xemu/target/hexagon/arch.c
Taylor Simpson 77ccf44453 Hexagon (target/hexagon) properly handle denorm in arch_sf_recip_common
The arch_sf_recip_common function was calling float32_getexp which
adjusts for denorm, but the we actually need the raw exponent bits.

This function is called from 3 instructions
    sfrecipa
    sffixupn
    sffixupd

Test cases added to tests/tcg/hexagon/fpstuff.c

Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <20220210021556.9217-6-tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2022-03-12 09:14:22 -08:00

412 lines
13 KiB
C

/*
* Copyright(c) 2019-2022 Qualcomm Innovation Center, Inc. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "fpu/softfloat.h"
#include "cpu.h"
#include "fma_emu.h"
#include "arch.h"
#include "macros.h"
#define SF_BIAS 127
#define SF_MAXEXP 254
#define SF_MANTBITS 23
#define float32_nan make_float32(0xffffffff)
/*
* These three tables are used by the cabacdecbin instruction
*/
const uint8_t rLPS_table_64x4[64][4] = {
{128, 176, 208, 240},
{128, 167, 197, 227},
{128, 158, 187, 216},
{123, 150, 178, 205},
{116, 142, 169, 195},
{111, 135, 160, 185},
{105, 128, 152, 175},
{100, 122, 144, 166},
{95, 116, 137, 158},
{90, 110, 130, 150},
{85, 104, 123, 142},
{81, 99, 117, 135},
{77, 94, 111, 128},
{73, 89, 105, 122},
{69, 85, 100, 116},
{66, 80, 95, 110},
{62, 76, 90, 104},
{59, 72, 86, 99},
{56, 69, 81, 94},
{53, 65, 77, 89},
{51, 62, 73, 85},
{48, 59, 69, 80},
{46, 56, 66, 76},
{43, 53, 63, 72},
{41, 50, 59, 69},
{39, 48, 56, 65},
{37, 45, 54, 62},
{35, 43, 51, 59},
{33, 41, 48, 56},
{32, 39, 46, 53},
{30, 37, 43, 50},
{29, 35, 41, 48},
{27, 33, 39, 45},
{26, 31, 37, 43},
{24, 30, 35, 41},
{23, 28, 33, 39},
{22, 27, 32, 37},
{21, 26, 30, 35},
{20, 24, 29, 33},
{19, 23, 27, 31},
{18, 22, 26, 30},
{17, 21, 25, 28},
{16, 20, 23, 27},
{15, 19, 22, 25},
{14, 18, 21, 24},
{14, 17, 20, 23},
{13, 16, 19, 22},
{12, 15, 18, 21},
{12, 14, 17, 20},
{11, 14, 16, 19},
{11, 13, 15, 18},
{10, 12, 15, 17},
{10, 12, 14, 16},
{9, 11, 13, 15},
{9, 11, 12, 14},
{8, 10, 12, 14},
{8, 9, 11, 13},
{7, 9, 11, 12},
{7, 9, 10, 12},
{7, 8, 10, 11},
{6, 8, 9, 11},
{6, 7, 9, 10},
{6, 7, 8, 9},
{2, 2, 2, 2}
};
const uint8_t AC_next_state_MPS_64[64] = {
1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
11, 12, 13, 14, 15, 16, 17, 18, 19, 20,
21, 22, 23, 24, 25, 26, 27, 28, 29, 30,
31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50,
51, 52, 53, 54, 55, 56, 57, 58, 59, 60,
61, 62, 62, 63
};
const uint8_t AC_next_state_LPS_64[64] = {
0, 0, 1, 2, 2, 4, 4, 5, 6, 7,
8, 9, 9, 11, 11, 12, 13, 13, 15, 15,
16, 16, 18, 18, 19, 19, 21, 21, 22, 22,
23, 24, 24, 25, 26, 26, 27, 27, 28, 29,
29, 30, 30, 30, 31, 32, 32, 33, 33, 33,
34, 34, 35, 35, 35, 36, 36, 36, 37, 37,
37, 38, 38, 63
};
#define BITS_MASK_8 0x5555555555555555ULL
#define PAIR_MASK_8 0x3333333333333333ULL
#define NYBL_MASK_8 0x0f0f0f0f0f0f0f0fULL
#define BYTE_MASK_8 0x00ff00ff00ff00ffULL
#define HALF_MASK_8 0x0000ffff0000ffffULL
#define WORD_MASK_8 0x00000000ffffffffULL
uint64_t interleave(uint32_t odd, uint32_t even)
{
/* Convert to long long */
uint64_t myodd = odd;
uint64_t myeven = even;
/* First, spread bits out */
myodd = (myodd | (myodd << 16)) & HALF_MASK_8;
myeven = (myeven | (myeven << 16)) & HALF_MASK_8;
myodd = (myodd | (myodd << 8)) & BYTE_MASK_8;
myeven = (myeven | (myeven << 8)) & BYTE_MASK_8;
myodd = (myodd | (myodd << 4)) & NYBL_MASK_8;
myeven = (myeven | (myeven << 4)) & NYBL_MASK_8;
myodd = (myodd | (myodd << 2)) & PAIR_MASK_8;
myeven = (myeven | (myeven << 2)) & PAIR_MASK_8;
myodd = (myodd | (myodd << 1)) & BITS_MASK_8;
myeven = (myeven | (myeven << 1)) & BITS_MASK_8;
/* Now OR together */
return myeven | (myodd << 1);
}
uint64_t deinterleave(uint64_t src)
{
/* Get odd and even bits */
uint64_t myodd = ((src >> 1) & BITS_MASK_8);
uint64_t myeven = (src & BITS_MASK_8);
/* Unspread bits */
myeven = (myeven | (myeven >> 1)) & PAIR_MASK_8;
myodd = (myodd | (myodd >> 1)) & PAIR_MASK_8;
myeven = (myeven | (myeven >> 2)) & NYBL_MASK_8;
myodd = (myodd | (myodd >> 2)) & NYBL_MASK_8;
myeven = (myeven | (myeven >> 4)) & BYTE_MASK_8;
myodd = (myodd | (myodd >> 4)) & BYTE_MASK_8;
myeven = (myeven | (myeven >> 8)) & HALF_MASK_8;
myodd = (myodd | (myodd >> 8)) & HALF_MASK_8;
myeven = (myeven | (myeven >> 16)) & WORD_MASK_8;
myodd = (myodd | (myodd >> 16)) & WORD_MASK_8;
/* Return odd bits in upper half */
return myeven | (myodd << 32);
}
int32_t conv_round(int32_t a, int n)
{
int64_t val;
if (n == 0) {
val = a;
} else if ((a & ((1 << (n - 1)) - 1)) == 0) { /* N-1..0 all zero? */
/* Add LSB from int part */
val = ((fSE32_64(a)) + (int64_t) (((uint32_t) ((1 << n) & a)) >> 1));
} else {
val = ((fSE32_64(a)) + (1 << (n - 1)));
}
val = val >> n;
return (int32_t)val;
}
/* Floating Point Stuff */
static const FloatRoundMode softfloat_roundingmodes[] = {
float_round_nearest_even,
float_round_to_zero,
float_round_down,
float_round_up,
};
void arch_fpop_start(CPUHexagonState *env)
{
set_float_exception_flags(0, &env->fp_status);
set_float_rounding_mode(
softfloat_roundingmodes[fREAD_REG_FIELD(USR, USR_FPRND)],
&env->fp_status);
}
#ifdef CONFIG_USER_ONLY
/*
* Hexagon Linux kernel only sets the relevant bits in USR (user status
* register). The exception isn't raised to user mode, so we don't
* model it in qemu user mode.
*/
#define RAISE_FP_EXCEPTION do {} while (0)
#endif
#define SOFTFLOAT_TEST_FLAG(FLAG, MYF, MYE) \
do { \
if (flags & FLAG) { \
if (GET_USR_FIELD(USR_##MYF) == 0) { \
SET_USR_FIELD(USR_##MYF, 1); \
if (GET_USR_FIELD(USR_##MYE)) { \
RAISE_FP_EXCEPTION; \
} \
} \
} \
} while (0)
void arch_fpop_end(CPUHexagonState *env)
{
int flags = get_float_exception_flags(&env->fp_status);
if (flags != 0) {
SOFTFLOAT_TEST_FLAG(float_flag_inexact, FPINPF, FPINPE);
SOFTFLOAT_TEST_FLAG(float_flag_divbyzero, FPDBZF, FPDBZE);
SOFTFLOAT_TEST_FLAG(float_flag_invalid, FPINVF, FPINVE);
SOFTFLOAT_TEST_FLAG(float_flag_overflow, FPOVFF, FPOVFE);
SOFTFLOAT_TEST_FLAG(float_flag_underflow, FPUNFF, FPUNFE);
}
}
int arch_sf_recip_common(float32 *Rs, float32 *Rt, float32 *Rd, int *adjust,
float_status *fp_status)
{
int n_exp;
int d_exp;
int ret = 0;
float32 RsV, RtV, RdV;
int PeV = 0;
RsV = *Rs;
RtV = *Rt;
if (float32_is_any_nan(RsV) && float32_is_any_nan(RtV)) {
if (extract32(RsV & RtV, 22, 1) == 0) {
float_raise(float_flag_invalid, fp_status);
}
RdV = RsV = RtV = float32_nan;
} else if (float32_is_any_nan(RsV)) {
if (extract32(RsV, 22, 1) == 0) {
float_raise(float_flag_invalid, fp_status);
}
RdV = RsV = RtV = float32_nan;
} else if (float32_is_any_nan(RtV)) {
/* or put NaN in num/den fixup? */
if (extract32(RtV, 22, 1) == 0) {
float_raise(float_flag_invalid, fp_status);
}
RdV = RsV = RtV = float32_nan;
} else if (float32_is_infinity(RsV) && float32_is_infinity(RtV)) {
/* or put Inf in num fixup? */
RdV = RsV = RtV = float32_nan;
float_raise(float_flag_invalid, fp_status);
} else if (float32_is_zero(RsV) && float32_is_zero(RtV)) {
/* or put zero in num fixup? */
RdV = RsV = RtV = float32_nan;
float_raise(float_flag_invalid, fp_status);
} else if (float32_is_zero(RtV)) {
/* or put Inf in num fixup? */
uint8_t RsV_sign = float32_is_neg(RsV);
uint8_t RtV_sign = float32_is_neg(RtV);
/* Check that RsV is NOT infinite before we overwrite it */
if (!float32_is_infinity(RsV)) {
float_raise(float_flag_divbyzero, fp_status);
}
RsV = infinite_float32(RsV_sign ^ RtV_sign);
RtV = float32_one;
RdV = float32_one;
} else if (float32_is_infinity(RtV)) {
RsV = make_float32(0x80000000 & (RsV ^ RtV));
RtV = float32_one;
RdV = float32_one;
} else if (float32_is_zero(RsV)) {
/* Does this just work itself out? */
/* No, 0/Inf causes problems. */
RsV = make_float32(0x80000000 & (RsV ^ RtV));
RtV = float32_one;
RdV = float32_one;
} else if (float32_is_infinity(RsV)) {
uint8_t RsV_sign = float32_is_neg(RsV);
uint8_t RtV_sign = float32_is_neg(RtV);
RsV = infinite_float32(RsV_sign ^ RtV_sign);
RtV = float32_one;
RdV = float32_one;
} else {
PeV = 0x00;
/* Basic checks passed */
n_exp = float32_getexp_raw(RsV);
d_exp = float32_getexp_raw(RtV);
if ((n_exp - d_exp + SF_BIAS) <= SF_MANTBITS) {
/* Near quotient underflow / inexact Q */
PeV = 0x80;
RtV = float32_scalbn(RtV, -64, fp_status);
RsV = float32_scalbn(RsV, 64, fp_status);
} else if ((n_exp - d_exp + SF_BIAS) > (SF_MAXEXP - 24)) {
/* Near quotient overflow */
PeV = 0x40;
RtV = float32_scalbn(RtV, 32, fp_status);
RsV = float32_scalbn(RsV, -32, fp_status);
} else if (n_exp <= SF_MANTBITS + 2) {
RtV = float32_scalbn(RtV, 64, fp_status);
RsV = float32_scalbn(RsV, 64, fp_status);
} else if (d_exp <= 1) {
RtV = float32_scalbn(RtV, 32, fp_status);
RsV = float32_scalbn(RsV, 32, fp_status);
} else if (d_exp > 252) {
RtV = float32_scalbn(RtV, -32, fp_status);
RsV = float32_scalbn(RsV, -32, fp_status);
}
RdV = 0;
ret = 1;
}
*Rs = RsV;
*Rt = RtV;
*Rd = RdV;
*adjust = PeV;
return ret;
}
int arch_sf_invsqrt_common(float32 *Rs, float32 *Rd, int *adjust,
float_status *fp_status)
{
float32 RsV, RdV;
int PeV = 0;
int r_exp;
int ret = 0;
RsV = *Rs;
if (float32_is_any_nan(RsV)) {
if (extract32(RsV, 22, 1) == 0) {
float_raise(float_flag_invalid, fp_status);
}
RdV = RsV = float32_nan;
} else if (float32_lt(RsV, float32_zero, fp_status)) {
/* Negative nonzero values are NaN */
float_raise(float_flag_invalid, fp_status);
RsV = float32_nan;
RdV = float32_nan;
} else if (float32_is_infinity(RsV)) {
/* or put Inf in num fixup? */
RsV = infinite_float32(1);
RdV = infinite_float32(1);
} else if (float32_is_zero(RsV)) {
/* or put zero in num fixup? */
RdV = float32_one;
} else {
PeV = 0x00;
/* Basic checks passed */
r_exp = float32_getexp(RsV);
if (r_exp <= 24) {
RsV = float32_scalbn(RsV, 64, fp_status);
PeV = 0xe0;
}
RdV = 0;
ret = 1;
}
*Rs = RsV;
*Rd = RdV;
*adjust = PeV;
return ret;
}
const uint8_t recip_lookup_table[128] = {
0x0fe, 0x0fa, 0x0f6, 0x0f2, 0x0ef, 0x0eb, 0x0e7, 0x0e4,
0x0e0, 0x0dd, 0x0d9, 0x0d6, 0x0d2, 0x0cf, 0x0cc, 0x0c9,
0x0c6, 0x0c2, 0x0bf, 0x0bc, 0x0b9, 0x0b6, 0x0b3, 0x0b1,
0x0ae, 0x0ab, 0x0a8, 0x0a5, 0x0a3, 0x0a0, 0x09d, 0x09b,
0x098, 0x096, 0x093, 0x091, 0x08e, 0x08c, 0x08a, 0x087,
0x085, 0x083, 0x080, 0x07e, 0x07c, 0x07a, 0x078, 0x075,
0x073, 0x071, 0x06f, 0x06d, 0x06b, 0x069, 0x067, 0x065,
0x063, 0x061, 0x05f, 0x05e, 0x05c, 0x05a, 0x058, 0x056,
0x054, 0x053, 0x051, 0x04f, 0x04e, 0x04c, 0x04a, 0x049,
0x047, 0x045, 0x044, 0x042, 0x040, 0x03f, 0x03d, 0x03c,
0x03a, 0x039, 0x037, 0x036, 0x034, 0x033, 0x032, 0x030,
0x02f, 0x02d, 0x02c, 0x02b, 0x029, 0x028, 0x027, 0x025,
0x024, 0x023, 0x021, 0x020, 0x01f, 0x01e, 0x01c, 0x01b,
0x01a, 0x019, 0x017, 0x016, 0x015, 0x014, 0x013, 0x012,
0x011, 0x00f, 0x00e, 0x00d, 0x00c, 0x00b, 0x00a, 0x009,
0x008, 0x007, 0x006, 0x005, 0x004, 0x003, 0x002, 0x000,
};
const uint8_t invsqrt_lookup_table[128] = {
0x069, 0x066, 0x063, 0x061, 0x05e, 0x05b, 0x059, 0x057,
0x054, 0x052, 0x050, 0x04d, 0x04b, 0x049, 0x047, 0x045,
0x043, 0x041, 0x03f, 0x03d, 0x03b, 0x039, 0x037, 0x036,
0x034, 0x032, 0x030, 0x02f, 0x02d, 0x02c, 0x02a, 0x028,
0x027, 0x025, 0x024, 0x022, 0x021, 0x01f, 0x01e, 0x01d,
0x01b, 0x01a, 0x019, 0x017, 0x016, 0x015, 0x014, 0x012,
0x011, 0x010, 0x00f, 0x00d, 0x00c, 0x00b, 0x00a, 0x009,
0x008, 0x007, 0x006, 0x005, 0x004, 0x003, 0x002, 0x001,
0x0fe, 0x0fa, 0x0f6, 0x0f3, 0x0ef, 0x0eb, 0x0e8, 0x0e4,
0x0e1, 0x0de, 0x0db, 0x0d7, 0x0d4, 0x0d1, 0x0ce, 0x0cb,
0x0c9, 0x0c6, 0x0c3, 0x0c0, 0x0be, 0x0bb, 0x0b8, 0x0b6,
0x0b3, 0x0b1, 0x0af, 0x0ac, 0x0aa, 0x0a8, 0x0a5, 0x0a3,
0x0a1, 0x09f, 0x09d, 0x09b, 0x099, 0x097, 0x095, 0x093,
0x091, 0x08f, 0x08d, 0x08b, 0x089, 0x087, 0x086, 0x084,
0x082, 0x080, 0x07f, 0x07d, 0x07b, 0x07a, 0x078, 0x077,
0x075, 0x074, 0x072, 0x071, 0x06f, 0x06e, 0x06c, 0x06b,
};