;; ARM Cortex-A15 pipeline description ;; Copyright (C) 2011 Free Software Foundation, Inc. ;; ;; Written by Matthew Gretton-Dann ;; 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 ;; . (define_automaton "cortex_a15") ;; The Cortex-A15 core is modelled as a triple issue pipeline that has ;; the following dispatch units. ;; 1. Two pipelines for simple integer operations: SX1, SX2 ;; 2. Two pipelines for Neon and FP data-processing operations: CX1, CX2 ;; 3. One pipeline for branch operations: BX ;; 4. One pipeline for integer multiply and divide operations: MX ;; 5. Two pipelines for load and store operations: LS1, LS2 ;; ;; We can issue into three pipelines per-cycle. ;; ;; We assume that where we have unit pairs xx1 is always filled before xx2. ;; The three issue units (define_cpu_unit "ca15_i0, ca15_i1, ca15_i2" "cortex_a15") (define_reservation "ca15_issue1" "(ca15_i0|ca15_i1|ca15_i2)") (define_reservation "ca15_issue2" "((ca15_i0+ca15_i1)|(ca15_i1+ca15_i2))") (define_reservation "ca15_issue3" "(ca15_i0+ca15_i1+ca15_i2)") (final_presence_set "ca15_i1" "ca15_i0") (final_presence_set "ca15_i2" "ca15_i1") ;; The main dispatch units (define_cpu_unit "ca15_sx1, ca15_sx2" "cortex_a15") (define_cpu_unit "ca15_cx1, ca15_cx2" "cortex_a15") (define_cpu_unit "ca15_ls1, ca15_ls2" "cortex_a15") (define_cpu_unit "ca15_bx, ca15_mx" "cortex_a15") (define_reservation "ca15_ls" "(ca15_ls1|ca15_ls2)") ;; The extended load-store pipeline (define_cpu_unit "ca15_ldr, ca15_str" "cortex_a15") ;; The extended ALU pipeline (define_cpu_unit "ca15_sx1_alu, ca15_sx1_shf, ca15_sx1_sat" "cortex_a15") (define_cpu_unit "ca15_sx2_alu, ca15_sx2_shf, ca15_sx2_sat" "cortex_a15") ;; Simple Execution Unit: ;; ;; Simple ALU without shift (define_insn_reservation "cortex_a15_alu" 2 (and (eq_attr "tune" "cortexa15") (and (eq_attr "type" "alu") (eq_attr "neon_type" "none"))) "ca15_issue1,(ca15_sx1,ca15_sx1_alu)|(ca15_sx2,ca15_sx2_alu)") ;; ALU ops with immediate shift (define_insn_reservation "cortex_a15_alu_shift" 3 (and (eq_attr "tune" "cortexa15") (and (eq_attr "type" "alu_shift") (eq_attr "neon_type" "none"))) "ca15_issue1,(ca15_sx1,ca15_sx1+ca15_sx1_shf,ca15_sx1_alu)\ |(ca15_sx2,ca15_sx2+ca15_sx2_shf,ca15_sx2_alu)") ;; ALU ops with register controlled shift (define_insn_reservation "cortex_a15_alu_shift_reg" 3 (and (eq_attr "tune" "cortexa15") (and (eq_attr "type" "alu_shift_reg") (eq_attr "neon_type" "none"))) "(ca15_issue2,ca15_sx1+ca15_sx2,ca15_sx1_shf,ca15_sx2_alu)\ |(ca15_issue1,(ca15_issue1+ca15_sx2,ca15_sx1+ca15_sx2_shf)\ |(ca15_issue1+ca15_sx1,ca15_sx1+ca15_sx1_shf),ca15_sx1_alu)") ;; Multiply Execution Unit: ;; ;; 32-bit multiplies (define_insn_reservation "cortex_a15_mult32" 3 (and (eq_attr "tune" "cortexa15") (and (eq_attr "type" "mult") (and (eq_attr "neon_type" "none") (eq_attr "mul64" "no")))) "ca15_issue1,ca15_mx") ;; 64-bit multiplies (define_insn_reservation "cortex_a15_mult64" 4 (and (eq_attr "tune" "cortexa15") (and (eq_attr "type" "mult") (and (eq_attr "neon_type" "none") (eq_attr "mul64" "yes")))) "ca15_issue1,ca15_mx*2") ;; Integer divide (define_insn_reservation "cortex_a15_udiv" 9 (and (eq_attr "tune" "cortexa15") (eq_attr "insn" "udiv")) "ca15_issue1,ca15_mx") (define_insn_reservation "cortex_a15_sdiv" 10 (and (eq_attr "tune" "cortexa15") (eq_attr "insn" "sdiv")) "ca15_issue1,ca15_mx") ;; Block all issue pipes for a cycle (define_insn_reservation "cortex_a15_block" 1 (and (eq_attr "tune" "cortexa15") (and (eq_attr "type" "block") (eq_attr "neon_type" "none"))) "ca15_issue3") ;; Branch execution Unit ;; ;; Branches take one issue slot. ;; No latency as there is no result (define_insn_reservation "cortex_a15_branch" 0 (and (eq_attr "tune" "cortexa15") (and (eq_attr "type" "branch") (eq_attr "neon_type" "none"))) "ca15_issue1,ca15_bx") ;; We lie with calls. They take up all issue slots, and form a block in the ;; pipeline. The result however is available the next cycle. ;; ;; Addition of new units requires this to be updated. (define_insn_reservation "cortex_a15_call" 1 (and (eq_attr "tune" "cortexa15") (and (eq_attr "type" "call") (eq_attr "neon_type" "none"))) "ca15_issue3,\ ca15_sx1+ca15_sx2+ca15_bx+ca15_mx+ca15_cx1+ca15_cx2+ca15_ls1+ca15_ls2,\ ca15_sx1_alu+ca15_sx1_shf+ca15_sx1_sat+ca15_sx2_alu+ca15_sx2_shf\ +ca15_sx2_sat+ca15_ldr+ca15_str") ;; Load-store execution Unit ;; ;; Loads of up to two words. (define_insn_reservation "cortex_a15_load1" 4 (and (eq_attr "tune" "cortexa15") (and (eq_attr "type" "load_byte,load1,load2") (eq_attr "neon_type" "none"))) "ca15_issue1,ca15_ls,ca15_ldr,nothing") ;; Loads of three or four words. (define_insn_reservation "cortex_a15_load3" 5 (and (eq_attr "tune" "cortexa15") (and (eq_attr "type" "load3,load4") (eq_attr "neon_type" "none"))) "ca15_issue2,ca15_ls1+ca15_ls2,ca15_ldr,ca15_ldr,nothing") ;; Stores of up to two words. (define_insn_reservation "cortex_a15_store1" 0 (and (eq_attr "tune" "cortexa15") (and (eq_attr "type" "store1,store2") (eq_attr "neon_type" "none"))) "ca15_issue1,ca15_ls,ca15_str") ;; Stores of three or four words. (define_insn_reservation "cortex_a15_store3" 0 (and (eq_attr "tune" "cortexa15") (and (eq_attr "type" "store3,store4") (eq_attr "neon_type" "none"))) "ca15_issue2,ca15_ls1+ca15_ls2,ca15_str,ca15_str") ;; Simple execution unit bypasses (define_bypass 1 "cortex_a15_alu" "cortex_a15_alu,cortex_a15_alu_shift,cortex_a15_alu_shift_reg") (define_bypass 2 "cortex_a15_alu_shift" "cortex_a15_alu,cortex_a15_alu_shift,cortex_a15_alu_shift_reg") (define_bypass 2 "cortex_a15_alu_shift_reg" "cortex_a15_alu,cortex_a15_alu_shift,cortex_a15_alu_shift_reg") (define_bypass 1 "cortex_a15_alu" "cortex_a15_load1,cortex_a15_load3") (define_bypass 2 "cortex_a15_alu_shift" "cortex_a15_load1,cortex_a15_load3") (define_bypass 2 "cortex_a15_alu_shift_reg" "cortex_a15_load1,cortex_a15_load3")