// unit-test: GVN // EMIT_MIR_FOR_EACH_PANIC_STRATEGY // only-64bit #![feature(raw_ref_op)] #![feature(rustc_attrs)] #![feature(custom_mir)] #![feature(core_intrinsics)] #![allow(unconditional_panic)] use std::intrinsics::mir::*; use std::mem::transmute; struct S(T); fn subexpression_elimination(x: u64, y: u64, mut z: u64) { // CHECK-LABEL: fn subexpression_elimination( // CHECK: [[add:_.*]] = Add(_1, _2); // CHECK: opaque::([[add]]) opaque(x + y); // CHECK: [[mul:_.*]] = Mul(_1, _2); // CHECK: opaque::([[mul]]) opaque(x * y); // CHECK: [[sub:_.*]] = Sub(_1, _2); // CHECK: opaque::([[sub]]) opaque(x - y); // CHECK: [[div:_.*]] = Div(_1, _2); // CHECK: opaque::([[div]]) opaque(x / y); // CHECK: [[rem:_.*]] = Rem(_1, _2); // CHECK: opaque::([[rem]]) opaque(x % y); // CHECK: [[and:_.*]] = BitAnd(_1, _2); // CHECK: opaque::([[and]]) opaque(x & y); // CHECK: [[or:_.*]] = BitOr(_1, _2); // CHECK: opaque::([[or]]) opaque(x | y); // CHECK: [[xor:_.*]] = BitXor(_1, _2); // CHECK: opaque::([[xor]]) opaque(x ^ y); // CHECK: [[shl:_.*]] = Shl(_1, _2); // CHECK: opaque::([[shl]]) opaque(x << y); // CHECK: [[shr:_.*]] = Shr(_1, _2); // CHECK: opaque::([[shr]]) opaque(x >> y); // CHECK: [[int:_.*]] = _1 as u32 (IntToInt); // CHECK: opaque::([[int]]) opaque(x as u32); // CHECK: [[float:_.*]] = _1 as f32 (IntToFloat); // CHECK: opaque::([[float]]) opaque(x as f32); // CHECK: [[wrap:_.*]] = S::(_1); // CHECK: opaque::>([[wrap]]) opaque(S(x)); // CHECK: opaque::(_1) opaque(S(x).0); // Those are duplicates to substitute somehow. // CHECK: opaque::([[add]]) opaque(x + y); // CHECK: opaque::([[mul]]) opaque(x * y); // CHECK: opaque::([[sub]]) opaque(x - y); // CHECK: opaque::([[div]]) opaque(x / y); // CHECK: opaque::([[rem]]) opaque(x % y); // CHECK: opaque::([[and]]) opaque(x & y); // CHECK: opaque::([[or]]) opaque(x | y); // CHECK: opaque::([[xor]]) opaque(x ^ y); // CHECK: opaque::([[shl]]) opaque(x << y); // CHECK: opaque::([[shr]]) opaque(x >> y); // CHECK: opaque::([[int]]) opaque(x as u32); // CHECK: opaque::([[float]]) opaque(x as f32); // CHECK: opaque::>([[wrap]]) opaque(S(x)); // CHECK: opaque::(_1) opaque(S(x).0); // We can substitute through a complex expression. // CHECK: [[compound:_.*]] = Sub([[mul]], _2); // CHECK: opaque::([[compound]]) // CHECK: opaque::([[compound]]) opaque((x * y) - y); opaque((x * y) - y); // We can substitute through an immutable reference too. // CHECK: [[ref:_.*]] = &_3; // CHECK: [[deref:_.*]] = (*[[ref]]); // CHECK: [[addref:_.*]] = Add([[deref]], _1); // CHECK: opaque::([[addref]]) // CHECK: opaque::([[addref]]) let a = &z; opaque(*a + x); opaque(*a + x); // But not through a mutable reference or a pointer. // CHECK: [[mut:_.*]] = &mut _3; // CHECK: [[addmut:_.*]] = Add( // CHECK: opaque::(move [[addmut]]) // CHECK: [[addmut2:_.*]] = Add( // CHECK: opaque::(move [[addmut2]]) let b = &mut z; opaque(*b + x); opaque(*b + x); unsafe { // CHECK: [[raw:_.*]] = &raw const _3; // CHECK: [[addraw:_.*]] = Add( // CHECK: opaque::(move [[addraw]]) // CHECK: [[addraw2:_.*]] = Add( // CHECK: opaque::(move [[addraw2]]) let c = &raw const z; opaque(*c + x); opaque(*c + x); // CHECK: [[ptr:_.*]] = &raw mut _3; // CHECK: [[addptr:_.*]] = Add( // CHECK: opaque::(move [[addptr]]) // CHECK: [[addptr2:_.*]] = Add( // CHECK: opaque::(move [[addptr2]]) let d = &raw mut z; opaque(*d + x); opaque(*d + x); } // We can substitute again, but not with the earlier computations. // Important: `e` is not `a`! // CHECK: [[ref2:_.*]] = &_3; // CHECK: [[deref2:_.*]] = (*[[ref2]]); // CHECK: [[addref2:_.*]] = Add([[deref2]], _1); // CHECK: opaque::([[addref2]]) // CHECK: opaque::([[addref2]]) let e = &z; opaque(*e + x); opaque(*e + x); } fn wrap_unwrap(x: T) -> T { // CHECK-LABEL: fn wrap_unwrap( // CHECK: [[some:_.*]] = Option::::Some(_1); // CHECK: switchInt(const 1_isize) // CHECK: _0 = _1; match Some(x) { Some(y) => y, None => panic!(), } } fn repeated_index(x: T, idx: usize) { // CHECK-LABEL: fn repeated_index( // CHECK: [[a:_.*]] = [_1; N]; let a = [x; N]; // CHECK: opaque::(_1) opaque(a[0]); // CHECK: opaque::(_1) opaque(a[idx]); } /// Verify symbolic integer arithmetic simplifications. fn arithmetic(x: u64) { // CHECK-LABEL: fn arithmetic( // CHECK: [[add:_.*]] = Add(_1, const 0_u64); // CHECK: opaque::(move [[add]]) opaque(x + 0); // CHECK: [[sub:_.*]] = Sub(_1, const 0_u64); // CHECK: opaque::(move [[sub]]) opaque(x - 0); // CHECK: [[mul0:_.*]] = Mul(_1, const 0_u64); // CHECK: opaque::(move [[mul0]]) opaque(x * 0); // CHECK: [[mul1:_.*]] = Mul(_1, const 1_u64); // CHECK: opaque::(move [[mul1]]) opaque(x * 1); // CHECK: [[div0:_.*]] = Div(_1, const 0_u64); // CHECK: opaque::(move [[div0]]) opaque(x / 0); // CHECK: [[div1:_.*]] = Div(_1, const 1_u64); // CHECK: opaque::(move [[div1]]) opaque(x / 1); // CHECK: [[zdiv:_.*]] = Div(const 0_u64, _1); // CHECK: opaque::(move [[zdiv]]) opaque(0 / x); // CHECK: [[odiv:_.*]] = Div(const 1_u64, _1); // CHECK: opaque::(move [[odiv]]) opaque(1 / x); // CHECK: [[rem0:_.*]] = Rem(_1, const 0_u64); // CHECK: opaque::(move [[rem0]]) opaque(x % 0); // CHECK: [[rem1:_.*]] = Rem(_1, const 1_u64); // CHECK: opaque::(move [[rem1]]) opaque(x % 1); // CHECK: [[zrem:_.*]] = Rem(const 0_u64, _1); // CHECK: opaque::(move [[zrem]]) opaque(0 % x); // CHECK: [[orem:_.*]] = Rem(const 1_u64, _1); // CHECK: opaque::(move [[orem]]) opaque(1 % x); // CHECK: [[and:_.*]] = BitAnd(_1, const 0_u64); // CHECK: opaque::(move [[and]]) opaque(x & 0); // CHECK: [[or:_.*]] = BitOr(_1, const 0_u64); // CHECK: opaque::(move [[or]]) opaque(x | 0); // CHECK: [[xor:_.*]] = BitXor(_1, const 0_u64); // CHECK: opaque::(move [[xor]]) opaque(x ^ 0); // CHECK: [[shr:_.*]] = Shr(_1, const 0_i32); // CHECK: opaque::(move [[shr]]) opaque(x >> 0); // CHECK: [[shl:_.*]] = Shl(_1, const 0_i32); // CHECK: opaque::(move [[shl]]) opaque(x << 0); } fn comparison(x: u64, y: u64) { // CHECK-LABEL: fn comparison( // CHECK: [[eqxx:_.*]] = Eq(_1, _1); // CHECK: opaque::(move [[eqxx]]) opaque(x == x); // CHECK: [[nexx:_.*]] = Ne(_1, _1); // CHECK: opaque::(move [[nexx]]) opaque(x != x); // CHECK: [[eqxy:_.*]] = Eq(_1, _2); // CHECK: opaque::(move [[eqxy]]) opaque(x == y); // CHECK: [[nexy:_.*]] = Ne(_1, _2); // CHECK: opaque::(move [[nexy]]) opaque(x != y); } /// Verify symbolic integer arithmetic simplifications on checked ops. #[rustc_inherit_overflow_checks] fn arithmetic_checked(x: u64) { // CHECK-LABEL: fn arithmetic_checked( // CHECK: [[cadd:_.*]] = CheckedAdd(_1, const 0_u64); // CHECK: [[add:_.*]] = move ([[cadd]].0: u64); // CHECK: opaque::(move [[add]]) opaque(x + 0); // CHECK: [[csub:_.*]] = CheckedSub(_1, const 0_u64); // CHECK: [[sub:_.*]] = move ([[csub]].0: u64); // CHECK: opaque::(move [[sub]]) opaque(x - 0); // CHECK: [[cmul0:_.*]] = CheckedMul(_1, const 0_u64); // CHECK: [[mul0:_.*]] = move ([[cmul0]].0: u64); // CHECK: opaque::(move [[mul0]]) opaque(x * 0); // CHECK: [[cmul1:_.*]] = CheckedMul(_1, const 1_u64); // CHECK: [[mul1:_.*]] = move ([[cmul1]].0: u64); // CHECK: opaque::(move [[mul1]]) opaque(x * 1); } /// Verify that we do not apply arithmetic simplifications on floats. fn arithmetic_float(x: f64) { // CHECK-LABEL: fn arithmetic_float( // CHECK: [[add:_.*]] = Add(_1, const 0f64); // CHECK: opaque::(move [[add]]) opaque(x + 0.); // CHECK: [[sub:_.*]] = Sub(_1, const 0f64); // CHECK: opaque::(move [[sub]]) opaque(x - 0.); // CHECK: [[mul:_.*]] = Mul(_1, const 0f64); // CHECK: opaque::(move [[mul]]) opaque(x * 0.); // CHECK: [[div0:_.*]] = Div(_1, const 0f64); // CHECK: opaque::(move [[div0]]) opaque(x / 0.); // CHECK: [[zdiv:_.*]] = Div(const 0f64, _1); // CHECK: opaque::(move [[zdiv]]) opaque(0. / x); // CHECK: [[rem0:_.*]] = Rem(_1, const 0f64); // CHECK: opaque::(move [[rem0]]) opaque(x % 0.); // CHECK: [[zrem:_.*]] = Rem(const 0f64, _1); // CHECK: opaque::(move [[zrem]]) opaque(0. % x); // Those are not simplifiable to `true`/`false`, thanks to NaNs. // CHECK: [[eq:_.*]] = Eq(_1, _1); // CHECK: opaque::(move [[eq]]) opaque(x == x); // CHECK: [[ne:_.*]] = Ne(_1, _1); // CHECK: opaque::(move [[ne]]) opaque(x != x); } fn cast() { // CHECK-LABEL: fn cast( let i = 1_i64; let u = 1_u64; let f = 1_f64; // CHECK: opaque::(const 1_u8) opaque(i as u8); // CHECK: opaque::(const 1_u16) opaque(i as u16); // CHECK: opaque::(const 1_u32) opaque(i as u32); // CHECK: opaque::(const 1_u64) opaque(i as u64); // CHECK: opaque::(const 1_i8) opaque(i as i8); // CHECK: opaque::(const 1_i16) opaque(i as i16); // CHECK: opaque::(const 1_i32) opaque(i as i32); // CHECK: opaque::(const 1_i64) opaque(i as i64); // CHECK: opaque::(const 1f32) opaque(i as f32); // CHECK: opaque::(const 1f64) opaque(i as f64); // CHECK: opaque::(const 1_u8) opaque(u as u8); // CHECK: opaque::(const 1_u16) opaque(u as u16); // CHECK: opaque::(const 1_u32) opaque(u as u32); // CHECK: opaque::(const 1_u64) opaque(u as u64); // CHECK: opaque::(const 1_i8) opaque(u as i8); // CHECK: opaque::(const 1_i16) opaque(u as i16); // CHECK: opaque::(const 1_i32) opaque(u as i32); // CHECK: opaque::(const 1_i64) opaque(u as i64); // CHECK: opaque::(const 1f32) opaque(u as f32); // CHECK: opaque::(const 1f64) opaque(u as f64); // CHECK: opaque::(const 1_u8) opaque(f as u8); // CHECK: opaque::(const 1_u16) opaque(f as u16); // CHECK: opaque::(const 1_u32) opaque(f as u32); // CHECK: opaque::(const 1_u64) opaque(f as u64); // CHECK: opaque::(const 1_i8) opaque(f as i8); // CHECK: opaque::(const 1_i16) opaque(f as i16); // CHECK: opaque::(const 1_i32) opaque(f as i32); // CHECK: opaque::(const 1_i64) opaque(f as i64); // CHECK: opaque::(const 1f32) opaque(f as f32); // CHECK: opaque::(const 1f64) opaque(f as f64); } fn multiple_branches(t: bool, x: u8, y: u8) { // CHECK-LABEL: fn multiple_branches( // CHECK: switchInt(_1) -> [0: [[bbf:bb.*]], otherwise: [[bbt:bb.*]]]; if t { // CHECK: [[bbt]]: { // CHECK: [[a:_.*]] = Add(_2, _3); // CHECK: opaque::([[a]]) // CHECK: opaque::([[a]]) // CHECK: goto -> [[bbc:bb.*]]; opaque(x + y); opaque(x + y); } else { // CHECK: [[bbf]]: { // CHECK: [[b:_.*]] = Add(_2, _3); // CHECK: opaque::([[b]]) // CHECK: opaque::([[b]]) // CHECK: goto -> [[bbc:bb.*]]; opaque(x + y); opaque(x + y); } // Neither `a` nor `b` dominate `c`, so we cannot reuse any of them. // CHECK: [[bbc]]: { // CHECK: [[c:_.*]] = Add(_2, _3); // CHECK: opaque::([[c]]) opaque(x + y); // `c` dominates both calls, so we can reuse it. if t { // CHECK: opaque::([[c]]) opaque(x + y); } else { // CHECK: opaque::([[c]]) opaque(x + y); } } /// Verify that we do not reuse a `&raw? mut?` rvalue. fn references(mut x: impl Sized) { // CHECK-LABEL: fn references( // CHECK: [[ref1:_.*]] = &_1; // CHECK: opaque::<&impl Sized>(move [[ref1]]) opaque(&x); // CHECK: [[ref2:_.*]] = &_1; // CHECK: opaque::<&impl Sized>(move [[ref2]]) opaque(&x); // CHECK: [[ref3:_.*]] = &mut _1; // CHECK: opaque::<&mut impl Sized>(move [[ref3]]) opaque(&mut x); // CHECK: [[ref4:_.*]] = &mut _1; // CHECK: opaque::<&mut impl Sized>(move [[ref4]]) opaque(&mut x); // CHECK: [[ref5:_.*]] = &raw const _1; // CHECK: opaque::<*const impl Sized>(move [[ref5]]) opaque(&raw const x); // CHECK: [[ref6:_.*]] = &raw const _1; // CHECK: opaque::<*const impl Sized>(move [[ref6]]) opaque(&raw const x); // CHECK: [[ref7:_.*]] = &raw mut _1; // CHECK: opaque::<*mut impl Sized>(move [[ref7]]) opaque(&raw mut x); // CHECK: [[ref8:_.*]] = &raw mut _1; // CHECK: opaque::<*mut impl Sized>(move [[ref8]]) opaque(&raw mut x); let r = &mut x; let s = S(r).0; // Obfuscate `r`. Following lines should still reborrow `r`. // CHECK: [[ref9:_.*]] = &mut _1; // CHECK: [[ref10:_.*]] = &(*[[ref9]]); // CHECK: opaque::<&impl Sized>(move [[ref10]]) opaque(&*s); // CHECK: [[ref11:_.*]] = &mut (*[[ref9]]); // CHECK: opaque::<&mut impl Sized>(move [[ref11]]) opaque(&mut *s); // CHECK: [[ref12:_.*]] = &raw const (*[[ref9]]); // CHECK: opaque::<*const impl Sized>(move [[ref12]]) opaque(&raw const *s); // CHECK: [[ref12:_.*]] = &raw mut (*[[ref9]]); // CHECK: opaque::<*mut impl Sized>(move [[ref12]]) opaque(&raw mut *s); } fn dereferences(t: &mut u32, u: &impl Copy, s: &S) { // CHECK-LABEL: fn dereferences( // Do not reuse dereferences of `&mut`. // CHECK: [[st1:_.*]] = (*_1); // CHECK: opaque::(move [[st1]]) // CHECK: [[st2:_.*]] = (*_1); // CHECK: opaque::(move [[st2]]) opaque(*t); opaque(*t); // Do not reuse dereferences of `*const`. // CHECK: [[raw:_.*]] = &raw const (*_1); // CHECK: [[st3:_.*]] = (*[[raw]]); // CHECK: opaque::(move [[st3]]) // CHECK: [[st4:_.*]] = (*[[raw]]); // CHECK: opaque::(move [[st4]]) let z = &raw const *t; unsafe { opaque(*z) }; unsafe { opaque(*z) }; // Do not reuse dereferences of `*mut`. // CHECK: [[ptr:_.*]] = &raw mut (*_1); // CHECK: [[st5:_.*]] = (*[[ptr]]); // CHECK: opaque::(move [[st5]]) // CHECK: [[st6:_.*]] = (*[[ptr]]); // CHECK: opaque::(move [[st6]]) let z = &raw mut *t; unsafe { opaque(*z) }; unsafe { opaque(*z) }; // We can reuse dereferences of `&Freeze`. // CHECK: [[ref:_.*]] = &(*_1); // CHECK: [[st7:_.*]] = (*[[ref]]); // CHECK: opaque::([[st7]]) // CHECK: opaque::([[st7]]) let z = &*t; opaque(*z); opaque(*z); // But not in reborrows. // CHECK: [[reborrow:_.*]] = &(*[[ref]]); // CHECK: opaque::<&u32>(move [[reborrow]]) opaque(&*z); // `*u` is not Freeze, so we cannot reuse. // CHECK: [[st8:_.*]] = (*_2); // CHECK: opaque::(move [[st8]]) // CHECK: [[st9:_.*]] = (*_2); // CHECK: opaque::(move [[st9]]) opaque(*u); opaque(*u); // `*s` is not Copy, by `(*s).0` is, so we can reuse. // CHECK: [[st10:_.*]] = ((*_3).0: u32); // CHECK: opaque::([[st10]]) // CHECK: opaque::([[st10]]) opaque(s.0); opaque(s.0); } fn slices() { // CHECK-LABEL: fn slices( // CHECK: {{_.*}} = const " // CHECK-NOT: {{_.*}} = const " let s = "my favourite slice"; // This is a `Const::Slice` in MIR. opaque(s); let t = s; // This should be the same pointer, so cannot be a `Const::Slice`. opaque(t); assert_eq!(s.as_ptr(), t.as_ptr()); let u = unsafe { transmute::<&str, &[u8]>(s) }; opaque(u); assert_eq!(s.as_ptr(), u.as_ptr()); } #[custom_mir(dialect = "analysis")] fn duplicate_slice() -> (bool, bool) { // CHECK-LABEL: fn duplicate_slice( mir!( let au: u128; let bu: u128; let cu: u128; let du: u128; let c: &str; let d: &str; { // CHECK: [[a:_.*]] = (const "a",); // CHECK: [[au:_.*]] = ([[a]].0: &str) as u128 (Transmute); let a = ("a",); Call(au = transmute::<_, u128>(a.0), bb1) } bb1 = { // CHECK: [[c:_.*]] = identity::<&str>(([[a]].0: &str)) Call(c = identity(a.0), bb2) } bb2 = { // CHECK: [[cu:_.*]] = [[c]] as u128 (Transmute); Call(cu = transmute::<_, u128>(c), bb3) } bb3 = { // This slice is different from `a.0`. Hence `bu` is not `au`. // CHECK: [[b:_.*]] = const "a"; // CHECK: [[bu:_.*]] = [[b]] as u128 (Transmute); let b = "a"; Call(bu = transmute::<_, u128>(b), bb4) } bb4 = { // This returns a copy of `b`, which is not `a`. // CHECK: [[d:_.*]] = identity::<&str>([[b]]) Call(d = identity(b), bb5) } bb5 = { // CHECK: [[du:_.*]] = [[d]] as u128 (Transmute); Call(du = transmute::<_, u128>(d), bb6) } bb6 = { // `direct` must not fold to `true`, as `indirect` will not. // CHECK: = Eq([[au]], [[bu]]); // CHECK: = Eq([[cu]], [[du]]); let direct = au == bu; let indirect = cu == du; RET = (direct, indirect); Return() } ) } fn repeat() { // CHECK-LABEL: fn repeat( // CHECK: = [const 5_i32; 10]; let val = 5; let array = [val, val, val, val, val, val, val, val, val, val]; } /// Verify that we do not merge fn pointers created by casts. fn fn_pointers() { // CHECK-LABEL: fn fn_pointers( // CHECK: [[f:_.*]] = identity:: as fn(u8) -> u8 (PointerCoercion(ReifyFnPointer // CHECK: opaque:: u8>([[f]]) let f = identity as fn(u8) -> u8; opaque(f); // CHECK: [[g:_.*]] = identity:: as fn(u8) -> u8 (PointerCoercion(ReifyFnPointer // CHECK: opaque:: u8>([[g]]) let g = identity as fn(u8) -> u8; opaque(g); // CHECK: [[cf:_.*]] = const {{.*}} as fn() (PointerCoercion(ClosureFnPointer // CHECK: opaque::([[cf]]) let closure = || {}; let cf = closure as fn(); opaque(cf); // CHECK: [[cg:_.*]] = const {{.*}} as fn() (PointerCoercion(ClosureFnPointer // CHECK: opaque::([[cg]]) let cg = closure as fn(); opaque(cg); } /// Verify that we do not create a `ConstValue::Indirect` backed by a static's AllocId. #[custom_mir(dialect = "analysis")] fn indirect_static() { static A: Option = None; mir!({ let ptr = Static(A); let out = Field::(Variant(*ptr, 1), 0); Return() }) } fn main() { subexpression_elimination(2, 4, 5); wrap_unwrap(5); repeated_index::(5, 3); arithmetic(5); comparison(5, 6); arithmetic_checked(5); arithmetic_float(5.); cast(); multiple_branches(true, 5, 9); references(5); dereferences(&mut 5, &6, &S(7)); slices(); let (direct, indirect) = duplicate_slice(); assert_eq!(direct, indirect); repeat(); fn_pointers(); indirect_static(); } #[inline(never)] fn opaque(_: impl Sized) {} #[inline(never)] fn identity(x: T) -> T { x } // EMIT_MIR gvn.subexpression_elimination.GVN.diff // EMIT_MIR gvn.wrap_unwrap.GVN.diff // EMIT_MIR gvn.repeated_index.GVN.diff // EMIT_MIR gvn.arithmetic.GVN.diff // EMIT_MIR gvn.comparison.GVN.diff // EMIT_MIR gvn.arithmetic_checked.GVN.diff // EMIT_MIR gvn.arithmetic_float.GVN.diff // EMIT_MIR gvn.cast.GVN.diff // EMIT_MIR gvn.multiple_branches.GVN.diff // EMIT_MIR gvn.references.GVN.diff // EMIT_MIR gvn.dereferences.GVN.diff // EMIT_MIR gvn.slices.GVN.diff // EMIT_MIR gvn.duplicate_slice.GVN.diff // EMIT_MIR gvn.repeat.GVN.diff // EMIT_MIR gvn.fn_pointers.GVN.diff // EMIT_MIR gvn.indirect_static.GVN.diff