OpenE2K/rust
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Optimize write_metadata.

Browse Source 
`write_metadata` currently generates metadata unnecessarily in some
cases, and also compresses it unnecessarily in some cases. This commit
fixes that. It speeds up three of the rustc-benchmarks by 1--4%.
This commit is contained in:
Nicholas Nethercote 2016-10-19 12:06:46 +11:00
parent 1d3dfa5301
commit 016f69f459
1 changed files with 26 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
src/librustc_trans/base.rs
View File

@ -1250,12 +1250,27 @@ fn write_metadata(cx: &SharedCrateContext,
reachable_ids: &NodeSet) -> Vec<u8> {
use flate;
let any_library = cx.sess()
.crate_types
.borrow()
.iter()
.any(|ty| *ty != config::CrateTypeExecutable);
if !any_library {
#[derive(PartialEq, Eq, PartialOrd, Ord)]
enum MetadataKind {
None,
Uncompressed,
Compressed
}
let kind = cx.sess().crate_types.borrow().iter().map(|ty| {
match *ty {
config::CrateTypeExecutable |
config::CrateTypeStaticlib |
config::CrateTypeCdylib => MetadataKind::None,
config::CrateTypeRlib => MetadataKind::Uncompressed,
config::CrateTypeDylib |
config::CrateTypeProcMacro => MetadataKind::Compressed,
}
}).max().unwrap();
if kind == MetadataKind::None {
return Vec::new();
}
@ -1265,6 +1280,11 @@ fn write_metadata(cx: &SharedCrateContext,
cx.link_meta(),
reachable_ids,
cx.mir_map());
if kind == MetadataKind::Uncompressed {
return metadata;
}
assert!(kind == MetadataKind::Compressed);
let mut compressed = cstore.metadata_encoding_version().to_vec();
compressed.extend_from_slice(&flate::deflate_bytes(&metadata));