Hello,
Some time ago I asked a question regarding the possibility to schedule an
operation on alternative functional units (FUs) AND depending on the chosen FUs
to generate a dedicated assembly mnemonic.
To give a simple example suppose I have a move operation that can be issued on
one of the 2 different FUs:
(define_reservation "si_move""(q_salu, r_salu_rp,r_salu + r_salu_r_wp)
|(q_smac, nothing, r_smac + r_smac_wp)
,nothing* 3")
Depending on the occupied FUs one of the following assembly instructions are
generated: move_salu or move_smac.
To find out which FUs were occupied I defined 2 query_cpu_unit-s:
(define_query_cpu_unit "q_salu" "aut1")
(define_query_cpu_unit "q_smac" "aut1")
,which further on (during the sched2 hook TARGET_SCHED_DFA_NEW_CYCLE) are used
to find out which of the 2 alternative reservations the automaton has taken.
Based on this decision I add some information within the insn rtx which later
on is used to dump "move_salu" or "move_smac".
This approach was successful as long as the units claimed by "si_move" belong
to one and the same automaton ( i.e., q_salu, q_smac, r_salu_rp, r_salu,
r_salu_r_wp, r_smac, r_smac_wp belong to "aut1").
If I try to split "aut1" into (lets say 2) automatons I get generated incorrect
code (i.e., the choice of choosing the proper unit is not correct anymore.)
QUESTION: Is there such constraint that the units part of the alternatives of a
reservation must belong to the same automaton?
