RISC-V Is Sloooow

Re:RISC-V Is Sloooow by inkyoto on Wednesday March 11, 2026 @02:59AM (#47332441)

PDP-11, m68k – to name a few, did not allow misaligned access to anything that was not a byte.

Neither are RISC nor modern.

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Re:RISC-V Is Sloooow by pjmlp on Wednesday March 11, 2026 @04:33AM (#47333035)

In regards to 68000 I don't remember, only used it during demoscene coding parties when allowed to touch Amiga from my friends.

I have only seen PDP-11 Assembly snippets in UNIX related books, wasn't aware of its alignment requirements.

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Re:RISC-V Is Sloooow by inkyoto on Wednesday March 11, 2026 @06:09AM (#47333707)

PDP-11 was a major source of inspiration for m68k architecture designers. The influence can be seen in multiple places, starting from the orthogonal ISA design down to instruction mnemonics.

It is quite likely that not allowing the misaligned access was also influenced by PDP-11.

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