/*
* Helpers for vax floating point instructions.
*
* Copyright (c) 2007 Jocelyn Mayer
*
* 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/helper-proto.h"
#include "fpu/softfloat.h"
#define FP_STATUS (env->fp_status)
/* F floating (VAX) */
static uint64_t float32_to_f(float32 fa)
{
uint64_t r, exp, mant, sig;
CPU_FloatU a;
a.f = fa;
sig = ((uint64_t)a.l & 0x80000000) << 32;
exp = (a.l >> 23) & 0xff;
mant = ((uint64_t)a.l & 0x007fffff) << 29;
if (exp == 255) {
/* NaN or infinity */
r = 1; /* VAX dirty zero */
} else if (exp == 0) {
if (mant == 0) {
/* Zero */
r = 0;
} else {
/* Denormalized */
r = sig | ((exp + 1) << 52) | mant;
}
} else {
if (exp >= 253) {
/* Overflow */
r = 1; /* VAX dirty zero */
} else {
r = sig | ((exp + 2) << 52);
}
}
return r;
}
static float32 f_to_float32(CPUAlphaState *env, uintptr_t retaddr, uint64_t a)
{
uint32_t exp, mant_sig;
CPU_FloatU r;
exp = ((a >> 55) & 0x80) | ((a >> 52) & 0x7f);
mant_sig = ((a >> 32) & 0x80000000) | ((a >> 29) & 0x007fffff);
if (unlikely(!exp && mant_sig)) {
/* Reserved operands / Dirty zero */
dynamic_excp(env, retaddr, EXCP_OPCDEC, 0);
}
if (exp < 3) {
/* Underflow */
r.l = 0;
} else {
r.l = ((exp - 2) << 23) | mant_sig;
}
return r.f;
}
uint32_t helper_f_to_memory(uint64_t a)
{
uint32_t r;
r = (a & 0x00001fffe0000000ull) >> 13;
r |= (a & 0x07ffe00000000000ull) >> 45;
r |= (a & 0xc000000000000000ull) >> 48;
return r;
}
uint64_t helper_memory_to_f(uint32_t a)
{
uint64_t r;
r = ((uint64_t)(a & 0x0000c000)) << 48;
r |= ((uint64_t)(a & 0x003fffff)) << 45;
r |= ((uint64_t)(a & 0xffff0000)) << 13;
if (!(a & 0x00004000)) {
r |= 0x7ll << 59;
}
return r;
}
/* ??? Emulating VAX arithmetic with IEEE arithmetic is wrong. We should
either implement VAX arithmetic properly or just signal invalid opcode. */
uint64_t helper_addf(CPUAlphaState *env, uint64_t a, uint64_t b)
{
float32 fa, fb, fr;
fa = f_to_float32(env, GETPC(), a);
fb = f_to_float32(env, GETPC(), b);
fr = float32_add(fa, fb, &FP_STATUS);
return float32_to_f(fr);
}
uint64_t helper_subf(CPUAlphaState *env, uint64_t a, uint64_t b)
{
float32 fa, fb, fr;
fa = f_to_float32(env, GETPC(), a);
fb = f_to_float32(env, GETPC(), b);
fr = float32_sub(fa, fb, &FP_STATUS);
return float32_to_f(fr);
}
uint64_t helper_mulf(CPUAlphaState *env, uint64_t a, uint64_t b)
{
float32 fa, fb, fr;
fa = f_to_float32(env, GETPC(), a);
fb = f_to_float32(env, GETPC(), b);
fr = float32_mul(fa, fb, &FP_STATUS);
return float32_to_f(fr);
}
uint64_t helper_divf(CPUAlphaState *env, uint64_t a, uint64_t b)
{
float32 fa, fb, fr;
fa = f_to_float32(env, GETPC(), a);
fb = f_to_float32(env, GETPC(), b);
fr = float32_div(fa, fb, &FP_STATUS);
return float32_to_f(fr);
}
uint64_t helper_sqrtf(CPUAlphaState *env, uint64_t t)
{
float32 ft, fr;
ft = f_to_float32(env, GETPC(), t);
fr = float32_sqrt(ft, &FP_STATUS);
return float32_to_f(fr);
}
/* G floating (VAX) */
static uint64_t float64_to_g(float64 fa)
{
uint64_t r, exp, mant, sig;
CPU_DoubleU a;
a.d = fa;
sig = a.ll & 0x8000000000000000ull;
exp = (a.ll >> 52) & 0x7ff;
mant = a.ll & 0x000fffffffffffffull;
if (exp == 2047) {
/* NaN or infinity */
r = 1; /* VAX dirty zero */
} else if (exp == 0) {
if (mant == 0) {
/* Zero */
r = 0;
} else {
/* Denormalized */
r = sig | ((exp + 1) << 52) | mant;
}
} else {
if (exp >= 2045) {
/* Overflow */
r = 1; /* VAX dirty zero */
} else {
r = sig | ((exp + 2) << 52);
}
}
return r;
}
static float64 g_to_float64(CPUAlphaState *env, uintptr_t retaddr, uint64_t a)
{
uint64_t exp, mant_sig;
CPU_DoubleU r;
exp = (a >> 52) & 0x7ff;
mant_sig = a & 0x800fffffffffffffull;
if (!exp && mant_sig) {
/* Reserved operands / Dirty zero */
dynamic_excp(env, retaddr, EXCP_OPCDEC, 0);
}
if (exp < 3) {
/* Underflow */
r.ll = 0;
} else {
r.ll = ((exp - 2) << 52) | mant_sig;
}
return r.d;
}
uint64_t helper_g_to_memory(uint64_t a)
{
uint64_t r;
r = (a & 0x000000000000ffffull) << 48;
r |= (a & 0x00000000ffff0000ull) << 16;
r |= (a & 0x0000ffff00000000ull) >> 16;
r |= (a & 0xffff000000000000ull) >> 48;
return r;
}
uint64_t helper_memory_to_g(uint64_t a)
{
uint64_t r;
r = (a & 0x000000000000ffffull) << 48;
r |= (a & 0x00000000ffff0000ull) << 16;
r |= (a & 0x0000ffff00000000ull) >> 16;
r |= (a & 0xffff000000000000ull) >> 48;
return r;
}
uint64_t helper_addg(CPUAlphaState *env, uint64_t a, uint64_t b)
{
float64 fa, fb, fr;
fa = g_to_float64(env, GETPC(), a);
fb = g_to_float64(env, GETPC(), b);
fr = float64_add(fa, fb, &FP_STATUS);
return float64_to_g(fr);
}
uint64_t helper_subg(CPUAlphaState *env, uint64_t a, uint64_t b)
{
float64 fa, fb, fr;
fa = g_to_float64(env, GETPC(), a);
fb = g_to_float64(env, GETPC(), b);
fr = float64_sub(fa, fb, &FP_STATUS);
return float64_to_g(fr);
}
uint64_t helper_mulg(CPUAlphaState *env, uint64_t a, uint64_t b)
{
float64 fa, fb, fr;
fa = g_to_float64(env, GETPC(), a);
fb = g_to_float64(env, GETPC(), b);
fr = float64_mul(fa, fb, &FP_STATUS);
return float64_to_g(fr);
}
uint64_t helper_divg(CPUAlphaState *env, uint64_t a, uint64_t b)
{
float64 fa, fb, fr;
fa = g_to_float64(env, GETPC(), a);
fb = g_to_float64(env, GETPC(), b);
fr = float64_div(fa, fb, &FP_STATUS);
return float64_to_g(fr);
}
uint64_t helper_sqrtg(CPUAlphaState *env, uint64_t a)
{
float64 fa, fr;
fa = g_to_float64(env, GETPC(), a);
fr = float64_sqrt(fa, &FP_STATUS);
return float64_to_g(fr);
}
uint64_t helper_cmpgeq(CPUAlphaState *env, uint64_t a, uint64_t b)
{
float64 fa, fb;
fa = g_to_float64(env, GETPC(), a);
fb = g_to_float64(env, GETPC(), b);
if (float64_eq_quiet(fa, fb, &FP_STATUS)) {
return 0x4000000000000000ULL;
} else {
return 0;
}
}
uint64_t helper_cmpgle(CPUAlphaState *env, uint64_t a, uint64_t b)
{
float64 fa, fb;
fa = g_to_float64(env, GETPC(), a);
fb = g_to_float64(env, GETPC(), b);
if (float64_le(fa, fb, &FP_STATUS)) {
return 0x4000000000000000ULL;
} else {
return 0;
}
}
uint64_t helper_cmpglt(CPUAlphaState *env, uint64_t a, uint64_t b)
{
float64 fa, fb;
fa = g_to_float64(env, GETPC(), a);
fb = g_to_float64(env, GETPC(), b);
if (float64_lt(fa, fb, &FP_STATUS)) {
return 0x4000000000000000ULL;
} else {
return 0;
}
}
uint64_t helper_cvtqf(CPUAlphaState *env, uint64_t a)
{
float32 fr = int64_to_float32(a, &FP_STATUS);
return float32_to_f(fr);
}
uint64_t helper_cvtgf(CPUAlphaState *env, uint64_t a)
{
float64 fa;
float32 fr;
fa = g_to_float64(env, GETPC(), a);
fr = float64_to_float32(fa, &FP_STATUS);
return float32_to_f(fr);
}
uint64_t helper_cvtgq(CPUAlphaState *env, uint64_t a)
{
float64 fa = g_to_float64(env, GETPC(), a);
return float64_to_int64_round_to_zero(fa, &FP_STATUS);
}
uint64_t helper_cvtqg(CPUAlphaState *env, uint64_t a)
{
float64 fr;
fr = int64_to_float64(a, &FP_STATUS);
return float64_to_g(fr);
}
