rust/src/test/mir-opt/const_debuginfo.main.ConstDebugInfo.diff, branch 1.51.0https://github.com/rust-lang/rust
http://git.dreamy.place/mirrors/rust/atom?h=1.51.02020-12-07T01:48:25+00:00[mir-opt] Allow debuginfo to be generated for a constant or a Place2020-12-07T01:48:25+00:00Wesley Wiserwwiser@gmail.com2020-05-30T19:02:32+00:00urn:sha1:01aec8d18556be5e8d498c2f331b9015b7befde2
Prior to this commit, debuginfo was always generated by mapping a name
to a Place. This has the side-effect that `SimplifyLocals` cannot remove
locals that are only used for debuginfo because their other uses have
been const-propagated.
To allow these locals to be removed, we now allow debuginfo to point to
a constant value. The `ConstProp` pass detects when debuginfo points to
a local with a known constant value and replaces it with the value. This
allows the later `SimplifyLocals` pass to remove the local.