Implement aarch64 CRC32 LLVM intrinsics#1651
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bryancostanich wants to merge 2 commits intorust-lang:mainfrom
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Implement aarch64 CRC32 LLVM intrinsics#1651bryancostanich wants to merge 2 commits intorust-lang:mainfrom
bryancostanich wants to merge 2 commits intorust-lang:mainfrom
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Covers all 8 LLVM intrinsics (llvm.aarch64.crc32{,c}{b,h,w,x}).
Reference values generated with the LLVM backend on aarch64-apple-darwin.
Currently fails: cg_clif emits a 'not yet supported' trap.
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Lower the eight CRC32 LLVM intrinsics to crc32{,c}{b,h,w,x} inline
assembly via the existing codegen_inline_asm_inner helper, mirroring
the existing x86 sse42.crc32 lowering.
Unblocks crc32fast on aarch64-{apple-darwin,unknown-linux-*}, which is
pulled in transitively by png -> image and Bevy's PNG screenshot path.
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Adds support for the eight
llvm.aarch64.crc32{,c}{b,h,w,x}intrinsics by lowering them tocrc32{,c}{b,h,w,x}inline assembly via the existingcodegen_inline_asm_innerhelper. Mirrors PR #1490 (the x86 sse42.crc32 family).This unblocks
crc32faston aarch64 under the cranelift backend, which is pulled in transitively by common crates includingpng→imageand Bevy's PNG screenshot path. Multiple users have reported this in #171 over the past year (llvm.aarch64.crc32bblocking Tauri builds,llvm.aarch64.crc32xblocking utoipa-swagger-ui, etc.).What's covered
Tests
`example/neon.rs` extended with `test_crc32()` covering all eight intrinsics. Reference values were generated by running the same call sequence under the LLVM backend on `aarch64-apple-darwin` and pasted into the assertions.
Verified locally on `aarch64-apple-darwin`:
Refs #171