source: libcfa/src/bits/align.hfa @ 09ee131

//
// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// align.hfa --
//
// Author           : Thierry Delisle
// Created On       : Mon Nov 28 12:27:26 2016
// Last Modified By : Peter A. Buhr
// Last Modified On : Sat Nov 16 18:58:22 2019
// Update Count     : 3
//
// This  library is free  software; you  can redistribute  it and/or  modify it
// under the terms of the GNU Lesser General Public License as published by the
// Free Software  Foundation; either  version 2.1 of  the License, or  (at your
// option) any later version.
//
// This library 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 Lesser General Public License
// for more details.
//
// You should  have received a  copy of the  GNU Lesser General  Public License
// along  with this library.
//

#pragma once

#include <assert.h>
#include <stdbool.h>

// Minimum size used to align memory boundaries for memory allocations.
//#define libAlign() (sizeof(double))
// gcc-7 uses xmms instructions, which require 16 byte alignment.
#define libAlign() (16)

// Check for power of 2
static inline bool libPow2( unsigned long int value ) {
    // clears all bits below value, rounding value down to the next lower multiple of value
    return (value & (value - 1ul)) == 0ul;
} // libPow2


// Returns value aligned at the floor of align.
static inline unsigned long int libFloor( unsigned long int value, unsigned long int align ) {
    assert( libPow2( align ) );
    // clears all bits above or equal to align, getting (value % align), the phase of value with regards to align
    return value & -align;
} // libFloor


// Returns value aligned at the ceiling of align.

static inline unsigned long int libCeiling( unsigned long int value, unsigned long int align ) {
    assert( libPow2( align ) );
    // "negate, round down, negate" is the same as round up
    return -libFloor( -value, align );
} // uCeiling

// Local Variables: //
// compile-command: "make install" //
// End: //