bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Auto merge of #92419 - erikdesjardins:coldland, r=nagisa

Browse source 
Mark drop calls in landing pads `cold` instead of `noinline`

Now that deferred inlining has been disabled in LLVM (#92110), this shouldn't cause catastrophic size blowup.

I confirmed that the test cases from https://github.com/rust-lang/rust/issues/41696#issuecomment-298696944 still compile quickly (<1s) after this change. ~Although note that I wasn't able to reproduce the original issue using a recent rustc/llvm with deferred inlining enabled, so those tests may no longer be representative. I was also unable to create a modified test case that reproduced the original issue.~ (edit: I reproduced it on CI by accident--the first commit timed out on the LLVM 12 builder, because I forgot to make it conditional on LLVM version)

r? `@nagisa`
cc `@arielb1` (this effectively reverts #42771 "mark calls in the unwind path as !noinline")
cc `@RalfJung` (fixes #46515)

edit: also fixes #87055
This commit is contained in:
bors 2022-01-01 13:28:13 +00:00
commit 4f49627c6f
9 changed files with 80 additions and 9 deletions
Download patch file Download diff file Expand all files Collapse all files

6
compiler/rustc_codegen_ssa/src/mir/block.rs
View file

@ -160,11 +160,7 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
let llret = bx.call(fn_ty, fn_ptr, &llargs, self.funclet(fx));
bx.apply_attrs_callsite(&fn_abi, llret);
if fx.mir[self.bb].is_cleanup {
// Cleanup is always the cold path. Don't inline
// drop glue. Also, when there is a deeply-nested
// struct, there are "symmetry" issues that cause
// exponential inlining - see issue #41696.
bx.do_not_inline(llret);
bx.apply_attrs_to_cleanup_callsite(llret);
}
if let Some((ret_dest, target)) = destination {

2
compiler/rustc_codegen_ssa/src/traits/builder.rs
View file

@ -311,5 +311,5 @@ pub trait BuilderMethods<'a, 'tcx>:
) -> Self::Value;
fn zext(&mut self, val: Self::Value, dest_ty: Self::Type) -> Self::Value;
fn do_not_inline(&mut self, llret: Self::Value);
fn apply_attrs_to_cleanup_callsite(&mut self, llret: Self::Value);
}