On 11/25/2015 01:21 PM, Richard Sandiford wrote:
- (plus:SI (match_operand:SI 0 "s_register_operand" "l, r") - (match_operand:SI 1 "arm_add_operand" "lPv,rIL")) + (plus:SI (match_operand:SI 0 "s_register_operand" "l,l, r,r") + (match_operand:SI 1 "arm_add_operand" "l,Pv,r,IL"))
I'll leave it to ARM maintainers to approve or reject, but I want to point out one thing: IMO this sort of thing is better written as "l,lPv,r,rIL", allowing a larger set of inputs for the later alternatives while still returning the more specific earlier one if it matches. I don't know whether LRA takes advantage of that, but it could help reload, and any post-reload pass might look at the current alternative for a given insn to see whether it can be replaced by a register.
Bernd
