[BPF] Add CLI option to enable misaligned memory access #191
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This proposal adds a cl::opt CLI flag -bpf-allow-misaligned-mem-access to BPF target that lets users enable allowing misaligned memory accesses.
The motivation behind the proposal is user space eBPF VMs (interpreters or JITs running in user space) typically run on real CPUs where unaligned memory accesses are acceptable (or handled efficiently) and can be enabled to simplify lowering and improve performance. In contrast, kernel eBPF must obey verifier constraints and platform-specific alignment restrictions.
A new CLI option keeps kernel behavior unchanged while giving userspace VMs an explicit opt-in to enable more permissive codegen. It supports both use-cases without diverging codebases.