bjoernager/rust
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Don't reset cast kind without also updating the operand in simplify_cast

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This commit is contained in:
Michael Goulet 2025-02-02 18:57:59 +00:00
parent c215e80aa9
commit de7d4a840e
4 changed files with 15 additions and 13 deletions
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20
compiler/rustc_mir_transform/src/gvn.rs
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@ -1367,16 +1367,17 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
fn simplify_cast(
&mut self,
kind: &mut CastKind,
operand: &mut Operand<'tcx>,
initial_kind: &mut CastKind,
initial_operand: &mut Operand<'tcx>,
to: Ty<'tcx>,
location: Location,
) -> Option<VnIndex> {
use CastKind::*;
use rustc_middle::ty::adjustment::PointerCoercion::*;
let mut from = operand.ty(self.local_decls, self.tcx);
let mut value = self.simplify_operand(operand, location)?;
let mut from = initial_operand.ty(self.local_decls, self.tcx);
let mut kind = *initial_kind;
let mut value = self.simplify_operand(initial_operand, location)?;
if from == to {
return Some(value);
}
@ -1400,7 +1401,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
&& to.is_unsafe_ptr()
&& self.pointers_have_same_metadata(from, to)
{
*kind = PtrToPtr;
kind = PtrToPtr;
was_updated_this_iteration = true;
}
@ -1443,7 +1444,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
to: inner_to,
} = *self.get(value)
{
let new_kind = match (inner_kind, *kind) {
let new_kind = match (inner_kind, kind) {
// Even if there's a narrowing cast in here that's fine, because
// things like `*mut [i32] -> *mut i32 -> *const i32` and
// `*mut [i32] -> *const [i32] -> *const i32` can skip the middle in MIR.
@ -1471,7 +1472,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
_ => None,
};
if let Some(new_kind) = new_kind {
*kind = new_kind;
kind = new_kind;
from = inner_from;
value = inner_value;
was_updated_this_iteration = true;
@ -1489,10 +1490,11 @@ impl<'body, 'tcx> VnState<'body, 'tcx> {
}
if was_ever_updated && let Some(op) = self.try_as_operand(value, location) {
*operand = op;
*initial_operand = op;
*initial_kind = kind;
}
Some(self.insert(Value::Cast { kind: *kind, value, from, to }))
Some(self.insert(Value::Cast { kind, value, from, to }))
}
fn simplify_len(&mut self, place: &mut Place<'tcx>, location: Location) -> Option<VnIndex> {