include/tcg/tcg-gvec-desc.h

/*
 * Generic vector operation descriptor
 *
 * Copyright (c) 2018 Linaro
 *
 * 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; if not, see <http://www.gnu.org/licenses/>.
 */

#ifndef TCG_TCG_GVEC_DESC_H
#define TCG_TCG_GVEC_DESC_H

/*
 * This configuration allows MAXSZ to represent 2048 bytes, and
 * OPRSZ to match MAXSZ, or represent the smaller values 8, 16, or 32.
 *
 * Encode this with:
 *   0, 1, 3 -> 8, 16, 32
 *   2       -> maxsz
 *
 * This steals the input that would otherwise map to 24 to match maxsz.
 */
#define SIMD_MAXSZ_SHIFT   0
#define SIMD_MAXSZ_BITS    8

#define SIMD_OPRSZ_SHIFT   (SIMD_MAXSZ_SHIFT + SIMD_MAXSZ_BITS)
#define SIMD_OPRSZ_BITS    2

#define SIMD_DATA_SHIFT    (SIMD_OPRSZ_SHIFT + SIMD_OPRSZ_BITS)
#define SIMD_DATA_BITS     (32 - SIMD_DATA_SHIFT)

/* Create a descriptor from components.  */
uint32_t simd_desc(uint32_t oprsz, uint32_t maxsz, int32_t data);

/* Extract the max vector size from a descriptor.  */
static inline intptr_t simd_maxsz(uint32_t desc)
{
    return extract32(desc, SIMD_MAXSZ_SHIFT, SIMD_MAXSZ_BITS) * 8 + 8;
}

/* Extract the operation size from a descriptor.  */
static inline intptr_t simd_oprsz(uint32_t desc)
{
    uint32_t f = extract32(desc, SIMD_OPRSZ_SHIFT, SIMD_OPRSZ_BITS);
    intptr_t o = f * 8 + 8;
    intptr_t m = simd_maxsz(desc);
    return f == 2 ? m : o;
}

/* Extract the operation-specific data from a descriptor.  */
static inline int32_t simd_data(uint32_t desc)
{
    return sextract32(desc, SIMD_DATA_SHIFT, SIMD_DATA_BITS);
}

#endif