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Auto merge of #122671 - Mark-Simulacrum:const-panic-msg, r=Nilstrieb

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Codegen const panic messages as function calls

This skips emitting extra arguments at every callsite (of which there
can be many). For a librustc_driver build with overflow checks enabled,
this cuts 0.7MB from the resulting shared library (see [perf]).

A sample improvement from nightly:

```
        leaq    str.0(%rip), %rdi
        leaq    .Lalloc_d6aeb8e2aa19de39a7f0e861c998af13(%rip), %rdx
        movl    $25, %esi
        callq   *_ZN4core9panicking5panic17h17cabb89c5bcc999E@GOTPCREL(%rip)
```

to this PR:

```
        leaq    .Lalloc_d6aeb8e2aa19de39a7f0e861c998af13(%rip), %rdi
        callq   *_RNvNtNtCsduqIKoij8JB_4core9panicking11panic_const23panic_const_div_by_zero@GOTPCREL(%rip)
```

[perf]: https://perf.rust-lang.org/compare.html?start=a7e4de13c1785819f4d61da41f6704ed69d5f203&end=64fbb4f0b2d621ff46d559d1e9f5ad89a8d7789b&stat=instructions:u
This commit is contained in:
bors 2024-03-29 00:24:01 +00:00
commit db2f9759f4
12 changed files with 253 additions and 61 deletions
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19
compiler/rustc_hir/src/lang_items.rs
View file

@ -248,6 +248,25 @@ language_item_table! {
PanicImpl, sym::panic_impl, panic_impl, Target::Fn, GenericRequirement::None;
PanicCannotUnwind, sym::panic_cannot_unwind, panic_cannot_unwind, Target::Fn, GenericRequirement::Exact(0);
PanicInCleanup, sym::panic_in_cleanup, panic_in_cleanup, Target::Fn, GenericRequirement::Exact(0);
/// Constant panic messages, used for codegen of MIR asserts.
PanicAddOverflow, sym::panic_const_add_overflow, panic_const_add_overflow, Target::Fn, GenericRequirement::None;
PanicSubOverflow, sym::panic_const_sub_overflow, panic_const_sub_overflow, Target::Fn, GenericRequirement::None;
PanicMulOverflow, sym::panic_const_mul_overflow, panic_const_mul_overflow, Target::Fn, GenericRequirement::None;
PanicDivOverflow, sym::panic_const_div_overflow, panic_const_div_overflow, Target::Fn, GenericRequirement::None;
PanicRemOverflow, sym::panic_const_rem_overflow, panic_const_rem_overflow, Target::Fn, GenericRequirement::None;
PanicNegOverflow, sym::panic_const_neg_overflow, panic_const_neg_overflow, Target::Fn, GenericRequirement::None;
PanicShrOverflow, sym::panic_const_shr_overflow, panic_const_shr_overflow, Target::Fn, GenericRequirement::None;
PanicShlOverflow, sym::panic_const_shl_overflow, panic_const_shl_overflow, Target::Fn, GenericRequirement::None;
PanicDivZero, sym::panic_const_div_by_zero, panic_const_div_by_zero, Target::Fn, GenericRequirement::None;
PanicRemZero, sym::panic_const_rem_by_zero, panic_const_rem_by_zero, Target::Fn, GenericRequirement::None;
PanicCoroutineResumed, sym::panic_const_coroutine_resumed, panic_const_coroutine_resumed, Target::Fn, GenericRequirement::None;
PanicAsyncFnResumed, sym::panic_const_async_fn_resumed, panic_const_async_fn_resumed, Target::Fn, GenericRequirement::None;
PanicAsyncGenFnResumed, sym::panic_const_async_gen_fn_resumed, panic_const_async_gen_fn_resumed, Target::Fn, GenericRequirement::None;
PanicGenFnNone, sym::panic_const_gen_fn_none, panic_const_gen_fn_none, Target::Fn, GenericRequirement::None;
PanicCoroutineResumedPanic, sym::panic_const_coroutine_resumed_panic, panic_const_coroutine_resumed_panic, Target::Fn, GenericRequirement::None;
PanicAsyncFnResumedPanic, sym::panic_const_async_fn_resumed_panic, panic_const_async_fn_resumed_panic, Target::Fn, GenericRequirement::None;
PanicAsyncGenFnResumedPanic, sym::panic_const_async_gen_fn_resumed_panic, panic_const_async_gen_fn_resumed_panic, Target::Fn, GenericRequirement::None;
PanicGenFnNonePanic, sym::panic_const_gen_fn_none_panic, panic_const_gen_fn_none_panic, Target::Fn, GenericRequirement::None;
/// libstd panic entry point. Necessary for const eval to be able to catch it
BeginPanic, sym::begin_panic, begin_panic_fn, Target::Fn, GenericRequirement::None;