Auto merge of #126844 - scottmcm:more-ptr-cast-gvn, r=saethlin

Remove more `PtrToPtr` casts in GVN

This addresses two things I noticed in MIR:

1. `NonNull::<T>::eq` does `(a as *mut T) == (b as *mut T)`, but it could just compare the `*const T`s, so this removes `PtrToPtr` casts that are on both sides of a pointer comparison, so long as they're not fat-to-thin casts.

2. `NonNull::<T>::addr` does `transmute::<_, usize>(p as *const ())`, but so long as `T: Thin` that cast doesn't do anything, and thus we can directly transmute the `*const T` instead.

r? mir-opt
This commit is contained in:
bors 2024-06-26 14:22:31 +00:00
commit d7c59370ce
23 changed files with 1573 additions and 160 deletions

View File

@ -289,19 +289,7 @@ impl<'tcx> UnOp {
pub fn ty(&self, tcx: TyCtxt<'tcx>, arg_ty: Ty<'tcx>) -> Ty<'tcx> {
match self {
UnOp::Not | UnOp::Neg => arg_ty,
UnOp::PtrMetadata => {
let pointee_ty = arg_ty
.builtin_deref(true)
.unwrap_or_else(|| bug!("PtrMetadata of non-dereferenceable ty {arg_ty:?}"));
if pointee_ty.is_trivially_sized(tcx) {
tcx.types.unit
} else {
let Some(metadata_def_id) = tcx.lang_items().metadata_type() else {
bug!("No metadata_type lang item while looking at {arg_ty:?}")
};
Ty::new_projection(tcx, metadata_def_id, [pointee_ty])
}
}
UnOp::PtrMetadata => arg_ty.pointee_metadata_ty_or_projection(tcx),
}
}
}

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@ -1647,6 +1647,34 @@ impl<'tcx> Ty<'tcx> {
}
}
/// Given a pointer or reference type, returns the type of the *pointee*'s
/// metadata. If it can't be determined exactly (perhaps due to still
/// being generic) then a projection through `ptr::Pointee` will be returned.
///
/// This is particularly useful for getting the type of the result of
/// [`UnOp::PtrMetadata`](crate::mir::UnOp::PtrMetadata).
///
/// Panics if `self` is not dereferencable.
#[track_caller]
pub fn pointee_metadata_ty_or_projection(self, tcx: TyCtxt<'tcx>) -> Ty<'tcx> {
let Some(pointee_ty) = self.builtin_deref(true) else {
bug!("Type {self:?} is not a pointer or reference type")
};
if pointee_ty.is_trivially_sized(tcx) {
tcx.types.unit
} else {
match pointee_ty.ptr_metadata_ty_or_tail(tcx, |x| x) {
Ok(metadata_ty) => metadata_ty,
Err(tail_ty) => {
let Some(metadata_def_id) = tcx.lang_items().metadata_type() else {
bug!("No metadata_type lang item while looking at {self:?}")
};
Ty::new_projection(tcx, metadata_def_id, [tail_ty])
}
}
}
}
/// When we create a closure, we record its kind (i.e., what trait
/// it implements, constrained by how it uses its borrows) into its
/// [`ty::ClosureArgs`] or [`ty::CoroutineClosureArgs`] using a type

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@ -60,7 +60,15 @@ impl<'tcx> Visitor<'tcx> for CostChecker<'_, 'tcx> {
fn visit_rvalue(&mut self, rvalue: &Rvalue<'tcx>, _location: Location) {
match rvalue {
Rvalue::NullaryOp(NullOp::UbChecks, ..) if !self.tcx.sess.ub_checks() => {
Rvalue::NullaryOp(NullOp::UbChecks, ..)
if !self
.tcx
.sess
.opts
.unstable_opts
.inline_mir_preserve_debug
.unwrap_or(self.tcx.sess.ub_checks()) =>
{
// If this is in optimized MIR it's because it's used later,
// so if we don't need UB checks this session, give a bonus
// here to offset the cost of the call later.
@ -111,12 +119,19 @@ impl<'tcx> Visitor<'tcx> for CostChecker<'_, 'tcx> {
}
}
TerminatorKind::Assert { unwind, msg, .. } => {
self.penalty +=
if msg.is_optional_overflow_check() && !self.tcx.sess.overflow_checks() {
INSTR_COST
} else {
CALL_PENALTY
};
self.penalty += if msg.is_optional_overflow_check()
&& !self
.tcx
.sess
.opts
.unstable_opts
.inline_mir_preserve_debug
.unwrap_or(self.tcx.sess.overflow_checks())
{
INSTR_COST
} else {
CALL_PENALTY
};
if let UnwindAction::Cleanup(_) = unwind {
self.penalty += LANDINGPAD_PENALTY;
}

View File

@ -823,18 +823,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
return self.simplify_cast(kind, value, to, location);
}
Rvalue::BinaryOp(op, box (ref mut lhs, ref mut rhs)) => {
let ty = lhs.ty(self.local_decls, self.tcx);
let lhs = self.simplify_operand(lhs, location);
let rhs = self.simplify_operand(rhs, location);
// Only short-circuit options after we called `simplify_operand`
// on both operands for side effect.
let lhs = lhs?;
let rhs = rhs?;
if let Some(value) = self.simplify_binary(op, ty, lhs, rhs) {
return Some(value);
}
Value::BinaryOp(op, lhs, rhs)
return self.simplify_binary(op, lhs, rhs, location);
}
Rvalue::UnaryOp(op, ref mut arg_op) => {
return self.simplify_unary(op, arg_op, location);
@ -987,23 +976,10 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
// `*const [T]` -> `*const T` which remove metadata.
// We run on potentially-generic MIR, though, so unlike codegen
// we can't always know exactly what the metadata are.
// Thankfully, equality on `ptr_metadata_ty_or_tail` gives us
// what we need: `Ok(meta_ty)` if the metadata is known, or
// `Err(tail_ty)` if not. Matching metadata is ok, but if
// that's not known, then matching tail types is also ok,
// allowing things like `*mut (?A, ?T)` <-> `*mut (?B, ?T)`.
// FIXME: Would it be worth trying to normalize, rather than
// passing the identity closure? Or are the types in the
// Cast realistically about as normalized as we can get anyway?
// To allow things like `*mut (?A, ?T)` <-> `*mut (?B, ?T)`,
// it's fine to get a projection as the type.
Value::Cast { kind: CastKind::PtrToPtr, value: inner, from, to }
if from
.builtin_deref(true)
.unwrap()
.ptr_metadata_ty_or_tail(self.tcx, |t| t)
== to
.builtin_deref(true)
.unwrap()
.ptr_metadata_ty_or_tail(self.tcx, |t| t) =>
if self.pointers_have_same_metadata(*from, *to) =>
{
arg_index = *inner;
was_updated = true;
@ -1068,6 +1044,52 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
#[instrument(level = "trace", skip(self), ret)]
fn simplify_binary(
&mut self,
op: BinOp,
lhs_operand: &mut Operand<'tcx>,
rhs_operand: &mut Operand<'tcx>,
location: Location,
) -> Option<VnIndex> {
let lhs = self.simplify_operand(lhs_operand, location);
let rhs = self.simplify_operand(rhs_operand, location);
// Only short-circuit options after we called `simplify_operand`
// on both operands for side effect.
let mut lhs = lhs?;
let mut rhs = rhs?;
let lhs_ty = lhs_operand.ty(self.local_decls, self.tcx);
// If we're comparing pointers, remove `PtrToPtr` casts if the from
// types of both casts and the metadata all match.
if let BinOp::Eq | BinOp::Ne | BinOp::Lt | BinOp::Le | BinOp::Gt | BinOp::Ge = op
&& lhs_ty.is_any_ptr()
&& let Value::Cast {
kind: CastKind::PtrToPtr, value: lhs_value, from: lhs_from, ..
} = self.get(lhs)
&& let Value::Cast {
kind: CastKind::PtrToPtr, value: rhs_value, from: rhs_from, ..
} = self.get(rhs)
&& lhs_from == rhs_from
&& self.pointers_have_same_metadata(*lhs_from, lhs_ty)
{
lhs = *lhs_value;
rhs = *rhs_value;
if let Some(op) = self.try_as_operand(lhs, location) {
*lhs_operand = op;
}
if let Some(op) = self.try_as_operand(rhs, location) {
*rhs_operand = op;
}
}
if let Some(value) = self.simplify_binary_inner(op, lhs_ty, lhs, rhs) {
return Some(value);
}
let value = Value::BinaryOp(op, lhs, rhs);
Some(self.insert(value))
}
fn simplify_binary_inner(
&mut self,
op: BinOp,
lhs_ty: Ty<'tcx>,
@ -1228,6 +1250,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
}
}
// PtrToPtr-then-PtrToPtr can skip the intermediate step
if let PtrToPtr = kind
&& let Value::Cast { kind: inner_kind, value: inner_value, from: inner_from, to: _ } =
*self.get(value)
@ -1235,7 +1258,25 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
{
from = inner_from;
value = inner_value;
*kind = PtrToPtr;
was_updated = true;
if inner_from == to {
return Some(inner_value);
}
}
// PtrToPtr-then-Transmute can just transmute the original, so long as the
// PtrToPtr didn't change metadata (and thus the size of the pointer)
if let Transmute = kind
&& let Value::Cast {
kind: PtrToPtr,
value: inner_value,
from: inner_from,
to: inner_to,
} = *self.get(value)
&& self.pointers_have_same_metadata(inner_from, inner_to)
{
from = inner_from;
value = inner_value;
was_updated = true;
if inner_from == to {
return Some(inner_value);
@ -1289,6 +1330,21 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
// Fallback: a symbolic `Len`.
Some(self.insert(Value::Len(inner)))
}
fn pointers_have_same_metadata(&self, left_ptr_ty: Ty<'tcx>, right_ptr_ty: Ty<'tcx>) -> bool {
let left_meta_ty = left_ptr_ty.pointee_metadata_ty_or_projection(self.tcx);
let right_meta_ty = right_ptr_ty.pointee_metadata_ty_or_projection(self.tcx);
if left_meta_ty == right_meta_ty {
true
} else if let Ok(left) =
self.tcx.try_normalize_erasing_regions(self.param_env, left_meta_ty)
&& let Ok(right) = self.tcx.try_normalize_erasing_regions(self.param_env, right_meta_ty)
{
left == right
} else {
false
}
}
}
fn op_to_prop_const<'tcx>(

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@ -22,19 +22,19 @@ Number of file 0 mappings: 5
- Code(Counter(0)) at (prev + 3, 1) to (start + 0, 2)
Function name: closure_macro::main::{closure#0}
Raw bytes (35): 0x[01, 01, 03, 01, 05, 05, 0b, 09, 0d, 05, 01, 10, 1c, 03, 21, 05, 04, 11, 01, 27, 02, 03, 11, 00, 16, 0d, 00, 17, 00, 1e, 07, 02, 09, 00, 0a]
Raw bytes (35): 0x[01, 01, 03, 01, 05, 05, 0b, 09, 00, 05, 01, 10, 1c, 03, 21, 05, 04, 11, 01, 27, 02, 03, 11, 00, 16, 00, 00, 17, 00, 1e, 07, 02, 09, 00, 0a]
Number of files: 1
- file 0 => global file 1
Number of expressions: 3
- expression 0 operands: lhs = Counter(0), rhs = Counter(1)
- expression 1 operands: lhs = Counter(1), rhs = Expression(2, Add)
- expression 2 operands: lhs = Counter(2), rhs = Counter(3)
- expression 2 operands: lhs = Counter(2), rhs = Zero
Number of file 0 mappings: 5
- Code(Counter(0)) at (prev + 16, 28) to (start + 3, 33)
- Code(Counter(1)) at (prev + 4, 17) to (start + 1, 39)
- Code(Expression(0, Sub)) at (prev + 3, 17) to (start + 0, 22)
= (c0 - c1)
- Code(Counter(3)) at (prev + 0, 23) to (start + 0, 30)
- Code(Zero) at (prev + 0, 23) to (start + 0, 30)
- Code(Expression(1, Add)) at (prev + 2, 9) to (start + 0, 10)
= (c1 + (c2 + c3))
= (c1 + (c2 + Zero))

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@ -30,19 +30,19 @@ Number of file 0 mappings: 5
- Code(Counter(0)) at (prev + 3, 1) to (start + 0, 2)
Function name: closure_macro_async::test::{closure#0}::{closure#0}
Raw bytes (35): 0x[01, 01, 03, 01, 05, 05, 0b, 09, 0d, 05, 01, 12, 1c, 03, 21, 05, 04, 11, 01, 27, 02, 03, 11, 00, 16, 0d, 00, 17, 00, 1e, 07, 02, 09, 00, 0a]
Raw bytes (35): 0x[01, 01, 03, 01, 05, 05, 0b, 09, 00, 05, 01, 12, 1c, 03, 21, 05, 04, 11, 01, 27, 02, 03, 11, 00, 16, 00, 00, 17, 00, 1e, 07, 02, 09, 00, 0a]
Number of files: 1
- file 0 => global file 1
Number of expressions: 3
- expression 0 operands: lhs = Counter(0), rhs = Counter(1)
- expression 1 operands: lhs = Counter(1), rhs = Expression(2, Add)
- expression 2 operands: lhs = Counter(2), rhs = Counter(3)
- expression 2 operands: lhs = Counter(2), rhs = Zero
Number of file 0 mappings: 5
- Code(Counter(0)) at (prev + 18, 28) to (start + 3, 33)
- Code(Counter(1)) at (prev + 4, 17) to (start + 1, 39)
- Code(Expression(0, Sub)) at (prev + 3, 17) to (start + 0, 22)
= (c0 - c1)
- Code(Counter(3)) at (prev + 0, 23) to (start + 0, 30)
- Code(Zero) at (prev + 0, 23) to (start + 0, 30)
- Code(Expression(1, Add)) at (prev + 2, 9) to (start + 0, 10)
= (c1 + (c2 + c3))
= (c1 + (c2 + Zero))

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@ -0,0 +1,134 @@
- // MIR for `cast_pointer_eq` before GVN
+ // MIR for `cast_pointer_eq` after GVN
fn cast_pointer_eq(_1: *mut u8, _2: *mut u32, _3: *mut u32, _4: *mut [u32]) -> () {
debug p1 => _1;
debug p2 => _2;
debug p3 => _3;
debug p4 => _4;
let mut _0: ();
let _5: *const u32;
let mut _6: *mut u8;
let mut _8: *const u32;
let mut _9: *mut u32;
let mut _11: *const u32;
let mut _12: *mut u32;
let mut _14: *mut [u32];
let mut _16: *const u32;
let mut _17: *const u32;
let mut _19: *const u32;
let mut _20: *const u32;
let mut _22: *const u32;
let mut _23: *const u32;
scope 1 {
debug m1 => _5;
let _7: *const u32;
scope 2 {
debug m2 => _7;
let _10: *const u32;
scope 3 {
debug m3 => _10;
let _13: *const u32;
scope 4 {
debug m4 => _13;
let _15: bool;
scope 5 {
debug eq_different_thing => _15;
let _18: bool;
scope 6 {
debug eq_optimize => _18;
let _21: bool;
scope 7 {
debug eq_thin_fat => _21;
}
}
}
}
}
}
}
bb0: {
- StorageLive(_5);
+ nop;
StorageLive(_6);
_6 = _1;
- _5 = move _6 as *const u32 (PtrToPtr);
+ _5 = _1 as *const u32 (PtrToPtr);
StorageDead(_6);
StorageLive(_7);
- StorageLive(_8);
+ nop;
StorageLive(_9);
_9 = _2;
- _8 = move _9 as *const u32 (PtrToPtr);
+ _8 = _2 as *const u32 (PtrToPtr);
StorageDead(_9);
- _7 = move _8 as *const u32 (PtrToPtr);
- StorageDead(_8);
+ _7 = _8;
+ nop;
StorageLive(_10);
- StorageLive(_11);
+ nop;
StorageLive(_12);
_12 = _3;
- _11 = move _12 as *const u32 (PtrToPtr);
+ _11 = _3 as *const u32 (PtrToPtr);
StorageDead(_12);
- _10 = move _11 as *const u32 (PtrToPtr);
- StorageDead(_11);
- StorageLive(_13);
+ _10 = _11;
+ nop;
+ nop;
StorageLive(_14);
_14 = _4;
- _13 = move _14 as *const u32 (PtrToPtr);
+ _13 = _4 as *const u32 (PtrToPtr);
StorageDead(_14);
StorageLive(_15);
StorageLive(_16);
_16 = _5;
StorageLive(_17);
- _17 = _7;
- _15 = Eq(move _16, move _17);
+ _17 = _8;
+ _15 = Eq(_5, _8);
StorageDead(_17);
StorageDead(_16);
StorageLive(_18);
StorageLive(_19);
- _19 = _7;
+ _19 = _8;
StorageLive(_20);
- _20 = _10;
- _18 = Eq(move _19, move _20);
+ _20 = _11;
+ _18 = Eq(_2, _3);
StorageDead(_20);
StorageDead(_19);
StorageLive(_21);
StorageLive(_22);
- _22 = _10;
+ _22 = _11;
StorageLive(_23);
_23 = _13;
- _21 = Eq(move _22, move _23);
+ _21 = Eq(_11, _13);
StorageDead(_23);
StorageDead(_22);
_0 = const ();
StorageDead(_21);
StorageDead(_18);
StorageDead(_15);
- StorageDead(_13);
+ nop;
StorageDead(_10);
StorageDead(_7);
- StorageDead(_5);
+ nop;
return;
}
}

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@ -0,0 +1,134 @@
- // MIR for `cast_pointer_eq` before GVN
+ // MIR for `cast_pointer_eq` after GVN
fn cast_pointer_eq(_1: *mut u8, _2: *mut u32, _3: *mut u32, _4: *mut [u32]) -> () {
debug p1 => _1;
debug p2 => _2;
debug p3 => _3;
debug p4 => _4;
let mut _0: ();
let _5: *const u32;
let mut _6: *mut u8;
let mut _8: *const u32;
let mut _9: *mut u32;
let mut _11: *const u32;
let mut _12: *mut u32;
let mut _14: *mut [u32];
let mut _16: *const u32;
let mut _17: *const u32;
let mut _19: *const u32;
let mut _20: *const u32;
let mut _22: *const u32;
let mut _23: *const u32;
scope 1 {
debug m1 => _5;
let _7: *const u32;
scope 2 {
debug m2 => _7;
let _10: *const u32;
scope 3 {
debug m3 => _10;
let _13: *const u32;
scope 4 {
debug m4 => _13;
let _15: bool;
scope 5 {
debug eq_different_thing => _15;
let _18: bool;
scope 6 {
debug eq_optimize => _18;
let _21: bool;
scope 7 {
debug eq_thin_fat => _21;
}
}
}
}
}
}
}
bb0: {
- StorageLive(_5);
+ nop;
StorageLive(_6);
_6 = _1;
- _5 = move _6 as *const u32 (PtrToPtr);
+ _5 = _1 as *const u32 (PtrToPtr);
StorageDead(_6);
StorageLive(_7);
- StorageLive(_8);
+ nop;
StorageLive(_9);
_9 = _2;
- _8 = move _9 as *const u32 (PtrToPtr);
+ _8 = _2 as *const u32 (PtrToPtr);
StorageDead(_9);
- _7 = move _8 as *const u32 (PtrToPtr);
- StorageDead(_8);
+ _7 = _8;
+ nop;
StorageLive(_10);
- StorageLive(_11);
+ nop;
StorageLive(_12);
_12 = _3;
- _11 = move _12 as *const u32 (PtrToPtr);
+ _11 = _3 as *const u32 (PtrToPtr);
StorageDead(_12);
- _10 = move _11 as *const u32 (PtrToPtr);
- StorageDead(_11);
- StorageLive(_13);
+ _10 = _11;
+ nop;
+ nop;
StorageLive(_14);
_14 = _4;
- _13 = move _14 as *const u32 (PtrToPtr);
+ _13 = _4 as *const u32 (PtrToPtr);
StorageDead(_14);
StorageLive(_15);
StorageLive(_16);
_16 = _5;
StorageLive(_17);
- _17 = _7;
- _15 = Eq(move _16, move _17);
+ _17 = _8;
+ _15 = Eq(_5, _8);
StorageDead(_17);
StorageDead(_16);
StorageLive(_18);
StorageLive(_19);
- _19 = _7;
+ _19 = _8;
StorageLive(_20);
- _20 = _10;
- _18 = Eq(move _19, move _20);
+ _20 = _11;
+ _18 = Eq(_2, _3);
StorageDead(_20);
StorageDead(_19);
StorageLive(_21);
StorageLive(_22);
- _22 = _10;
+ _22 = _11;
StorageLive(_23);
_23 = _13;
- _21 = Eq(move _22, move _23);
+ _21 = Eq(_11, _13);
StorageDead(_23);
StorageDead(_22);
_0 = const ();
StorageDead(_21);
StorageDead(_18);
StorageDead(_15);
- StorageDead(_13);
+ nop;
StorageDead(_10);
StorageDead(_7);
- StorageDead(_5);
+ nop;
return;
}
}

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@ -0,0 +1,47 @@
- // MIR for `cast_pointer_then_transmute` before GVN
+ // MIR for `cast_pointer_then_transmute` after GVN
fn cast_pointer_then_transmute(_1: *mut u32, _2: *mut [u8]) -> () {
debug thin => _1;
debug fat => _2;
let mut _0: ();
let _3: usize;
let mut _4: *const ();
let mut _5: *mut u32;
let mut _7: *const ();
let mut _8: *mut [u8];
scope 1 {
debug thin_addr => _3;
let _6: usize;
scope 2 {
debug fat_addr => _6;
}
}
bb0: {
StorageLive(_3);
StorageLive(_4);
StorageLive(_5);
_5 = _1;
- _4 = move _5 as *const () (PtrToPtr);
+ _4 = _1 as *const () (PtrToPtr);
StorageDead(_5);
- _3 = move _4 as usize (Transmute);
+ _3 = _1 as usize (Transmute);
StorageDead(_4);
StorageLive(_6);
StorageLive(_7);
StorageLive(_8);
_8 = _2;
- _7 = move _8 as *const () (PtrToPtr);
+ _7 = _2 as *const () (PtrToPtr);
StorageDead(_8);
_6 = move _7 as usize (Transmute);
StorageDead(_7);
_0 = const ();
StorageDead(_6);
StorageDead(_3);
return;
}
}

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@ -0,0 +1,47 @@
- // MIR for `cast_pointer_then_transmute` before GVN
+ // MIR for `cast_pointer_then_transmute` after GVN
fn cast_pointer_then_transmute(_1: *mut u32, _2: *mut [u8]) -> () {
debug thin => _1;
debug fat => _2;
let mut _0: ();
let _3: usize;
let mut _4: *const ();
let mut _5: *mut u32;
let mut _7: *const ();
let mut _8: *mut [u8];
scope 1 {
debug thin_addr => _3;
let _6: usize;
scope 2 {
debug fat_addr => _6;
}
}
bb0: {
StorageLive(_3);
StorageLive(_4);
StorageLive(_5);
_5 = _1;
- _4 = move _5 as *const () (PtrToPtr);
+ _4 = _1 as *const () (PtrToPtr);
StorageDead(_5);
- _3 = move _4 as usize (Transmute);
+ _3 = _1 as usize (Transmute);
StorageDead(_4);
StorageLive(_6);
StorageLive(_7);
StorageLive(_8);
_8 = _2;
- _7 = move _8 as *const () (PtrToPtr);
+ _7 = _2 as *const () (PtrToPtr);
StorageDead(_8);
_6 = move _7 as usize (Transmute);
StorageDead(_7);
_0 = const ();
StorageDead(_6);
StorageDead(_3);
return;
}
}

View File

@ -883,6 +883,49 @@ fn generic_cast_metadata<T, A: ?Sized, B: ?Sized>(ps: *const [T], pa: *const A,
}
}
fn cast_pointer_eq(p1: *mut u8, p2: *mut u32, p3: *mut u32, p4: *mut [u32]) {
// CHECK-LABEL: fn cast_pointer_eq
// CHECK: debug p1 => [[P1:_1]];
// CHECK: debug p2 => [[P2:_2]];
// CHECK: debug p3 => [[P3:_3]];
// CHECK: debug p4 => [[P4:_4]];
// CHECK: [[M1:_.+]] = [[P1]] as *const u32 (PtrToPtr);
// CHECK: [[M2:_.+]] = [[P2]] as *const u32 (PtrToPtr);
// CHECK: [[M3:_.+]] = [[P3]] as *const u32 (PtrToPtr);
// CHECK: [[M4:_.+]] = [[P4]] as *const u32 (PtrToPtr);
let m1 = p1 as *const u32;
let m2 = p2 as *const u32;
let m3 = p3 as *const u32;
let m4 = p4 as *const u32;
// CHECK-NOT: Eq
// CHECK: Eq([[M1]], [[M2]])
// CHECK-NOT: Eq
// CHECK: Eq([[P2]], [[P3]])
// CHECK-NOT: Eq
// CHECK: Eq([[M3]], [[M4]])
// CHECK-NOT: Eq
let eq_different_thing = m1 == m2;
let eq_optimize = m2 == m3;
let eq_thin_fat = m3 == m4;
// CHECK: _0 = const ();
}
// Transmuting can skip a pointer cast so long as it wasn't a fat-to-thin cast.
unsafe fn cast_pointer_then_transmute(thin: *mut u32, fat: *mut [u8]) {
// CHECK-LABEL: fn cast_pointer_then_transmute
// CHECK: [[UNUSED:_.+]] = _1 as *const () (PtrToPtr);
// CHECK: = _1 as usize (Transmute);
let thin_addr: usize = std::intrinsics::transmute(thin as *const ());
// CHECK: [[TEMP2:_.+]] = _2 as *const () (PtrToPtr);
// CHECK: = move [[TEMP2]] as usize (Transmute);
let fat_addr: usize = std::intrinsics::transmute(fat as *const ());
}
fn main() {
subexpression_elimination(2, 4, 5);
wrap_unwrap(5);
@ -950,3 +993,5 @@ fn identity<T>(x: T) -> T {
// EMIT_MIR gvn.manual_slice_mut_len.GVN.diff
// EMIT_MIR gvn.array_len.GVN.diff
// EMIT_MIR gvn.generic_cast_metadata.GVN.diff
// EMIT_MIR gvn.cast_pointer_eq.GVN.diff
// EMIT_MIR gvn.cast_pointer_then_transmute.GVN.diff

View File

@ -15,10 +15,12 @@
let mut _10: bool;
bb0: {
StorageLive(_3);
- StorageLive(_3);
+ nop;
StorageLive(_4);
_4 = _1;
StorageLive(_5);
- StorageLive(_5);
+ nop;
StorageLive(_6);
StorageLive(_7);
_7 = &(*_2);
@ -32,12 +34,14 @@
bb1: {
StorageDead(_6);
- _3 = Lt(move _4, move _5);
+ _3 = Lt(_1, move _5);
switchInt(move _3) -> [0: bb4, otherwise: bb2];
- switchInt(move _3) -> [0: bb4, otherwise: bb2];
+ _3 = Lt(_1, const N);
+ switchInt(_3) -> [0: bb4, otherwise: bb2];
}
bb2: {
StorageDead(_5);
- StorageDead(_5);
+ nop;
StorageDead(_4);
StorageLive(_8);
_8 = _1;
@ -45,8 +49,8 @@
- _10 = Lt(_8, _9);
- assert(move _10, "index out of bounds: the length is {} but the index is {}", move _9, _8) -> [success: bb3, unwind unreachable];
+ _9 = const N;
+ _10 = Lt(_1, const N);
+ assert(move _10, "index out of bounds: the length is {} but the index is {}", const N, _1) -> [success: bb3, unwind unreachable];
+ _10 = _3;
+ assert(_3, "index out of bounds: the length is {} but the index is {}", const N, _1) -> [success: bb3, unwind unreachable];
}
bb3: {
@ -57,14 +61,16 @@
}
bb4: {
StorageDead(_5);
- StorageDead(_5);
+ nop;
StorageDead(_4);
_0 = const 42_u8;
goto -> bb5;
}
bb5: {
StorageDead(_3);
- StorageDead(_3);
+ nop;
return;
}
}

View File

@ -15,10 +15,12 @@
let mut _10: bool;
bb0: {
StorageLive(_3);
- StorageLive(_3);
+ nop;
StorageLive(_4);
_4 = _1;
StorageLive(_5);
- StorageLive(_5);
+ nop;
StorageLive(_6);
StorageLive(_7);
_7 = &(*_2);
@ -32,12 +34,14 @@
bb1: {
StorageDead(_6);
- _3 = Lt(move _4, move _5);
+ _3 = Lt(_1, move _5);
switchInt(move _3) -> [0: bb4, otherwise: bb2];
- switchInt(move _3) -> [0: bb4, otherwise: bb2];
+ _3 = Lt(_1, const N);
+ switchInt(_3) -> [0: bb4, otherwise: bb2];
}
bb2: {
StorageDead(_5);
- StorageDead(_5);
+ nop;
StorageDead(_4);
StorageLive(_8);
_8 = _1;
@ -45,8 +49,8 @@
- _10 = Lt(_8, _9);
- assert(move _10, "index out of bounds: the length is {} but the index is {}", move _9, _8) -> [success: bb3, unwind continue];
+ _9 = const N;
+ _10 = Lt(_1, const N);
+ assert(move _10, "index out of bounds: the length is {} but the index is {}", const N, _1) -> [success: bb3, unwind continue];
+ _10 = _3;
+ assert(_3, "index out of bounds: the length is {} but the index is {}", const N, _1) -> [success: bb3, unwind continue];
}
bb3: {
@ -57,14 +61,16 @@
}
bb4: {
StorageDead(_5);
- StorageDead(_5);
+ nop;
StorageDead(_4);
_0 = const 42_u8;
goto -> bb5;
}
bb5: {
StorageDead(_3);
- StorageDead(_3);
+ nop;
return;
}
}

View File

@ -18,10 +18,12 @@
let mut _13: bool;
bb0: {
StorageLive(_3);
- StorageLive(_3);
+ nop;
StorageLive(_4);
_4 = _1;
StorageLive(_5);
- StorageLive(_5);
+ nop;
StorageLive(_6);
StorageLive(_7);
_7 = &(*_2);
@ -35,12 +37,14 @@
bb1: {
StorageDead(_6);
- _3 = Lt(move _4, move _5);
+ _3 = Lt(_1, move _5);
switchInt(move _3) -> [0: bb4, otherwise: bb2];
- switchInt(move _3) -> [0: bb4, otherwise: bb2];
+ _3 = Lt(_1, const N);
+ switchInt(_3) -> [0: bb4, otherwise: bb2];
}
bb2: {
StorageDead(_5);
- StorageDead(_5);
+ nop;
StorageDead(_4);
StorageLive(_8);
_8 = _1;
@ -48,8 +52,8 @@
- _10 = Lt(_8, _9);
- assert(move _10, "index out of bounds: the length is {} but the index is {}", move _9, _8) -> [success: bb3, unwind unreachable];
+ _9 = const N;
+ _10 = Lt(_1, const N);
+ assert(move _10, "index out of bounds: the length is {} but the index is {}", const N, _1) -> [success: bb3, unwind unreachable];
+ _10 = _3;
+ assert(_3, "index out of bounds: the length is {} but the index is {}", const N, _1) -> [success: bb3, unwind unreachable];
}
bb3: {
@ -60,7 +64,8 @@
}
bb4: {
StorageDead(_5);
- StorageDead(_5);
+ nop;
StorageDead(_4);
StorageLive(_11);
_11 = const 0_usize;
@ -81,7 +86,8 @@
}
bb6: {
StorageDead(_3);
- StorageDead(_3);
+ nop;
return;
}
}

View File

@ -18,10 +18,12 @@
let mut _13: bool;
bb0: {
StorageLive(_3);
- StorageLive(_3);
+ nop;
StorageLive(_4);
_4 = _1;
StorageLive(_5);
- StorageLive(_5);
+ nop;
StorageLive(_6);
StorageLive(_7);
_7 = &(*_2);
@ -35,12 +37,14 @@
bb1: {
StorageDead(_6);
- _3 = Lt(move _4, move _5);
+ _3 = Lt(_1, move _5);
switchInt(move _3) -> [0: bb4, otherwise: bb2];
- switchInt(move _3) -> [0: bb4, otherwise: bb2];
+ _3 = Lt(_1, const N);
+ switchInt(_3) -> [0: bb4, otherwise: bb2];
}
bb2: {
StorageDead(_5);
- StorageDead(_5);
+ nop;
StorageDead(_4);
StorageLive(_8);
_8 = _1;
@ -48,8 +52,8 @@
- _10 = Lt(_8, _9);
- assert(move _10, "index out of bounds: the length is {} but the index is {}", move _9, _8) -> [success: bb3, unwind continue];
+ _9 = const N;
+ _10 = Lt(_1, const N);
+ assert(move _10, "index out of bounds: the length is {} but the index is {}", const N, _1) -> [success: bb3, unwind continue];
+ _10 = _3;
+ assert(_3, "index out of bounds: the length is {} but the index is {}", const N, _1) -> [success: bb3, unwind continue];
}
bb3: {
@ -60,7 +64,8 @@
}
bb4: {
StorageDead(_5);
- StorageDead(_5);
+ nop;
StorageDead(_4);
StorageLive(_11);
_11 = const 0_usize;
@ -81,7 +86,8 @@
}
bb6: {
StorageDead(_3);
- StorageDead(_3);
+ nop;
return;
}
}

View File

@ -5,16 +5,20 @@
// EMIT_MIR lower_array_len.array_bound.GVN.diff
pub fn array_bound<const N: usize>(index: usize, slice: &[u8; N]) -> u8 {
// CHECK-LABEL: fn array_bound(
// CHECK: [[len:_.*]] = const N;
// CHECK: Lt(_1, move [[len]]);
// CHECK-NOT: Lt
// CHECK: Lt(_1, const N);
// CHECK-NOT: Lt
if index < slice.len() { slice[index] } else { 42 }
}
// EMIT_MIR lower_array_len.array_bound_mut.GVN.diff
pub fn array_bound_mut<const N: usize>(index: usize, slice: &mut [u8; N]) -> u8 {
// CHECK-LABEL: fn array_bound_mut(
// CHECK: [[len:_.*]] = const N;
// CHECK: Lt(_1, move [[len]]);
// CHECK-NOT: Lt
// CHECK: Lt(_1, const N);
// CHECK-NOT: Lt
// CHECK: Lt(const 0_usize, const N)
// CHECK-NOT: Lt
if index < slice.len() {
slice[index]
} else {

View File

@ -7,19 +7,90 @@ fn reverse_loop(_1: &[T], _2: impl Fn(&T)) -> () {
let mut _11: std::slice::Iter<'_, T>;
let mut _12: std::iter::Rev<std::slice::Iter<'_, T>>;
let mut _13: std::iter::Rev<std::slice::Iter<'_, T>>;
let mut _15: std::option::Option<&T>;
let mut _16: isize;
let mut _18: &impl Fn(&T);
let mut _19: (&T,);
let _20: ();
let mut _37: std::option::Option<&T>;
let mut _39: &impl Fn(&T);
let mut _40: (&T,);
let _41: ();
scope 1 {
debug iter => _13;
let _17: &T;
let _38: &T;
scope 2 {
debug x => _17;
debug x => _38;
}
scope 17 (inlined <Rev<std::slice::Iter<'_, T>> as Iterator>::next) {
let mut _14: &mut std::slice::Iter<'_, T>;
scope 18 (inlined <std::slice::Iter<'_, T> as DoubleEndedIterator>::next_back) {
let mut _14: *const *const T;
let mut _15: *const std::ptr::NonNull<T>;
let mut _20: bool;
let mut _21: *const T;
let _36: &T;
scope 19 {
let _16: std::ptr::NonNull<T>;
let _22: usize;
scope 20 {
}
scope 21 {
scope 25 (inlined <NonNull<T> as PartialEq>::eq) {
let mut _17: std::ptr::NonNull<T>;
scope 26 (inlined NonNull::<T>::as_ptr) {
let mut _18: *const T;
}
scope 27 (inlined NonNull::<T>::as_ptr) {
let mut _19: *const T;
}
}
}
scope 22 (inlined std::ptr::const_ptr::<impl *const T>::addr) {
scope 23 (inlined std::ptr::const_ptr::<impl *const T>::cast::<()>) {
}
}
scope 24 (inlined std::ptr::const_ptr::<impl *const *const T>::cast::<NonNull<T>>) {
}
}
scope 28 (inlined std::slice::Iter::<'_, T>::next_back_unchecked) {
let _29: std::ptr::NonNull<T>;
scope 29 (inlined std::slice::Iter::<'_, T>::pre_dec_end) {
let mut _23: *mut *const T;
let mut _24: *mut std::ptr::NonNull<T>;
let mut _25: std::ptr::NonNull<T>;
let mut _28: std::ptr::NonNull<T>;
let mut _30: *mut *const T;
let mut _31: *mut usize;
let mut _32: usize;
let mut _33: usize;
scope 30 {
scope 31 {
}
scope 32 {
scope 35 (inlined NonNull::<T>::sub) {
scope 36 (inlined core::num::<impl isize>::unchecked_neg) {
scope 37 (inlined core::ub_checks::check_language_ub) {
scope 38 (inlined core::ub_checks::check_language_ub::runtime) {
}
}
}
scope 39 (inlined NonNull::<T>::offset) {
let mut _26: *const T;
let mut _27: *const T;
}
}
}
scope 33 (inlined std::ptr::mut_ptr::<impl *mut *const T>::cast::<usize>) {
}
scope 34 (inlined std::ptr::mut_ptr::<impl *mut *const T>::cast::<NonNull<T>>) {
}
}
}
scope 40 (inlined NonNull::<T>::as_ref::<'_>) {
let mut _34: std::ptr::NonNull<T>;
scope 41 (inlined NonNull::<T>::as_ptr) {
let mut _35: *const T;
}
scope 42 (inlined std::ptr::mut_ptr::<impl *mut T>::cast_const) {
}
}
}
}
}
}
scope 3 (inlined core::slice::<impl [T]>::iter) {
@ -107,45 +178,147 @@ fn reverse_loop(_1: &[T], _2: impl Fn(&T)) -> () {
}
bb4: {
StorageLive(_15);
StorageLive(_14);
_14 = &mut (_13.0: std::slice::Iter<'_, T>);
_15 = <std::slice::Iter<'_, T> as DoubleEndedIterator>::next_back(move _14) -> [return: bb5, unwind unreachable];
StorageLive(_37);
StorageLive(_22);
StorageLive(_21);
StorageLive(_16);
StorageLive(_36);
StorageLive(_20);
switchInt(const <T as std::mem::SizedTypeProperties>::IS_ZST) -> [0: bb5, otherwise: bb6];
}
bb5: {
StorageLive(_15);
StorageLive(_14);
_14 = &raw const ((_13.0: std::slice::Iter<'_, T>).1: *const T);
_15 = _14 as *const std::ptr::NonNull<T> (PtrToPtr);
StorageDead(_14);
_16 = discriminant(_15);
switchInt(move _16) -> [0: bb6, 1: bb8, otherwise: bb10];
_16 = (*_15);
StorageDead(_15);
StorageLive(_18);
StorageLive(_19);
StorageLive(_17);
_17 = ((_13.0: std::slice::Iter<'_, T>).0: std::ptr::NonNull<T>);
_18 = (_17.0: *const T);
StorageDead(_17);
_19 = (_16.0: *const T);
_20 = Eq(_18, _19);
StorageDead(_19);
StorageDead(_18);
goto -> bb7;
}
bb6: {
StorageDead(_15);
StorageDead(_13);
drop(_2) -> [return: bb7, unwind unreachable];
_21 = ((_13.0: std::slice::Iter<'_, T>).1: *const T);
_22 = _21 as usize (Transmute);
_20 = Eq(_22, const 0_usize);
goto -> bb7;
}
bb7: {
return;
switchInt(move _20) -> [0: bb8, otherwise: bb16];
}
bb8: {
_17 = ((_15 as Some).0: &T);
StorageLive(_18);
_18 = &_2;
StorageLive(_19);
_19 = (_17,);
_20 = <impl Fn(&T) as Fn<(&T,)>>::call(move _18, move _19) -> [return: bb9, unwind unreachable];
StorageLive(_35);
StorageLive(_29);
StorageLive(_31);
StorageLive(_24);
switchInt(const <T as std::mem::SizedTypeProperties>::IS_ZST) -> [0: bb9, otherwise: bb13];
}
bb9: {
StorageDead(_19);
StorageDead(_18);
StorageDead(_15);
goto -> bb4;
StorageLive(_23);
_23 = &raw mut ((_13.0: std::slice::Iter<'_, T>).1: *const T);
_24 = _23 as *mut std::ptr::NonNull<T> (PtrToPtr);
StorageDead(_23);
StorageLive(_28);
_25 = (*_24);
switchInt(const <T as std::mem::SizedTypeProperties>::IS_ZST) -> [0: bb10, otherwise: bb11];
}
bb10: {
unreachable;
StorageLive(_27);
StorageLive(_26);
_26 = (_25.0: *const T);
_27 = Offset(move _26, const -1_isize);
StorageDead(_26);
_28 = NonNull::<T> { pointer: move _27 };
StorageDead(_27);
goto -> bb12;
}
bb11: {
_28 = _25;
goto -> bb12;
}
bb12: {
(*_24) = move _28;
StorageDead(_28);
_29 = (*_24);
goto -> bb14;
}
bb13: {
StorageLive(_30);
_30 = &raw mut ((_13.0: std::slice::Iter<'_, T>).1: *const T);
_31 = _30 as *mut usize (PtrToPtr);
StorageDead(_30);
StorageLive(_33);
StorageLive(_32);
_32 = (*_31);
_33 = SubUnchecked(move _32, const 1_usize);
StorageDead(_32);
(*_31) = move _33;
StorageDead(_33);
_29 = ((_13.0: std::slice::Iter<'_, T>).0: std::ptr::NonNull<T>);
goto -> bb14;
}
bb14: {
StorageDead(_24);
StorageDead(_31);
StorageLive(_34);
_34 = _29;
_35 = (_34.0: *const T);
StorageDead(_34);
_36 = &(*_35);
StorageDead(_29);
StorageDead(_35);
_37 = Option::<&T>::Some(_36);
StorageDead(_20);
StorageDead(_36);
StorageDead(_16);
StorageDead(_21);
StorageDead(_22);
_38 = ((_37 as Some).0: &T);
StorageLive(_39);
_39 = &_2;
StorageLive(_40);
_40 = (_38,);
_41 = <impl Fn(&T) as Fn<(&T,)>>::call(move _39, move _40) -> [return: bb15, unwind unreachable];
}
bb15: {
StorageDead(_40);
StorageDead(_39);
StorageDead(_37);
goto -> bb4;
}
bb16: {
StorageDead(_20);
StorageDead(_36);
StorageDead(_16);
StorageDead(_21);
StorageDead(_22);
StorageDead(_37);
StorageDead(_13);
drop(_2) -> [return: bb17, unwind unreachable];
}
bb17: {
return;
}
}

View File

@ -7,19 +7,90 @@ fn reverse_loop(_1: &[T], _2: impl Fn(&T)) -> () {
let mut _11: std::slice::Iter<'_, T>;
let mut _12: std::iter::Rev<std::slice::Iter<'_, T>>;
let mut _13: std::iter::Rev<std::slice::Iter<'_, T>>;
let mut _15: std::option::Option<&T>;
let mut _16: isize;
let mut _18: &impl Fn(&T);
let mut _19: (&T,);
let _20: ();
let mut _37: std::option::Option<&T>;
let mut _39: &impl Fn(&T);
let mut _40: (&T,);
let _41: ();
scope 1 {
debug iter => _13;
let _17: &T;
let _38: &T;
scope 2 {
debug x => _17;
debug x => _38;
}
scope 17 (inlined <Rev<std::slice::Iter<'_, T>> as Iterator>::next) {
let mut _14: &mut std::slice::Iter<'_, T>;
scope 18 (inlined <std::slice::Iter<'_, T> as DoubleEndedIterator>::next_back) {
let mut _14: *const *const T;
let mut _15: *const std::ptr::NonNull<T>;
let mut _20: bool;
let mut _21: *const T;
let _36: &T;
scope 19 {
let _16: std::ptr::NonNull<T>;
let _22: usize;
scope 20 {
}
scope 21 {
scope 25 (inlined <NonNull<T> as PartialEq>::eq) {
let mut _17: std::ptr::NonNull<T>;
scope 26 (inlined NonNull::<T>::as_ptr) {
let mut _18: *const T;
}
scope 27 (inlined NonNull::<T>::as_ptr) {
let mut _19: *const T;
}
}
}
scope 22 (inlined std::ptr::const_ptr::<impl *const T>::addr) {
scope 23 (inlined std::ptr::const_ptr::<impl *const T>::cast::<()>) {
}
}
scope 24 (inlined std::ptr::const_ptr::<impl *const *const T>::cast::<NonNull<T>>) {
}
}
scope 28 (inlined std::slice::Iter::<'_, T>::next_back_unchecked) {
let _29: std::ptr::NonNull<T>;
scope 29 (inlined std::slice::Iter::<'_, T>::pre_dec_end) {
let mut _23: *mut *const T;
let mut _24: *mut std::ptr::NonNull<T>;
let mut _25: std::ptr::NonNull<T>;
let mut _28: std::ptr::NonNull<T>;
let mut _30: *mut *const T;
let mut _31: *mut usize;
let mut _32: usize;
let mut _33: usize;
scope 30 {
scope 31 {
}
scope 32 {
scope 35 (inlined NonNull::<T>::sub) {
scope 36 (inlined core::num::<impl isize>::unchecked_neg) {
scope 37 (inlined core::ub_checks::check_language_ub) {
scope 38 (inlined core::ub_checks::check_language_ub::runtime) {
}
}
}
scope 39 (inlined NonNull::<T>::offset) {
let mut _26: *const T;
let mut _27: *const T;
}
}
}
scope 33 (inlined std::ptr::mut_ptr::<impl *mut *const T>::cast::<usize>) {
}
scope 34 (inlined std::ptr::mut_ptr::<impl *mut *const T>::cast::<NonNull<T>>) {
}
}
}
scope 40 (inlined NonNull::<T>::as_ref::<'_>) {
let mut _34: std::ptr::NonNull<T>;
scope 41 (inlined NonNull::<T>::as_ptr) {
let mut _35: *const T;
}
scope 42 (inlined std::ptr::mut_ptr::<impl *mut T>::cast_const) {
}
}
}
}
}
}
scope 3 (inlined core::slice::<impl [T]>::iter) {
@ -107,53 +178,155 @@ fn reverse_loop(_1: &[T], _2: impl Fn(&T)) -> () {
}
bb4: {
StorageLive(_15);
StorageLive(_14);
_14 = &mut (_13.0: std::slice::Iter<'_, T>);
_15 = <std::slice::Iter<'_, T> as DoubleEndedIterator>::next_back(move _14) -> [return: bb5, unwind: bb11];
StorageLive(_37);
StorageLive(_22);
StorageLive(_21);
StorageLive(_16);
StorageLive(_36);
StorageLive(_20);
switchInt(const <T as std::mem::SizedTypeProperties>::IS_ZST) -> [0: bb5, otherwise: bb6];
}
bb5: {
StorageLive(_15);
StorageLive(_14);
_14 = &raw const ((_13.0: std::slice::Iter<'_, T>).1: *const T);
_15 = _14 as *const std::ptr::NonNull<T> (PtrToPtr);
StorageDead(_14);
_16 = discriminant(_15);
switchInt(move _16) -> [0: bb6, 1: bb8, otherwise: bb10];
_16 = (*_15);
StorageDead(_15);
StorageLive(_18);
StorageLive(_19);
StorageLive(_17);
_17 = ((_13.0: std::slice::Iter<'_, T>).0: std::ptr::NonNull<T>);
_18 = (_17.0: *const T);
StorageDead(_17);
_19 = (_16.0: *const T);
_20 = Eq(_18, _19);
StorageDead(_19);
StorageDead(_18);
goto -> bb7;
}
bb6: {
StorageDead(_15);
StorageDead(_13);
drop(_2) -> [return: bb7, unwind continue];
_21 = ((_13.0: std::slice::Iter<'_, T>).1: *const T);
_22 = _21 as usize (Transmute);
_20 = Eq(_22, const 0_usize);
goto -> bb7;
}
bb7: {
return;
switchInt(move _20) -> [0: bb8, otherwise: bb18];
}
bb8: {
_17 = ((_15 as Some).0: &T);
StorageLive(_18);
_18 = &_2;
StorageLive(_19);
_19 = (_17,);
_20 = <impl Fn(&T) as Fn<(&T,)>>::call(move _18, move _19) -> [return: bb9, unwind: bb11];
StorageLive(_35);
StorageLive(_29);
StorageLive(_31);
StorageLive(_24);
switchInt(const <T as std::mem::SizedTypeProperties>::IS_ZST) -> [0: bb9, otherwise: bb13];
}
bb9: {
StorageDead(_19);
StorageDead(_18);
StorageDead(_15);
goto -> bb4;
StorageLive(_23);
_23 = &raw mut ((_13.0: std::slice::Iter<'_, T>).1: *const T);
_24 = _23 as *mut std::ptr::NonNull<T> (PtrToPtr);
StorageDead(_23);
StorageLive(_28);
_25 = (*_24);
switchInt(const <T as std::mem::SizedTypeProperties>::IS_ZST) -> [0: bb10, otherwise: bb11];
}
bb10: {
unreachable;
StorageLive(_27);
StorageLive(_26);
_26 = (_25.0: *const T);
_27 = Offset(move _26, const -1_isize);
StorageDead(_26);
_28 = NonNull::<T> { pointer: move _27 };
StorageDead(_27);
goto -> bb12;
}
bb11 (cleanup): {
drop(_2) -> [return: bb12, unwind terminate(cleanup)];
bb11: {
_28 = _25;
goto -> bb12;
}
bb12 (cleanup): {
bb12: {
(*_24) = move _28;
StorageDead(_28);
_29 = (*_24);
goto -> bb14;
}
bb13: {
StorageLive(_30);
_30 = &raw mut ((_13.0: std::slice::Iter<'_, T>).1: *const T);
_31 = _30 as *mut usize (PtrToPtr);
StorageDead(_30);
StorageLive(_33);
StorageLive(_32);
_32 = (*_31);
_33 = SubUnchecked(move _32, const 1_usize);
StorageDead(_32);
(*_31) = move _33;
StorageDead(_33);
_29 = ((_13.0: std::slice::Iter<'_, T>).0: std::ptr::NonNull<T>);
goto -> bb14;
}
bb14: {
StorageDead(_24);
StorageDead(_31);
StorageLive(_34);
_34 = _29;
_35 = (_34.0: *const T);
StorageDead(_34);
_36 = &(*_35);
StorageDead(_29);
StorageDead(_35);
_37 = Option::<&T>::Some(_36);
StorageDead(_20);
StorageDead(_36);
StorageDead(_16);
StorageDead(_21);
StorageDead(_22);
_38 = ((_37 as Some).0: &T);
StorageLive(_39);
_39 = &_2;
StorageLive(_40);
_40 = (_38,);
_41 = <impl Fn(&T) as Fn<(&T,)>>::call(move _39, move _40) -> [return: bb15, unwind: bb16];
}
bb15: {
StorageDead(_40);
StorageDead(_39);
StorageDead(_37);
goto -> bb4;
}
bb16 (cleanup): {
drop(_2) -> [return: bb17, unwind terminate(cleanup)];
}
bb17 (cleanup): {
resume;
}
bb18: {
StorageDead(_20);
StorageDead(_36);
StorageDead(_16);
StorageDead(_21);
StorageDead(_22);
StorageDead(_37);
StorageDead(_13);
drop(_2) -> [return: bb19, unwind continue];
}
bb19: {
return;
}
}

View File

@ -1,8 +1,10 @@
// skip-filecheck
//@ compile-flags: -O -C debuginfo=0 -Zmir-opt-level=2
//@ only-64bit (constants for `None::<&T>` show in the output)
// EMIT_MIR_FOR_EACH_PANIC_STRATEGY
#![crate_type = "lib"]
#![feature(exact_size_is_empty)]
// When this test was added, the MIR for `next` was 174 lines just for the basic
// blocks -- far more if you counted the scopes. The goal of having this here
@ -13,6 +15,11 @@
// As such, feel free to `--bless` whatever changes you get here, so long as
// doing so doesn't add substantially more MIR.
// EMIT_MIR slice_iter.slice_iter_generic_is_empty.PreCodegen.after.mir
pub fn slice_iter_generic_is_empty<T>(it: &std::slice::Iter<'_, T>) -> bool {
it.is_empty()
}
// EMIT_MIR slice_iter.slice_iter_next.PreCodegen.after.mir
pub fn slice_iter_next<'a, T>(it: &mut std::slice::Iter<'a, T>) -> Option<&'a T> {
it.next()

View File

@ -0,0 +1,76 @@
// MIR for `slice_iter_generic_is_empty` after PreCodegen
fn slice_iter_generic_is_empty(_1: &std::slice::Iter<'_, T>) -> bool {
debug it => _1;
let mut _0: bool;
scope 1 (inlined <std::slice::Iter<'_, T> as ExactSizeIterator>::is_empty) {
let mut _2: *const *const T;
let mut _3: *const std::ptr::NonNull<T>;
let mut _8: *const T;
scope 2 {
let _4: std::ptr::NonNull<T>;
let _9: usize;
scope 3 {
}
scope 4 {
scope 8 (inlined <NonNull<T> as PartialEq>::eq) {
let mut _5: std::ptr::NonNull<T>;
scope 9 (inlined NonNull::<T>::as_ptr) {
let mut _6: *const T;
}
scope 10 (inlined NonNull::<T>::as_ptr) {
let mut _7: *const T;
}
}
}
scope 5 (inlined std::ptr::const_ptr::<impl *const T>::addr) {
scope 6 (inlined std::ptr::const_ptr::<impl *const T>::cast::<()>) {
}
}
scope 7 (inlined std::ptr::const_ptr::<impl *const *const T>::cast::<NonNull<T>>) {
}
}
}
bb0: {
StorageLive(_9);
StorageLive(_8);
StorageLive(_4);
switchInt(const <T as std::mem::SizedTypeProperties>::IS_ZST) -> [0: bb1, otherwise: bb2];
}
bb1: {
StorageLive(_3);
StorageLive(_2);
_2 = &raw const ((*_1).1: *const T);
_3 = _2 as *const std::ptr::NonNull<T> (PtrToPtr);
StorageDead(_2);
_4 = (*_3);
StorageDead(_3);
StorageLive(_6);
StorageLive(_7);
StorageLive(_5);
_5 = ((*_1).0: std::ptr::NonNull<T>);
_6 = (_5.0: *const T);
StorageDead(_5);
_7 = (_4.0: *const T);
_0 = Eq(_6, _7);
StorageDead(_7);
StorageDead(_6);
goto -> bb3;
}
bb2: {
_8 = ((*_1).1: *const T);
_9 = _8 as usize (Transmute);
_0 = Eq(_9, const 0_usize);
goto -> bb3;
}
bb3: {
StorageDead(_4);
StorageDead(_8);
StorageDead(_9);
return;
}
}

View File

@ -0,0 +1,76 @@
// MIR for `slice_iter_generic_is_empty` after PreCodegen
fn slice_iter_generic_is_empty(_1: &std::slice::Iter<'_, T>) -> bool {
debug it => _1;
let mut _0: bool;
scope 1 (inlined <std::slice::Iter<'_, T> as ExactSizeIterator>::is_empty) {
let mut _2: *const *const T;
let mut _3: *const std::ptr::NonNull<T>;
let mut _8: *const T;
scope 2 {
let _4: std::ptr::NonNull<T>;
let _9: usize;
scope 3 {
}
scope 4 {
scope 8 (inlined <NonNull<T> as PartialEq>::eq) {
let mut _5: std::ptr::NonNull<T>;
scope 9 (inlined NonNull::<T>::as_ptr) {
let mut _6: *const T;
}
scope 10 (inlined NonNull::<T>::as_ptr) {
let mut _7: *const T;
}
}
}
scope 5 (inlined std::ptr::const_ptr::<impl *const T>::addr) {
scope 6 (inlined std::ptr::const_ptr::<impl *const T>::cast::<()>) {
}
}
scope 7 (inlined std::ptr::const_ptr::<impl *const *const T>::cast::<NonNull<T>>) {
}
}
}
bb0: {
StorageLive(_9);
StorageLive(_8);
StorageLive(_4);
switchInt(const <T as std::mem::SizedTypeProperties>::IS_ZST) -> [0: bb1, otherwise: bb2];
}
bb1: {
StorageLive(_3);
StorageLive(_2);
_2 = &raw const ((*_1).1: *const T);
_3 = _2 as *const std::ptr::NonNull<T> (PtrToPtr);
StorageDead(_2);
_4 = (*_3);
StorageDead(_3);
StorageLive(_6);
StorageLive(_7);
StorageLive(_5);
_5 = ((*_1).0: std::ptr::NonNull<T>);
_6 = (_5.0: *const T);
StorageDead(_5);
_7 = (_4.0: *const T);
_0 = Eq(_6, _7);
StorageDead(_7);
StorageDead(_6);
goto -> bb3;
}
bb2: {
_8 = ((*_1).1: *const T);
_9 = _8 as usize (Transmute);
_0 = Eq(_9, const 0_usize);
goto -> bb3;
}
bb3: {
StorageDead(_4);
StorageDead(_8);
StorageDead(_9);
return;
}
}

View File

@ -3,12 +3,205 @@
fn slice_iter_mut_next_back(_1: &mut std::slice::IterMut<'_, T>) -> Option<&mut T> {
debug it => _1;
let mut _0: std::option::Option<&mut T>;
scope 1 (inlined <std::slice::IterMut<'_, T> as DoubleEndedIterator>::next_back) {
let mut _2: *const *mut T;
let mut _3: *const std::ptr::NonNull<T>;
let mut _8: bool;
let mut _9: *mut T;
let mut _25: &mut T;
scope 2 {
let _4: std::ptr::NonNull<T>;
let _10: usize;
scope 3 {
}
scope 4 {
scope 8 (inlined <NonNull<T> as PartialEq>::eq) {
let mut _5: std::ptr::NonNull<T>;
scope 9 (inlined NonNull::<T>::as_ptr) {
let mut _6: *const T;
}
scope 10 (inlined NonNull::<T>::as_ptr) {
let mut _7: *const T;
}
}
}
scope 5 (inlined std::ptr::mut_ptr::<impl *mut T>::addr) {
scope 6 (inlined std::ptr::mut_ptr::<impl *mut T>::cast::<()>) {
}
}
scope 7 (inlined std::ptr::const_ptr::<impl *const *mut T>::cast::<NonNull<T>>) {
}
}
scope 11 (inlined std::slice::IterMut::<'_, T>::next_back_unchecked) {
let mut _17: std::ptr::NonNull<T>;
scope 12 (inlined std::slice::IterMut::<'_, T>::pre_dec_end) {
let mut _11: *mut *mut T;
let mut _12: *mut std::ptr::NonNull<T>;
let mut _13: std::ptr::NonNull<T>;
let mut _16: std::ptr::NonNull<T>;
let mut _18: *mut *mut T;
let mut _19: *mut usize;
let mut _20: usize;
let mut _21: usize;
scope 13 {
scope 14 {
}
scope 15 {
scope 18 (inlined NonNull::<T>::sub) {
scope 19 (inlined core::num::<impl isize>::unchecked_neg) {
scope 20 (inlined core::ub_checks::check_language_ub) {
scope 21 (inlined core::ub_checks::check_language_ub::runtime) {
}
}
}
scope 22 (inlined NonNull::<T>::offset) {
let mut _14: *const T;
let mut _15: *const T;
}
}
}
scope 16 (inlined std::ptr::mut_ptr::<impl *mut *mut T>::cast::<usize>) {
}
scope 17 (inlined std::ptr::mut_ptr::<impl *mut *mut T>::cast::<NonNull<T>>) {
}
}
}
scope 23 (inlined NonNull::<T>::as_mut::<'_>) {
let mut _22: std::ptr::NonNull<T>;
let mut _24: *mut T;
scope 24 (inlined NonNull::<T>::as_ptr) {
let mut _23: *const T;
}
}
}
}
bb0: {
_0 = <std::slice::IterMut<'_, T> as DoubleEndedIterator>::next_back(move _1) -> [return: bb1, unwind unreachable];
StorageLive(_10);
StorageLive(_9);
StorageLive(_4);
StorageLive(_25);
StorageLive(_8);
switchInt(const <T as std::mem::SizedTypeProperties>::IS_ZST) -> [0: bb1, otherwise: bb2];
}
bb1: {
StorageLive(_3);
StorageLive(_2);
_2 = &raw const ((*_1).1: *mut T);
_3 = _2 as *const std::ptr::NonNull<T> (PtrToPtr);
StorageDead(_2);
_4 = (*_3);
StorageDead(_3);
StorageLive(_6);
StorageLive(_7);
StorageLive(_5);
_5 = ((*_1).0: std::ptr::NonNull<T>);
_6 = (_5.0: *const T);
StorageDead(_5);
_7 = (_4.0: *const T);
_8 = Eq(_6, _7);
StorageDead(_7);
StorageDead(_6);
goto -> bb3;
}
bb2: {
_9 = ((*_1).1: *mut T);
_10 = _9 as usize (Transmute);
_8 = Eq(_10, const 0_usize);
goto -> bb3;
}
bb3: {
switchInt(move _8) -> [0: bb4, otherwise: bb11];
}
bb4: {
StorageLive(_24);
StorageLive(_17);
StorageLive(_19);
StorageLive(_12);
switchInt(const <T as std::mem::SizedTypeProperties>::IS_ZST) -> [0: bb5, otherwise: bb9];
}
bb5: {
StorageLive(_11);
_11 = &raw mut ((*_1).1: *mut T);
_12 = _11 as *mut std::ptr::NonNull<T> (PtrToPtr);
StorageDead(_11);
StorageLive(_16);
_13 = (*_12);
switchInt(const <T as std::mem::SizedTypeProperties>::IS_ZST) -> [0: bb6, otherwise: bb7];
}
bb6: {
StorageLive(_15);
StorageLive(_14);
_14 = (_13.0: *const T);
_15 = Offset(move _14, const -1_isize);
StorageDead(_14);
_16 = NonNull::<T> { pointer: move _15 };
StorageDead(_15);
goto -> bb8;
}
bb7: {
_16 = _13;
goto -> bb8;
}
bb8: {
(*_12) = move _16;
StorageDead(_16);
_17 = (*_12);
goto -> bb10;
}
bb9: {
StorageLive(_18);
_18 = &raw mut ((*_1).1: *mut T);
_19 = _18 as *mut usize (PtrToPtr);
StorageDead(_18);
StorageLive(_21);
StorageLive(_20);
_20 = (*_19);
_21 = SubUnchecked(move _20, const 1_usize);
StorageDead(_20);
(*_19) = move _21;
StorageDead(_21);
_17 = ((*_1).0: std::ptr::NonNull<T>);
goto -> bb10;
}
bb10: {
StorageDead(_12);
StorageDead(_19);
StorageLive(_22);
_22 = _17;
StorageLive(_23);
_23 = (_22.0: *const T);
_24 = move _23 as *mut T (PtrToPtr);
StorageDead(_23);
StorageDead(_22);
_25 = &mut (*_24);
StorageDead(_17);
StorageDead(_24);
_0 = Option::<&mut T>::Some(_25);
goto -> bb12;
}
bb11: {
_0 = const {transmute(0x0000000000000000): Option<&mut T>};
goto -> bb12;
}
bb12: {
StorageDead(_8);
StorageDead(_25);
StorageDead(_4);
StorageDead(_9);
StorageDead(_10);
return;
}
}

View File

@ -3,12 +3,205 @@
fn slice_iter_mut_next_back(_1: &mut std::slice::IterMut<'_, T>) -> Option<&mut T> {
debug it => _1;
let mut _0: std::option::Option<&mut T>;
scope 1 (inlined <std::slice::IterMut<'_, T> as DoubleEndedIterator>::next_back) {
let mut _2: *const *mut T;
let mut _3: *const std::ptr::NonNull<T>;
let mut _8: bool;
let mut _9: *mut T;
let mut _25: &mut T;
scope 2 {
let _4: std::ptr::NonNull<T>;
let _10: usize;
scope 3 {
}
scope 4 {
scope 8 (inlined <NonNull<T> as PartialEq>::eq) {
let mut _5: std::ptr::NonNull<T>;
scope 9 (inlined NonNull::<T>::as_ptr) {
let mut _6: *const T;
}
scope 10 (inlined NonNull::<T>::as_ptr) {
let mut _7: *const T;
}
}
}
scope 5 (inlined std::ptr::mut_ptr::<impl *mut T>::addr) {
scope 6 (inlined std::ptr::mut_ptr::<impl *mut T>::cast::<()>) {
}
}
scope 7 (inlined std::ptr::const_ptr::<impl *const *mut T>::cast::<NonNull<T>>) {
}
}
scope 11 (inlined std::slice::IterMut::<'_, T>::next_back_unchecked) {
let mut _17: std::ptr::NonNull<T>;
scope 12 (inlined std::slice::IterMut::<'_, T>::pre_dec_end) {
let mut _11: *mut *mut T;
let mut _12: *mut std::ptr::NonNull<T>;
let mut _13: std::ptr::NonNull<T>;
let mut _16: std::ptr::NonNull<T>;
let mut _18: *mut *mut T;
let mut _19: *mut usize;
let mut _20: usize;
let mut _21: usize;
scope 13 {
scope 14 {
}
scope 15 {
scope 18 (inlined NonNull::<T>::sub) {
scope 19 (inlined core::num::<impl isize>::unchecked_neg) {
scope 20 (inlined core::ub_checks::check_language_ub) {
scope 21 (inlined core::ub_checks::check_language_ub::runtime) {
}
}
}
scope 22 (inlined NonNull::<T>::offset) {
let mut _14: *const T;
let mut _15: *const T;
}
}
}
scope 16 (inlined std::ptr::mut_ptr::<impl *mut *mut T>::cast::<usize>) {
}
scope 17 (inlined std::ptr::mut_ptr::<impl *mut *mut T>::cast::<NonNull<T>>) {
}
}
}
scope 23 (inlined NonNull::<T>::as_mut::<'_>) {
let mut _22: std::ptr::NonNull<T>;
let mut _24: *mut T;
scope 24 (inlined NonNull::<T>::as_ptr) {
let mut _23: *const T;
}
}
}
}
bb0: {
_0 = <std::slice::IterMut<'_, T> as DoubleEndedIterator>::next_back(move _1) -> [return: bb1, unwind continue];
StorageLive(_10);
StorageLive(_9);
StorageLive(_4);
StorageLive(_25);
StorageLive(_8);
switchInt(const <T as std::mem::SizedTypeProperties>::IS_ZST) -> [0: bb1, otherwise: bb2];
}
bb1: {
StorageLive(_3);
StorageLive(_2);
_2 = &raw const ((*_1).1: *mut T);
_3 = _2 as *const std::ptr::NonNull<T> (PtrToPtr);
StorageDead(_2);
_4 = (*_3);
StorageDead(_3);
StorageLive(_6);
StorageLive(_7);
StorageLive(_5);
_5 = ((*_1).0: std::ptr::NonNull<T>);
_6 = (_5.0: *const T);
StorageDead(_5);
_7 = (_4.0: *const T);
_8 = Eq(_6, _7);
StorageDead(_7);
StorageDead(_6);
goto -> bb3;
}
bb2: {
_9 = ((*_1).1: *mut T);
_10 = _9 as usize (Transmute);
_8 = Eq(_10, const 0_usize);
goto -> bb3;
}
bb3: {
switchInt(move _8) -> [0: bb4, otherwise: bb11];
}
bb4: {
StorageLive(_24);
StorageLive(_17);
StorageLive(_19);
StorageLive(_12);
switchInt(const <T as std::mem::SizedTypeProperties>::IS_ZST) -> [0: bb5, otherwise: bb9];
}
bb5: {
StorageLive(_11);
_11 = &raw mut ((*_1).1: *mut T);
_12 = _11 as *mut std::ptr::NonNull<T> (PtrToPtr);
StorageDead(_11);
StorageLive(_16);
_13 = (*_12);
switchInt(const <T as std::mem::SizedTypeProperties>::IS_ZST) -> [0: bb6, otherwise: bb7];
}
bb6: {
StorageLive(_15);
StorageLive(_14);
_14 = (_13.0: *const T);
_15 = Offset(move _14, const -1_isize);
StorageDead(_14);
_16 = NonNull::<T> { pointer: move _15 };
StorageDead(_15);
goto -> bb8;
}
bb7: {
_16 = _13;
goto -> bb8;
}
bb8: {
(*_12) = move _16;
StorageDead(_16);
_17 = (*_12);
goto -> bb10;
}
bb9: {
StorageLive(_18);
_18 = &raw mut ((*_1).1: *mut T);
_19 = _18 as *mut usize (PtrToPtr);
StorageDead(_18);
StorageLive(_21);
StorageLive(_20);
_20 = (*_19);
_21 = SubUnchecked(move _20, const 1_usize);
StorageDead(_20);
(*_19) = move _21;
StorageDead(_21);
_17 = ((*_1).0: std::ptr::NonNull<T>);
goto -> bb10;
}
bb10: {
StorageDead(_12);
StorageDead(_19);
StorageLive(_22);
_22 = _17;
StorageLive(_23);
_23 = (_22.0: *const T);
_24 = move _23 as *mut T (PtrToPtr);
StorageDead(_23);
StorageDead(_22);
_25 = &mut (*_24);
StorageDead(_17);
StorageDead(_24);
_0 = Option::<&mut T>::Some(_25);
goto -> bb12;
}
bb11: {
_0 = const {transmute(0x0000000000000000): Option<&mut T>};
goto -> bb12;
}
bb12: {
StorageDead(_8);
StorageDead(_25);
StorageDead(_4);
StorageDead(_9);
StorageDead(_10);
return;
}
}