aarch64: Add new qualifier AARCH64_OPND_QLF_UNUSED
Replaces QLF_NIL with QLF_UNUSED for qualifier sequence list padding in AArch64 opcode definitions.
This patch introduces a new qualifier, AARCH64_OPND_QLF_UNUSED, to replace QLF_NIL for padding qualifier sequence lists in AArch64 opcode definitions. This change clarifies the distinct meanings of qualifiers and simplifies the detection of empty qualifier sequences. By separating the concepts of “no further qualification” and “unused entry”, the patch improves the clarity and maintainability of the AArch64 opcode definitions.
- proposer
Proposes replacing QLF_NIL with QLF_UNUSED for padding qualifier sequence lists, to improve clarity and simplify detection of empty sequences.
“Replace QLF_NIL with QLF_UNUSED for qualifier sequence list padding. This splits apart distinct qualifier meanings, and simplifies detection of empty qualifier sequences.”
In Details
This patch modifies the AArch64 opcode definitions in include/opcode/aarch64.h and related files. Qualifiers are used to distinguish between different forms of AArch64 instructions. The AARCH64_OPND_QLF_UNUSED qualifier is introduced to explicitly mark unused entries in the qualifier sequence lists, improving the clarity and maintainability of the opcode definitions.
For Context
This patch refines how AArch64 instructions are defined within binutils. AArch64 instructions can have variations based on the types of operands they use. These variations are described using "qualifiers." This patch introduces a specific marker to indicate unused qualifier entries, making the instruction definitions clearer and easier to understand, thus simplifying future maintenance and extensions.