Subversion Repositories openrisc_2011-10-31

;; DFA scheduling description for ST40-300.

;; Copyright (C) 2004, 2006, 2007 Free Software Foundation, Inc.

;; This file is part of GCC.

;; GCC is free software; you can redistribute it and/or modify

;; it under the terms of the GNU General Public License as published by

;; the Free Software Foundation; either version 3, or (at your option)

;; any later version.

;; GCC is distributed in the hope that it will be useful,

;; but WITHOUT ANY WARRANTY; without even the implied warranty of

;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License

;; along with GCC; see the file COPYING3.  If not see

;; .

;; Load and store instructions save a cycle if they are aligned on a

;; four byte boundary.  Using a function unit for stores encourages

;; gcc to separate load and store instructions by one instruction,

;; which makes it more likely that the linker will be able to word

;; align them when relaxing.

;; The following description models the ST40-300 pipeline using the DFA based

;; scheduler.

;; Two automata are defined to reduce number of states

;; which a single large automaton will have. (Factoring)

(define_automaton "sh4_300_inst_pipeline,sh4_300_fpu_pipe")

;; This unit is basically the decode unit of the processor.

;; Since SH4 is a dual issue machine,it is as if there are two

;; units so that any insn can be processed by either one

;; of the decoding unit.

(define_cpu_unit "sh4_300_pipe_01,sh4_300_pipe_02" "sh4_300_inst_pipeline")

;; The floating point units.

(define_cpu_unit "sh4_300_fpt,sh4_300_fpu,sh4_300_fds" "sh4_300_fpu_pipe")

;; integer multiplier unit

(define_cpu_unit "sh4_300_mul" "sh4_300_inst_pipeline")

;; LS unit

(define_cpu_unit "sh4_300_ls" "sh4_300_inst_pipeline")

;; The address calculator used for branch instructions.

;; This will be reserved after "issue" of branch instructions

;; and this is to make sure that no two branch instructions

;; can be issued in parallel.

(define_cpu_unit "sh4_300_br" "sh4_300_inst_pipeline")

;; ----------------------------------------------------

;; This reservation is to simplify the dual issue description.

(define_reservation  "sh4_300_issue"  "sh4_300_pipe_01|sh4_300_pipe_02")

(define_reservation "all" "sh4_300_pipe_01+sh4_300_pipe_02")

;;(define_insn_reservation "nil" 0 (eq_attr "type" "nil") "nothing")

;; MOV RM,RN / MOV #imm8,RN / STS PR,RN

(define_insn_reservation "sh4_300_mov" 0

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "move,movi8,prget"))

  "sh4_300_issue")

;; Fixed STS from MACL / MACH

(define_insn_reservation "sh4_300_mac_gp" 0

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "mac_gp"))

  "sh4_300_issue+sh4_300_mul")

;; Fixed LDS to MACL / MACH

(define_insn_reservation "sh4_300_gp_mac" 1

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "gp_mac"))

  "sh4_300_issue+sh4_300_mul")

;; Instructions without specific resource requirements with latency 1.

(define_insn_reservation "sh4_300_simple_arith" 1

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "mt_group,arith,dyn_shift,prset"))

  "sh4_300_issue")

;; Load and store instructions have no alignment peculiarities for the ST40-300,

;; but they use the load-store unit, which they share with the fmove type

;; insns (fldi[01]; fmov frn,frm; flds; fsts; fabs; fneg) .

;; Loads have a latency of three.

;; Load Store instructions.

(define_insn_reservation "sh4_300_load" 3

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "load,pcload,load_si,pcload_si,pload"))

  "sh4_300_issue+sh4_300_ls")

(define_insn_reservation "sh4_300_mac_load" 3

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "mem_mac"))

  "sh4_300_issue+sh4_300_ls+sh4_300_mul")

(define_insn_reservation "sh4_300_fload" 4

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "fload,pcfload"))

  "sh4_300_issue+sh4_300_ls+sh4_300_fpt")

;; sh_adjust_cost describes the reduced latency of the feeding insns of a store.

;; The latency of an auto-increment register is 1; the latency of the memory

;; output is not actually considered here anyway.

(define_insn_reservation "sh4_300_store" 1

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "store,pstore"))

  "sh4_300_issue+sh4_300_ls")

(define_insn_reservation "sh4_300_fstore" 1

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "fstore"))

  "sh4_300_issue+sh4_300_ls+sh4_300_fpt")

;; Fixed STS.L from MACL / MACH

(define_insn_reservation "sh4_300_mac_store" 1

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "mac_mem"))

  "sh4_300_issue+sh4_300_mul+sh4_300_ls")

(define_insn_reservation "sh4_300_gp_fpul" 2

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "gp_fpul"))

  "sh4_300_issue+sh4_300_fpt")

(define_insn_reservation "sh4_300_fpul_gp" 1

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "fpul_gp"))

  "sh4_300_issue+sh4_300_fpt")

;; Branch (BF,BF/S,BT,BT/S,BRA)

;; Branch Far (JMP,RTS,BRAF)

;; Group:       BR

;; When displacement is 0 for BF / BT, we have effectively conditional

;; execution of one instruction, without pipeline disruption.

;; Otherwise, the latency depends on prediction success.

;; We can't really do much with the latency, even if we could express it,

;; but the pairing restrictions are useful to take into account.

;; ??? If the branch is likely, and not paired with a preceding insn,

;; or likely and likely not predicted, we might want to fill the delay slot.

;; However, there appears to be no machinery to make the compiler

;; recognize these scenarios.

(define_insn_reservation "sh4_300_branch"  1

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "cbranch,jump,return,jump_ind"))

  "sh4_300_issue+sh4_300_br")

;; RTE

(define_insn_reservation "sh4_300_return_from_exp" 9

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "rte"))

  "sh4_300_pipe_01+sh4_300_pipe_02*9")

;; OCBP, OCBWB

;; Group:       CO

;; Latency:     1-5

;; Issue Rate:  1

;; cwb is used for the sequence ocbwb @%0; extu.w %0,%2; or %1,%2; mov.l %0,@%2

;; This description is likely inexact, but this pattern should not actually

;; appear when compiling for sh4-300; we should use isbi instead.

;; If a -mtune option is added later, we should use the icache array

;; dispatch method instead.

(define_insn_reservation "sh4_300_ocbwb"  3

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "cwb"))

  "all*3")

;; JSR,BSR,BSRF

;; Calls have a mandatory delay slot, which we'd like to fill with an insn

;; that can be paired with the call itself.

;; Scheduling runs before reorg, so we approximate this by saying that we

;; want the call to be paired with a preceding insn.

;; In most cases, the insn that loads the address of the call should have

;; a nonzero latency (mov rn,rm doesn't make sense since we could use rn

;; for the address then).  Thus, a preceding insn that can be paired with

;; a call should be eligible for the delay slot.

;;

;; calls introduce a longisch delay that is likely to flush the pipelines

;; of the caller's instructions.  Ordinary functions tend to end with a

;; load to restore a register (in the delay slot of rts), while sfuncs

;; tend to end with an EX or MT insn.  But that is not actually relevant,

;; since there are no instructions that contend for memory access early.

;; We could, of course, provide exact scheduling information for specific

;; sfuncs, if that should prove useful.

(define_insn_reservation "sh4_300_call" 16

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "call,sfunc"))

  "sh4_300_issue+sh4_300_br,all*15")

;; FMOV.S / FMOV.D

(define_insn_reservation "sh4_300_fmov" 1

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "fmove"))

  "sh4_300_issue+sh4_300_fpt")

;; LDS to FPSCR

(define_insn_reservation "sh4_300_fpscr_load" 8

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "gp_fpscr"))

  "sh4_300_issue+sh4_300_fpu+sh4_300_fpt")

;; LDS.L to FPSCR

(define_insn_reservation "sh4_300_fpscr_load_mem" 8

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type"  "mem_fpscr"))

  "sh4_300_issue+sh4_300_fpu+sh4_300_fpt+sh4_300_ls")

;; Fixed point multiplication (DMULS.L DMULU.L MUL.L MULS.W,MULU.W)

(define_insn_reservation "multi" 2

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "smpy,dmpy"))

  "sh4_300_issue+sh4_300_mul")

;; FPCHG, FRCHG, FSCHG

(define_insn_reservation "fpscr_toggle"  1

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "fpscr_toggle"))

  "sh4_300_issue+sh4_300_fpu+sh4_300_fpt")

;; FCMP/EQ, FCMP/GT

(define_insn_reservation "fp_cmp"  3

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "fp_cmp,dfp_cmp"))

  "sh4_300_issue+sh4_300_fpu")

;; Single precision floating point (FADD,FLOAT,FMAC,FMUL,FSUB,FTRC)

;; Double-precision floating-point (FADD,FCNVDS,FCNVSD,FLOAT,FSUB,FTRC)

(define_insn_reservation "fp_arith"  6

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "fp,ftrc_s,dfp_arith,dfp_conv"))

  "sh4_300_issue+sh4_300_fpu")

;; Single Precision FDIV/SQRT

(define_insn_reservation "fp_div" 19

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "fdiv"))

  "sh4_300_issue+sh4_300_fpu+sh4_300_fds,sh4_300_fds*15")

;; Double-precision floating-point FMUL

(define_insn_reservation "dfp_mul" 9

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "dfp_mul"))

  "sh4_300_issue+sh4_300_fpu,sh4_300_fpu*3")

;; Double precision FDIV/SQRT

(define_insn_reservation "dp_div" 35

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "dfdiv"))

  "sh4_300_issue+sh4_300_fpu+sh4_300_fds,sh4_300_fds*31")

;; ??? We don't really want these for sh4-300.

;; this pattern itself is likely to finish in 3 cycles, but also

;; to disrupt branch prediction for taken branches for the following

;; condbranch.

(define_insn_reservation "sh4_300_arith3" 5

  (and (eq_attr "pipe_model" "sh4_300")

       (eq_attr "type" "arith3"))

  "sh4_300_issue,all*4")

;; arith3b insns without brach redirection make use of the 0-offset 0-latency

;; branch feature, and thus schedule the same no matter if the branch is taken

;; or not.  If the branch is redirected, the taken branch might take longer,

;; but then, we don't have to take the next branch.

;; ??? should we suppress branch redirection for sh4-300 to improve branch

;; target hit rates?

(define_insn_reservation "arith3b" 2

  (and (eq_attr "pipe_model" "sh4")

       (eq_attr "type" "arith3"))

  "issue,all")