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| author | Ariel Ben-Yehuda <arielb1@mail.tau.ac.il> | 2017-04-05 23:01:09 +0000 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2017-04-05 23:01:09 +0000 |
| commit | b712950d7b3a91e78d195adff49afb4a27abeb8d (patch) | |
| tree | 02770b3b6645580c61106ef78c3b13e67159679c | |
| parent | 9d074473da5fef4b1d9ebbbb7f181edcb7a365a0 (diff) | |
| parent | 09ac56d6efd41c02cbb7f8714d59bdd43f663ec8 (diff) | |
| download | rust-b712950d7b3a91e78d195adff49afb4a27abeb8d.tar.gz rust-b712950d7b3a91e78d195adff49afb4a27abeb8d.zip | |
Rollup merge of #41015 - arielb1:new-block-stack, r=alexcrichton
mark build::cfg::start_new_block as inline(never) LLVM has a bug - [PR32488](https://bugs.llvm.org//show_bug.cgi?id=32488) - where it fails to deduplicate allocas in some circumstances. The function `start_new_block` has allocas totalling 1216 bytes, and when LLVM inlines several copies of that function into the recursive function `expr::into`, that function's stack space usage goes into tens of kiBs, causing stack overflows. Mark `start_new_block` as inline(never) to keep it from being inlined, getting stack usage under control. Fixes #40493. Fixes #40573. r? @eddyb
| -rw-r--r-- | src/librustc_mir/build/cfg.rs | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/src/librustc_mir/build/cfg.rs b/src/librustc_mir/build/cfg.rs index 71e97e4bfe0..c503b8c7fe0 100644 --- a/src/librustc_mir/build/cfg.rs +++ b/src/librustc_mir/build/cfg.rs @@ -25,6 +25,9 @@ impl<'tcx> CFG<'tcx> { &mut self.basic_blocks[blk] } + // llvm.org/PR32488 makes this function use an excess of stack space. Mark + // it as #[inline(never)] to keep rustc's stack use in check. + #[inline(never)] pub fn start_new_block(&mut self) -> BasicBlock { self.basic_blocks.push(BasicBlockData::new(None)) } |