[release/6.0] Fix CRC32 encoding #60360
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On x64, when the crc32 instruction 2nd operand is a memory address (such as for a static field), and that address is containable (which normally doesn't happen, because the address will be above the 4GB lower address space), then the instruction was being improperly encoded.
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Tagging subscribers to this area: @JulieLeeMSFT Issue DetailsBackport of #60329 to release/6.0 /cc @BruceForstall Customer ImpactTestingRisk
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jeffschwMSFT
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Approved. Please get a code review and we can consider this one for .NET 6.
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@tannergooding PTAL: port of fix to .NET 6 |
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Backport of #60329 to release/6.0
/cc @BruceForstall
Customer Impact
This fixes a bug affecting an internal partner using .NET on special OS builds using low (<4GB) memory address space on x64 processors.
Testing
Hand testing, forcing low memory for a crc32 argument; plus normal CI testing and SPMI assembly diffs (none, as expected).
Risk
Very low: the change affects only one instruction (crc32), and only for the immediate addressing mode, which is not encountered on x64 except in this low-address-space system.