xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/config/riscv/constraints.md (revision 8feb0f0b7eaff0608f8350bbfa3098827b4bb91b)
1;; Constraint definitions for RISC-V target.
2;; Copyright (C) 2011-2020 Free Software Foundation, Inc.
3;; Contributed by Andrew Waterman (andrew@sifive.com).
4;; Based on MIPS target for GNU compiler.
5;;
6;; This file is part of GCC.
7;;
8;; GCC is free software; you can redistribute it and/or modify
9;; it under the terms of the GNU General Public License as published by
10;; the Free Software Foundation; either version 3, or (at your option)
11;; any later version.
12;;
13;; GCC is distributed in the hope that it will be useful,
14;; but WITHOUT ANY WARRANTY; without even the implied warranty of
15;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16;; GNU General Public License for more details.
17;;
18;; You should have received a copy of the GNU General Public License
19;; along with GCC; see the file COPYING3.  If not see
20;; <http://www.gnu.org/licenses/>.
21
22;; Register constraints
23
24(define_register_constraint "f" "TARGET_HARD_FLOAT ? FP_REGS : NO_REGS"
25  "A floating-point register (if available).")
26
27(define_register_constraint "j" "SIBCALL_REGS"
28  "@internal")
29
30;; Avoid using register t0 for JALR's argument, because for some
31;; microarchitectures that is a return-address stack hint.
32(define_register_constraint "l" "JALR_REGS"
33  "@internal")
34
35;; General constraints
36
37(define_constraint "I"
38  "An I-type 12-bit signed immediate."
39  (and (match_code "const_int")
40       (match_test "SMALL_OPERAND (ival)")))
41
42(define_constraint "J"
43  "Integer zero."
44  (and (match_code "const_int")
45       (match_test "ival == 0")))
46
47(define_constraint "K"
48  "A 5-bit unsigned immediate for CSR access instructions."
49  (and (match_code "const_int")
50       (match_test "IN_RANGE (ival, 0, 31)")))
51
52(define_constraint "L"
53  "A U-type 20-bit signed immediate."
54  (and (match_code "const_int")
55       (match_test "LUI_OPERAND (ival)")))
56
57;; Floating-point constant +0.0, used for FCVT-based moves when FMV is
58;; not available in RV32.
59(define_constraint "G"
60  "@internal"
61  (and (match_code "const_double")
62       (match_test "op == CONST0_RTX (mode)")))
63
64(define_memory_constraint "A"
65  "An address that is held in a general-purpose register."
66  (and (match_code "mem")
67       (match_test "GET_CODE(XEXP(op,0)) == REG")))
68
69(define_constraint "S"
70  "@internal
71   A constant call address."
72  (match_operand 0 "absolute_symbolic_operand"))
73
74(define_constraint "U"
75  "@internal
76   A PLT-indirect call address."
77  (match_operand 0 "plt_symbolic_operand"))
78
79(define_constraint "T"
80  "@internal
81   A constant @code{move_operand}."
82  (and (match_operand 0 "move_operand")
83       (match_test "CONSTANT_P (op)")))
84