tests: Update enc= values to preserve useless 0x67 address-size prefix#804
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mattst88 wants to merge 5 commits into
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tests: Update enc= values to preserve useless 0x67 address-size prefix#804mattst88 wants to merge 5 commits into
mattst88 wants to merge 5 commits into
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Track whether the original encoding contained a 0x67 address-size prefix that had no semantic effect (i.e. the instruction has no memory operand). Backed by a free bit (bit 20) in InstrFlags1::flags1, following the same pattern as has_lock_prefix.
…0x67 OpCodeHandler_Prefix67 flips the address size and delegates to the real opcode handler. If the decoded instruction has no memory operand of any kind (OpKind >= MemorySegSI), the 0x67 byte had no semantic effect and was previously silently discarded. Record it via has_address_size_prefix so the encoder and formatters can reproduce the original bytes.
Extend write_prefixes() to emit the address-size prefix byte when instruction.has_address_size_prefix() is true, in addition to the existing EncoderFlags::P67 path that handles memory operands.
When has_address_size_prefix() is true and show_useless_prefixes is enabled, emit the NASM address-size keyword (a16 in 32-bit mode, a32 otherwise) so NASM can reproduce the original 0x67-prefixed bytes.
For 25 decoder test entries that have a 0x67 prefix on a non-memory instruction, the enc= field previously specified the canonical form with 0x67 stripped. Now that the encoder round-trips has_address_size_prefix, update all enc= values to include the leading 67 byte. Affected entries: - 22 x "66 67 4E <rm8-r8 ops>" in DecoderTest64.txt - "67 8F E9 78 12 C3" (XOP Llwpcb_r32) in all three bitness files - "67 8F E9 F8 12 C3" (XOP Llwpcb_r64) in DecoderTest64.txt
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Summary
enc=entries inDecoderTest{16,32,64}.txtto include the leading67byte0x67prefix in the original bytes; withhas_address_size_prefixnow preserved through encode, the re-encoded bytes include67and the test expectations must matchDepends on: #802, #803
Test plan
cargo test -p iced-x86 -- encode_16 encode_32 encode_64passes