xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/config/riscv/peephole.md (revision e670fd5c413e99c2f6a37901bb21c537fcd322d2)
1;; Peephole optimizations for RISC-V for GNU compiler.
2;; Copyright (C) 2011-2019 Free Software Foundation, Inc.
3;; Contributed by Andrew Waterman (andrew@sifive.com).
4
5;; This file is part of GCC.
6
7;; GCC is free software; you can redistribute it and/or modify
8;; it under the terms of the GNU General Public License as published by
9;; the Free Software Foundation; either version 3, or (at your option)
10;; any later version.
11
12;; GCC is distributed in the hope that it will be useful,
13;; but WITHOUT ANY WARRANTY; without even the implied warranty of
14;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15;; GNU General Public License for more details.
16
17;; You should have received a copy of the GNU General Public License
18;; along with GCC; see the file COPYING3.  If not see
19;; <http://www.gnu.org/licenses/>.
20
21;; Simplify (unsigned long)(unsigned int)a << const
22(define_peephole2
23  [(set (match_operand:DI 0 "register_operand")
24	(ashift:DI (match_operand:DI 1 "register_operand")
25		   (match_operand 2 "const_int_operand")))
26   (set (match_operand:DI 3 "register_operand")
27	(lshiftrt:DI (match_dup 0) (match_dup 2)))
28   (set (match_operand:DI 4 "register_operand")
29	(ashift:DI (match_dup 3) (match_operand 5 "const_int_operand")))]
30  "TARGET_64BIT
31   && INTVAL (operands[5]) < INTVAL (operands[2])
32   && (REGNO (operands[3]) == REGNO (operands[4])
33       || peep2_reg_dead_p (3, operands[3]))"
34  [(set (match_dup 0)
35	(ashift:DI (match_dup 1) (match_dup 2)))
36   (set (match_dup 4)
37	(lshiftrt:DI (match_dup 0) (match_operand 5)))]
38{
39  operands[5] = GEN_INT (INTVAL (operands[2]) - INTVAL (operands[5]));
40})
41