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Auto merge of #15571 - Veykril:mir-alloc, r=Veykril
Remove allocation on mir eval memory write
| -rw-r--r-- | crates/hir-ty/src/mir/eval.rs | 46 |
1 files changed, 43 insertions, 3 deletions
diff --git a/crates/hir-ty/src/mir/eval.rs b/crates/hir-ty/src/mir/eval.rs index 3944feb128..5b267641a3 100644 --- a/crates/hir-ty/src/mir/eval.rs +++ b/crates/hir-ty/src/mir/eval.rs @@ -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 |