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Auto merge of #15571 - Veykril:mir-alloc, r=Veykril

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Remove allocation on mir eval memory write
This commit is contained in:
bors 2023-09-07 17:27:57 +00:00
commit d5b6ab2fa5
1 changed files with 43 additions and 3 deletions
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46
crates/hir-ty/src/mir/eval.rs
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@ -215,9 +215,7 @@ impl Interval {
}
fn write_from_interval(&self, memory: &mut Evaluator<'_>, interval: Interval) -> Result<()> {
// FIXME: this could be more efficient
let bytes = &interval.get(memory)?.to_vec();
memory.write_memory(self.addr, bytes)
memory.copy_from_interval(self.addr, interval)
}
fn slice(self, range: Range<usize>) -> Interval {
@ -1760,6 +1758,48 @@ impl Evaluator<'_> {
Ok(())
}
fn copy_from_interval(&mut self, addr: Address, r: Interval) -> Result<()> {
if r.size == 0 {
return Ok(());
}
let oob = || MirEvalError::UndefinedBehavior("out of bounds memory write".to_string());
match (addr, r.addr) {
(Stack(dst), Stack(src)) => {
if self.stack.len() < src + r.size || self.stack.len() < dst + r.size {
return Err(oob());
}
self.stack.copy_within(src..src + r.size, dst)
}
(Heap(dst), Heap(src)) => {
if self.stack.len() < src + r.size || self.stack.len() < dst + r.size {
return Err(oob());
}
self.heap.copy_within(src..src + r.size, dst)
}
(Stack(dst), Heap(src)) => {
self.stack
.get_mut(dst..dst + r.size)
.ok_or_else(oob)?
.copy_from_slice(self.heap.get(src..src + r.size).ok_or_else(oob)?);
}
(Heap(dst), Stack(src)) => {
self.heap
.get_mut(dst..dst + r.size)
.ok_or_else(oob)?
.copy_from_slice(self.stack.get(src..src + r.size).ok_or_else(oob)?);
}
_ => {
return Err(MirEvalError::UndefinedBehavior(format!(
"invalid memory write at address {addr:?}"
)))
}
}
Ok(())
}
fn size_align_of(&self, ty: &Ty, locals: &Locals) -> Result<Option<(usize, usize)>> {
if let Some(layout) = self.layout_cache.borrow().get(ty) {
return Ok(layout