scatter and gather are not strict provenance compatible
#271
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I think this is easy to fix, we just need a new intrinsic for vector pointer offset |
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So how would one start fixing this? Add a new |
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Yeah, that seems right to me. It might also be possible to implement it in |
Are there other SIMD intrinsics that do that that could be used as a template? |
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Hmm, I was thinking offsetting pointers is pretty backend-agnostic but I don't see anything similar. It's probably fine putting it in the LLVM backend with all of the other SIMD intrinsics. |
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…ubilee implement SIMD gather/scatter via vector getelementptr Fixes rust-lang/portable-simd#271 However, I don't *really* know what I am doing here... Cc `@workingjubilee` `@calebzulawski` I didn't do anything for cranelift -- `@bjorn3` not sure if it's okay for that backend to temporarily break. I'm happy to cherry-pick a patch that adds cranelift support. :)
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…ubilee implement SIMD gather/scatter via vector getelementptr Fixes rust-lang/portable-simd#271 However, I don't *really* know what I am doing here... Cc ``@workingjubilee`` ``@calebzulawski`` I didn't do anything for cranelift -- ``@bjorn3`` not sure if it's okay for that backend to temporarily break. I'm happy to cherry-pick a patch that adds cranelift support. :)
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…ubilee implement SIMD gather/scatter via vector getelementptr Fixes rust-lang/portable-simd#271 However, I don't *really* know what I am doing here... Cc ```@workingjubilee``` ```@calebzulawski``` I didn't do anything for cranelift -- ```@bjorn3``` not sure if it's okay for that backend to temporarily break. I'm happy to cherry-pick a patch that adds cranelift support. :)
RalfJung
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…ubilee implement SIMD gather/scatter via vector getelementptr Fixes rust-lang/portable-simd#271 However, I don't *really* know what I am doing here... Cc `@workingjubilee` `@calebzulawski` I didn't do anything for cranelift -- `@bjorn3` not sure if it's okay for that backend to temporarily break. I'm happy to cherry-pick a patch that adds cranelift support. :)
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implement SIMD gather/scatter via vector getelementptr Fixes rust-lang/portable-simd#271 However, I don't *really* know what I am doing here... Cc ``@workingjubilee`` ``@calebzulawski`` I didn't do anything for cranelift -- ``@bjorn3`` not sure if it's okay for that backend to temporarily break. I'm happy to cherry-pick a patch that adds cranelift support. :)
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The implementations of
gatherandscatterin portable-simd currently are not compatible with strict provenance. Specifically, it isSimdConstPtr::wrapping_addthat transmutes a vector of pointers to a vector of integers, does integer arithmetic, and then transmutes back the result. It also has safety comments that are somewhat in conflict with what I am writing in rust-lang/rust#95547. ;)The text was updated successfully, but these errors were encountered: