> From: Richard Sandiford <richard.sandif...@arm.com> > Date: Tue, 24 Oct 2023 11:14:20 +0100
> reload and constrain_operands had some old code to look through unary > operators. E.g. an operand could be (sign_extend (reg X)), and the > constraints would match the reg rather than the sign_extend. > > This was previously used by the MIPS port. But relying on it was a > recurring source of problems, so Eric and I removed it in the MIPS > rewrite from ~20 years back. I don't know of any other port that used it. The SH did. I remember this being one of the ugliest warts of reload. IIRC, there was a bit of a discourse involving me and Joern way-back (also IIRC some 20 years ago, at least before IRA and LRA). The conclusion was that removing this misfeature would be ok, as already at that time, there was no de-facto beneficial effect for sh, likely due to code rot. However, no action was taken; no code changed. Thanks for removing the last(?) bits! brgds, H-P
