/*
* AArch64 specific helpers
*
* Copyright (c) 2013 Alexander Graf <agraf@suse.de>
*
* 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 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/>.
*/
#include "cpu.h"
#include "exec/gdbstub.h"
#include "helper.h"
#include "qemu/host-utils.h"
#include "sysemu/sysemu.h"
#include "qemu/bitops.h"
/* C2.4.7 Multiply and divide */
/* special cases for 0 and LLONG_MIN are mandated by the standard */
uint64_t HELPER(udiv64)(uint64_t num, uint64_t den)
{
if (den == 0) {
return 0;
}
return num / den;
}
int64_t HELPER(sdiv64)(int64_t num, int64_t den)
{
if (den == 0) {
return 0;
}
if (num == LLONG_MIN && den == -1) {
return LLONG_MIN;
}
return num / den;
}
uint64_t HELPER(clz64)(uint64_t x)
{
return clz64(x);
}
uint64_t HELPER(cls64)(uint64_t x)
{
return clrsb64(x);
}
uint32_t HELPER(cls32)(uint32_t x)
{
return clrsb32(x);
}
uint64_t HELPER(rbit64)(uint64_t x)
{
/* assign the correct byte position */
x = bswap64(x);
/* assign the correct nibble position */
x = ((x & 0xf0f0f0f0f0f0f0f0ULL) >> 4)
| ((x & 0x0f0f0f0f0f0f0f0fULL) << 4);
/* assign the correct bit position */
x = ((x & 0x8888888888888888ULL) >> 3)
| ((x & 0x4444444444444444ULL) >> 1)
| ((x & 0x2222222222222222ULL) << 1)
| ((x & 0x1111111111111111ULL) << 3);
return x;
}
/* Convert a softfloat float_relation_ (as returned by
* the float*_compare functions) to the correct ARM
* NZCV flag state.
*/
static inline uint32_t float_rel_to_flags(int res)
{
uint64_t flags;
switch (res) {
case float_relation_equal:
flags = PSTATE_Z | PSTATE_C;
break;
case float_relation_less:
flags = PSTATE_N;
break;
case float_relation_greater:
flags = PSTATE_C;
break;
case float_relation_unordered:
default:
flags = PSTATE_C | PSTATE_V;
break;
}
return flags;
}
uint64_t HELPER(vfp_cmps_a64)(float32 x, float32 y, void *fp_status)
{
return float_rel_to_flags(float32_compare_quiet(x, y, fp_status));
}
uint64_t HELPER(vfp_cmpes_a64)(float32 x, float32 y, void *fp_status)
{
return float_rel_to_flags(float32_compare(x, y, fp_status));
}
uint64_t HELPER(vfp_cmpd_a64)(float64 x, float64 y, void *fp_status)
{
return float_rel_to_flags(float64_compare_quiet(x, y, fp_status));
}
uint64_t HELPER(vfp_cmped_a64)(float64 x, float64 y, void *fp_status)
{
return float_rel_to_flags(float64_compare(x, y, fp_status));
}
float32 HELPER(vfp_mulxs)(float32 a, float32 b, void *fpstp)
{
float_status *fpst = fpstp;
if ((float32_is_zero(a) && float32_is_infinity(b)) ||
(float32_is_infinity(a) && float32_is_zero(b))) {
/* 2.0 with the sign bit set to sign(A) XOR sign(B) */
return make_float32((1U << 30) |
((float32_val(a) ^ float32_val(b)) & (1U << 31)));
}
return float32_mul(a, b, fpst);
}
float64 HELPER(vfp_mulxd)(float64 a, float64 b, void *fpstp)
{
float_status *fpst = fpstp;
if ((float64_is_zero(a) && float64_is_infinity(b)) ||
(float64_is_infinity(a) && float64_is_zero(b))) {
/* 2.0 with the sign bit set to sign(A) XOR sign(B) */
return make_float64((1ULL << 62) |
((float64_val(a) ^ float64_val(b)) & (1ULL << 63)));
}
return float64_mul(a, b, fpst);
}
uint64_t HELPER(simd_tbl)(CPUARMState *env, uint64_t result, uint64_t indices,
uint32_t rn, uint32_t numregs)
{
/* Helper function for SIMD TBL and TBX. We have to do the table
* lookup part for the 64 bits worth of indices we're passed in.
* result is the initial results vector (either zeroes for TBL
* or some guest values for TBX), rn the register number where
* the table starts, and numregs the number of registers in the table.
* We return the results of the lookups.
*/
int shift;
for (shift = 0; shift < 64; shift += 8) {
int index = extract64(indices, shift, 8);
if (index < 16 * numregs) {
/* Convert index (a byte offset into the virtual table
* which is a series of 128-bit vectors concatenated)
* into the correct vfp.regs[] element plus a bit offset
* into that element, bearing in mind that the table
* can wrap around from V31 to V0.
*/
int elt = (rn * 2 + (index >> 3)) % 64;
int bitidx = (index & 7) * 8;
uint64_t val = extract64(env->vfp.regs[elt], bitidx, 8);
result = deposit64(result, shift, 8, val);
}
}
return result;
}
/* 64bit/double versions of the neon float compare functions */
uint64_t HELPER(neon_ceq_f64)(float64 a, float64 b, void *fpstp)
{
float_status *fpst = fpstp;
return -float64_eq_quiet(a, b, fpst);
}
uint64_t HELPER(neon_cge_f64)(float64 a, float64 b, void *fpstp)
{
float_status *fpst = fpstp;
return -float64_le(b, a, fpst);
}
uint64_t HELPER(neon_cgt_f64)(float64 a, float64 b, void *fpstp)
{
float_status *fpst = fpstp;
return -float64_lt(b, a, fpst);
}
/* Reciprocal step and sqrt step. Note that unlike the A32/T32
* versions, these do a fully fused multiply-add or
* multiply-add-and-halve.
*/
#define float32_two make_float32(0x40000000)
#define float32_three make_float32(0x40400000)
#define float32_one_point_five make_float32(0x3fc00000)
#define float64_two make_float64(0x4000000000000000ULL)
#define float64_three make_float64(0x4008000000000000ULL)
#define float64_one_point_five make_float64(0x3FF8000000000000ULL)
float32 HELPER(recpsf_f32)(float32 a, float32 b, void *fpstp)
{
float_status *fpst = fpstp;
a = float32_chs(a);
if ((float32_is_infinity(a) && float32_is_zero(b)) ||
(float32_is_infinity(b) && float32_is_zero(a))) {
return float32_two;
}
return float32_muladd(a, b, float32_two, 0, fpst);
}
float64 HELPER(recpsf_f64)(float64 a, float64 b, void *fpstp)
{
float_status *fpst = fpstp;
a = float64_chs(a);
if ((float64_is_infinity(a) && float64_is_zero(b)) ||
(float64_is_infinity(b) && float64_is_zero(a))) {
return float64_two;
}
return float64_muladd(a, b, float64_two, 0, fpst);
}
float32 HELPER(rsqrtsf_f32)(float32 a, float32 b, void *fpstp)
{
float_status *fpst = fpstp;
a = float32_chs(a);
if ((float32_is_infinity(a) && float32_is_zero(b)) ||
(float32_is_infinity(b) && float32_is_zero(a))) {
return float32_one_point_five;
}
return float32_muladd(a, b, float32_three, float_muladd_halve_result, fpst);
}
float64 HELPER(rsqrtsf_f64)(float64 a, float64 b, void *fpstp)
{
float_status *fpst = fpstp;
a = float64_chs(a);
if ((float64_is_infinity(a) && float64_is_zero(b)) ||
(float64_is_infinity(b) && float64_is_zero(a))) {
return float64_one_point_five;
}
return float64_muladd(a, b, float64_three, float_muladd_halve_result, fpst);
}
