🚀 go-pugleaf

  There are a couple of improvements which can be made to the handling
of compare instructions in m68k.md.  Both cmpsi and cmphi ommit the
cmp a0@+, a1@+ addressing mode (but cmpqi doesn't).  Also, on the
68020 and 68030 (at least), cmp <EA>, d0 is faster than cmpa <EA>, a0,
so I have added register prefernces to try to make this happen.

  Could someone more familiar with m68k.md double check these changes?

			Matthew Self
		  NASA Ames Research Center
		   self@bayes.arc.nasa.gov

*** gcc/m68k.md	Wed Feb 22 09:31:17 1989
--- gcc-pld/m68k.md	Wed Mar 15 13:29:37 1989
***************
*** 364,372 ****
  ;; compare instructions.
  
! ;; A composite of the cmp, cmpa, & cmpi m68000 op codes.
  (define_insn "cmpsi"
    [(set (cc0)
! 	(compare (match_operand:SI 0 "general_operand" "rKs,mr")
! 		 (match_operand:SI 1 "general_operand" "mr,Ksr")))]
    ""
    "*
--- 364,373 ----
  ;; compare instructions.
  
! ;; A composite of the cmp, cmpa, cmpi, and cmpm m68000 op codes.
! ;; cmp is faster than cmpa on 68020 and 68030 -- self@bayes.arc.nasa.gov
  (define_insn "cmpsi"
    [(set (cc0)
! 	(compare (match_operand:SI 0 "general_operand" "d*aKs,md*a,>")
! 		 (match_operand:SI 1 "general_operand" "md*a,Ksd*a,>")))]
    ""
    "*
***************
*** 390,395 ****
  (define_insn "cmphi"
    [(set (cc0)
! 	(compare (match_operand:HI 0 "general_operand" "rn,mr")
! 		 (match_operand:HI 1 "general_operand" "mr,nr")))]
    ""
    "*
--- 391,396 ----
  (define_insn "cmphi"
    [(set (cc0)
! 	(compare (match_operand:HI 0 "general_operand" "d*an,md*a,>")
! 		 (match_operand:HI 1 "general_operand" "md*a,nd*a,>")))]
    ""
    "*