78da577650
Cleanup blocks are declared with `bb (cleanup) = { ... }`.
`Call` and `Drop` terminators take an additional argument describing the
unwind action, which is one of the following:
* `UnwindContinue()`
* `UnwindUnreachable()`
* `UnwindTerminate(reason)`, where reason is `ReasonAbi` or `ReasonInCleanup`
* `UnwindCleanup(block)`
Also support unwind resume and unwind terminate terminators:
* `UnwindResume()`
* `UnwindTerminate(reason)`
44 lines
1.0 KiB
Rust
44 lines
1.0 KiB
Rust
// skip-filecheck
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// This example is interesting because the non-transitive version of `MaybeLiveLocals` would
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// report that *all* of these stores are live.
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//
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// needs-unwind
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// unit-test: DeadStoreElimination
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#![feature(core_intrinsics, custom_mir)]
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use std::intrinsics::mir::*;
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#[inline(never)]
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fn cond() -> bool {
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false
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}
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// EMIT_MIR cycle.cycle.DeadStoreElimination.diff
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#[custom_mir(dialect = "runtime", phase = "post-cleanup")]
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fn cycle(mut x: i32, mut y: i32, mut z: i32) {
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// We use custom MIR to avoid generating debuginfo, that would force to preserve writes.
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mir!(
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let condition: bool;
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{
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Call(condition = cond(), bb1, UnwindContinue())
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}
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bb1 = {
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match condition { true => bb2, _ => ret }
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}
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bb2 = {
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let temp = z;
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z = y;
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y = x;
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x = temp;
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Call(condition = cond(), bb1, UnwindContinue())
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}
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ret = {
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Return()
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}
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)
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}
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fn main() {
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cycle(1, 2, 3);
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}
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