Backing this up, here's an ancient usenet post by John R. Mashey (one of the MIPS designers at SGI) defending HP's use of BCD instructions in their RISC core.

Backing this up, here's an ancient usenet post by John R. Mashey (one of the MIPS designers at SGI) defending HP's use of BCD instructions in their RISC core. https://www.yarchive.net/comp/bcd_instructions.html https://www.yarchive.net/comp/bcd_instructions.html HP looked at their actual uses at the time, found a lot of COBOL that required BCD, and included single cycle, register-register instructions to accelerate that use case that was very important to them.