| 1 |
gbeauche |
1.1 |
/* |
| 2 |
|
|
* fpu/flags.cpp - Floating-point flags |
| 3 |
|
|
* |
| 4 |
cebix |
1.2 |
* Basilisk II (C) 1997-2004 Christian Bauer |
| 5 |
gbeauche |
1.1 |
* |
| 6 |
|
|
* MC68881/68040 fpu emulation |
| 7 |
|
|
* |
| 8 |
|
|
* Original UAE FPU, copyright 1996 Herman ten Brugge |
| 9 |
|
|
* Rewrite for x86, copyright 1999-2000 Lauri Pesonen |
| 10 |
|
|
* New framework, copyright 2000 Gwenole Beauchesne |
| 11 |
|
|
* Adapted for JIT compilation (c) Bernd Meyer, 2000 |
| 12 |
|
|
* |
| 13 |
|
|
* This program is free software; you can redistribute it and/or modify |
| 14 |
|
|
* it under the terms of the GNU General Public License as published by |
| 15 |
|
|
* the Free Software Foundation; either version 2 of the License, or |
| 16 |
|
|
* (at your option) any later version. |
| 17 |
|
|
* |
| 18 |
|
|
* This program is distributed in the hope that it will be useful, |
| 19 |
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 20 |
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 21 |
|
|
* GNU General Public License for more details. |
| 22 |
|
|
* |
| 23 |
|
|
* You should have received a copy of the GNU General Public License |
| 24 |
|
|
* along with this program; if not, write to the Free Software |
| 25 |
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 26 |
|
|
*/ |
| 27 |
|
|
|
| 28 |
|
|
/* NOTE: this file shall be included only from fpu/fpu_*.cpp */ |
| 29 |
|
|
#undef PRIVATE |
| 30 |
|
|
#define PRIVATE /**/ |
| 31 |
|
|
|
| 32 |
|
|
#undef PUBLIC |
| 33 |
|
|
#define PUBLIC /**/ |
| 34 |
|
|
|
| 35 |
|
|
#undef FFPU |
| 36 |
|
|
#define FFPU /**/ |
| 37 |
|
|
|
| 38 |
|
|
#undef FPU |
| 39 |
|
|
#define FPU fpu. |
| 40 |
|
|
|
| 41 |
|
|
/* -------------------------------------------------------------------------- */ |
| 42 |
|
|
/* --- Native X86 floating-point flags --- */ |
| 43 |
|
|
/* -------------------------------------------------------------------------- */ |
| 44 |
|
|
|
| 45 |
|
|
#ifdef FPU_USE_X86_FLAGS |
| 46 |
|
|
|
| 47 |
|
|
/* Initialization */ |
| 48 |
|
|
void FFPU fpu_init_native_fflags(void) |
| 49 |
|
|
{ |
| 50 |
|
|
// Adapted from fpu_x86.cpp |
| 51 |
|
|
#define SW_Z_I_NAN_MASK (SW_C0|SW_C2|SW_C3) |
| 52 |
|
|
#define SW_Z (SW_C3) |
| 53 |
|
|
#define SW_I (SW_C0|SW_C2) |
| 54 |
|
|
#define SW_NAN (SW_C0) |
| 55 |
|
|
#define SW_FINITE (SW_C2) |
| 56 |
|
|
#define SW_EMPTY_REGISTER (SW_C0|SW_C3) |
| 57 |
|
|
#define SW_DENORMAL (SW_C2|SW_C3) |
| 58 |
|
|
#define SW_UNSUPPORTED (0) |
| 59 |
|
|
#define SW_N (SW_C1) |
| 60 |
|
|
|
| 61 |
|
|
// Sanity checks |
| 62 |
|
|
#if (SW_Z != NATIVE_FFLAG_ZERO) |
| 63 |
|
|
#error "Incorrect X86 Z fflag" |
| 64 |
|
|
#endif |
| 65 |
|
|
#if (SW_I != NATIVE_FFLAG_INFINITY) |
| 66 |
|
|
#error "Incorrect X86 I fflag" |
| 67 |
|
|
#endif |
| 68 |
|
|
#if (SW_N != NATIVE_FFLAG_NEGATIVE) |
| 69 |
|
|
#error "Incorrect X86 N fflag" |
| 70 |
|
|
#endif |
| 71 |
|
|
#if (SW_NAN != NATIVE_FFLAG_NAN) |
| 72 |
|
|
#error "Incorrect X86 NAN fflag" |
| 73 |
|
|
#endif |
| 74 |
|
|
|
| 75 |
|
|
// Native status word to m68k mappings |
| 76 |
|
|
for (uae_u32 i = 0; i < 0x48; i++) { |
| 77 |
|
|
to_m68k_fpcond[i] = 0; |
| 78 |
|
|
const uae_u32 native_fpcond = i << 8; |
| 79 |
|
|
switch (native_fpcond & SW_Z_I_NAN_MASK) { |
| 80 |
|
|
#ifndef FPU_UAE |
| 81 |
|
|
// gb-- enabling it would lead to incorrect drawing of digits |
| 82 |
|
|
// in Speedometer Performance Test |
| 83 |
|
|
case SW_UNSUPPORTED: |
| 84 |
|
|
#endif |
| 85 |
|
|
case SW_NAN: |
| 86 |
|
|
case SW_EMPTY_REGISTER: |
| 87 |
|
|
to_m68k_fpcond[i] |= FPSR_CCB_NAN; |
| 88 |
|
|
break; |
| 89 |
|
|
case SW_FINITE: |
| 90 |
|
|
case SW_DENORMAL: |
| 91 |
|
|
break; |
| 92 |
|
|
case SW_I: |
| 93 |
|
|
to_m68k_fpcond[i] |= FPSR_CCB_INFINITY; |
| 94 |
|
|
break; |
| 95 |
|
|
case SW_Z: |
| 96 |
|
|
to_m68k_fpcond[i] |= FPSR_CCB_ZERO; |
| 97 |
|
|
break; |
| 98 |
|
|
} |
| 99 |
|
|
if (native_fpcond & SW_N) |
| 100 |
|
|
to_m68k_fpcond[i] |= FPSR_CCB_NEGATIVE; |
| 101 |
|
|
} |
| 102 |
|
|
|
| 103 |
|
|
// m68k to native status word mappings |
| 104 |
|
|
for (uae_u32 i = 0; i < 0x10; i++) { |
| 105 |
|
|
const uae_u32 m68k_fpcond = i << 24; |
| 106 |
|
|
if (m68k_fpcond & FPSR_CCB_NAN) |
| 107 |
|
|
to_host_fpcond[i] = SW_NAN; |
| 108 |
|
|
else if (m68k_fpcond & FPSR_CCB_ZERO) |
| 109 |
|
|
to_host_fpcond[i] = SW_Z; |
| 110 |
|
|
else if (m68k_fpcond & FPSR_CCB_INFINITY) |
| 111 |
|
|
to_host_fpcond[i] = SW_I; |
| 112 |
|
|
else |
| 113 |
|
|
to_host_fpcond[i] = SW_FINITE; |
| 114 |
|
|
if (m68k_fpcond & FPSR_CCB_NEGATIVE) |
| 115 |
|
|
to_host_fpcond[i] |= SW_N; |
| 116 |
|
|
} |
| 117 |
|
|
|
| 118 |
|
|
// truth-table for FPU conditions |
| 119 |
|
|
for (uae_u32 host_fpcond = 0; host_fpcond < 0x08; host_fpcond++) { |
| 120 |
|
|
// host_fpcond: C3 on bit 2, C1 and C0 are respectively on bits 1 and 0 |
| 121 |
|
|
const uae_u32 real_host_fpcond = ((host_fpcond & 4) << 12) | ((host_fpcond & 3) << 8); |
| 122 |
|
|
const bool N = ((real_host_fpcond & NATIVE_FFLAG_NEGATIVE) == NATIVE_FFLAG_NEGATIVE); |
| 123 |
|
|
const bool Z = ((real_host_fpcond & NATIVE_FFLAG_ZERO) == NATIVE_FFLAG_ZERO); |
| 124 |
|
|
const bool NaN = ((real_host_fpcond & NATIVE_FFLAG_NAN) == NATIVE_FFLAG_NAN); |
| 125 |
|
|
|
| 126 |
|
|
int value; |
| 127 |
|
|
for (uae_u32 m68k_fpcond = 0; m68k_fpcond < 0x20; m68k_fpcond++) { |
| 128 |
|
|
switch (m68k_fpcond) { |
| 129 |
|
|
case 0x00: value = 0; break; // False |
| 130 |
|
|
case 0x01: value = Z; break; // Equal |
| 131 |
|
|
case 0x02: value = !(NaN || Z || N); break; // Ordered Greater Than |
| 132 |
|
|
case 0x03: value = Z || !(NaN || N); break; // Ordered Greater Than or Equal |
| 133 |
|
|
case 0x04: value = N && !(NaN || Z); break; // Ordered Less Than |
| 134 |
|
|
case 0x05: value = Z || (N && !NaN); break; // Ordered Less Than or Equal |
| 135 |
|
|
case 0x06: value = !(NaN || Z); break; // Ordered Greater or Less Than |
| 136 |
|
|
case 0x07: value = !NaN; break; // Ordered |
| 137 |
|
|
case 0x08: value = NaN; break; // Unordered |
| 138 |
|
|
case 0x09: value = NaN || Z; break; // Unordered or Equal |
| 139 |
|
|
case 0x0a: value = NaN || !(N || Z); break; // Unordered or Greater Than |
| 140 |
|
|
case 0x0b: value = NaN || Z || !N; break; // Unordered or Greater or Equal |
| 141 |
|
|
case 0x0c: value = NaN || (N && !Z); break; // Unordered or Less Than |
| 142 |
|
|
case 0x0d: value = NaN || Z || N; break; // Unordered or Less or Equal |
| 143 |
|
|
case 0x0e: value = !Z; break; // Not Equal |
| 144 |
|
|
case 0x0f: value = 1; break; // True |
| 145 |
|
|
case 0x10: value = 0; break; // Signaling False |
| 146 |
|
|
case 0x11: value = Z; break; // Signaling Equal |
| 147 |
|
|
case 0x12: value = !(NaN || Z || N); break; // Greater Than |
| 148 |
|
|
case 0x13: value = Z || !(NaN || N); break; // Greater Than or Equal |
| 149 |
|
|
case 0x14: value = N && !(NaN || Z); break; // Less Than |
| 150 |
|
|
case 0x15: value = Z || (N && !NaN); break; // Less Than or Equal |
| 151 |
|
|
case 0x16: value = !(NaN || Z); break; // Greater or Less Than |
| 152 |
|
|
case 0x17: value = !NaN; break; // Greater, Less or Equal |
| 153 |
|
|
case 0x18: value = NaN; break; // Not Greater, Less or Equal |
| 154 |
|
|
case 0x19: value = NaN || Z; break; // Not Greater or Less Than |
| 155 |
|
|
case 0x1a: value = NaN || !(N || Z); break; // Not Less Than or Equal |
| 156 |
|
|
case 0x1b: value = NaN || Z || !N; break; // Not Less Than |
| 157 |
|
|
case 0x1c: value = NaN || (N && !Z); break; // Not Greater Than or Equal |
| 158 |
|
|
// case 0x1c: value = !Z && (NaN || N); break; // Not Greater Than or Equal |
| 159 |
|
|
case 0x1d: value = NaN || Z || N; break; // Not Greater Than |
| 160 |
|
|
case 0x1e: value = !Z; break; // Signaling Not Equal |
| 161 |
|
|
case 0x1f: value = 1; break; // Signaling True |
| 162 |
|
|
default: value = -1; |
| 163 |
|
|
} |
| 164 |
|
|
fpcond_truth_table[m68k_fpcond][host_fpcond] = value; |
| 165 |
|
|
} |
| 166 |
|
|
} |
| 167 |
|
|
} |
| 168 |
|
|
|
| 169 |
|
|
#endif |
