269 lines
7.2 KiB
C
269 lines
7.2 KiB
C
/*
|
|
* Utility compute operations used by translated code.
|
|
*
|
|
* Copyright (c) 2003 Fabrice Bellard
|
|
* Copyright (c) 2007 Aurelien Jarno
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
|
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
* THE SOFTWARE.
|
|
*/
|
|
|
|
#include "qemu/osdep.h"
|
|
#include "qemu/host-utils.h"
|
|
|
|
#ifndef CONFIG_INT128
|
|
/* Long integer helpers */
|
|
static inline void mul64(uint64_t *plow, uint64_t *phigh,
|
|
uint64_t a, uint64_t b)
|
|
{
|
|
typedef union {
|
|
uint64_t ll;
|
|
struct {
|
|
#if HOST_BIG_ENDIAN
|
|
uint32_t high, low;
|
|
#else
|
|
uint32_t low, high;
|
|
#endif
|
|
} l;
|
|
} LL;
|
|
LL rl, rm, rn, rh, a0, b0;
|
|
uint64_t c;
|
|
|
|
a0.ll = a;
|
|
b0.ll = b;
|
|
|
|
rl.ll = (uint64_t)a0.l.low * b0.l.low;
|
|
rm.ll = (uint64_t)a0.l.low * b0.l.high;
|
|
rn.ll = (uint64_t)a0.l.high * b0.l.low;
|
|
rh.ll = (uint64_t)a0.l.high * b0.l.high;
|
|
|
|
c = (uint64_t)rl.l.high + rm.l.low + rn.l.low;
|
|
rl.l.high = c;
|
|
c >>= 32;
|
|
c = c + rm.l.high + rn.l.high + rh.l.low;
|
|
rh.l.low = c;
|
|
rh.l.high += (uint32_t)(c >> 32);
|
|
|
|
*plow = rl.ll;
|
|
*phigh = rh.ll;
|
|
}
|
|
|
|
/* Unsigned 64x64 -> 128 multiplication */
|
|
void mulu64 (uint64_t *plow, uint64_t *phigh, uint64_t a, uint64_t b)
|
|
{
|
|
mul64(plow, phigh, a, b);
|
|
}
|
|
|
|
/* Signed 64x64 -> 128 multiplication */
|
|
void muls64 (uint64_t *plow, uint64_t *phigh, int64_t a, int64_t b)
|
|
{
|
|
uint64_t rh;
|
|
|
|
mul64(plow, &rh, a, b);
|
|
|
|
/* Adjust for signs. */
|
|
if (b < 0) {
|
|
rh -= a;
|
|
}
|
|
if (a < 0) {
|
|
rh -= b;
|
|
}
|
|
*phigh = rh;
|
|
}
|
|
|
|
/*
|
|
* Unsigned 128-by-64 division.
|
|
* Returns the remainder.
|
|
* Returns quotient via plow and phigh.
|
|
* Also returns the remainder via the function return value.
|
|
*/
|
|
uint64_t divu128(uint64_t *plow, uint64_t *phigh, uint64_t divisor)
|
|
{
|
|
uint64_t dhi = *phigh;
|
|
uint64_t dlo = *plow;
|
|
uint64_t rem, dhighest;
|
|
int sh;
|
|
|
|
if (divisor == 0 || dhi == 0) {
|
|
*plow = dlo / divisor;
|
|
*phigh = 0;
|
|
return dlo % divisor;
|
|
} else {
|
|
sh = clz64(divisor);
|
|
|
|
if (dhi < divisor) {
|
|
if (sh != 0) {
|
|
/* normalize the divisor, shifting the dividend accordingly */
|
|
divisor <<= sh;
|
|
dhi = (dhi << sh) | (dlo >> (64 - sh));
|
|
dlo <<= sh;
|
|
}
|
|
|
|
*phigh = 0;
|
|
*plow = udiv_qrnnd(&rem, dhi, dlo, divisor);
|
|
} else {
|
|
if (sh != 0) {
|
|
/* normalize the divisor, shifting the dividend accordingly */
|
|
divisor <<= sh;
|
|
dhighest = dhi >> (64 - sh);
|
|
dhi = (dhi << sh) | (dlo >> (64 - sh));
|
|
dlo <<= sh;
|
|
|
|
*phigh = udiv_qrnnd(&dhi, dhighest, dhi, divisor);
|
|
} else {
|
|
/**
|
|
* dhi >= divisor
|
|
* Since the MSB of divisor is set (sh == 0),
|
|
* (dhi - divisor) < divisor
|
|
*
|
|
* Thus, the high part of the quotient is 1, and we can
|
|
* calculate the low part with a single call to udiv_qrnnd
|
|
* after subtracting divisor from dhi
|
|
*/
|
|
dhi -= divisor;
|
|
*phigh = 1;
|
|
}
|
|
|
|
*plow = udiv_qrnnd(&rem, dhi, dlo, divisor);
|
|
}
|
|
|
|
/*
|
|
* since the dividend/divisor might have been normalized,
|
|
* the remainder might also have to be shifted back
|
|
*/
|
|
return rem >> sh;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Signed 128-by-64 division.
|
|
* Returns quotient via plow and phigh.
|
|
* Also returns the remainder via the function return value.
|
|
*/
|
|
int64_t divs128(uint64_t *plow, int64_t *phigh, int64_t divisor)
|
|
{
|
|
bool neg_quotient = false, neg_remainder = false;
|
|
uint64_t unsig_hi = *phigh, unsig_lo = *plow;
|
|
uint64_t rem;
|
|
|
|
if (*phigh < 0) {
|
|
neg_quotient = !neg_quotient;
|
|
neg_remainder = !neg_remainder;
|
|
|
|
if (unsig_lo == 0) {
|
|
unsig_hi = -unsig_hi;
|
|
} else {
|
|
unsig_hi = ~unsig_hi;
|
|
unsig_lo = -unsig_lo;
|
|
}
|
|
}
|
|
|
|
if (divisor < 0) {
|
|
neg_quotient = !neg_quotient;
|
|
|
|
divisor = -divisor;
|
|
}
|
|
|
|
rem = divu128(&unsig_lo, &unsig_hi, (uint64_t)divisor);
|
|
|
|
if (neg_quotient) {
|
|
if (unsig_lo == 0) {
|
|
*phigh = -unsig_hi;
|
|
*plow = 0;
|
|
} else {
|
|
*phigh = ~unsig_hi;
|
|
*plow = -unsig_lo;
|
|
}
|
|
} else {
|
|
*phigh = unsig_hi;
|
|
*plow = unsig_lo;
|
|
}
|
|
|
|
if (neg_remainder) {
|
|
return -rem;
|
|
} else {
|
|
return rem;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* urshift - 128-bit Unsigned Right Shift.
|
|
* @plow: in/out - lower 64-bit integer.
|
|
* @phigh: in/out - higher 64-bit integer.
|
|
* @shift: in - bytes to shift, between 0 and 127.
|
|
*
|
|
* Result is zero-extended and stored in plow/phigh, which are
|
|
* input/output variables. Shift values outside the range will
|
|
* be mod to 128. In other words, the caller is responsible to
|
|
* verify/assert both the shift range and plow/phigh pointers.
|
|
*/
|
|
void urshift(uint64_t *plow, uint64_t *phigh, int32_t shift)
|
|
{
|
|
shift &= 127;
|
|
if (shift == 0) {
|
|
return;
|
|
}
|
|
|
|
uint64_t h = *phigh >> (shift & 63);
|
|
if (shift >= 64) {
|
|
*plow = h;
|
|
*phigh = 0;
|
|
} else {
|
|
*plow = (*plow >> (shift & 63)) | (*phigh << (64 - (shift & 63)));
|
|
*phigh = h;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* ulshift - 128-bit Unsigned Left Shift.
|
|
* @plow: in/out - lower 64-bit integer.
|
|
* @phigh: in/out - higher 64-bit integer.
|
|
* @shift: in - bytes to shift, between 0 and 127.
|
|
* @overflow: out - true if any 1-bit is shifted out.
|
|
*
|
|
* Result is zero-extended and stored in plow/phigh, which are
|
|
* input/output variables. Shift values outside the range will
|
|
* be mod to 128. In other words, the caller is responsible to
|
|
* verify/assert both the shift range and plow/phigh pointers.
|
|
*/
|
|
void ulshift(uint64_t *plow, uint64_t *phigh, int32_t shift, bool *overflow)
|
|
{
|
|
uint64_t low = *plow;
|
|
uint64_t high = *phigh;
|
|
|
|
shift &= 127;
|
|
if (shift == 0) {
|
|
return;
|
|
}
|
|
|
|
/* check if any bit will be shifted out */
|
|
urshift(&low, &high, 128 - shift);
|
|
if (low | high) {
|
|
*overflow = true;
|
|
}
|
|
|
|
if (shift >= 64) {
|
|
*phigh = *plow << (shift & 63);
|
|
*plow = 0;
|
|
} else {
|
|
*phigh = (*plow >> (64 - (shift & 63))) | (*phigh << (shift & 63));
|
|
*plow = *plow << shift;
|
|
}
|
|
}
|