
| // CHECK: bb2: { |
| // CHECK: goto -> bb3; |
| a = x; |
| b = x; |
| Goto(bb3) |
| } |
| bb3 = { |
| // CHECK: bb3: { |
| // CHECK: switchInt({{.*}}) -> [0: bb4, otherwise: bb5]; |
| match a { false => bb4, _ => bb5 } |
| } |
| bb4 = { |
| // CHECK: bb4: { |
| // CHECK: switchInt({{.*}}) -> [0: bb6, otherwise: bb7]; |
| match b { false => bb6, _ => bb7 } |
| } |
| bb5 = { |
| // CHECK: bb5: { |
| // CHECK: _0 = const 7_u8; |
| RET = 7; |
| Return() |
| } |
| bb6 = { |
| // CHECK: bb6: { |
| // CHECK: _0 = const 9_u8; |
| RET = 9; |
| Return() |
| } |
| bb7 = { |
| // CHECK: bb7: { |
| // CHECK: _0 = const 11_u8; |
| RET = 11; |
| Return() |
| } |
| // Duplicate of bb3. |
| // CHECK: bb8: { |
| // CHECK-NEXT: goto -> bb9; |
| // Duplicate of bb4. |
| // CHECK: bb9: { |
| // CHECK-NEXT: goto -> bb6; |
| } |
| } |
| |
| /// This function has 3 TOs: 1-4-5, 0-1-4-7-5-8 and 3-4-7-5-6 |
| /// After applying the first TO, we create bb9 to replace 4, and rename 1-4 edge by 1-9. The |
| /// second TO may try to thread non-existing edge 9-4. |
| /// This test verifies that we preserve semantics by bailing out of this second TO. |
| #[custom_mir(dialect = "runtime", phase = "post-cleanup")] |
| fn disappearing_bb(x: u8) -> u8 { |
| // CHECK-LABEL: fn disappearing_bb( |
| mir! { |
| let a: bool; |
| let b: bool; |
| { |
| a = true; |
| b = true; |
| match x { 0 => bb3, 1 => bb3, 2 => bb1, _ => bb2 } |
| } |
| bb1 = { |
| // CHECK: bb1: { |
| // CHECK: goto -> bb9; |
| b = false; |
| Goto(bb4) |
| } |
| bb2 = { |
| Unreachable() |
| } |
| bb3 = { |
| // CHECK: bb3: { |
| // CHECK: goto -> bb10; |
| a = false; |
| Goto(bb4) |
| } |
| bb4 = { |
| match b { false => bb5, _ => bb7 } |
| } |
| bb5 = { |
| match a { false => bb6, _ => bb8 } |
| } |
| bb6 = { |
| Return() |
| } |
| bb7 = { |
| Goto(bb5) |
| } |
| bb8 = { |
| Goto(bb6) |
| } |
| // CHECK: bb9: { |
| // CHECK: goto -> bb5; |
| // CHECK: bb10: { |
| // CHECK: goto -> bb6; |
| } |
| } |
| |
| /// Verify that we can thread jumps when we assign from an aggregate constant. |
| fn aggregate(x: u8) -> u8 { |
| // CHECK-LABEL: fn aggregate( |
| // CHECK-NOT: switchInt( |
| |
| const FOO: (u8, u8) = (5, 13); |
| |
| let (a, b) = FOO; |
| if a == 7 { b } else { a } |
| } |
| |
| /// Verify that we can leverage the existence of an `Assume` terminator. |
| #[custom_mir(dialect = "runtime", phase = "post-cleanup")] |
| fn assume(a: u8, b: bool) -> u8 { |
| // CHECK-LABEL: fn assume( |
| mir! { |
| { |
| // CHECK: bb0: { |
| // CHECK-NEXT: switchInt(copy _1) -> [7: bb1, otherwise: bb2] |
| match a { 7 => bb1, _ => bb2 } |
| } |
| bb1 = { |
| // CHECK: bb1: { |
| // CHECK-NEXT: assume(copy _2); |
| // CHECK-NEXT: goto -> bb6; |
| Assume(b); |
| Goto(bb3) |
| } |
| bb2 = { |
| // CHECK: bb2: { |
| // CHECK-NEXT: goto -> bb3; |
| Goto(bb3) |
| } |
| bb3 = { |
| // CHECK: bb3: { |
| // CHECK-NEXT: switchInt(copy _2) -> [0: bb4, otherwise: bb5]; |
| match b { false => bb4, _ => bb5 } |
| } |
| bb4 = { |
| // CHECK: bb4: { |
| // CHECK-NEXT: _0 = const 4_u8; |
| // CHECK-NEXT: return; |
| RET = 4; |
| Return() |
| } |
| bb5 = { |
| // CHECK: bb5: { |
| // CHECK-NEXT: _0 = const 5_u8; |
| // CHECK-NEXT: return; |
| RET = 5; |
| Return() |
| } |
| // CHECK: bb6: { |
| // CHECK-NEXT: goto -> bb5; |
| } |
| } |
| |
| /// Verify that jump threading succeeds seeing through copies of aggregates. |
| fn aggregate_copy() -> u32 { |
| // CHECK-LABEL: fn aggregate_copy( |
| // CHECK-NOT: switchInt( |
| |
| const Foo: (u32, u32) = (5, 3); |
| |
| let a = Foo; |
| // This copies a tuple, we want to ensure that the threading condition on `b.1` propagates to a |
| // condition on `a.1`. |
| let b = a; |
| let c = b.1; |
| if c == 2 { b.0 } else { 13 } |
| } |
| |
| fn floats() -> u32 { |
| // CHECK-LABEL: fn floats( |
| // CHECK: switchInt( |
| |
| // Test for issue #128243, where float equality was assumed to be bitwise. |
| // When adding float support, it must be ensured that this continues working properly. |
| let x = if true { -0.0 } else { 1.0 }; |
| if x == 0.0 { 0 } else { 1 } |
| } |
| |
| pub fn bitwise_not() -> i32 { |
| // CHECK-LABEL: fn bitwise_not( |
| // CHECK: switchInt( |
| |
| // Test for #131195, which was optimizing `!a == b` into `a != b`. |
| let mut a: i32 = 0; |
| a = 1; |
| if !a == 0 { 1 } else { 0 } |
| } |
| |
| fn main() { |
| // CHECK-LABEL: fn main( |
| too_complex(Ok(0)); |
| identity(Ok(0)); |
| custom_discr(false); |
| dfa(); |
| multiple_match(5); |
| duplicate_chain(false); |
| mutate_discriminant(); |
| mutable_ref(); |
| renumbered_bb(true); |
| disappearing_bb(7); |
| aggregate(7); |
| assume(7, false); |
| floats(); |
| } |
| |
| // EMIT_MIR jump_threading.too_complex.JumpThreading.diff |
| // EMIT_MIR jump_threading.identity.JumpThreading.diff |
| // EMIT_MIR jump_threading.custom_discr.JumpThreading.diff |
| // EMIT_MIR jump_threading.dfa.JumpThreading.diff |
| // EMIT_MIR jump_threading.multiple_match.JumpThreading.diff |
| // EMIT_MIR jump_threading.duplicate_chain.JumpThreading.diff |
| // EMIT_MIR jump_threading.mutate_discriminant.JumpThreading.diff |
| // EMIT_MIR jump_threading.mutable_ref.JumpThreading.diff |
| // EMIT_MIR jump_threading.renumbered_bb.JumpThreading.diff |
| // EMIT_MIR jump_threading.disappearing_bb.JumpThreading.diff |
| // EMIT_MIR jump_threading.aggregate.JumpThreading.diff |
| // EMIT_MIR jump_threading.assume.JumpThreading.diff |
| // EMIT_MIR jump_threading.aggregate_copy.JumpThreading.diff |
| // EMIT_MIR jump_threading.floats.JumpThreading.diff |
| // EMIT_MIR jump_threading.bitwise_not.JumpThreading.diff |
