On Mon, 2026-03-09 at 14:41 +0000, Richard Sandiford wrote: > > As Andrew said in one of the PRs, although the older MIPS ISA specs > required inputs to 32-bit instructions to be sign-extended, no MIPS > hardware that I know of actually trapped on invalid register inputs. > And almost all MIPS hardware does the obvious thing. (IIRC, SB-1 > didn't sign-extend the result if the inputs weren't sign-extended, but > I don't remember any others caring either way.)
For 32-bit division with non-sign-extended register input, Loongson 3A4000 really produces trashes (for some cases happen to be the non- extended result, but completely nonsense for other cases). The other 32-bit arithmetic operations seem mostly "rational" there. -- Xi Ruoyao <[email protected]>
