;; Constraint definitions for Xtensa. ;; Copyright (C) 2006-2021 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 ;; http://www.gnu.org/licenses/.

;; Register constraints.

(define_register_constraint “a” “TARGET_WINDOWED_ABI ? GR_REGS : AR_REGS” “General-purpose AR registers @code{a0}-@code{a15}, except @code{a1} (@code{sp}).”)

(define_register_constraint “b” “TARGET_BOOLEANS ? BR_REGS : NO_REGS” “Boolean registers @code{b0}-@code{b15}; only available if the Xtensa Boolean Option is configured.”)

(define_register_constraint “d” “TARGET_DENSITY ? AR_REGS: NO_REGS” “@internal All AR registers, including sp, but only if the Xtensa Code Density Option is configured.”)

(define_register_constraint “f” “TARGET_HARD_FLOAT ? FP_REGS : NO_REGS” “Floating-point registers @code{f0}-@code{f15}; only available if the Xtensa Floating-Pointer Coprocessor is configured.”)

(define_register_constraint “q” “TARGET_WINDOWED_ABI ? SP_REG : NO_REGS” “@internal The stack pointer (register @code{a1}).”)

(define_register_constraint “A” “TARGET_MAC16 ? ACC_REG : NO_REGS” “The low 32 bits of the accumulator from the Xtensa MAC16 Option.”)

(define_register_constraint “B” “TARGET_SEXT ? GR_REGS : NO_REGS” “@internal General-purpose AR registers, but only if the Xtensa Sign Extend Option is configured.”)

(define_register_constraint “C” “TARGET_MUL16 ? GR_REGS: NO_REGS” “@internal General-purpose AR registers, but only if the Xtensa 16-Bit Integer Multiply Option is configured.”)

(define_register_constraint “D” “TARGET_DENSITY ? (TARGET_WINDOWED_ABI ? GR_REGS : AR_REGS) : NO_REGS” “@internal General-purpose AR registers, but only if the Xtensa Code Density Option is configured.”)

(define_register_constraint “W” “TARGET_CONST16 ? GR_REGS: NO_REGS” “@internal General-purpose AR registers, but only if the Xtensa Const16 Option is configured.”)

;; Integer constant constraints.

(define_constraint “I” “A signed 12-bit integer constant for use with MOVI instructions.” (and (match_code “const_int”) (match_test “xtensa_simm12b (ival)”)))

(define_constraint “J” “A signed 8-bit integer constant for use with ADDI instructions.” (and (match_code “const_int”) (match_test “xtensa_simm8 (ival)”)))

(define_constraint “K” “A constant integer that can be an immediate operand of an Xtensa conditional branch instruction that performs a signed comparison or a comparison against zero.” (and (match_code “const_int”) (match_test “xtensa_b4const_or_zero (ival)”)))

(define_constraint “L” “A constant integer that can be an immediate operand of an Xtensa conditional branch instruction that performs an unsigned comparison.” (and (match_code “const_int”) (match_test “xtensa_b4constu (ival)”)))

(define_constraint “M” “An integer constant in the range @minus{}32-95 for use with MOVI.N instructions.” (and (match_code “const_int”) (match_test “ival >= -32 && ival <= 95”)))

(define_constraint “N” “An unsigned 8-bit integer constant shifted left by 8 bits for use with ADDMI instructions.” (and (match_code “const_int”) (match_test “xtensa_simm8x256 (ival)”)))

(define_constraint “O” “An integer constant that can be used in ADDI.N instructions.” (and (match_code “const_int”) (match_test “ival == -1 || (ival >= 1 && ival <= 15)”)))

(define_constraint “P” “An integer constant that can be used as a mask value in an EXTUI instruction.” (and (match_code “const_int”) (match_test “xtensa_mask_immediate (ival)”)))

(define_constraint “Y” “A constant that can be used in relaxed MOVI instructions.” (and (match_code “const_int,const_double,const,symbol_ref,label_ref”) (match_test “TARGET_AUTO_LITPOOLS”)))

;; Memory constraints. Do not use define_memory_constraint here. Doing so ;; causes reload to force some constants into the constant pool, but since ;; the Xtensa constant pool can only be accessed with L32R instructions, it ;; is always better to just copy a constant into a register. Instead, use ;; regular constraints but add a check to allow pseudos during reload.

(define_constraint “R” “Memory that can be accessed with a 4-bit unsigned offset from a register.” (ior (and (match_code “mem”) (match_test “smalloffset_mem_p (op)”)) (and (match_code “reg”) (match_test “reload_in_progress && REGNO (op) >= FIRST_PSEUDO_REGISTER”))))

(define_constraint “T” “Memory in a literal pool (addressable with an L32R instruction).” (and (match_code “mem”) (match_test “!TARGET_CONST16 && constantpool_mem_p (op)”)))

(define_constraint “U” “Memory that is not in a literal pool.” (ior (and (match_code “mem”) (match_test “! constantpool_mem_p (op)”)) (and (match_code “reg”) (match_test “reload_in_progress && REGNO (op) >= FIRST_PSEUDO_REGISTER”))))