bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Merge basic blocks where possible when generating LLVM IR.

Browse source 
In `codegen_assert_terminator` we decide if a BB's successor is a
candidate for merging, which requires that it be the only successor, and
that it only have one predecessor. That result then gets passed down,
and if it reaches `funclet_br` with the appropriate BB characteristics,
then no `br` instruction is issued, a `MergingSucc::True` result is
passed back, and the merging proceeds in `codegen_block`.

The commit also adds `CachedLlbb`, a new type to help keep track of
each BB that has been merged into its predecessor.
This commit is contained in:
Nicholas Nethercote 2022-10-17 08:29:40 +11:00
parent 68194aa8d5
commit 54082dd216
4 changed files with 261 additions and 144 deletions
Download patch file Download diff file Expand all files Collapse all files

11
compiler/rustc_codegen_ssa/src/lib.rs
View file

@ -1,12 +1,13 @@
#![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
#![feature(box_patterns)]
#![feature(try_blocks)]
#![feature(once_cell)]
#![feature(associated_type_bounds)]
#![feature(strict_provenance)]
#![feature(int_roundings)]
#![feature(box_patterns)]
#![feature(if_let_guard)]
#![feature(int_roundings)]
#![feature(let_chains)]
#![feature(never_type)]
#![feature(once_cell)]
#![feature(strict_provenance)]
#![feature(try_blocks)]
#![recursion_limit = "256"]
#![allow(rustc::potential_query_instability)]