* pa.md (load high pattern): Rework constraints to reduce %r1 spillage.

From-SVN: r3510
This commit is contained in:
Jeff Law 1993-02-21 11:10:37 -07:00
parent 99efce9d6b
commit e53bfc4bb6
1 changed files with 13 additions and 1 deletions

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@ -934,8 +934,20 @@
;; For all symbolic operands *except* function addresses and read-only
;; operands (which live in TEXT space and do not require relocation).
;;
;; The constraints are a little strange.
;; The basic idea is to prefer %r1 as much as possible for register
;; allocation (hence we do not allow regclass to know about the general
;; register case (via *r).
;; We also want to avoid spilling %r1 as that will cause every use
;; of %r1 to be reloaded, so we make the %r1 case very expensive
;; as far as reload is concerned (via !a).
;;
;; The real solution is to not spill all pseudos allocated to %r1
;; when %r1 is needed as a spill register, but that is considerably
;; more difficult than coercing decent behavior via constraints.
(define_insn ""
[(set (match_operand:SI 0 "register_operand" "=a,!*r")
[(set (match_operand:SI 0 "register_operand" "=!a,*r")
(high:SI (match_operand 1 "" "")))]
"! TARGET_KERNEL && symbolic_operand(operands[1], Pmode)
&& ! function_label_operand (operands[1])