Logo
Explore Help
Register Sign In
rust-lang/rust
1
0
Fork 0
You've already forked rust
Code Issues Pull Requests Actions 1 Packages Projects Releases Wiki Activity
Files
b3827e4f3728b77bd3e60587487ebfc3cc8d901b
rust/tests/codegen/vtable-loads.rs

17 lines
363 B
Rust
Raw Normal View History

tests/codegen: use -Copt-level=3 instead of -O
2025-02-08 19:45:40 -08:00
//@ compile-flags: -Copt-level=3
Omit non-needs_drop drop_in_place in vtables This replaces the drop_in_place reference with null in vtables. On librustc_driver.so, this drops about ~17k dynamic relocations from the output, since many vtables can now be placed in read-only memory, rather than having a relocated pointer included. This makes a tradeoff by adding a null check at vtable call sites. That's hard to avoid without changing the vtable format (e.g., to use a pc-relative relocation instead of an absolute address, and avoid the dynamic relocation that way). But it seems likely that the check is cheap at runtime.
2024-03-17 17:42:37 -04:00
#![crate_type = "lib"]
// CHECK-LABEL: @loop_skips_vtable_load
#[no_mangle]
pub fn loop_skips_vtable_load(x: &dyn Fn()) {
// CHECK: load ptr, ptr %0{{.*}}, !invariant.load
// CHECK-NEXT: tail call void %1
// CHECK-NOT: load ptr
x();
for _ in 0..100 {
// CHECK: tail call void %1
x();
}
}
Reference in New Issue Copy Permalink
Powered by Gitea Version: 1.24.6 Page: 263ms Template: 4ms
English
Bahasa Indonesia Deutsch English Español Français Gaeilge Italiano Latviešu Magyar nyelv Nederlands Polski Português de Portugal Português do Brasil Suomi Svenska Türkçe Čeština Ελληνικά Български Русский Українська فارسی മലയാളം 日本語 简体中文 繁體中文(台灣) 繁體中文(香港) 한국어
Licenses API