asmmacro.h

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/*
 * include/asm-xtensa/asmmacro.h
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2005 Tensilica Inc.
 */

#ifndef _XTENSA_ASMMACRO_H
#define _XTENSA_ASMMACRO_H

#include <variant/core.h>

/*
 * Some little helpers for loops. Use zero-overhead-loops
 * where applicable and if supported by the processor.
 *
 * __loopi ar, at, size, inc
 *         ar   register initialized with the start address
 *     at   scratch register used by macro
 *     size size immediate value
 *     inc  increment
 *
 * __loops ar, as, at, inc_log2[, mask_log2][, cond][, ncond]
 *     ar   register initialized with the start address
 *     as   register initialized with the size
 *     at   scratch register use by macro
 *     inc_log2 increment [in log2]
 *     mask_log2    mask [in log2]
 *     cond     true condition (used in loop'cond')
 *     ncond    false condition (used in b'ncond')
 *
 * __loop  as
 *     restart loop. 'as' register must not have been modified!
 *
 * __endla ar, at, incr
 *     ar   start address (modified)
 *     as   scratch register used by macro
 *     inc  increment
 */

/*
 * loop for given size as immediate
 */

    .macro  __loopi ar, at, size, incr

#if XCHAL_HAVE_LOOPS
        movi	\at, ((\size + \incr - 1) / (\incr))
        loop    \at, 99f
#else
        addi    \at, \ar, \size
        98:
#endif

    .endm

/*
 * loop for given size in register
 */

    .macro  __loops ar, as, at, incr_log2, mask_log2, cond, ncond

#if XCHAL_HAVE_LOOPS
        .ifgt \incr_log2 - 1
            addi    \at, \as, (1 << \incr_log2) - 1
            .ifnc \mask_log2,
                extui	\at, \at, \incr_log2, \mask_log2
            .else
                srli	\at, \at, \incr_log2
            .endif
        .endif
        loop\cond	\at, 99f
#else
        .ifnc \mask_log2,
            extui	\at, \as, \incr_log2, \mask_log2
        .else
            .ifnc \ncond,
                srli	\at, \as, \incr_log2
            .endif
        .endif
        .ifnc \ncond,
            b\ncond	\at, 99f

        .endif
        .ifnc \mask_log2,
            slli	\at, \at, \incr_log2
            add	\at, \ar, \at
        .else
            add	\at, \ar, \as
        .endif
#endif
        98:

    .endm

/*
 * loop from ar to ax
 */

    .macro  __loopt ar, as, at, incr_log2

#if XCHAL_HAVE_LOOPS
        sub	\at, \as, \ar
        .ifgt   \incr_log2 - 1
            addi	\at, \at, (1 << \incr_log2) - 1
            srli    \at, \at, \incr_log2
        .endif
        loop    \at, 99f
#else
        98:
#endif

    .endm

/*
 * restart loop. registers must be unchanged
 */

    .macro  __loop  as

#if XCHAL_HAVE_LOOPS
        loop    \as, 99f
#else
        98:
#endif

    .endm

/*
 * end of loop with no increment of the address.
 */

    .macro  __endl  ar, as
#if !XCHAL_HAVE_LOOPS
        bltu    \ar, \as, 98b
#endif
        99:
    .endm

/*
 * end of loop with increment of the address.
 */

    .macro  __endla ar, as, incr
        addi    \ar, \ar, \incr
        __endl  \ar \as
    .endm


#endif /* _XTENSA_ASMMACRO_H */