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Rollup merge of #106856 - vadorovsky:fix-atomic-annotations, r=joshtriplett

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core: Support variety of atomic widths in width-agnostic functions

Before this change, the following functions and macros were annotated with `#[cfg(target_has_atomic = "8")]` or
`#[cfg(target_has_atomic_load_store = "8")]`:

* `atomic_int`
* `strongest_failure_ordering`
* `atomic_swap`
* `atomic_add`
* `atomic_sub`
* `atomic_compare_exchange`
* `atomic_compare_exchange_weak`
* `atomic_and`
* `atomic_nand`
* `atomic_or`
* `atomic_xor`
* `atomic_max`
* `atomic_min`
* `atomic_umax`
* `atomic_umin`

However, none of those functions and macros actually depend on 8-bit width and they are needed for all atomic widths (16-bit, 32-bit, 64-bit etc.). Some targets might not support 8-bit atomics (i.e. BPF, if we would enable atomic CAS for it).

This change fixes that by removing the `"8"` argument from annotations, which results in accepting the whole variety of widths.

Fixes #106845
Fixes #106795

Signed-off-by: Michal Rostecki <vadorovsky@gmail.com>
This commit is contained in:
Yuki Okushi 2023-01-27 12:57:54 +09:00 • committed by GitHub
commit bf321ece1e
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2 changed files with 38 additions and 15 deletions
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8
compiler/rustc_session/src/config.rs
View file

@ -945,6 +945,7 @@ fn default_configuration(sess: &Session) -> CrateConfig {
if sess.target.has_thread_local {
ret.insert((sym::target_thread_local, None));
}
let mut has_atomic = false;
for (i, align) in [
(8, layout.i8_align.abi),
(16, layout.i16_align.abi),
@ -953,6 +954,7 @@ fn default_configuration(sess: &Session) -> CrateConfig {
(128, layout.i128_align.abi),
] {
if i >= min_atomic_width && i <= max_atomic_width {
has_atomic = true;
let mut insert_atomic = |s, align: Align| {
ret.insert((sym::target_has_atomic_load_store, Some(Symbol::intern(s))));
if atomic_cas {
@ -969,6 +971,12 @@ fn default_configuration(sess: &Session) -> CrateConfig {
}
}
}
if sess.is_nightly_build() && has_atomic {
ret.insert((sym::target_has_atomic_load_store, None));
if atomic_cas {
ret.insert((sym::target_has_atomic, None));
}
}
let panic_strategy = sess.panic_strategy();
ret.insert((sym::panic, Some(panic_strategy.desc_symbol())));