add a fallback implementation for the prefetch_* intrinsics
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The fallback is to just ignore the arguments. That is a valid implementation because this intrinsic is just a hint. I also added `miri::intrinsic_fallback_is_spec` annotation, so that miri now supports these operations. A prefetch intrinsic call is valid on any pointer.
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Rollup of 13 pull requests Successful merges: - #139357 (Fix parameter order for `_by()` variants of `min` / `max`/ `minmax` in `std::cmp`) - #140314 (Rustdoc: typecheck scrape-examples.js) - #140794 (mention lint group in default level lint note) - #145006 (Clarify EOF handling for `BufRead::skip_until`) - #145252 (Demote x86_64-apple-darwin to Tier 2 with host tools) - #145359 (Fix bug where `rustdoc-js` tester would not pick the right `search.js` file if there is more than one) - #145381 (Implement feature `int_lowest_highest_one` for integer and NonZero types) - #145417 (std_detect: RISC-V platform guide documentation) - #145531 (Add runtime detection for APX-F and AVX10) - #145619 (`std_detect`: Use `rustc-std-workspace-*` to pull in `compiler-builtins`) - #145622 (Remove the std workspace patch for `compiler-builtins`) - #145623 (Pretty print the name of an future from calling async closure) - #145626 (add a fallback implementation for the `prefetch_*` intrinsics ) r? `@ghost` `@rustbot` modify labels: rollup
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Rollup merge of #145626 - folkertdev:prefetch-fallback, r=Amanieu add a fallback implementation for the `prefetch_*` intrinsics related ACP: rust-lang/libs-team#638 The fallback is to just ignore the arguments. That is a valid implementation because this intrinsic is just a hint. I also added the `miri::intrinsic_fallback_is_spec` annotation, so that miri now supports these operations. A prefetch intrinsic call is valid on any pointer. (specifically LLVM guarantees this https://llvm.org/docs/LangRef.html#llvm-prefetch-intrinsic) Next, I made the `LOCALITY` argument a const generic. That argument must be const (otherwise LLVM crashes), but that was not reflected in the type. Finally, with these changes, the intrinsic can be safe and `const` (a prefetch at const evaluation time is just a no-op). cc `@Amanieu` r? `@RalfJung`
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| @@ -330,10 +330,16 @@ impl<'ll, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> { | |||
| _ => bug!(), | |||
| }; | |||
| let ptr = args[0].immediate(); | |||
| let locality = fn_args.const_at(1).to_value().valtree.unwrap_leaf().to_u32() as i32; | |||
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Weird, I suspect my autocomplete only showed the unsigned versions? Or I missed the signed versions when looking through the docs somehow.
Anyway, to_i32 would be better, but also only the values 0..4 are supported.
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Rollup of 13 pull requests Successful merges: - rust-lang/rust#139357 (Fix parameter order for `_by()` variants of `min` / `max`/ `minmax` in `std::cmp`) - rust-lang/rust#140314 (Rustdoc: typecheck scrape-examples.js) - rust-lang/rust#140794 (mention lint group in default level lint note) - rust-lang/rust#145006 (Clarify EOF handling for `BufRead::skip_until`) - rust-lang/rust#145252 (Demote x86_64-apple-darwin to Tier 2 with host tools) - rust-lang/rust#145359 (Fix bug where `rustdoc-js` tester would not pick the right `search.js` file if there is more than one) - rust-lang/rust#145381 (Implement feature `int_lowest_highest_one` for integer and NonZero types) - rust-lang/rust#145417 (std_detect: RISC-V platform guide documentation) - rust-lang/rust#145531 (Add runtime detection for APX-F and AVX10) - rust-lang/rust#145619 (`std_detect`: Use `rustc-std-workspace-*` to pull in `compiler-builtins`) - rust-lang/rust#145622 (Remove the std workspace patch for `compiler-builtins`) - rust-lang/rust#145623 (Pretty print the name of an future from calling async closure) - rust-lang/rust#145626 (add a fallback implementation for the `prefetch_*` intrinsics ) r? `@ghost` `@rustbot` modify labels: rollup
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related ACP: rust-lang/libs-team#638
The fallback is to just ignore the arguments. That is a valid implementation because this intrinsic is just a hint.
I also added the
miri::intrinsic_fallback_is_specannotation, so that miri now supports these operations. A prefetch intrinsic call is valid on any pointer. (specifically LLVM guarantees this https://llvm.org/docs/LangRef.html#llvm-prefetch-intrinsic)Next, I made the
LOCALITYargument a const generic. That argument must be const (otherwise LLVM crashes), but that was not reflected in the type.Finally, with these changes, the intrinsic can be safe and
const(a prefetch at const evaluation time is just a no-op).cc @Amanieu
r? @RalfJung