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gem5/amd/gem5/refs/heads/master/./src/arch/arm/insts/fplib.cc
blob: e01644887ea3201e21ca2299273c2b324cd62539 [file] [edit]
/*
* Copyright (c) 2012-2013 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
* not be construed as granting a license to any other intellectual
* property including but not limited to intellectual property relating
* to a hardware implementation of the functionality of the software
* licensed hereunder. You may use the software subject to the license
* terms below provided that you ensure that this notice is replicated
* unmodified and in its entirety in all distributions of the software,
* modified or unmodified, in source code or in binary form.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Edmund Grimley Evans
* Thomas Grocutt
*/
#include <stdint.h>
#include <cassert>
#include "fplib.hh"
namespace ArmISA
{
#define FPLIB_RN 0
#define FPLIB_RP 1
#define FPLIB_RM 2
#define FPLIB_RZ 3
#define FPLIB_FZ 4
#define FPLIB_DN 8
#define FPLIB_AHP 16
#define FPLIB_IDC 128 // Input Denormal
#define FPLIB_IXC 16 // Inexact
#define FPLIB_UFC 8 // Underflow
#define FPLIB_OFC 4 // Overflow
#define FPLIB_DZC 2 // Division by Zero
#define FPLIB_IOC 1 // Invalid Operation
static inline uint16_t
lsl16(uint16_t x, uint32_t shift)
{
return shift < 16 ? x << shift : 0;
}
static inline uint16_t
lsr16(uint16_t x, uint32_t shift)
{
return shift < 16 ? x >> shift : 0;
}
static inline uint32_t
lsl32(uint32_t x, uint32_t shift)
{
return shift < 32 ? x << shift : 0;
}
static inline uint32_t
lsr32(uint32_t x, uint32_t shift)
{
return shift < 32 ? x >> shift : 0;
}
static inline uint64_t
lsl64(uint64_t x, uint32_t shift)
{
return shift < 64 ? x << shift : 0;
}
static inline uint64_t
lsr64(uint64_t x, uint32_t shift)
{
return shift < 64 ? x >> shift : 0;
}
static inline void
lsl128(uint64_t *r0, uint64_t *r1, uint64_t x0, uint64_t x1, uint32_t shift)
{
if (shift == 0) {
*r1 = x1;
*r0 = x0;
} else if (shift < 64) {
*r1 = x1 << shift | x0 >> (64 - shift);
*r0 = x0 << shift;
} else if (shift < 128) {
*r1 = x0 << (shift - 64);
*r0 = 0;
} else {
*r1 = 0;
*r0 = 0;
}
}
static inline void
lsr128(uint64_t *r0, uint64_t *r1, uint64_t x0, uint64_t x1, uint32_t shift)
{
if (shift == 0) {
*r1 = x1;
*r0 = x0;
} else if (shift < 64) {
*r0 = x0 >> shift | x1 << (64 - shift);
*r1 = x1 >> shift;
} else if (shift < 128) {
*r0 = x1 >> (shift - 64);
*r1 = 0;
} else {
*r0 = 0;
*r1 = 0;
}
}
static inline void
mul62x62(uint64_t *x0, uint64_t *x1, uint64_t a, uint64_t b)
{
uint32_t mask = ((uint32_t)1 << 31) - 1;
uint64_t a0 = a & mask;
uint64_t a1 = a >> 31 & mask;
uint64_t b0 = b & mask;
uint64_t b1 = b >> 31 & mask;
uint64_t p0 = a0 * b0;
uint64_t p2 = a1 * b1;
uint64_t p1 = (a0 + a1) * (b0 + b1) - p0 - p2;
uint64_t s0 = p0;
uint64_t s1 = (s0 >> 31) + p1;
uint64_t s2 = (s1 >> 31) + p2;
*x0 = (s0 & mask) | (s1 & mask) << 31 | s2 << 62;
*x1 = s2 >> 2;
}
static inline
void mul64x32(uint64_t *x0, uint64_t *x1, uint64_t a, uint32_t b)
{
uint64_t t0 = (uint64_t)(uint32_t)a * b;
uint64_t t1 = (t0 >> 32) + (a >> 32) * b;
*x0 = t1 << 32 | (uint32_t)t0;
*x1 = t1 >> 32;
}
static inline void
add128(uint64_t *x0, uint64_t *x1, uint64_t a0, uint64_t a1, uint64_t b0,
uint64_t b1)
{
*x0 = a0 + b0;
*x1 = a1 + b1 + (*x0 < a0);
}
static inline void
sub128(uint64_t *x0, uint64_t *x1, uint64_t a0, uint64_t a1, uint64_t b0,
uint64_t b1)
{
*x0 = a0 - b0;
*x1 = a1 - b1 - (*x0 > a0);
}
static inline int
cmp128(uint64_t a0, uint64_t a1, uint64_t b0, uint64_t b1)
{
return (a1 < b1 ? -1 : a1 > b1 ? 1 : a0 < b0 ? -1 : a0 > b0 ? 1 : 0);
}
static inline uint16_t
fp16_normalise(uint16_t mnt, int *exp)
{
int shift;
if (!mnt) {
return 0;
}
for (shift = 8; shift; shift >>= 1) {
if (!(mnt >> (16 - shift))) {
mnt <<= shift;
*exp -= shift;
}
}
return mnt;
}
static inline uint32_t
fp32_normalise(uint32_t mnt, int *exp)
{
int shift;
if (!mnt) {
return 0;
}
for (shift = 16; shift; shift >>= 1) {
if (!(mnt >> (32 - shift))) {
mnt <<= shift;
*exp -= shift;
}
}
return mnt;
}
static inline uint64_t
fp64_normalise(uint64_t mnt, int *exp)
{
int shift;
if (!mnt) {
return 0;
}
for (shift = 32; shift; shift >>= 1) {
if (!(mnt >> (64 - shift))) {
mnt <<= shift;
*exp -= shift;
}
}
return mnt;
}
static inline void
fp128_normalise(uint64_t *mnt0, uint64_t *mnt1, int *exp)
{
uint64_t x0 = *mnt0;
uint64_t x1 = *mnt1;
int shift;
if (!x0 && !x1) {
return;
}
if (!x1) {
x1 = x0;
x0 = 0;
*exp -= 64;
}
for (shift = 32; shift; shift >>= 1) {
if (!(x1 >> (64 - shift))) {
x1 = x1 << shift | x0 >> (64 - shift);
x0 <<= shift;
*exp -= shift;
}
}
*mnt0 = x0;
*mnt1 = x1;
}
static inline uint16_t
fp16_pack(uint16_t sgn, uint16_t exp, uint16_t mnt)
{
return sgn << 15 | exp << 10 | (mnt & (((uint16_t)1 << 10) - 1));
}
static inline uint32_t
fp32_pack(uint32_t sgn, uint32_t exp, uint32_t mnt)
{
return sgn << 31 | exp << 23 | (mnt & (((uint32_t)1 << 23) - 1));
}
static inline uint64_t
fp64_pack(uint64_t sgn, uint64_t exp, uint64_t mnt)
{
return (uint64_t)sgn << 63 | exp << 52 | (mnt & (((uint64_t)1 << 52) - 1));
}
static inline uint16_t
fp16_zero(int sgn)
{
return fp16_pack(sgn, 0, 0);
}
static inline uint32_t
fp32_zero(int sgn)
{
return fp32_pack(sgn, 0, 0);
}
static inline uint64_t
fp64_zero(int sgn)
{
return fp64_pack(sgn, 0, 0);
}
static inline uint16_t
fp16_max_normal(int sgn)
{
return fp16_pack(sgn, 30, -1);
}
static inline uint32_t
fp32_max_normal(int sgn)
{
return fp32_pack(sgn, 254, -1);
}
static inline uint64_t
fp64_max_normal(int sgn)
{
return fp64_pack(sgn, 2046, -1);
}
static inline uint16_t
fp16_infinity(int sgn)
{
return fp16_pack(sgn, 31, 0);
}
static inline uint32_t
fp32_infinity(int sgn)
{
return fp32_pack(sgn, 255, 0);
}
static inline uint64_t
fp64_infinity(int sgn)
{
return fp64_pack(sgn, 2047, 0);
}
static inline uint16_t
fp16_defaultNaN()
{
return fp16_pack(0, 31, (uint16_t)1 << 9);
}
static inline uint32_t
fp32_defaultNaN()
{
return fp32_pack(0, 255, (uint32_t)1 << 22);
}
static inline uint64_t
fp64_defaultNaN()
{
return fp64_pack(0, 2047, (uint64_t)1 << 51);
}
static inline void
fp16_unpack(int *sgn, int *exp, uint16_t *mnt, uint16_t x, int mode,
int *flags)
{
*sgn = x >> 15;
*exp = x >> 10 & 31;
*mnt = x & (((uint16_t)1 << 10) - 1);
// Handle subnormals:
if (*exp) {
*mnt |= (uint16_t)1 << 10;
} else {
++*exp;
// There is no flush to zero in this case!
}
}
static inline void
fp32_unpack(int *sgn, int *exp, uint32_t *mnt, uint32_t x, int mode,
int *flags)
{
*sgn = x >> 31;
*exp = x >> 23 & 255;
*mnt = x & (((uint32_t)1 << 23) - 1);
// Handle subnormals:
if (*exp) {
*mnt |= (uint32_t)1 << 23;
} else {
++*exp;
if ((mode & FPLIB_FZ) && *mnt) {
*flags |= FPLIB_IDC;
*mnt = 0;
}
}
}
static inline void
fp64_unpack(int *sgn, int *exp, uint64_t *mnt, uint64_t x, int mode,
int *flags)
{
*sgn = x >> 63;
*exp = x >> 52 & 2047;
*mnt = x & (((uint64_t)1 << 52) - 1);
// Handle subnormals:
if (*exp) {
*mnt |= (uint64_t)1 << 52;
} else {
++*exp;
if ((mode & FPLIB_FZ) && *mnt) {
*flags |= FPLIB_IDC;
*mnt = 0;
}
}
}
static inline uint32_t
fp32_process_NaN(uint32_t a, int mode, int *flags)
{
if (!(a >> 22 & 1)) {
*flags |= FPLIB_IOC;
a |= (uint32_t)1 << 22;
}
return mode & FPLIB_DN ? fp32_defaultNaN() : a;
}
static inline uint64_t
fp64_process_NaN(uint64_t a, int mode, int *flags)
{
if (!(a >> 51 & 1)) {
*flags |= FPLIB_IOC;
a |= (uint64_t)1 << 51;
}
return mode & FPLIB_DN ? fp64_defaultNaN() : a;
}
static uint32_t
fp32_process_NaNs(uint32_t a, uint32_t b, int mode, int *flags)
{
int a_exp = a >> 23 & 255;
uint32_t a_mnt = a & (((uint32_t)1 << 23) - 1);
int b_exp = b >> 23 & 255;
uint32_t b_mnt = b & (((uint32_t)1 << 23) - 1);
// Handle signalling NaNs:
if (a_exp == 255 && a_mnt && !(a_mnt >> 22 & 1))
return fp32_process_NaN(a, mode, flags);
if (b_exp == 255 && b_mnt && !(b_mnt >> 22 & 1))
return fp32_process_NaN(b, mode, flags);
// Handle quiet NaNs:
if (a_exp == 255 && a_mnt)
return fp32_process_NaN(a, mode, flags);
if (b_exp == 255 && b_mnt)
return fp32_process_NaN(b, mode, flags);
return 0;
}
static uint64_t
fp64_process_NaNs(uint64_t a, uint64_t b, int mode, int *flags)
{
int a_exp = a >> 52 & 2047;
uint64_t a_mnt = a & (((uint64_t)1 << 52) - 1);
int b_exp = b >> 52 & 2047;
uint64_t b_mnt = b & (((uint64_t)1 << 52) - 1);
// Handle signalling NaNs:
if (a_exp == 2047 && a_mnt && !(a_mnt >> 51 & 1))
return fp64_process_NaN(a, mode, flags);
if (b_exp == 2047 && b_mnt && !(b_mnt >> 51 & 1))
return fp64_process_NaN(b, mode, flags);
// Handle quiet NaNs:
if (a_exp == 2047 && a_mnt)
return fp64_process_NaN(a, mode, flags);
if (b_exp == 2047 && b_mnt)
return fp64_process_NaN(b, mode, flags);
return 0;
}
static uint32_t
fp32_process_NaNs3(uint32_t a, uint32_t b, uint32_t c, int mode, int *flags)
{
int a_exp = a >> 23 & 255;
uint32_t a_mnt = a & (((uint32_t)1 << 23) - 1);
int b_exp = b >> 23 & 255;
uint32_t b_mnt = b & (((uint32_t)1 << 23) - 1);
int c_exp = c >> 23 & 255;
uint32_t c_mnt = c & (((uint32_t)1 << 23) - 1);
// Handle signalling NaNs:
if (a_exp == 255 && a_mnt && !(a_mnt >> 22 & 1))
return fp32_process_NaN(a, mode, flags);
if (b_exp == 255 && b_mnt && !(b_mnt >> 22 & 1))
return fp32_process_NaN(b, mode, flags);
if (c_exp == 255 && c_mnt && !(c_mnt >> 22 & 1))
return fp32_process_NaN(c, mode, flags);
// Handle quiet NaNs:
if (a_exp == 255 && a_mnt)
return fp32_process_NaN(a, mode, flags);
if (b_exp == 255 && b_mnt)
return fp32_process_NaN(b, mode, flags);
if (c_exp == 255 && c_mnt)
return fp32_process_NaN(c, mode, flags);
return 0;
}
static uint64_t
fp64_process_NaNs3(uint64_t a, uint64_t b, uint64_t c, int mode, int *flags)
{
int a_exp = a >> 52 & 2047;
uint64_t a_mnt = a & (((uint64_t)1 << 52) - 1);
int b_exp = b >> 52 & 2047;
uint64_t b_mnt = b & (((uint64_t)1 << 52) - 1);
int c_exp = c >> 52 & 2047;
uint64_t c_mnt = c & (((uint64_t)1 << 52) - 1);
// Handle signalling NaNs:
if (a_exp == 2047 && a_mnt && !(a_mnt >> 51 & 1))
return fp64_process_NaN(a, mode, flags);
if (b_exp == 2047 && b_mnt && !(b_mnt >> 51 & 1))
return fp64_process_NaN(b, mode, flags);
if (c_exp == 2047 && c_mnt && !(c_mnt >> 51 & 1))
return fp64_process_NaN(c, mode, flags);
// Handle quiet NaNs:
if (a_exp == 2047 && a_mnt)
return fp64_process_NaN(a, mode, flags);
if (b_exp == 2047 && b_mnt)
return fp64_process_NaN(b, mode, flags);
if (c_exp == 2047 && c_mnt)
return fp64_process_NaN(c, mode, flags);
return 0;
}
static uint16_t
fp16_round_(int sgn, int exp, uint16_t mnt, int rm, int mode, int *flags)
{
int biased_exp; // non-negative exponent value for result
uint16_t int_mant; // mantissa for result, less than (1 << 11)
int error; // 0, 1, 2 or 3, where 2 means int_mant is wrong by exactly 0.5
assert(rm != FPRounding_TIEAWAY);
// There is no flush to zero in this case!
// The bottom 5 bits of mnt are orred together:
mnt = (uint16_t)1 << 12 | mnt >> 4 | ((mnt & 31) != 0);
if (exp > 0) {
biased_exp = exp;
int_mant = mnt >> 2;
error = mnt & 3;
} else {
biased_exp = 0;
int_mant = lsr16(mnt, 3 - exp);
error = (lsr16(mnt, 1 - exp) & 3) | !!(mnt & (lsl16(1, 1 - exp) - 1));
}
if (!biased_exp && error) { // xx should also check fpscr_val<11>
*flags |= FPLIB_UFC;
}
// Round up:
if ((rm == FPLIB_RN && (error == 3 ||
(error == 2 && (int_mant & 1)))) ||
(((rm == FPLIB_RP && !sgn) || (rm == FPLIB_RM && sgn)) && error)) {
++int_mant;
if (int_mant == (uint32_t)1 << 10) {
// Rounded up from denormalized to normalized
biased_exp = 1;
}
if (int_mant == (uint32_t)1 << 11) {
// Rounded up to next exponent
++biased_exp;
int_mant >>= 1;
}
}
// Handle rounding to odd aka Von Neumann rounding:
if (error && rm == FPRounding_ODD)
int_mant |= 1;
// Handle overflow:
if (!(mode & FPLIB_AHP)) {
if (biased_exp >= 31) {
*flags |= FPLIB_OFC | FPLIB_IXC;
if (rm == FPLIB_RN || (rm == FPLIB_RP && !sgn) ||
(rm == FPLIB_RM && sgn)) {
return fp16_infinity(sgn);
} else {
return fp16_max_normal(sgn);
}
}
} else {
if (biased_exp >= 32) {
*flags |= FPLIB_IOC;
return fp16_pack(sgn, 31, -1);
}
}
if (error) {
*flags |= FPLIB_IXC;
}
return fp16_pack(sgn, biased_exp, int_mant);
}
static uint32_t
fp32_round_(int sgn, int exp, uint32_t mnt, int rm, int mode, int *flags)
{
int biased_exp; // non-negative exponent value for result
uint32_t int_mant; // mantissa for result, less than (1 << 24)
int error; // 0, 1, 2 or 3, where 2 means int_mant is wrong by exactly 0.5
assert(rm != FPRounding_TIEAWAY);
// Flush to zero:
if ((mode & FPLIB_FZ) && exp < 1) {
*flags |= FPLIB_UFC;
return fp32_zero(sgn);
}
// The bottom 8 bits of mnt are orred together:
mnt = (uint32_t)1 << 25 | mnt >> 7 | ((mnt & 255) != 0);
if (exp > 0) {
biased_exp = exp;
int_mant = mnt >> 2;
error = mnt & 3;
} else {
biased_exp = 0;
int_mant = lsr32(mnt, 3 - exp);
error = (lsr32(mnt, 1 - exp) & 3) | !!(mnt & (lsl32(1, 1 - exp) - 1));
}
if (!biased_exp && error) { // xx should also check fpscr_val<11>
*flags |= FPLIB_UFC;
}
// Round up:
if ((rm == FPLIB_RN && (error == 3 ||
(error == 2 && (int_mant & 1)))) ||
(((rm == FPLIB_RP && !sgn) || (rm == FPLIB_RM && sgn)) && error)) {
++int_mant;
if (int_mant == (uint32_t)1 << 23) {
// Rounded up from denormalized to normalized
biased_exp = 1;
}
if (int_mant == (uint32_t)1 << 24) {
// Rounded up to next exponent
++biased_exp;
int_mant >>= 1;
}
}
// Handle rounding to odd aka Von Neumann rounding:
if (error && rm == FPRounding_ODD)
int_mant |= 1;
// Handle overflow:
if (biased_exp >= 255) {
*flags |= FPLIB_OFC | FPLIB_IXC;
if (rm == FPLIB_RN || (rm == FPLIB_RP && !sgn) ||
(rm == FPLIB_RM && sgn)) {
return fp32_infinity(sgn);
} else {
return fp32_max_normal(sgn);
}
}
if (error) {
*flags |= FPLIB_IXC;
}
return fp32_pack(sgn, biased_exp, int_mant);
}
static uint32_t
fp32_round(int sgn, int exp, uint32_t mnt, int mode, int *flags)
{
return fp32_round_(sgn, exp, mnt, mode & 3, mode, flags);
}
static uint64_t
fp64_round_(int sgn, int exp, uint64_t mnt, int rm, int mode, int *flags)
{
int biased_exp; // non-negative exponent value for result
uint64_t int_mant; // mantissa for result, less than (1 << 52)
int error; // 0, 1, 2 or 3, where 2 means int_mant is wrong by exactly 0.5
assert(rm != FPRounding_TIEAWAY);
// Flush to zero:
if ((mode & FPLIB_FZ) && exp < 1) {
*flags |= FPLIB_UFC;
return fp64_zero(sgn);
}
// The bottom 11 bits of mnt are orred together:
mnt = (uint64_t)1 << 54 | mnt >> 10 | ((mnt & 0x3ff) != 0);
if (exp > 0) {
biased_exp = exp;
int_mant = mnt >> 2;
error = mnt & 3;
} else {
biased_exp = 0;
int_mant = lsr64(mnt, 3 - exp);
error = (lsr64(mnt, 1 - exp) & 3) | !!(mnt & (lsl64(1, 1 - exp) - 1));
}
if (!biased_exp && error) { // xx should also check fpscr_val<11>
*flags |= FPLIB_UFC;
}
// Round up:
if ((rm == FPLIB_RN && (error == 3 ||
(error == 2 && (int_mant & 1)))) ||
(((rm == FPLIB_RP && !sgn) || (rm == FPLIB_RM && sgn)) && error)) {
++int_mant;
if (int_mant == (uint64_t)1 << 52) {
// Rounded up from denormalized to normalized
biased_exp = 1;
}
if (int_mant == (uint64_t)1 << 53) {
// Rounded up to next exponent
++biased_exp;
int_mant >>= 1;
}
}
// Handle rounding to odd aka Von Neumann rounding:
if (error && rm == FPRounding_ODD)
int_mant |= 1;
// Handle overflow:
if (biased_exp >= 2047) {
*flags |= FPLIB_OFC | FPLIB_IXC;
if (rm == FPLIB_RN || (rm == FPLIB_RP && !sgn) ||
(rm == FPLIB_RM && sgn)) {
return fp64_infinity(sgn);
} else {
return fp64_max_normal(sgn);
}
}
if (error) {
*flags |= FPLIB_IXC;
}
return fp64_pack(sgn, biased_exp, int_mant);
}
static uint64_t
fp64_round(int sgn, int exp, uint64_t mnt, int mode, int *flags)
{
return fp64_round_(sgn, exp, mnt, mode & 3, mode, flags);
}
static int
fp32_compare_eq(uint32_t a, uint32_t b, int mode, int *flags)
{
int a_sgn, a_exp, b_sgn, b_exp;
uint32_t a_mnt, b_mnt;
fp32_unpack(&a_sgn, &a_exp, &a_mnt, a, mode, flags);
fp32_unpack(&b_sgn, &b_exp, &b_mnt, b, mode, flags);
if ((a_exp == 255 && (uint32_t)(a_mnt << 9)) ||
(b_exp == 255 && (uint32_t)(b_mnt << 9))) {
if ((a_exp == 255 && (uint32_t)(a_mnt << 9) && !(a >> 22 & 1)) ||
(b_exp == 255 && (uint32_t)(b_mnt << 9) && !(b >> 22 & 1)))
*flags |= FPLIB_IOC;
return 0;
}
return a == b || (!a_mnt && !b_mnt);
}
static int
fp32_compare_ge(uint32_t a, uint32_t b, int mode, int *flags)
{
int a_sgn, a_exp, b_sgn, b_exp;
uint32_t a_mnt, b_mnt;
fp32_unpack(&a_sgn, &a_exp, &a_mnt, a, mode, flags);
fp32_unpack(&b_sgn, &b_exp, &b_mnt, b, mode, flags);
if ((a_exp == 255 && (uint32_t)(a_mnt << 9)) ||
(b_exp == 255 && (uint32_t)(b_mnt << 9))) {
*flags |= FPLIB_IOC;
return 0;
}
if (!a_mnt && !b_mnt)
return 1;
if (a_sgn != b_sgn)
return b_sgn;
if (a_exp != b_exp)
return a_sgn ^ (a_exp > b_exp);
if (a_mnt != b_mnt)
return a_sgn ^ (a_mnt > b_mnt);
return 1;
}
static int
fp32_compare_gt(uint32_t a, uint32_t b, int mode, int *flags)
{
int a_sgn, a_exp, b_sgn, b_exp;
uint32_t a_mnt, b_mnt;
fp32_unpack(&a_sgn, &a_exp, &a_mnt, a, mode, flags);
fp32_unpack(&b_sgn, &b_exp, &b_mnt, b, mode, flags);
if ((a_exp == 255 && (uint32_t)(a_mnt << 9)) ||
(b_exp == 255 && (uint32_t)(b_mnt << 9))) {
*flags |= FPLIB_IOC;
return 0;
}
if (!a_mnt && !b_mnt)
return 0;
if (a_sgn != b_sgn)
return b_sgn;
if (a_exp != b_exp)
return a_sgn ^ (a_exp > b_exp);
if (a_mnt != b_mnt)
return a_sgn ^ (a_mnt > b_mnt);
return 0;
}
static int
fp64_compare_eq(uint64_t a, uint64_t b, int mode, int *flags)
{
int a_sgn, a_exp, b_sgn, b_exp;
uint64_t a_mnt, b_mnt;
fp64_unpack(&a_sgn, &a_exp, &a_mnt, a, mode, flags);
fp64_unpack(&b_sgn, &b_exp, &b_mnt, b, mode, flags);
if ((a_exp == 2047 && (uint64_t)(a_mnt << 12)) ||
(b_exp == 2047 && (uint64_t)(b_mnt << 12))) {
if ((a_exp == 2047 && (uint64_t)(a_mnt << 12) && !(a >> 51 & 1)) ||
(b_exp == 2047 && (uint64_t)(b_mnt << 12) && !(b >> 51 & 1)))
*flags |= FPLIB_IOC;
return 0;
}
return a == b || (!a_mnt && !b_mnt);
}
static int
fp64_compare_ge(uint64_t a, uint64_t b, int mode, int *flags)
{
int a_sgn, a_exp, b_sgn, b_exp;
uint64_t a_mnt, b_mnt;
fp64_unpack(&a_sgn, &a_exp, &a_mnt, a, mode, flags);
fp64_unpack(&b_sgn, &b_exp, &b_mnt, b, mode, flags);
if ((a_exp == 2047 && (uint64_t)(a_mnt << 12)) ||
(b_exp == 2047 && (uint64_t)(b_mnt << 12))) {
*flags |= FPLIB_IOC;
return 0;
}
if (!a_mnt && !b_mnt)
return 1;
if (a_sgn != b_sgn)
return b_sgn;
if (a_exp != b_exp)
return a_sgn ^ (a_exp > b_exp);
if (a_mnt != b_mnt)
return a_sgn ^ (a_mnt > b_mnt);
return 1;
}
static int
fp64_compare_gt(uint64_t a, uint64_t b, int mode, int *flags)
{
int a_sgn, a_exp, b_sgn, b_exp;
uint64_t a_mnt, b_mnt;
fp64_unpack(&a_sgn, &a_exp, &a_mnt, a, mode, flags);
fp64_unpack(&b_sgn, &b_exp, &b_mnt, b, mode, flags);
if ((a_exp == 2047 && (uint64_t)(a_mnt << 12)) ||
(b_exp == 2047 && (uint64_t)(b_mnt << 12))) {
*flags |= FPLIB_IOC;
return 0;
}
if (!a_mnt && !b_mnt)
return 0;
if (a_sgn != b_sgn)
return b_sgn;
if (a_exp != b_exp)
return a_sgn ^ (a_exp > b_exp);
if (a_mnt != b_mnt)
return a_sgn ^ (a_mnt > b_mnt);
return 0;
}
static uint32_t
fp32_add(uint32_t a, uint32_t b, int neg, int mode, int *flags)
{
int a_sgn, a_exp, b_sgn, b_exp, x_sgn, x_exp;
uint32_t a_mnt, b_mnt, x, x_mnt;
fp32_unpack(&a_sgn, &a_exp, &a_mnt, a, mode, flags);
fp32_unpack(&b_sgn, &b_exp, &b_mnt, b, mode, flags);
if ((x = fp32_process_NaNs(a, b, mode, flags))) {
return x;
}
b_sgn ^= neg;
// Handle infinities and zeroes:
if (a_exp == 255 && b_exp == 255 && a_sgn != b_sgn) {
*flags |= FPLIB_IOC;
return fp32_defaultNaN();
} else if (a_exp == 255) {
return fp32_infinity(a_sgn);
} else if (b_exp == 255) {
return fp32_infinity(b_sgn);
} else if (!a_mnt && !b_mnt && a_sgn == b_sgn) {
return fp32_zero(a_sgn);
}
a_mnt <<= 3;
b_mnt <<= 3;
if (a_exp >= b_exp) {
b_mnt = (lsr32(b_mnt, a_exp - b_exp) |
!!(b_mnt & (lsl32(1, a_exp - b_exp) - 1)));
b_exp = a_exp;
} else {
a_mnt = (lsr32(a_mnt, b_exp - a_exp) |
!!(a_mnt & (lsl32(1, b_exp - a_exp) - 1)));
a_exp = b_exp;
}
x_sgn = a_sgn;
x_exp = a_exp;
if (a_sgn == b_sgn) {
x_mnt = a_mnt + b_mnt;
} else if (a_mnt >= b_mnt) {
x_mnt = a_mnt - b_mnt;
} else {
x_sgn ^= 1;
x_mnt = b_mnt - a_mnt;
}
if (!x_mnt) {
// Sign of exact zero result depends on rounding mode
return fp32_zero((mode & 3) == 2);
}
x_mnt = fp32_normalise(x_mnt, &x_exp);
return fp32_round(x_sgn, x_exp + 5, x_mnt << 1, mode, flags);
}
static uint64_t
fp64_add(uint64_t a, uint64_t b, int neg, int mode, int *flags)
{
int a_sgn, a_exp, b_sgn, b_exp, x_sgn, x_exp;
uint64_t a_mnt, b_mnt, x, x_mnt;
fp64_unpack(&a_sgn, &a_exp, &a_mnt, a, mode, flags);
fp64_unpack(&b_sgn, &b_exp, &b_mnt, b, mode, flags);
if ((x = fp64_process_NaNs(a, b, mode, flags))) {
return x;
}
b_sgn ^= neg;
// Handle infinities and zeroes:
if (a_exp == 2047 && b_exp == 2047 && a_sgn != b_sgn) {
*flags |= FPLIB_IOC;
return fp64_defaultNaN();
} else if (a_exp == 2047) {
return fp64_infinity(a_sgn);
} else if (b_exp == 2047) {
return fp64_infinity(b_sgn);
} else if (!a_mnt && !b_mnt && a_sgn == b_sgn) {
return fp64_zero(a_sgn);
}
a_mnt <<= 3;
b_mnt <<= 3;
if (a_exp >= b_exp) {
b_mnt = (lsr64(b_mnt, a_exp - b_exp) |
!!(b_mnt & (lsl64(1, a_exp - b_exp) - 1)));
b_exp = a_exp;
} else {
a_mnt = (lsr64(a_mnt, b_exp - a_exp) |
!!(a_mnt & (lsl64(1, b_exp - a_exp) - 1)));
a_exp = b_exp;
}
x_sgn = a_sgn;
x_exp = a_exp;
if (a_sgn == b_sgn) {
x_mnt = a_mnt + b_mnt;
} else if (a_mnt >= b_mnt) {
x_mnt = a_mnt - b_mnt;
} else {
x_sgn ^= 1;
x_mnt = b_mnt - a_mnt;
}
if (!x_mnt) {
// Sign of exact zero result depends on rounding mode
return fp64_zero((mode & 3) == 2);
}
x_mnt = fp64_normalise(x_mnt, &x_exp);
return fp64_round(x_sgn, x_exp + 8, x_mnt << 1, mode, flags);
}
static uint32_t
fp32_mul(uint32_t a, uint32_t b, int mode, int *flags)
{
int a_sgn, a_exp, b_sgn, b_exp, x_sgn, x_exp;
uint32_t a_mnt, b_mnt, x;
uint64_t x_mnt;
fp32_unpack(&a_sgn, &a_exp, &a_mnt, a, mode, flags);
fp32_unpack(&b_sgn, &b_exp, &b_mnt, b, mode, flags);
if ((x = fp32_process_NaNs(a, b, mode, flags))) {
return x;
}
// Handle infinities and zeroes:
if ((a_exp == 255 && !b_mnt) || (b_exp == 255 && !a_mnt)) {
*flags |= FPLIB_IOC;
return fp32_defaultNaN();
} else if (a_exp == 255 || b_exp == 255) {
return fp32_infinity(a_sgn ^ b_sgn);
} else if (!a_mnt || !b_mnt) {
return fp32_zero(a_sgn ^ b_sgn);
}
// Multiply and normalise:
x_sgn = a_sgn ^ b_sgn;
x_exp = a_exp + b_exp - 110;
x_mnt = (uint64_t)a_mnt * b_mnt;
x_mnt = fp64_normalise(x_mnt, &x_exp);
// Convert to 32 bits, collapsing error into bottom bit:
x_mnt = lsr64(x_mnt, 31) | !!lsl64(x_mnt, 33);
return fp32_round(x_sgn, x_exp, x_mnt, mode, flags);
}
static uint64_t
fp64_mul(uint64_t a, uint64_t b, int mode, int *flags)
{
int a_sgn, a_exp, b_sgn, b_exp, x_sgn, x_exp;
uint64_t a_mnt, b_mnt, x;
uint64_t x0_mnt, x1_mnt;
fp64_unpack(&a_sgn, &a_exp, &a_mnt, a, mode, flags);
fp64_unpack(&b_sgn, &b_exp, &b_mnt, b, mode, flags);
if ((x = fp64_process_NaNs(a, b, mode, flags))) {
return x;
}
// Handle infinities and zeroes:
if ((a_exp == 2047 && !b_mnt) || (b_exp == 2047 && !a_mnt)) {
*flags |= FPLIB_IOC;
return fp64_defaultNaN();
} else if (a_exp == 2047 || b_exp == 2047) {
return fp64_infinity(a_sgn ^ b_sgn);
} else if (!a_mnt || !b_mnt) {
return fp64_zero(a_sgn ^ b_sgn);
}
// Multiply and normalise:
x_sgn = a_sgn ^ b_sgn;
x_exp = a_exp + b_exp - 1000;
mul62x62(&x0_mnt, &x1_mnt, a_mnt, b_mnt);
fp128_normalise(&x0_mnt, &x1_mnt, &x_exp);
// Convert to 64 bits, collapsing error into bottom bit:
x0_mnt = x1_mnt << 1 | !!x0_mnt;
return fp64_round(x_sgn, x_exp, x0_mnt, mode, flags);
}
static uint32_t
fp32_muladd(uint32_t a, uint32_t b, uint32_t c, int scale,
int mode, int *flags)
{
int a_sgn, a_exp, b_sgn, b_exp, c_sgn, c_exp, x_sgn, x_exp, y_sgn, y_exp;
uint32_t a_mnt, b_mnt, c_mnt, x;
uint64_t x_mnt, y_mnt;
fp32_unpack(&a_sgn, &a_exp, &a_mnt, a, mode, flags);
fp32_unpack(&b_sgn, &b_exp, &b_mnt, b, mode, flags);
fp32_unpack(&c_sgn, &c_exp, &c_mnt, c, mode, flags);
x = fp32_process_NaNs3(a, b, c, mode, flags);
// Quiet NaN added to product of zero and infinity:
if (a_exp == 255 && (a_mnt >> 22 & 1) &&
((!b_mnt && c_exp == 255 && !(uint32_t)(c_mnt << 9)) ||
(!c_mnt && b_exp == 255 && !(uint32_t)(b_mnt << 9)))) {
x = fp32_defaultNaN();
*flags |= FPLIB_IOC;
}
if (x) {
return x;
}
// Handle infinities and zeroes:
if ((b_exp == 255 && !c_mnt) ||
(c_exp == 255 && !b_mnt) ||
(a_exp == 255 && (b_exp == 255 || c_exp == 255) &&
(a_sgn != (b_sgn ^ c_sgn)))) {
*flags |= FPLIB_IOC;
return fp32_defaultNaN();
}
if (a_exp == 255)
return fp32_infinity(a_sgn);
if (b_exp == 255 || c_exp == 255)
return fp32_infinity(b_sgn ^ c_sgn);
if (!a_mnt && (!b_mnt || !c_mnt) && a_sgn == (b_sgn ^ c_sgn))
return fp32_zero(a_sgn);
x_sgn = a_sgn;
x_exp = a_exp + 13;
x_mnt = (uint64_t)a_mnt << 27;
// Multiply:
y_sgn = b_sgn ^ c_sgn;
y_exp = b_exp + c_exp - 113;
y_mnt = (uint64_t)b_mnt * c_mnt << 3;
if (!y_mnt) {
y_exp = x_exp;
}
// Add:
if (x_exp >= y_exp) {
y_mnt = (lsr64(y_mnt, x_exp - y_exp) |
!!(y_mnt & (lsl64(1, x_exp - y_exp) - 1)));
y_exp = x_exp;
} else {
x_mnt = (lsr64(x_mnt, y_exp - x_exp) |
!!(x_mnt & (lsl64(1, y_exp - x_exp) - 1)));
x_exp = y_exp;
}
if (x_sgn == y_sgn) {
x_mnt = x_mnt + y_mnt;
} else if (x_mnt >= y_mnt) {
x_mnt = x_mnt - y_mnt;
} else {
x_sgn ^= 1;
x_mnt = y_mnt - x_mnt;
}
if (!x_mnt) {
// Sign of exact zero result depends on rounding mode
return fp32_zero((mode & 3) == 2);
}
// Normalise and convert to 32 bits, collapsing error into bottom bit:
x_mnt = fp64_normalise(x_mnt, &x_exp);
x_mnt = x_mnt >> 31 | !!(uint32_t)(x_mnt << 1);
return fp32_round(x_sgn, x_exp + scale, x_mnt, mode, flags);
}
static uint64_t
fp64_muladd(uint64_t a, uint64_t b, uint64_t c, int scale,
int mode, int *flags)
{
int a_sgn, a_exp, b_sgn, b_exp, c_sgn, c_exp, x_sgn, x_exp, y_sgn, y_exp;
uint64_t a_mnt, b_mnt, c_mnt, x;
uint64_t x0_mnt, x1_mnt, y0_mnt, y1_mnt;
fp64_unpack(&a_sgn, &a_exp, &a_mnt, a, mode, flags);
fp64_unpack(&b_sgn, &b_exp, &b_mnt, b, mode, flags);
fp64_unpack(&c_sgn, &c_exp, &c_mnt, c, mode, flags);
x = fp64_process_NaNs3(a, b, c, mode, flags);
// Quiet NaN added to product of zero and infinity:
if (a_exp == 2047 && (a_mnt >> 51 & 1) &&
((!b_mnt && c_exp == 2047 && !(uint64_t)(c_mnt << 12)) ||
(!c_mnt && b_exp == 2047 && !(uint64_t)(b_mnt << 12)))) {
x = fp64_defaultNaN();
*flags |= FPLIB_IOC;
}
if (x) {
return x;
}
// Handle infinities and zeroes:
if ((b_exp == 2047 && !c_mnt) ||
(c_exp == 2047 && !b_mnt) ||
(a_exp == 2047 && (b_exp == 2047 || c_exp == 2047) &&
(a_sgn != (b_sgn ^ c_sgn)))) {
*flags |= FPLIB_IOC;
return fp64_defaultNaN();
}
if (a_exp == 2047)
return fp64_infinity(a_sgn);
if (b_exp == 2047 || c_exp == 2047)
return fp64_infinity(b_sgn ^ c_sgn);
if (!a_mnt && (!b_mnt || !c_mnt) && a_sgn == (b_sgn ^ c_sgn))
return fp64_zero(a_sgn);
x_sgn = a_sgn;
x_exp = a_exp + 11;
x0_mnt = 0;
x1_mnt = a_mnt;
// Multiply:
y_sgn = b_sgn ^ c_sgn;
y_exp = b_exp + c_exp - 1003;
mul62x62(&y0_mnt, &y1_mnt, b_mnt, c_mnt << 3);
if (!y0_mnt && !y1_mnt) {
y_exp = x_exp;
}
// Add:
if (x_exp >= y_exp) {
uint64_t t0, t1;
lsl128(&t0, &t1, y0_mnt, y1_mnt,
x_exp - y_exp < 128 ? 128 - (x_exp - y_exp) : 0);
lsr128(&y0_mnt, &y1_mnt, y0_mnt, y1_mnt, x_exp - y_exp);
y0_mnt |= !!(t0 | t1);
y_exp = x_exp;
} else {
uint64_t t0, t1;
lsl128(&t0, &t1, x0_mnt, x1_mnt,
y_exp - x_exp < 128 ? 128 - (y_exp - x_exp) : 0);
lsr128(&x0_mnt, &x1_mnt, x0_mnt, x1_mnt, y_exp - x_exp);
x0_mnt |= !!(t0 | t1);
x_exp = y_exp;
}
if (x_sgn == y_sgn) {
add128(&x0_mnt, &x1_mnt, x0_mnt, x1_mnt, y0_mnt, y1_mnt);
} else if (cmp128(x0_mnt, x1_mnt, y0_mnt, y1_mnt) >= 0) {
sub128(&x0_mnt, &x1_mnt, x0_mnt, x1_mnt, y0_mnt, y1_mnt);
} else {
x_sgn ^= 1;
sub128(&x0_mnt, &x1_mnt, y0_mnt, y1_mnt, x0_mnt, x1_mnt);
}
if (!x0_mnt && !x1_mnt) {
// Sign of exact zero result depends on rounding mode
return fp64_zero((mode & 3) == 2);
}
// Normalise and convert to 64 bits, collapsing error into bottom bit:
fp128_normalise(&x0_mnt, &x1_mnt, &x_exp);
x0_mnt = x1_mnt << 1 | !!x0_mnt;
return fp64_round(x_sgn, x_exp + scale, x0_mnt, mode, flags);
}
static uint32_t
fp32_div(uint32_t a, uint32_t b, int mode, int *flags)
{
int a_sgn, a_exp, b_sgn, b_exp, x_sgn, x_exp;
uint32_t a_mnt, b_mnt, x;
uint64_t x_mnt;
fp32_unpack(&a_sgn, &a_exp, &a_mnt, a, mode, flags);
fp32_unpack(&b_sgn, &b_exp, &b_mnt, b, mode, flags);
if ((x = fp32_process_NaNs(a, b, mode, flags)))
return x;
// Handle infinities and zeroes:
if ((a_exp == 255 && b_exp == 255) || (!a_mnt && !b_mnt)) {
*flags |= FPLIB_IOC;
return fp32_defaultNaN();
}
if (a_exp == 255 || !b_mnt) {
if (a_exp != 255)
*flags |= FPLIB_DZC;
return fp32_infinity(a_sgn ^ b_sgn);
}
if (!a_mnt || b_exp == 255)
return fp32_zero(a_sgn ^ b_sgn);
// Divide, setting bottom bit if inexact:
a_mnt = fp32_normalise(a_mnt, &a_exp);
x_sgn = a_sgn ^ b_sgn;
x_exp = a_exp - b_exp + 172;
x_mnt = ((uint64_t)a_mnt << 18) / b_mnt;
x_mnt |= (x_mnt * b_mnt != (uint64_t)a_mnt << 18);
// Normalise and convert to 32 bits, collapsing error into bottom bit:
x_mnt = fp64_normalise(x_mnt, &x_exp);
x_mnt = x_mnt >> 31 | !!(uint32_t)(x_mnt << 1);
return fp32_round(x_sgn, x_exp, x_mnt, mode, flags);
}
static uint64_t
fp64_div(uint64_t a, uint64_t b, int mode, int *flags)
{
int a_sgn, a_exp, b_sgn, b_exp, x_sgn, x_exp, c;
uint64_t a_mnt, b_mnt, x, x_mnt, x0_mnt, x1_mnt;
fp64_unpack(&a_sgn, &a_exp, &a_mnt, a, mode, flags);
fp64_unpack(&b_sgn, &b_exp, &b_mnt, b, mode, flags);
if ((x = fp64_process_NaNs(a, b, mode, flags)))
return x;
// Handle infinities and zeroes:
if ((a_exp == 2047 && b_exp == 2047) || (!a_mnt && !b_mnt)) {
*flags |= FPLIB_IOC;
return fp64_defaultNaN();
}
if (a_exp == 2047 || !b_mnt) {
if (a_exp != 2047)
*flags |= FPLIB_DZC;
return fp64_infinity(a_sgn ^ b_sgn);
}
if (!a_mnt || b_exp == 2047)
return fp64_zero(a_sgn ^ b_sgn);
// Find reciprocal of divisor with Newton-Raphson:
a_mnt = fp64_normalise(a_mnt, &a_exp);
b_mnt = fp64_normalise(b_mnt, &b_exp);
x_mnt = ~(uint64_t)0 / (b_mnt >> 31);
mul64x32(&x0_mnt, &x1_mnt, b_mnt, x_mnt);
sub128(&x0_mnt, &x1_mnt, 0, (uint64_t)1 << 32, x0_mnt, x1_mnt);
lsr128(&x0_mnt, &x1_mnt, x0_mnt, x1_mnt, 32);
mul64x32(&x0_mnt, &x1_mnt, x0_mnt, x_mnt);
lsr128(&x0_mnt, &x1_mnt, x0_mnt, x1_mnt, 33);
// Multiply by dividend:
x_sgn = a_sgn ^ b_sgn;
x_exp = a_exp - b_exp + 1031;
mul62x62(&x0_mnt, &x1_mnt, x0_mnt, a_mnt >> 2); // xx 62x62 is enough
lsr128(&x0_mnt, &x1_mnt, x0_mnt, x1_mnt, 4);
x_mnt = x1_mnt;
// This is an underestimate, so try adding one:
mul62x62(&x0_mnt, &x1_mnt, b_mnt >> 2, x_mnt + 1); // xx 62x62 is enough
c = cmp128(x0_mnt, x1_mnt, 0, a_mnt >> 11);
if (c <= 0) {
++x_mnt;
}
x_mnt = fp64_normalise(x_mnt, &x_exp);
return fp64_round(x_sgn, x_exp, x_mnt << 1 | !!c, mode, flags);
}
static void
set_fpscr0(FPSCR &fpscr, int flags)
{
if (flags & FPLIB_IDC) {
fpscr.idc = 1;
}
if (flags & FPLIB_IOC) {
fpscr.ioc = 1;
}
if (flags & FPLIB_DZC) {
fpscr.dzc = 1;
}
if (flags & FPLIB_OFC) {
fpscr.ofc = 1;
}
if (flags & FPLIB_UFC) {
fpscr.ufc = 1;
}
if (flags & FPLIB_IXC) {
fpscr.ixc = 1;
}
}
static uint32_t
fp32_sqrt(uint32_t a, int mode, int *flags)
{
int a_sgn, a_exp, x_sgn, x_exp;
uint32_t a_mnt, x, x_mnt;
uint64_t t0, t1;
fp32_unpack(&a_sgn, &a_exp, &a_mnt, a, mode, flags);
// Handle NaNs:
if (a_exp == 255 && (uint32_t)(a_mnt << 9))
return fp32_process_NaN(a, mode, flags);
// Handle infinities and zeroes:
if (!a_mnt) {
return fp32_zero(a_sgn);
}
if (a_exp == 255 && !a_sgn) {
return fp32_infinity(a_sgn);
}
if (a_sgn) {
*flags |= FPLIB_IOC;
return fp32_defaultNaN();
}
a_mnt = fp32_normalise(a_mnt, &a_exp);
if (!(a_exp & 1)) {
++a_exp;
a_mnt >>= 1;
}
// x = (a * 3 + 5) / 8
x = (a_mnt >> 2) + (a_mnt >> 3) + (5 << 28);
// x = (a / x + x) / 2; // 16-bit accuracy
x = (a_mnt / (x >> 15) + (x >> 16)) << 15;
// x = (a / x + x) / 2; // 16-bit accuracy
x = (a_mnt / (x >> 15) + (x >> 16)) << 15;
// x = (a / x + x) / 2; // 32-bit accuracy
x = ((((uint64_t)a_mnt << 32) / x) >> 2) + (x >> 1);
x_sgn = 0;
x_exp = (a_exp + 147) >> 1;
x_mnt = ((x - (1 << 5)) >> 6) + 1;
t1 = (uint64_t)x_mnt * x_mnt;
t0 = (uint64_t)a_mnt << 19;
if (t1 > t0) {
--x_mnt;
}
x_mnt = fp32_normalise(x_mnt, &x_exp);
return fp32_round(x_sgn, x_exp, x_mnt << 1 | (t1 != t0), mode, flags);
}
static uint64_t
fp64_sqrt(uint64_t a, int mode, int *flags)
{
int a_sgn, a_exp, x_sgn, x_exp, c;
uint64_t a_mnt, x_mnt, r, x0, x1;
uint32_t x;
fp64_unpack(&a_sgn, &a_exp, &a_mnt, a, mode, flags);
// Handle NaNs:
if (a_exp == 2047 && (uint64_t)(a_mnt << 12)) {
return fp64_process_NaN(a, mode, flags);
}
// Handle infinities and zeroes:
if (!a_mnt)
return fp64_zero(a_sgn);
if (a_exp == 2047 && !a_sgn)
return fp64_infinity(a_sgn);
if (a_sgn) {
*flags |= FPLIB_IOC;
return fp64_defaultNaN();
}
a_mnt = fp64_normalise(a_mnt, &a_exp);
if (a_exp & 1) {
++a_exp;
a_mnt >>= 1;
}
// x = (a * 3 + 5) / 8
x = (a_mnt >> 34) + (a_mnt >> 35) + (5 << 28);
// x = (a / x + x) / 2; // 16-bit accuracy
x = ((a_mnt >> 32) / (x >> 15) + (x >> 16)) << 15;
// x = (a / x + x) / 2; // 16-bit accuracy
x = ((a_mnt >> 32) / (x >> 15) + (x >> 16)) << 15;
// x = (a / x + x) / 2; // 32-bit accuracy
x = ((a_mnt / x) >> 2) + (x >> 1);
// r = 1 / x; // 32-bit accuracy
r = ((uint64_t)1 << 62) / x;
// r = r * (2 - x * r); // 64-bit accuracy
mul64x32(&x0, &x1, -(uint64_t)x * r << 1, r);
lsr128(&x0, &x1, x0, x1, 31);
// x = (x + a * r) / 2; // 64-bit accuracy
mul62x62(&x0, &x1, a_mnt >> 10, x0 >> 2);
lsl128(&x0, &x1, x0, x1, 5);
lsr128(&x0, &x1, x0, x1, 56);
x0 = ((uint64_t)x << 31) + (x0 >> 1);
x_sgn = 0;
x_exp = (a_exp + 1053) >> 1;
x_mnt = x0;
x_mnt = ((x_mnt - (1 << 8)) >> 9) + 1;
mul62x62(&x0, &x1, x_mnt, x_mnt);
lsl128(&x0, &x1, x0, x1, 19);
c = cmp128(x0, x1, 0, a_mnt);
if (c > 0)
--x_mnt;
x_mnt = fp64_normalise(x_mnt, &x_exp);
return fp64_round(x_sgn, x_exp, x_mnt << 1 | !!c, mode, flags);
}
static int
modeConv(FPSCR fpscr)
{
return (((int) fpscr) >> 22) & 0xF;
}
static void
set_fpscr(FPSCR &fpscr, int flags)
{
// translate back to FPSCR
bool underflow = false;
if (flags & FPLIB_IDC) {
fpscr.idc = 1;
}
if (flags & FPLIB_IOC) {
fpscr.ioc = 1;
}
if (flags & FPLIB_DZC) {
fpscr.dzc = 1;
}
if (flags & FPLIB_OFC) {
fpscr.ofc = 1;
}
if (flags & FPLIB_UFC) {
underflow = true; //xx Why is this required?
fpscr.ufc = 1;
}
if ((flags & FPLIB_IXC) && !(underflow && fpscr.fz)) {
fpscr.ixc = 1;
}
}
template <>
bool
fplibCompareEQ(uint32_t a, uint32_t b, FPSCR &fpscr)
{
int flags = 0;
int x = fp32_compare_eq(a, b, modeConv(fpscr), &flags);
set_fpscr(fpscr, flags);
return x;
}
template <>
bool
fplibCompareGE(uint32_t a, uint32_t b, FPSCR &fpscr)
{
int flags = 0;
int x = fp32_compare_ge(a, b, modeConv(fpscr), &flags);
set_fpscr(fpscr, flags);
return x;
}
template <>
bool
fplibCompareGT(uint32_t a, uint32_t b, FPSCR &fpscr)
{
int flags = 0;
int x = fp32_compare_gt(a, b, modeConv(fpscr), &flags);
set_fpscr(fpscr, flags);
return x;
}
template <>
bool
fplibCompareEQ(uint64_t a, uint64_t b, FPSCR &fpscr)
{
int flags = 0;
int x = fp64_compare_eq(a, b, modeConv(fpscr), &flags);
set_fpscr(fpscr, flags);
return x;
}
template <>
bool
fplibCompareGE(uint64_t a, uint64_t b, FPSCR &fpscr)
{
int flags = 0;
int x = fp64_compare_ge(a, b, modeConv(fpscr), &flags);
set_fpscr(fpscr, flags);
return x;
}
template <>
bool
fplibCompareGT(uint64_t a, uint64_t b, FPSCR &fpscr)
{
int flags = 0;
int x = fp64_compare_gt(a, b, modeConv(fpscr), &flags);
set_fpscr(fpscr, flags);
return x;
}
template <>
uint32_t
fplibAbs(uint32_t op)
{
return op & ~((uint32_t)1 << 31);
}
template <>
uint64_t
fplibAbs(uint64_t op)
{
return op & ~((uint64_t)1 << 63);
}
template <>
uint32_t
fplibAdd(uint32_t op1, uint32_t op2, FPSCR &fpscr)
{
int flags = 0;
uint32_t result = fp32_add(op1, op2, 0, modeConv(fpscr), &flags);
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint64_t
fplibAdd(uint64_t op1, uint64_t op2, FPSCR &fpscr)
{
int flags = 0;
uint64_t result = fp64_add(op1, op2, 0, modeConv(fpscr), &flags);
set_fpscr0(fpscr, flags);
return result;
}
template <>
int
fplibCompare(uint32_t op1, uint32_t op2, bool signal_nans, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn1, exp1, sgn2, exp2, result;
uint32_t mnt1, mnt2;
fp32_unpack(&sgn1, &exp1, &mnt1, op1, mode, &flags);
fp32_unpack(&sgn2, &exp2, &mnt2, op2, mode, &flags);
if ((exp1 == 255 && (uint32_t)(mnt1 << 9)) ||
(exp2 == 255 && (uint32_t)(mnt2 << 9))) {
result = 3;
if ((exp1 == 255 && (uint32_t)(mnt1 << 9) && !(mnt1 >> 22 & 1)) ||
(exp2 == 255 && (uint32_t)(mnt2 << 9) && !(mnt2 >> 22 & 1)) ||
signal_nans)
flags |= FPLIB_IOC;
} else {
if (op1 == op2 || (!mnt1 && !mnt2)) {
result = 6;
} else if (sgn1 != sgn2) {
result = sgn1 ? 8 : 2;
} else if (exp1 != exp2) {
result = sgn1 ^ (exp1 < exp2) ? 8 : 2;
} else {
result = sgn1 ^ (mnt1 < mnt2) ? 8 : 2;
}
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
int
fplibCompare(uint64_t op1, uint64_t op2, bool signal_nans, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn1, exp1, sgn2, exp2, result;
uint64_t mnt1, mnt2;
fp64_unpack(&sgn1, &exp1, &mnt1, op1, mode, &flags);
fp64_unpack(&sgn2, &exp2, &mnt2, op2, mode, &flags);
if ((exp1 == 2047 && (uint64_t)(mnt1 << 12)) ||
(exp2 == 2047 && (uint64_t)(mnt2 << 12))) {
result = 3;
if ((exp1 == 2047 && (uint64_t)(mnt1 << 12) && !(mnt1 >> 51 & 1)) ||
(exp2 == 2047 && (uint64_t)(mnt2 << 12) && !(mnt2 >> 51 & 1)) ||
signal_nans)
flags |= FPLIB_IOC;
} else {
if (op1 == op2 || (!mnt1 && !mnt2)) {
result = 6;
} else if (sgn1 != sgn2) {
result = sgn1 ? 8 : 2;
} else if (exp1 != exp2) {
result = sgn1 ^ (exp1 < exp2) ? 8 : 2;
} else {
result = sgn1 ^ (mnt1 < mnt2) ? 8 : 2;
}
}
set_fpscr0(fpscr, flags);
return result;
}
static uint16_t
fp16_FPConvertNaN_32(uint32_t op)
{
return fp16_pack(op >> 31, 31, (uint16_t)1 << 9 | op >> 13);
}
static uint16_t
fp16_FPConvertNaN_64(uint64_t op)
{
return fp16_pack(op >> 63, 31, (uint16_t)1 << 9 | op >> 42);
}
static uint32_t
fp32_FPConvertNaN_16(uint16_t op)
{
return fp32_pack(op >> 15, 255, (uint32_t)1 << 22 | (uint32_t)op << 13);
}
static uint32_t
fp32_FPConvertNaN_64(uint64_t op)
{
return fp32_pack(op >> 63, 255, (uint32_t)1 << 22 | op >> 29);
}
static uint64_t
fp64_FPConvertNaN_16(uint16_t op)
{
return fp64_pack(op >> 15, 2047, (uint64_t)1 << 51 | (uint64_t)op << 42);
}
static uint64_t
fp64_FPConvertNaN_32(uint32_t op)
{
return fp64_pack(op >> 31, 2047, (uint64_t)1 << 51 | (uint64_t)op << 29);
}
static uint32_t
fp32_FPOnePointFive(int sgn)
{
return fp32_pack(sgn, 127, (uint64_t)1 << 22);
}
static uint64_t
fp64_FPOnePointFive(int sgn)
{
return fp64_pack(sgn, 1023, (uint64_t)1 << 51);
}
static uint32_t
fp32_FPThree(int sgn)
{
return fp32_pack(sgn, 128, (uint64_t)1 << 22);
}
static uint64_t
fp64_FPThree(int sgn)
{
return fp64_pack(sgn, 1024, (uint64_t)1 << 51);
}
static uint32_t
fp32_FPTwo(int sgn)
{
return fp32_pack(sgn, 128, 0);
}
static uint64_t
fp64_FPTwo(int sgn)
{
return fp64_pack(sgn, 1024, 0);
}
template <>
uint16_t
fplibConvert(uint32_t op, FPRounding rounding, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn, exp;
uint32_t mnt;
uint16_t result;
// Unpack floating-point operand optionally with flush-to-zero:
fp32_unpack(&sgn, &exp, &mnt, op, mode, &flags);
bool alt_hp = fpscr.ahp;
if (exp == 255 && (uint32_t)(mnt << 9)) {
if (alt_hp) {
result = fp16_zero(sgn);
} else if (fpscr.dn) {
result = fp16_defaultNaN();
} else {
result = fp16_FPConvertNaN_32(op);
}
if (!(mnt >> 22 & 1) || alt_hp) {
flags |= FPLIB_IOC;
}
} else if (exp == 255) {
if (alt_hp) {
result = sgn << 15 | (uint16_t)0x7fff;
flags |= FPLIB_IOC;
} else {
result = fp16_infinity(sgn);
}
} else if (!mnt) {
result = fp16_zero(sgn);
} else {
result = fp16_round_(sgn, exp - 127 + 15,
mnt >> 7 | !!(uint32_t)(mnt << 25),
rounding, mode | alt_hp << 4, &flags);
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint16_t
fplibConvert(uint64_t op, FPRounding rounding, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn, exp;
uint64_t mnt;
uint16_t result;
// Unpack floating-point operand optionally with flush-to-zero:
fp64_unpack(&sgn, &exp, &mnt, op, mode, &flags);
bool alt_hp = fpscr.ahp;
if (exp == 2047 && (uint64_t)(mnt << 12)) {
if (alt_hp) {
result = fp16_zero(sgn);
} else if (fpscr.dn) {
result = fp16_defaultNaN();
} else {
result = fp16_FPConvertNaN_64(op);
}
if (!(mnt >> 51 & 1) || alt_hp) {
flags |= FPLIB_IOC;
}
} else if (exp == 2047) {
if (alt_hp) {
result = sgn << 15 | (uint16_t)0x7fff;
flags |= FPLIB_IOC;
} else {
result = fp16_infinity(sgn);
}
} else if (!mnt) {
result = fp16_zero(sgn);
} else {
result = fp16_round_(sgn, exp - 1023 + 15,
mnt >> 36 | !!(uint64_t)(mnt << 28),
rounding, mode | alt_hp << 4, &flags);
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint32_t
fplibConvert(uint16_t op, FPRounding rounding, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn, exp;
uint16_t mnt;
uint32_t result;
// Unpack floating-point operand optionally with flush-to-zero:
fp16_unpack(&sgn, &exp, &mnt, op, mode, &flags);
if (exp == 31 && !fpscr.ahp && (uint16_t)(mnt << 6)) {
if (fpscr.dn) {
result = fp32_defaultNaN();
} else {
result = fp32_FPConvertNaN_16(op);
}
if (!(mnt >> 9 & 1)) {
flags |= FPLIB_IOC;
}
} else if (exp == 31 && !fpscr.ahp) {
result = fp32_infinity(sgn);
} else if (!mnt) {
result = fp32_zero(sgn);
} else {
mnt = fp16_normalise(mnt, &exp);
result = fp32_pack(sgn, exp - 15 + 127 + 5, (uint32_t)mnt << 8);
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint32_t
fplibConvert(uint64_t op, FPRounding rounding, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn, exp;
uint64_t mnt;
uint32_t result;
// Unpack floating-point operand optionally with flush-to-zero:
fp64_unpack(&sgn, &exp, &mnt, op, mode, &flags);
if (exp == 2047 && (uint64_t)(mnt << 12)) {
if (fpscr.dn) {
result = fp32_defaultNaN();
} else {
result = fp32_FPConvertNaN_64(op);
}
if (!(mnt >> 51 & 1)) {
flags |= FPLIB_IOC;
}
} else if (exp == 2047) {
result = fp32_infinity(sgn);
} else if (!mnt) {
result = fp32_zero(sgn);
} else {
result = fp32_round_(sgn, exp - 1023 + 127,
mnt >> 20 | !!(uint64_t)(mnt << 44),
rounding, mode, &flags);
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint64_t
fplibConvert(uint16_t op, FPRounding rounding, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn, exp;
uint16_t mnt;
uint64_t result;
// Unpack floating-point operand optionally with flush-to-zero:
fp16_unpack(&sgn, &exp, &mnt, op, mode, &flags);
if (exp == 31 && !fpscr.ahp && (uint16_t)(mnt << 6)) {
if (fpscr.dn) {
result = fp64_defaultNaN();
} else {
result = fp64_FPConvertNaN_16(op);
}
if (!(mnt >> 9 & 1)) {
flags |= FPLIB_IOC;
}
} else if (exp == 31 && !fpscr.ahp) {
result = fp64_infinity(sgn);
} else if (!mnt) {
result = fp64_zero(sgn);
} else {
mnt = fp16_normalise(mnt, &exp);
result = fp64_pack(sgn, exp - 15 + 1023 + 5, (uint64_t)mnt << 37);
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint64_t
fplibConvert(uint32_t op, FPRounding rounding, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn, exp;
uint32_t mnt;
uint64_t result;
// Unpack floating-point operand optionally with flush-to-zero:
fp32_unpack(&sgn, &exp, &mnt, op, mode, &flags);
if (exp == 255 && (uint32_t)(mnt << 9)) {
if (fpscr.dn) {
result = fp64_defaultNaN();
} else {
result = fp64_FPConvertNaN_32(op);
}
if (!(mnt >> 22 & 1)) {
flags |= FPLIB_IOC;
}
} else if (exp == 255) {
result = fp64_infinity(sgn);
} else if (!mnt) {
result = fp64_zero(sgn);
} else {
mnt = fp32_normalise(mnt, &exp);
result = fp64_pack(sgn, exp - 127 + 1023 + 8, (uint64_t)mnt << 21);
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint32_t
fplibMulAdd(uint32_t addend, uint32_t op1, uint32_t op2, FPSCR &fpscr)
{
int flags = 0;
uint32_t result = fp32_muladd(addend, op1, op2, 0, modeConv(fpscr), &flags);
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint64_t
fplibMulAdd(uint64_t addend, uint64_t op1, uint64_t op2, FPSCR &fpscr)
{
int flags = 0;
uint64_t result = fp64_muladd(addend, op1, op2, 0, modeConv(fpscr), &flags);
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint32_t
fplibDiv(uint32_t op1, uint32_t op2, FPSCR &fpscr)
{
int flags = 0;
uint32_t result = fp32_div(op1, op2, modeConv(fpscr), &flags);
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint64_t
fplibDiv(uint64_t op1, uint64_t op2, FPSCR &fpscr)
{
int flags = 0;
uint64_t result = fp64_div(op1, op2, modeConv(fpscr), &flags);
set_fpscr0(fpscr, flags);
return result;
}
static uint32_t
fp32_repack(int sgn, int exp, uint32_t mnt)
{
return fp32_pack(sgn, mnt >> 23 ? exp : 0, mnt);
}
static uint64_t
fp64_repack(int sgn, int exp, uint64_t mnt)
{
return fp64_pack(sgn, mnt >> 52 ? exp : 0, mnt);
}
static void
fp32_minmaxnum(uint32_t *op1, uint32_t *op2, int sgn)
{
// Treat a single quiet-NaN as +Infinity/-Infinity
if (!((uint32_t)~(*op1 << 1) >> 23) && (uint32_t)~(*op2 << 1) >> 23)
*op1 = fp32_infinity(sgn);
if (!((uint32_t)~(*op2 << 1) >> 23) && (uint32_t)~(*op1 << 1) >> 23)
*op2 = fp32_infinity(sgn);
}
static void
fp64_minmaxnum(uint64_t *op1, uint64_t *op2, int sgn)
{
// Treat a single quiet-NaN as +Infinity/-Infinity
if (!((uint64_t)~(*op1 << 1) >> 52) && (uint64_t)~(*op2 << 1) >> 52)
*op1 = fp64_infinity(sgn);
if (!((uint64_t)~(*op2 << 1) >> 52) && (uint64_t)~(*op1 << 1) >> 52)
*op2 = fp64_infinity(sgn);
}
template <>
uint32_t
fplibMax(uint32_t op1, uint32_t op2, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn1, exp1, sgn2, exp2;
uint32_t mnt1, mnt2, x, result;
fp32_unpack(&sgn1, &exp1, &mnt1, op1, mode, &flags);
fp32_unpack(&sgn2, &exp2, &mnt2, op2, mode, &flags);
if ((x = fp32_process_NaNs(op1, op2, mode, &flags))) {
result = x;
} else {
result = ((sgn1 != sgn2 ? sgn2 : sgn1 ^ (op1 > op2)) ?
fp32_repack(sgn1, exp1, mnt1) :
fp32_repack(sgn2, exp2, mnt2));
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint64_t
fplibMax(uint64_t op1, uint64_t op2, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn1, exp1, sgn2, exp2;
uint64_t mnt1, mnt2, x, result;
fp64_unpack(&sgn1, &exp1, &mnt1, op1, mode, &flags);
fp64_unpack(&sgn2, &exp2, &mnt2, op2, mode, &flags);
if ((x = fp64_process_NaNs(op1, op2, mode, &flags))) {
result = x;
} else {
result = ((sgn1 != sgn2 ? sgn2 : sgn1 ^ (op1 > op2)) ?
fp64_repack(sgn1, exp1, mnt1) :
fp64_repack(sgn2, exp2, mnt2));
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint32_t
fplibMaxNum(uint32_t op1, uint32_t op2, FPSCR &fpscr)
{
fp32_minmaxnum(&op1, &op2, 1);
return fplibMax<uint32_t>(op1, op2, fpscr);
}
template <>
uint64_t
fplibMaxNum(uint64_t op1, uint64_t op2, FPSCR &fpscr)
{
fp64_minmaxnum(&op1, &op2, 1);
return fplibMax<uint64_t>(op1, op2, fpscr);
}
template <>
uint32_t
fplibMin(uint32_t op1, uint32_t op2, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn1, exp1, sgn2, exp2;
uint32_t mnt1, mnt2, x, result;
fp32_unpack(&sgn1, &exp1, &mnt1, op1, mode, &flags);
fp32_unpack(&sgn2, &exp2, &mnt2, op2, mode, &flags);
if ((x = fp32_process_NaNs(op1, op2, mode, &flags))) {
result = x;
} else {
result = ((sgn1 != sgn2 ? sgn1 : sgn1 ^ (op1 < op2)) ?
fp32_repack(sgn1, exp1, mnt1) :
fp32_repack(sgn2, exp2, mnt2));
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint64_t
fplibMin(uint64_t op1, uint64_t op2, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn1, exp1, sgn2, exp2;
uint64_t mnt1, mnt2, x, result;
fp64_unpack(&sgn1, &exp1, &mnt1, op1, mode, &flags);
fp64_unpack(&sgn2, &exp2, &mnt2, op2, mode, &flags);
if ((x = fp64_process_NaNs(op1, op2, mode, &flags))) {
result = x;
} else {
result = ((sgn1 != sgn2 ? sgn1 : sgn1 ^ (op1 < op2)) ?
fp64_repack(sgn1, exp1, mnt1) :
fp64_repack(sgn2, exp2, mnt2));
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint32_t
fplibMinNum(uint32_t op1, uint32_t op2, FPSCR &fpscr)
{
fp32_minmaxnum(&op1, &op2, 0);
return fplibMin<uint32_t>(op1, op2, fpscr);
}
template <>
uint64_t
fplibMinNum(uint64_t op1, uint64_t op2, FPSCR &fpscr)
{
fp64_minmaxnum(&op1, &op2, 0);
return fplibMin<uint64_t>(op1, op2, fpscr);
}
template <>
uint32_t
fplibMul(uint32_t op1, uint32_t op2, FPSCR &fpscr)
{
int flags = 0;
uint32_t result = fp32_mul(op1, op2, modeConv(fpscr), &flags);
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint64_t
fplibMul(uint64_t op1, uint64_t op2, FPSCR &fpscr)
{
int flags = 0;
uint64_t result = fp64_mul(op1, op2, modeConv(fpscr), &flags);
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint32_t
fplibMulX(uint32_t op1, uint32_t op2, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn1, exp1, sgn2, exp2;
uint32_t mnt1, mnt2, result;
fp32_unpack(&sgn1, &exp1, &mnt1, op1, mode, &flags);
fp32_unpack(&sgn2, &exp2, &mnt2, op2, mode, &flags);
result = fp32_process_NaNs(op1, op2, mode, &flags);
if (!result) {
if ((exp1 == 255 && !mnt2) || (exp2 == 255 && !mnt1)) {
result = fp32_FPTwo(sgn1 ^ sgn2);
} else if (exp1 == 255 || exp2 == 255) {
result = fp32_infinity(sgn1 ^ sgn2);
} else if (!mnt1 || !mnt2) {
result = fp32_zero(sgn1 ^ sgn2);
} else {
result = fp32_mul(op1, op2, mode, &flags);
}
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint64_t
fplibMulX(uint64_t op1, uint64_t op2, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn1, exp1, sgn2, exp2;
uint64_t mnt1, mnt2, result;
fp64_unpack(&sgn1, &exp1, &mnt1, op1, mode, &flags);
fp64_unpack(&sgn2, &exp2, &mnt2, op2, mode, &flags);
result = fp64_process_NaNs(op1, op2, mode, &flags);
if (!result) {
if ((exp1 == 2047 && !mnt2) || (exp2 == 2047 && !mnt1)) {
result = fp64_FPTwo(sgn1 ^ sgn2);
} else if (exp1 == 2047 || exp2 == 2047) {
result = fp64_infinity(sgn1 ^ sgn2);
} else if (!mnt1 || !mnt2) {
result = fp64_zero(sgn1 ^ sgn2);
} else {
result = fp64_mul(op1, op2, mode, &flags);
}
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint32_t
fplibNeg(uint32_t op)
{
return op ^ (uint32_t)1 << 31;
}
template <>
uint64_t
fplibNeg(uint64_t op)
{
return op ^ (uint64_t)1 << 63;
}
static const uint8_t recip_sqrt_estimate[256] = {
255, 253, 251, 249, 247, 245, 243, 242, 240, 238, 236, 234, 233, 231, 229, 228,
226, 224, 223, 221, 219, 218, 216, 215, 213, 212, 210, 209, 207, 206, 204, 203,
201, 200, 198, 197, 196, 194, 193, 192, 190, 189, 188, 186, 185, 184, 183, 181,
180, 179, 178, 176, 175, 174, 173, 172, 170, 169, 168, 167, 166, 165, 164, 163,
162, 160, 159, 158, 157, 156, 155, 154, 153, 152, 151, 150, 149, 148, 147, 146,
145, 144, 143, 142, 141, 140, 140, 139, 138, 137, 136, 135, 134, 133, 132, 131,
131, 130, 129, 128, 127, 126, 126, 125, 124, 123, 122, 121, 121, 120, 119, 118,
118, 117, 116, 115, 114, 114, 113, 112, 111, 111, 110, 109, 109, 108, 107, 106,
105, 104, 103, 101, 100, 99, 97, 96, 95, 93, 92, 91, 90, 88, 87, 86,
85, 84, 82, 81, 80, 79, 78, 77, 76, 75, 74, 72, 71, 70, 69, 68,
67, 66, 65, 64, 63, 62, 61, 60, 60, 59, 58, 57, 56, 55, 54, 53,
52, 51, 51, 50, 49, 48, 47, 46, 46, 45, 44, 43, 42, 42, 41, 40,
39, 38, 38, 37, 36, 35, 35, 34, 33, 33, 32, 31, 30, 30, 29, 28,
28, 27, 26, 26, 25, 24, 24, 23, 22, 22, 21, 20, 20, 19, 19, 18,
17, 17, 16, 16, 15, 14, 14, 13, 13, 12, 11, 11, 10, 10, 9, 9,
8, 8, 7, 6, 6, 5, 5, 4, 4, 3, 3, 2, 2, 1, 1, 0
};
template <>
uint32_t
fplibRSqrtEstimate(uint32_t op, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn, exp;
uint32_t mnt, result;
fp32_unpack(&sgn, &exp, &mnt, op, mode, &flags);
if (exp == 255 && (uint32_t)(mnt << 9)) {
result = fp32_process_NaN(op, mode, &flags);
} else if (!mnt) {
result = fp32_infinity(sgn);
flags |= FPLIB_DZC;
} else if (sgn) {
result = fp32_defaultNaN();
flags |= FPLIB_IOC;
} else if (exp == 255) {
result = fp32_zero(0);
} else {
exp += 8;
mnt = fp32_normalise(mnt, &exp);
mnt = recip_sqrt_estimate[(~exp & 1) << 7 | (mnt >> 24 & 127)];
result = fp32_pack(0, (380 - exp) >> 1, mnt << 15);
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint64_t
fplibRSqrtEstimate(uint64_t op, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn, exp;
uint64_t mnt, result;
fp64_unpack(&sgn, &exp, &mnt, op, mode, &flags);
if (exp == 2047 && (uint64_t)(mnt << 12)) {
result = fp64_process_NaN(op, mode, &flags);
} else if (!mnt) {
result = fp64_infinity(sgn);
flags |= FPLIB_DZC;
} else if (sgn) {
result = fp64_defaultNaN();
flags |= FPLIB_IOC;
} else if (exp == 2047) {
result = fp32_zero(0);
} else {
exp += 11;
mnt = fp64_normalise(mnt, &exp);
mnt = recip_sqrt_estimate[(~exp & 1) << 7 | (mnt >> 56 & 127)];
result = fp64_pack(0, (3068 - exp) >> 1, mnt << 44);
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint32_t
fplibRSqrtStepFused(uint32_t op1, uint32_t op2, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn1, exp1, sgn2, exp2;
uint32_t mnt1, mnt2, result;
op1 = fplibNeg<uint32_t>(op1);
fp32_unpack(&sgn1, &exp1, &mnt1, op1, mode, &flags);
fp32_unpack(&sgn2, &exp2, &mnt2, op2, mode, &flags);
result = fp32_process_NaNs(op1, op2, mode, &flags);
if (!result) {
if ((exp1 == 255 && !mnt2) || (exp2 == 255 && !mnt1)) {
result = fp32_FPOnePointFive(0);
} else if (exp1 == 255 || exp2 == 255) {
result = fp32_infinity(sgn1 ^ sgn2);
} else {
result = fp32_muladd(fp32_FPThree(0), op1, op2, -1, mode, &flags);
}
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint64_t
fplibRSqrtStepFused(uint64_t op1, uint64_t op2, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn1, exp1, sgn2, exp2;
uint64_t mnt1, mnt2, result;
op1 = fplibNeg<uint64_t>(op1);
fp64_unpack(&sgn1, &exp1, &mnt1, op1, mode, &flags);
fp64_unpack(&sgn2, &exp2, &mnt2, op2, mode, &flags);
result = fp64_process_NaNs(op1, op2, mode, &flags);
if (!result) {
if ((exp1 == 2047 && !mnt2) || (exp2 == 2047 && !mnt1)) {
result = fp64_FPOnePointFive(0);
} else if (exp1 == 2047 || exp2 == 2047) {
result = fp64_infinity(sgn1 ^ sgn2);
} else {
result = fp64_muladd(fp64_FPThree(0), op1, op2, -1, mode, &flags);
}
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint32_t
fplibRecipStepFused(uint32_t op1, uint32_t op2, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn1, exp1, sgn2, exp2;
uint32_t mnt1, mnt2, result;
op1 = fplibNeg<uint32_t>(op1);
fp32_unpack(&sgn1, &exp1, &mnt1, op1, mode, &flags);
fp32_unpack(&sgn2, &exp2, &mnt2, op2, mode, &flags);
result = fp32_process_NaNs(op1, op2, mode, &flags);
if (!result) {
if ((exp1 == 255 && !mnt2) || (exp2 == 255 && !mnt1)) {
result = fp32_FPTwo(0);
} else if (exp1 == 255 || exp2 == 255) {
result = fp32_infinity(sgn1 ^ sgn2);
} else {
result = fp32_muladd(fp32_FPTwo(0), op1, op2, 0, mode, &flags);
}
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint32_t
fplibRecipEstimate(uint32_t op, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn, exp;
uint32_t mnt, result;
fp32_unpack(&sgn, &exp, &mnt, op, mode, &flags);
if (exp == 255 && (uint32_t)(mnt << 9)) {
result = fp32_process_NaN(op, mode, &flags);
} else if (exp == 255) {
result = fp32_zero(sgn);
} else if (!mnt) {
result = fp32_infinity(sgn);
flags |= FPLIB_DZC;
} else if (!((uint32_t)(op << 1) >> 22)) {
bool overflow_to_inf = false;
switch (FPCRRounding(fpscr)) {
case FPRounding_TIEEVEN:
overflow_to_inf = true;
break;
case FPRounding_POSINF:
overflow_to_inf = !sgn;
break;
case FPRounding_NEGINF:
overflow_to_inf = sgn;
break;
case FPRounding_ZERO:
overflow_to_inf = false;
break;
default:
assert(0);
}
result = overflow_to_inf ? fp32_infinity(sgn) : fp32_max_normal(sgn);
flags |= FPLIB_OFC | FPLIB_IXC;
} else if (fpscr.fz && exp >= 253) {
result = fp32_zero(sgn);
flags |= FPLIB_UFC;
} else {
exp += 8;
mnt = fp32_normalise(mnt, &exp);
int result_exp = 253 - exp;
uint32_t fraction = (((uint32_t)1 << 19) / (mnt >> 22 | 1) + 1) >> 1;
fraction <<= 15;
if (result_exp == 0) {
fraction >>= 1;
} else if (result_exp == -1) {
fraction >>= 2;
result_exp = 0;
}
result = fp32_pack(sgn, result_exp, fraction);
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint64_t
fplibRecipEstimate(uint64_t op, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn, exp;
uint64_t mnt, result;
fp64_unpack(&sgn, &exp, &mnt, op, mode, &flags);
if (exp == 2047 && (uint64_t)(mnt << 12)) {
result = fp64_process_NaN(op, mode, &flags);
} else if (exp == 2047) {
result = fp64_zero(sgn);
} else if (!mnt) {
result = fp64_infinity(sgn);
flags |= FPLIB_DZC;
} else if (!((uint64_t)(op << 1) >> 51)) {
bool overflow_to_inf = false;
switch (FPCRRounding(fpscr)) {
case FPRounding_TIEEVEN:
overflow_to_inf = true;
break;
case FPRounding_POSINF:
overflow_to_inf = !sgn;
break;
case FPRounding_NEGINF:
overflow_to_inf = sgn;
break;
case FPRounding_ZERO:
overflow_to_inf = false;
break;
default:
assert(0);
}
result = overflow_to_inf ? fp64_infinity(sgn) : fp64_max_normal(sgn);
flags |= FPLIB_OFC | FPLIB_IXC;
} else if (fpscr.fz && exp >= 2045) {
result = fp64_zero(sgn);
flags |= FPLIB_UFC;
} else {
exp += 11;
mnt = fp64_normalise(mnt, &exp);
int result_exp = 2045 - exp;
uint64_t fraction = (((uint32_t)1 << 19) / (mnt >> 54 | 1) + 1) >> 1;
fraction <<= 44;
if (result_exp == 0) {
fraction >>= 1;
} else if (result_exp == -1) {
fraction >>= 2;
result_exp = 0;
}
result = fp64_pack(sgn, result_exp, fraction);
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint64_t
fplibRecipStepFused(uint64_t op1, uint64_t op2, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn1, exp1, sgn2, exp2;
uint64_t mnt1, mnt2, result;
op1 = fplibNeg<uint64_t>(op1);
fp64_unpack(&sgn1, &exp1, &mnt1, op1, mode, &flags);
fp64_unpack(&sgn2, &exp2, &mnt2, op2, mode, &flags);
result = fp64_process_NaNs(op1, op2, mode, &flags);
if (!result) {
if ((exp1 == 2047 && !mnt2) || (exp2 == 2047 && !mnt1)) {
result = fp64_FPTwo(0);
} else if (exp1 == 2047 || exp2 == 2047) {
result = fp64_infinity(sgn1 ^ sgn2);
} else {
result = fp64_muladd(fp64_FPTwo(0), op1, op2, 0, mode, &flags);
}
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint32_t
fplibRecpX(uint32_t op, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn, exp;
uint32_t mnt, result;
fp32_unpack(&sgn, &exp, &mnt, op, mode, &flags);
if (exp == 255 && (uint32_t)(mnt << 9)) {
result = fp32_process_NaN(op, mode, &flags);
}
else {
if (!mnt) { // Zero and denormals
result = fp32_pack(sgn, 254, 0);
} else { // Infinities and normals
result = fp32_pack(sgn, exp ^ 255, 0);
}
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint64_t
fplibRecpX(uint64_t op, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn, exp;
uint64_t mnt, result;
fp64_unpack(&sgn, &exp, &mnt, op, mode, &flags);
if (exp == 2047 && (uint64_t)(mnt << 12)) {
result = fp64_process_NaN(op, mode, &flags);
}
else {
if (!mnt) { // Zero and denormals
result = fp64_pack(sgn, 2046, 0);
} else { // Infinities and normals
result = fp64_pack(sgn, exp ^ 2047, 0);
}
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint32_t
fplibRoundInt(uint32_t op, FPRounding rounding, bool exact, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn, exp;
uint32_t mnt, result;
// Unpack using FPCR to determine if subnormals are flushed-to-zero:
fp32_unpack(&sgn, &exp, &mnt, op, mode, &flags);
// Handle NaNs, infinities and zeroes:
if (exp == 255 && (uint32_t)(mnt << 9)) {
result = fp32_process_NaN(op, mode, &flags);
} else if (exp == 255) {
result = fp32_infinity(sgn);
} else if (!mnt) {
result = fp32_zero(sgn);
} else if (exp >= 150) {
// There are no fractional bits
result = op;
} else {
// Truncate towards zero:
uint32_t x = 150 - exp >= 32 ? 0 : mnt >> (150 - exp);
int err = exp < 118 ? 1 :
(mnt << 1 >> (149 - exp) & 3) | (mnt << 2 << (exp - 118) != 0);
switch (rounding) {
case FPRounding_TIEEVEN:
x += (err == 3 || (err == 2 && (x & 1)));
break;
case FPRounding_POSINF:
x += err && !sgn;
break;
case FPRounding_NEGINF:
x += err && sgn;
break;
case FPRounding_ZERO:
break;
case FPRounding_TIEAWAY:
x += err >> 1;
break;
default:
assert(0);
}
if (x == 0) {
result = fp32_zero(sgn);
} else {
exp = 150;
mnt = fp32_normalise(x, &exp);
result = fp32_pack(sgn, exp + 8, mnt >> 8);
}
if (err && exact)
flags |= FPLIB_IXC;
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint64_t
fplibRoundInt(uint64_t op, FPRounding rounding, bool exact, FPSCR &fpscr)
{
int mode = modeConv(fpscr);
int flags = 0;
int sgn, exp;
uint64_t mnt, result;
// Unpack using FPCR to determine if subnormals are flushed-to-zero:
fp64_unpack(&sgn, &exp, &mnt, op, mode, &flags);
// Handle NaNs, infinities and zeroes:
if (exp == 2047 && (uint64_t)(mnt << 12)) {
result = fp64_process_NaN(op, mode, &flags);
} else if (exp == 2047) {
result = fp64_infinity(sgn);
} else if (!mnt) {
result = fp64_zero(sgn);
} else if (exp >= 1075) {
// There are no fractional bits
result = op;
} else {
// Truncate towards zero:
uint64_t x = 1075 - exp >= 64 ? 0 : mnt >> (1075 - exp);
int err = exp < 1011 ? 1 :
(mnt << 1 >> (1074 - exp) & 3) | (mnt << 2 << (exp - 1011) != 0);
switch (rounding) {
case FPRounding_TIEEVEN:
x += (err == 3 || (err == 2 && (x & 1)));
break;
case FPRounding_POSINF:
x += err && !sgn;
break;
case FPRounding_NEGINF:
x += err && sgn;
break;
case FPRounding_ZERO:
break;
case FPRounding_TIEAWAY:
x += err >> 1;
break;
default:
assert(0);
}
if (x == 0) {
result = fp64_zero(sgn);
} else {
exp = 1075;
mnt = fp64_normalise(x, &exp);
result = fp64_pack(sgn, exp + 11, mnt >> 11);
}
if (err && exact)
flags |= FPLIB_IXC;
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint32_t
fplibSqrt(uint32_t op, FPSCR &fpscr)
{
int flags = 0;
uint32_t result = fp32_sqrt(op, modeConv(fpscr), &flags);
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint64_t
fplibSqrt(uint64_t op, FPSCR &fpscr)
{
int flags = 0;
uint64_t result = fp64_sqrt(op, modeConv(fpscr), &flags);
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint32_t
fplibSub(uint32_t op1, uint32_t op2, FPSCR &fpscr)
{
int flags = 0;
uint32_t result = fp32_add(op1, op2, 1, modeConv(fpscr), &flags);
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint64_t
fplibSub(uint64_t op1, uint64_t op2, FPSCR &fpscr)
{
int flags = 0;
uint64_t result = fp64_add(op1, op2, 1, modeConv(fpscr), &flags);
set_fpscr0(fpscr, flags);
return result;
}
static uint64_t
FPToFixed_64(int sgn, int exp, uint64_t mnt, bool u, FPRounding rounding,
int *flags)
{
uint64_t x;
int err;
if (exp > 1023 + 63) {
*flags = FPLIB_IOC;
return ((uint64_t)!u << 63) - !sgn;
}
x = lsr64(mnt << 11, 1023 + 63 - exp);
err = (exp > 1023 + 63 - 2 ? 0 :
(lsr64(mnt << 11, 1023 + 63 - 2 - exp) & 3) |
!!(mnt << 11 & (lsl64(1, 1023 + 63 - 2 - exp) - 1)));
switch (rounding) {
case FPRounding_TIEEVEN:
x += (err == 3 || (err == 2 && (x & 1)));
break;
case FPRounding_POSINF:
x += err && !sgn;
break;
case FPRounding_NEGINF:
x += err && sgn;
break;
case FPRounding_ZERO:
break;
case FPRounding_TIEAWAY:
x += err >> 1;
break;
default:
assert(0);
}
if (u ? sgn && x : x > ((uint64_t)1 << 63) - !sgn) {
*flags = FPLIB_IOC;
return ((uint64_t)!u << 63) - !sgn;
}
if (err) {
*flags = FPLIB_IXC;
}
return sgn ? -x : x;
}
static uint32_t
FPToFixed_32(int sgn, int exp, uint64_t mnt, bool u, FPRounding rounding,
int *flags)
{
uint64_t x = FPToFixed_64(sgn, exp, mnt, u, rounding, flags);
if (u ? x >= (uint64_t)1 << 32 :
!(x < (uint64_t)1 << 31 ||
(uint64_t)-x <= (uint64_t)1 << 31)) {
*flags = FPLIB_IOC;
x = ((uint32_t)!u << 31) - !sgn;
}
return x;
}
template <>
uint32_t
fplibFPToFixed(uint32_t op, int fbits, bool u, FPRounding rounding, FPSCR &fpscr)
{
int flags = 0;
int sgn, exp;
uint32_t mnt, result;
// Unpack using FPCR to determine if subnormals are flushed-to-zero:
fp32_unpack(&sgn, &exp, &mnt, op, modeConv(fpscr), &flags);
// If NaN, set cumulative flag or take exception:
if (exp == 255 && (uint32_t)(mnt << 9)) {
flags = FPLIB_IOC;
result = 0;
} else {
result = FPToFixed_32(sgn, exp + 1023 - 127 + fbits,
(uint64_t)mnt << (52 - 23), u, rounding, &flags);
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint32_t
fplibFPToFixed(uint64_t op, int fbits, bool u, FPRounding rounding, FPSCR &fpscr)
{
int flags = 0;
int sgn, exp;
uint64_t mnt;
uint32_t result;
// Unpack using FPCR to determine if subnormals are flushed-to-zero:
fp64_unpack(&sgn, &exp, &mnt, op, modeConv(fpscr), &flags);
// If NaN, set cumulative flag or take exception:
if (exp == 2047 && (uint64_t)(mnt << 12)) {
flags = FPLIB_IOC;
result = 0;
} else {
result = FPToFixed_32(sgn, exp + fbits, mnt, u, rounding, &flags);
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint64_t
fplibFPToFixed(uint32_t op, int fbits, bool u, FPRounding rounding, FPSCR &fpscr)
{
int flags = 0;
int sgn, exp;
uint32_t mnt;
uint64_t result;
// Unpack using FPCR to determine if subnormals are flushed-to-zero:
fp32_unpack(&sgn, &exp, &mnt, op, modeConv(fpscr), &flags);
// If NaN, set cumulative flag or take exception:
if (exp == 255 && (uint32_t)(mnt << 9)) {
flags = FPLIB_IOC;
result = 0;
} else {
result = FPToFixed_64(sgn, exp + 1023 - 127 + fbits,
(uint64_t)mnt << (52 - 23), u, rounding, &flags);
}
set_fpscr0(fpscr, flags);
return result;
}
template <>
uint64_t
fplibFPToFixed(uint64_t op, int fbits, bool u, FPRounding rounding, FPSCR &fpscr)
{
int flags = 0;
int sgn, exp;
uint64_t mnt, result;
// Unpack using FPCR to determine if subnormals are flushed-to-zero:
fp64_unpack(&sgn, &exp, &mnt, op, modeConv(fpscr), &flags);
// If NaN, set cumulative flag or take exception:
if (exp == 2047 && (uint64_t)(mnt << 12)) {
flags = FPLIB_IOC;
result = 0;
} else {
result = FPToFixed_64(sgn, exp + fbits, mnt, u, rounding, &flags);
}
set_fpscr0(fpscr, flags);
return result;
}
static uint32_t
fp32_cvtf(uint64_t a, int fbits, int u, int mode, int *flags)
{
int x_sgn = !u && a >> 63;
int x_exp = 190 - fbits;
uint64_t x_mnt = x_sgn ? -a : a;
// Handle zero:
if (!x_mnt) {
return fp32_zero(0);
}
// Normalise and convert to 32 bits, collapsing error into bottom bit:
x_mnt = fp64_normalise(x_mnt, &x_exp);
x_mnt = x_mnt >> 31 | !!(uint32_t)(x_mnt << 1);
return fp32_round(x_sgn, x_exp, x_mnt, mode, flags);
}
static uint64_t
fp64_cvtf(uint64_t a, int fbits, int u, int mode, int *flags)
{
int x_sgn = !u && a >> 63;
int x_exp = 1024 + 62 - fbits;
uint64_t x_mnt = x_sgn ? -a : a;
// Handle zero:
if (!x_mnt) {
return fp64_zero(0);
}
x_mnt = fp64_normalise(x_mnt, &x_exp);
return fp64_round(x_sgn, x_exp, x_mnt << 1, mode, flags);
}
template <>
uint32_t
fplibFixedToFP(uint64_t op, int fbits, bool u, FPRounding rounding, FPSCR &fpscr)
{
int flags = 0;
uint32_t res = fp32_cvtf(op, fbits, u,
(int)rounding | ((uint32_t)fpscr >> 22 & 12),
&flags);
set_fpscr0(fpscr, flags);
return res;
}
template <>
uint64_t
fplibFixedToFP(uint64_t op, int fbits, bool u, FPRounding rounding, FPSCR &fpscr)
{
int flags = 0;
uint64_t res = fp64_cvtf(op, fbits, u,
(int)rounding | ((uint32_t)fpscr >> 22 & 12),
&flags);
set_fpscr0(fpscr, flags);
return res;
}
}