On Wed, 6 Aug 2025 15:18:04 -0400, David Cole <[email protected]> wrote:
>My question is, why did IBM choose have the instruction's name end >with B in one case and with C in the other? > - On the one hand, Why didn't they choose LC (instead of LB) as >that instruction's name? > - Or on the other, why didn't they choose LLB (instead of LLC) as >that instruction's name? There are a few possibilities to consider. 1. The x86 POPS is a hot mess at more than 6,000 pages 2005 z/Arch POPS is 1,144 pages 2010 z/Arch POPS is 1,496 pages 2025 z/Arch POPS is 2,240 pages I'm of the opinion that naming standards are becoming unmanageable and probably driving their choices. 2. Was LLC justified because of CLC? I'm guessing they used CLC (simple mnemonic acronym) because of it's conflict with CC(condition code). 3. They could have justified LLB over LLC because of LH and LLH but chose not to use this justification. 4. LC cannot be justified because a character is not a binary integer. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
