/*
 * QEMU TCG support -- s390x vector support instructions
 *
 * Copyright (C) 2019 Red Hat Inc
 *
 * Authors:
 *   David Hildenbrand <david@redhat.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 */
#include "qemu/osdep.h"
#include "cpu.h"
#include "s390x-internal.h"
#include "vec.h"
#include "tcg/tcg.h"
#include "tcg/tcg-gvec-desc.h"
#include "exec/helper-proto.h"
#include "exec/cpu_ldst.h"
#include "exec/exec-all.h"

void HELPER(gvec_vbperm)(void *v1, const void *v2, const void *v3,
                         uint32_t desc)
{
    S390Vector tmp = {};
    uint16_t result = 0;
    int i;

    for (i = 0; i < 16; i++) {
        const uint8_t bit_nr = s390_vec_read_element8(v3, i);
        uint16_t bit;

        if (bit_nr >= 128) {
            continue;
        }
        bit = (s390_vec_read_element8(v2, bit_nr / 8)
               >> (7 - (bit_nr % 8))) & 1;
        result |= (bit << (15 - i));
    }
    s390_vec_write_element16(&tmp, 3, result);
    *(S390Vector *)v1 = tmp;
}

void HELPER(vll)(CPUS390XState *env, void *v1, uint64_t addr, uint64_t bytes)
{
    if (likely(bytes >= 16)) {
        uint64_t t0, t1;

        t0 = cpu_ldq_data_ra(env, addr, GETPC());
        addr = wrap_address(env, addr + 8);
        t1 = cpu_ldq_data_ra(env, addr, GETPC());
        s390_vec_write_element64(v1, 0, t0);
        s390_vec_write_element64(v1, 1, t1);
    } else {
        S390Vector tmp = {};
        int i;

        for (i = 0; i < bytes; i++) {
            uint8_t byte = cpu_ldub_data_ra(env, addr, GETPC());

            s390_vec_write_element8(&tmp, i, byte);
            addr = wrap_address(env, addr + 1);
        }
        *(S390Vector *)v1 = tmp;
    }
}

#define DEF_VPK_HFN(BITS, TBITS)                                               \
typedef uint##TBITS##_t (*vpk##BITS##_fn)(uint##BITS##_t, int *);              \
static int vpk##BITS##_hfn(S390Vector *v1, const S390Vector *v2,               \
                           const S390Vector *v3, vpk##BITS##_fn fn)            \
{                                                                              \
    int i, saturated = 0;                                                      \
    S390Vector tmp;                                                            \
                                                                               \
    for (i = 0; i < (128 / TBITS); i++) {                                      \
        uint##BITS##_t src;                                                    \
                                                                               \
        if (i < (128 / BITS)) {                                                \
            src = s390_vec_read_element##BITS(v2, i);                          \
        } else {                                                               \
            src = s390_vec_read_element##BITS(v3, i - (128 / BITS));           \
        }                                                                      \
        s390_vec_write_element##TBITS(&tmp, i, fn(src, &saturated));           \
    }                                                                          \
    *v1 = tmp;                                                                 \
    return saturated;                                                          \
}
DEF_VPK_HFN(64, 32)
DEF_VPK_HFN(32, 16)
DEF_VPK_HFN(16, 8)

#define DEF_VPK(BITS, TBITS)                                                   \
static uint##TBITS##_t vpk##BITS##e(uint##BITS##_t src, int *saturated)        \
{                                                                              \
    return src;                                                                \
}                                                                              \
void HELPER(gvec_vpk##BITS)(void *v1, const void *v2, const void *v3,          \
                            uint32_t desc)                                     \
{                                                                              \
    vpk##BITS##_hfn(v1, v2, v3, vpk##BITS##e);                                 \
}
DEF_VPK(64, 32)
DEF_VPK(32, 16)
DEF_VPK(16, 8)

#define DEF_VPKS(BITS, TBITS)                                                  \
static uint##TBITS##_t vpks##BITS##e(uint##BITS##_t src, int *saturated)       \
{                                                                              \
    if ((int##BITS##_t)src > INT##TBITS##_MAX) {                               \
        (*saturated)++;                                                        \
        return INT##TBITS##_MAX;                                               \
    } else if ((int##BITS##_t)src < INT##TBITS##_MIN) {                        \
        (*saturated)++;                                                        \
        return INT##TBITS##_MIN;                                               \
    }                                                                          \
    return src;                                                                \
}                                                                              \
void HELPER(gvec_vpks##BITS)(void *v1, const void *v2, const void *v3,         \
                             uint32_t desc)                                    \
{                                                                              \
    vpk##BITS##_hfn(v1, v2, v3, vpks##BITS##e);                                \
}                                                                              \
void HELPER(gvec_vpks_cc##BITS)(void *v1, const void *v2, const void *v3,      \
                                CPUS390XState *env, uint32_t desc)             \
{                                                                              \
    int saturated = vpk##BITS##_hfn(v1, v2, v3, vpks##BITS##e);                \
                                                                               \
    if (saturated == (128 / TBITS)) {                                          \
        env->cc_op = 3;                                                        \
    } else if (saturated) {                                                    \
        env->cc_op = 1;                                                        \
    } else {                                                                   \
        env->cc_op = 0;                                                        \
    }                                                                          \
}
DEF_VPKS(64, 32)
DEF_VPKS(32, 16)
DEF_VPKS(16, 8)

#define DEF_VPKLS(BITS, TBITS)                                                 \
static uint##TBITS##_t vpkls##BITS##e(uint##BITS##_t src, int *saturated)      \
{                                                                              \
    if (src > UINT##TBITS##_MAX) {                                             \
        (*saturated)++;                                                        \
        return UINT##TBITS##_MAX;                                              \
    }                                                                          \
    return src;                                                                \
}                                                                              \
void HELPER(gvec_vpkls##BITS)(void *v1, const void *v2, const void *v3,        \
                              uint32_t desc)                                   \
{                                                                              \
    vpk##BITS##_hfn(v1, v2, v3, vpkls##BITS##e);                               \
}                                                                              \
void HELPER(gvec_vpkls_cc##BITS)(void *v1, const void *v2, const void *v3,     \
                                 CPUS390XState *env, uint32_t desc)            \
{                                                                              \
    int saturated = vpk##BITS##_hfn(v1, v2, v3, vpkls##BITS##e);               \
                                                                               \
    if (saturated == (128 / TBITS)) {                                          \
        env->cc_op = 3;                                                        \
    } else if (saturated) {                                                    \
        env->cc_op = 1;                                                        \
    } else {                                                                   \
        env->cc_op = 0;                                                        \
    }                                                                          \
}
DEF_VPKLS(64, 32)
DEF_VPKLS(32, 16)
DEF_VPKLS(16, 8)

void HELPER(gvec_vperm)(void *v1, const void *v2, const void *v3,
                        const void *v4, uint32_t desc)
{
    S390Vector tmp;
    int i;

    for (i = 0; i < 16; i++) {
        const uint8_t selector = s390_vec_read_element8(v4, i) & 0x1f;
        uint8_t byte;

        if (selector < 16) {
            byte = s390_vec_read_element8(v2, selector);
        } else {
            byte = s390_vec_read_element8(v3, selector - 16);
        }
        s390_vec_write_element8(&tmp, i, byte);
    }
    *(S390Vector *)v1 = tmp;
}

void HELPER(vstl)(CPUS390XState *env, const void *v1, uint64_t addr,
                  uint64_t bytes)
{
    /* Probe write access before actually modifying memory */
    probe_write_access(env, addr, bytes, GETPC());

    if (likely(bytes >= 16)) {
        cpu_stq_data_ra(env, addr, s390_vec_read_element64(v1, 0), GETPC());
        addr = wrap_address(env, addr + 8);
        cpu_stq_data_ra(env, addr, s390_vec_read_element64(v1, 1), GETPC());
    } else {
        int i;

        for (i = 0; i < bytes; i++) {
            uint8_t byte = s390_vec_read_element8(v1, i);

            cpu_stb_data_ra(env, addr, byte, GETPC());
            addr = wrap_address(env, addr + 1);
        }
    }
}
