blob: aa8ddc3afae7d5951924e6667a1fc0e96089ebfe [file] [log] [blame] [raw]
"use strict";
/** @const */
var FPU_LOG_OP = false;
/**
* @constructor
*/
function FPU(io)
{
this.is_fpu = 1;
// TODO:
// - Precision Control
// - QNaN, unordered comparison
// - Exceptions
var
/** @const */
C0 = 0x100,
/** @const */
C1 = 0x200,
/** @const */
C2 = 0x400,
/** @const */
C3 = 0x4000,
/** @const */
RESULT_FLAGS = C0 | C1 | C2 | C3,
/** @const */
STACK_TOP = 0x3800;
var
// precision, round & infinity control
/** @const */
PC = 3 << 8,
/** @const */
RC = 3 << 10,
/** @const */
IF = 1 << 12;
// exception bits in the status word
var EX_SF = 1 << 6,
EX_P = 1 << 5,
EX_U = 1 << 4,
EX_O = 1 << 3,
EX_Z = 1 << 2,
EX_D = 1 << 1,
EX_I = 1 << 0;
var
// Why no Float80Array :-(
st = new Float64Array(8),
st8 = new Uint8Array(st.buffer),
st32 = new Uint32Array(st.buffer),
// bitmap of which stack registers are empty
stack_empty = 0xff,
stack_ptr = 0,
// used for conversion
float32 = new Float32Array(1),
float32_byte = new Uint8Array(float32.buffer),
float32_int = new Uint32Array(float32.buffer),
float64 = new Float64Array(1),
float64_byte = new Uint8Array(float64.buffer),
float64_int = new Uint32Array(float64.buffer),
float80_int = new Uint8Array(10),
control_word = 0x37F,
status_word = 0,
fpu_ip = 0,
fpu_ip_selector = 0,
fpu_opcode = 0,
fpu_dp = 0,
fpu_dp_selector = 0,
/** @const */
indefinite_nan = NaN;
var constants = new Float64Array([
1, Math.log(10) / Math.LN2, Math.LOG2E, Math.PI,
Math.log(2) / Math.LN10, Math.LN2, 0
]);
function fpu_unimpl()
{
dbg_trace();
if(DEBUG) throw "fpu: unimplemented";
else trigger_ud();
}
function stack_fault()
{
// TODO: Interrupt
status_word |= EX_SF | EX_I;
}
function invalid_arithmatic()
{
status_word |= EX_I;
}
function fcom(y)
{
var x = get_st0();
status_word &= ~RESULT_FLAGS;
if(x > y)
{
}
else if(y > x)
{
status_word |= C0;
}
else if(x === y)
{
status_word |= C3;
}
else
{
status_word |= C0 | C2 | C3;
}
}
function fucom(y)
{
// TODO
fcom(y);
}
function fcomi(y)
{
var x = st[stack_ptr];
flags_changed &= ~(1 | flag_parity | flag_zero);
flags &= ~(1 | flag_parity | flag_zero);
if(x > y)
{
}
else if(y > x)
{
flags |= 1;
}
else if(x === y)
{
flags |= flag_zero;
}
else
{
flags |= 1 | flag_parity | flag_zero;
}
}
function fucomi(y)
{
// TODO
fcomi(y);
}
function ftst()
{
var st0 = get_st0();
status_word &= ~RESULT_FLAGS;
if(isNaN(st0))
{
status_word |= C3 | C2 | C0;
}
else if(st0 === 0)
{
status_word |= C3;
}
else if(st0 < 0)
{
status_word |= C0;
}
// TODO: unordered (st0 is nan, etc)
}
function fxam()
{
var x = get_st0();
status_word &= ~RESULT_FLAGS;
status_word |= sign(0) << 9;
if(stack_empty >> stack_ptr & 1)
{
status_word |= C3 | C0;
}
else if(isNaN(x))
{
status_word |= C0;
}
else if(x === 0)
{
status_word |= C3;
}
else if(x === Infinity || x === -Infinity)
{
status_word |= C2 | C0;
}
else
{
status_word |= C2;
}
// TODO:
// Unsupported, Denormal
}
function finit()
{
control_word = 0x37F;
status_word = 0;
fpu_ip = 0;
fpu_dp = 0;
fpu_opcode = 0;
stack_empty = 0xFF;
stack_ptr = 0;
}
function load_status_word()
{
return status_word & ~(7 << 11) | stack_ptr << 11;
}
function safe_status_word(sw)
{
status_word = sw & ~(7 << 11);
stack_ptr = sw >> 11 & 7;
}
function load_tag_word()
{
var tag_word = 0,
value;
for(var i = 0; i < 8; i++)
{
value = st[i];
if(stack_empty >> i & 1)
{
tag_word |= 3 << (i << 1);
}
else if(value === 0)
{
tag_word |= 1 << (i << 1);
}
else if(!isFinite(value))
{
tag_word |= 2 << (i << 1);
}
}
//dbg_log("load tw=" + h(tag_word) + " se=" + h(stack_empty) + " sp=" + stack_ptr, LOG_FPU);
return tag_word;
}
function safe_tag_word(tag_word)
{
stack_empty = 0;
for(var i = 0; i < 8; i++)
{
stack_empty |= (tag_word >> i) & (tag_word >> i + 1) & 1 << i;
}
//dbg_log("safe tw=" + h(tag_word) + " se=" + h(stack_empty), LOG_FPU);
}
function fstenv(addr)
{
if(operand_size_32)
{
safe_write16(addr, control_word);
safe_write16(addr + 4, load_status_word());
safe_write16(addr + 8, load_tag_word());
safe_write32(addr + 12, fpu_ip);
safe_write16(addr + 16, fpu_ip_selector);
safe_write16(addr + 18, fpu_opcode);
safe_write32(addr + 20, fpu_dp);
safe_write16(addr + 24, fpu_dp_selector);
}
else
{
fpu_unimpl();
}
}
function fldenv(addr)
{
if(operand_size_32)
{
control_word = safe_read16(addr);
safe_status_word(safe_read16(addr + 4));
safe_tag_word(safe_read16(addr + 8));
fpu_ip = safe_read32(addr + 12);
fpu_ip_selector = safe_read16(addr + 16);
fpu_opcode = safe_read16(addr + 18);
fpu_dp = safe_read32(addr + 20);
fpu_dp_selector = safe_read16(addr + 24);
}
else
{
fpu_unimpl();
}
}
function fsave(addr)
{
fstenv(addr);
addr += 28;
for(var i = 0; i < 8; i++)
{
store_m80(addr, i - stack_ptr & 7);
addr += 10;
}
//dbg_log("save " + [].slice.call(st), LOG_FPU);
finit();
}
function frstor(addr)
{
fldenv(addr);
addr += 28;
for(var i = 0; i < 8; i++)
{
st[i] = load_m80(addr);
addr += 10;
}
//dbg_log("rstor " + [].slice.call(st), LOG_FPU);
}
function integer_round(f)
{
var rc = control_word >> 10 & 3;
if(rc === 0)
{
// Round to nearest, or even if equidistant
var rounded = Math.round(f);
if(rounded - f === 0.5 && (rounded & 1))
{
// Special case: Math.round rounds to positive infinity
// if equidistant
rounded--;
}
return rounded;
}
// rc=3 is truncate -> floor for positive numbers
else if(rc === 1 || (rc === 3 && f > 0))
{
return Math.floor(f);
}
else
{
return Math.ceil(f);
}
}
function truncate(x)
{
return x > 0 ? Math.floor(x) : Math.ceil(x);
}
function push(x)
{
stack_ptr = stack_ptr - 1 & 7;
if(stack_empty >> stack_ptr & 1)
{
status_word &= ~C1;
stack_empty &= ~(1 << stack_ptr);
st[stack_ptr] = x;
}
else
{
status_word |= C1;
stack_fault();
st[stack_ptr] = indefinite_nan;
}
}
function pop()
{
stack_empty |= 1 << stack_ptr;
stack_ptr = stack_ptr + 1 & 7;
}
function get_sti(i)
{
dbg_assert(typeof i === "number" && i >= 0 && i < 8);
i = i + stack_ptr & 7;
if(stack_empty >> i & 1)
{
status_word &= ~C1;
stack_fault();
return indefinite_nan;
}
else
{
return st[i];
}
}
function get_st0()
{
if(stack_empty >> stack_ptr & 1)
{
status_word &= ~C1;
stack_fault();
return indefinite_nan;
}
else
{
return st[stack_ptr];
}
}
function assert_not_empty(i)
{
if(stack_empty >> (i + stack_ptr & 7) & 1)
{
status_word &= ~C1;
}
else
{
}
}
function load_m80(addr)
{
var exponent = safe_read16(addr + 8),
sign,
low = safe_read32(addr),
high = safe_read32(addr + 4);
sign = exponent >> 15;
exponent &= ~0x8000;
if(exponent === 0)
{
// TODO: denormal numbers
return 0;
}
if(exponent < 0x7FFF)
{
exponent -= 0x3FFF;
}
else
{
// TODO: NaN, Infinity
//dbg_log("Load m80 TODO", LOG_FPU);
float64_byte[7] = 0x7F | sign << 7;
float64_byte[6] = 0xF0 | high >> 30 << 3 & 0x08;
float64_byte[5] = 0;
float64_byte[4] = 0;
float64_int[0] = 0;
return float64[0];
}
// Note: some bits might be lost at this point
var mantissa = low + 0x100000000 * high;
if(sign)
{
mantissa = -mantissa;
}
//console.log("m: " + mantissa);
//console.log("e: " + exponent);
//console.log("s: " + sign);
//console.log("f: " + mantissa * Math.pow(2, exponent - 63));
// Simply compute the 64 bit floating point number.
// An alternative write the mantissa, sign and exponent in the
// float64_byte and return float64[0]
return mantissa * Math.pow(2, exponent - 63);
}
function store_m80(addr, i)
{
float64[0] = st[stack_ptr + i & 7];
var sign = float64_byte[7] & 0x80,
exponent = (float64_byte[7] & 0x7f) << 4 | float64_byte[6] >> 4,
low,
high;
if(exponent === 0x7FF)
{
// all bits set (NaN and infinity)
exponent = 0x7FFF;
low = 0;
high = 0x80000000 | (float64_int[1] & 0x80000) << 11;
}
else if(exponent === 0)
{
// zero and denormal numbers
// Just assume zero for now
low = 0;
high = 0;
}
else
{
exponent += 0x3FFF - 0x3FF;
// does the mantissa need to be adjusted?
low = float64_int[0] << 11;
high = 0x80000000 | (float64_int[1] & 0xFFFFF) << 11 | (float64_int[0] >>> 21);
}
dbg_assert(exponent >= 0 && exponent < 0x8000);
safe_write32(addr, low);
safe_write32(addr + 4, high);
safe_write16(addr + 8, sign << 8 | exponent);
}
function load_m64(addr)
{
float64_int[0] = safe_read32s(addr);
float64_int[1] = safe_read32s(addr + 4);
return float64[0];
};
function store_m64(addr, i)
{
// protect against writing only a single dword
// and then page-faulting
translate_address_write(addr + 7);
float64[0] = get_sti(i);
safe_write32(addr, float64_int[0]);
safe_write32(addr + 4, float64_int[1]);
};
function load_m32(addr)
{
float32_int[0] = safe_read32s(addr);
return float32[0];
};
function store_m32(addr, i)
{
float32[0] = get_sti(i);
safe_write32(addr, float32_int[0]);
};
// sign of a number on the stack
function sign(i)
{
return st8[(stack_ptr + i & 7) << 3 | 7] >> 7;
};
function dbg_log_fpu_op(op, imm8)
{
if(!FPU_LOG_OP)
{
return;
}
if(imm8 >= 0xC0)
{
dbg_log(h(op, 2) + " " + h(imm8, 2) + "/" + (imm8 >> 3 & 7) + "/" + (imm8 & 7) +
" @" + h(instruction_pointer >>> 0, 8) + " sp=" + stack_ptr + " st=" + h(stack_empty, 2), LOG_FPU);
}
else
{
dbg_log(h(op, 2) + " /" + (imm8 >> 3 & 7) +
" @" + h(instruction_pointer >>> 0, 8) + " sp=" + stack_ptr + " st=" + h(stack_empty, 2), LOG_FPU);
}
}
this.fwait = function()
{
// TODO:
// Exceptions
};
this.op_D8_reg = function(imm8)
{
dbg_log_fpu_op(0xD8, imm8);
var mod = imm8 >> 3 & 7,
low = imm8 & 7,
sti = get_sti(low),
st0 = get_st0();
switch(mod)
{
case 0:
// fadd
st[stack_ptr] = st0 + sti;
break;
case 1:
// fmul
st[stack_ptr] = st0 * sti;
break;
case 2:
// fcom
fcom(sti);
break;
case 3:
// fcomp
fcom(sti);
pop();
break;
case 4:
// fsub
st[stack_ptr] = st0 - sti;
break;
case 5:
// fsubr
st[stack_ptr] = sti - st0;
break;
case 6:
// fdiv
st[stack_ptr] = st0 / sti;
break;
case 7:
// fdivr
st[stack_ptr] = sti / st0;
break;
default:
dbg_log(mod);
fpu_unimpl();
}
};
this.op_D8_mem = function(imm8, addr)
{
dbg_log_fpu_op(0xD8, imm8);
var mod = imm8 >> 3 & 7,
m32 = load_m32(addr);
var st0 = get_st0();
switch(mod)
{
case 0:
// fadd
st[stack_ptr] = st0 + m32;
break;
case 1:
// fmul
st[stack_ptr] = st0 * m32;
break;
case 2:
// fcom
fcom(m32);
break;
case 3:
// fcomp
fcom(m32);
pop();
break;
case 4:
// fsub
st[stack_ptr] = st0 - m32;
break;
case 5:
// fsubr
st[stack_ptr] = m32 - st0;
break;
case 6:
// fdiv
st[stack_ptr] = st0 / m32;
break;
case 7:
// fdivr
st[stack_ptr] = m32 / st0;
break;
default:
dbg_log(mod);
fpu_unimpl();
}
};
this.op_D9_reg = function(imm8)
{
dbg_log_fpu_op(0xD9, imm8);
var mod = imm8 >> 3 & 7,
low = imm8 & 7;
switch(mod)
{
case 0:
// fld
var sti = get_sti(low);
push(sti);
break;
case 1:
// fxch
var sti = get_sti(low);
st[stack_ptr + low & 7] = get_st0();
st[stack_ptr] = sti;
break;
case 4:
switch(low)
{
case 0:
// fchs
st[stack_ptr] = -get_st0();
break;
case 1:
// fabs
st[stack_ptr] = Math.abs(get_st0());
break;
case 4:
ftst();
break;
case 5:
fxam();
break;
default:
dbg_log(low); fpu_unimpl();
}
break;
case 5:
push(constants[low]);
break;
case 6:
switch(low)
{
case 0:
// f2xm1
st[stack_ptr] = Math.pow(2, get_st0()) - 1;
break;
case 1:
// fyl2x
st[stack_ptr + 1 & 7] = get_sti(1) * Math.log(get_st0()) / Math.LN2;
pop();
break;
case 2:
// fptan
st[stack_ptr] = Math.tan(get_st0());
push(1); // no bug: push constant 1
break;
case 3:
// fpatan
//st[stack_ptr + 1 & 7] = Math.atan(get_sti(1) / get_st0());
st[stack_ptr + 1 & 7] = Math.atan2(get_sti(1), get_st0());
pop();
break;
case 5:
// fprem1
st[stack_ptr] = get_st0() % get_sti(1);
break;
default:
dbg_log(low); fpu_unimpl();
}
break;
case 7:
switch(low)
{
case 0:
// fprem
st[stack_ptr] = get_st0() % get_sti(1);
break;
case 1:
// fyl2xp1: y * log2(x+1) and pop
st[stack_ptr + 1 & 7] = get_sti(1) * Math.log(get_st0() + 1) / Math.LN2;
pop();
break;
case 2:
st[stack_ptr] = Math.sqrt(get_st0());
break;
case 3:
var st0 = get_st0();
st[stack_ptr] = Math.sin(st0);
push(Math.cos(st0));
break;
case 4:
// frndint
st[stack_ptr] = integer_round(get_st0());
break;
case 5:
// fscale
st[stack_ptr] = get_st0() * Math.pow(2, truncate(get_sti(1)));
break;
case 6:
st[stack_ptr] = Math.sin(get_st0());
break;
case 7:
st[stack_ptr] = Math.cos(get_st0());
break;
default:
dbg_log(low); fpu_unimpl();
}
break;
default:
dbg_log(mod);
fpu_unimpl();
}
};
this.op_D9_mem = function(imm8, addr)
{
dbg_log_fpu_op(0xD9, imm8);
var mod = imm8 >> 3 & 7;
switch(mod)
{
case 0:
var data = load_m32(addr);
push(data);
break;
case 2:
store_m32(addr, 0);
break;
case 3:
store_m32(addr, 0);
pop();
break;
case 4:
fldenv(addr);
break;
case 5:
var word = safe_read16(addr);
control_word = word;
break;
case 6:
fstenv(addr);
break;
case 7:
safe_write16(addr, control_word);
break;
default:
dbg_log(mod);
fpu_unimpl();
}
};
this.op_DA_reg = function(imm8)
{
dbg_log_fpu_op(0xDA, imm8);
var mod = imm8 >> 3 & 7,
low = imm8 & 7;
switch(mod)
{
case 0:
// fcmovb
if(test_b())
{
st[stack_ptr] = get_sti(low);
stack_empty &= ~(1 << stack_ptr);
}
break;
case 1:
// fcmove
if(test_z())
{
st[stack_ptr] = get_sti(low);
stack_empty &= ~(1 << stack_ptr);
}
break;
case 2:
// fcmovbe
if(test_be())
{
st[stack_ptr] = get_sti(low);
stack_empty &= ~(1 << stack_ptr);
}
break;
case 3:
// fcmovu
if(test_p())
{
st[stack_ptr] = get_sti(low);
stack_empty &= ~(1 << stack_ptr);
}
break;
case 5:
if(low === 1)
{
// fucompp
fucom(get_sti(1));
pop();
pop();
}
else
{
dbg_log(mod); fpu_unimpl();
}
break;
default:
dbg_log(mod);
fpu_unimpl();
}
};
this.op_DA_mem = function(imm8, addr)
{
dbg_log_fpu_op(0xDA, imm8);
var mod = imm8 >> 3 & 7,
m32 = safe_read32s(addr);
var st0 = get_st0();
switch(mod)
{
case 0:
// fadd
st[stack_ptr] = st0 + m32;
break;
case 1:
// fmul
st[stack_ptr] = st0 * m32;
break;
case 2:
// fcom
fcom(m32);
break;
case 3:
// fcomp
fcom(m32);
pop();
break;
case 4:
// fsub
st[stack_ptr] = st0 - m32;
break;
case 5:
// fsubr
st[stack_ptr] = m32 - st0;
break;
case 6:
// fdiv
st[stack_ptr] = st0 / m32;
break;
case 7:
// fdivr
st[stack_ptr] = m32 / st0;
break;
default:
dbg_log(mod);
fpu_unimpl();
}
};
this.op_DB_reg = function(imm8)
{
dbg_log_fpu_op(0xDB, imm8);
var mod = imm8 >> 3 & 7,
low = imm8 & 7;
switch(mod)
{
case 0:
// fcmovnb
if(!test_b())
{
st[stack_ptr] = get_sti(low);
stack_empty &= ~(1 << stack_ptr);
}
break;
case 1:
// fcmovne
if(!test_z())
{
st[stack_ptr] = get_sti(low);
stack_empty &= ~(1 << stack_ptr);
}
break;
case 2:
// fcmovnbe
if(!test_be())
{
st[stack_ptr] = get_sti(low);
stack_empty &= ~(1 << stack_ptr);
}
break;
case 3:
// fcmovnu
if(!test_p())
{
st[stack_ptr] = get_sti(low);
stack_empty &= ~(1 << stack_ptr);
}
break;
case 4:
if(imm8 === 0xE3)
{
finit();
}
else if(imm8 === 0xE4)
{
// fsetpm
// treat as nop
}
else if(imm8 === 0xE1)
{
// fdisi
// also treat as nop
}
else if(imm8 === 0xE2)
{
// fclex
status_word = 0;
}
else
{
dbg_log(h(imm8));
fpu_unimpl();
}
break;
case 5:
fucomi(get_sti(low));
break;
case 6:
fcomi(get_sti(low));
break;
default:
dbg_log(mod);
fpu_unimpl();
}
};
this.op_DB_mem = function(imm8, addr)
{
dbg_log_fpu_op(0xDB, imm8);
var mod = imm8 >> 3 & 7;
switch(mod)
{
case 0:
// fild
var int32 = safe_read32s(addr);
push(int32);
break;
case 2:
// fist
var st0 = get_st0();
if(st0 <= 0x7FFFFFFF && st0 >= -0x80000000)
{
// TODO: Invalid operation
safe_write32(addr, integer_round(st0));
}
else
{
invalid_arithmatic();
safe_write32(addr, 0x80000000);
}
break;
case 3:
// fistp
var st0 = get_st0();
if(st0 <= 0x7FFFFFFF && st0 >= -0x80000000)
{
safe_write32(addr, integer_round(st0));
}
else
{
invalid_arithmatic();
safe_write32(addr, 0x80000000);
}
pop();
break;
case 5:
// fld
push(load_m80(addr));
break;
case 7:
// fstp
store_m80(addr, 0);
pop();
break;
default:
dbg_log(mod);
fpu_unimpl();
}
};
this.op_DC_reg = function(imm8)
{
dbg_log_fpu_op(0xDC, imm8);
var mod = imm8 >> 3 & 7,
low = imm8 & 7,
low_ptr = stack_ptr + low & 7,
sti = get_sti(low),
st0 = get_st0();
switch(mod)
{
case 0:
// fadd
st[low_ptr] = sti + st0;
break;
case 1:
// fmul
st[low_ptr] = sti * st0;
break;
case 2:
// fcom
fcom(sti);
break;
case 3:
// fcomp
fcom(sti);
pop();
break;
case 4:
// fsubr
st[low_ptr] = st0 - sti;
break;
case 5:
// fsub
st[low_ptr] = sti - st0;
break;
case 6:
// fdivr
st[low_ptr] = st0 / sti;
break;
case 7:
// fdiv
st[low_ptr] = sti / st0;
break;
default:
dbg_log(mod);
fpu_unimpl();
}
};
this.op_DC_mem = function(imm8, addr)
{
dbg_log_fpu_op(0xDC, imm8);
var
mod = imm8 >> 3 & 7,
m64 = load_m64(addr);
var st0 = get_st0();
switch(mod)
{
case 0:
// fadd
st[stack_ptr] = st0 + m64;
break;
case 1:
// fmul
st[stack_ptr] = st0 * m64;
break;
case 2:
// fcom
fcom(m64);
break;
case 3:
// fcomp
fcom(m64);
pop();
break;
case 4:
// fsub
st[stack_ptr] = st0 - m64;
break;
case 5:
// fsubr
st[stack_ptr] = m64 - st0;
break;
case 6:
// fdiv
st[stack_ptr] = st0 / m64;
break;
case 7:
// fdivr
st[stack_ptr] = m64 / st0;
break;
default:
dbg_log(mod);
fpu_unimpl();
}
};
this.op_DD_reg = function(imm8)
{
dbg_log_fpu_op(0xDD, imm8);
var mod = imm8 >> 3 & 7,
low = imm8 & 7;
switch(mod)
{
case 0:
// ffree
stack_empty |= 1 << (stack_ptr + low & 7);
break;
case 2:
// fst
st[stack_ptr + low & 7] = get_st0();
break;
case 3:
// fstp
if(low === 0)
{
pop();
}
else
{
st[stack_ptr + low & 7] = get_st0();
pop();
}
break;
case 4:
fucom(get_sti(low));
break;
case 5:
// fucomp
fucom(get_sti(low));
pop();
break;
default:
dbg_log(mod);
fpu_unimpl();
}
};
this.op_DD_mem = function(imm8, addr)
{
dbg_log_fpu_op(0xDD, imm8);
var mod = imm8 >> 3 & 7;
switch(mod)
{
case 0:
// fld
var data = load_m64(addr);
push(data);
break;
case 2:
// fst
store_m64(addr, 0);
break;
case 3:
// fstp
store_m64(addr, 0);
pop();
break;
case 4:
frstor(addr);
break;
case 6:
// fsave
fsave(addr);
break;
case 7:
// fnstsw / store status word
safe_write16(addr, load_status_word());
break;
default:
dbg_log(mod);
fpu_unimpl();
}
};
this.op_DE_reg = function(imm8)
{
dbg_log_fpu_op(0xDE, imm8);
var mod = imm8 >> 3 & 7,
low = imm8 & 7,
low_ptr = stack_ptr + low & 7,
sti = get_sti(low),
st0 = get_st0();
switch(mod)
{
case 0:
// faddp
st[low_ptr] = sti + st0;
break;
case 1:
// fmulp
st[low_ptr] = sti * st0;
break;
case 2:
// fcomp
fcom(sti);
break;
case 3:
// fcompp
if(low === 1)
{
fcom(st[low_ptr]);
pop();
}
else
{
// not a valid encoding
dbg_log(mod);
fpu_unimpl();
}
break;
case 4:
// fsubrp
st[low_ptr] = st0 - sti;
break;
case 5:
// fsubp
st[low_ptr] = sti - st0;
break;
case 6:
// fdivrp
st[low_ptr] = st0 / sti;
break;
case 7:
// fdivp
st[low_ptr] = sti / st0;
break;
default:
dbg_log(mod);
fpu_unimpl();
}
pop();
};
this.op_DE_mem = function(imm8, addr)
{
dbg_log_fpu_op(0xDE, imm8);
var mod = imm8 >> 3 & 7,
m16 = safe_read16s(addr);
var st0 = get_st0();
switch(mod)
{
case 0:
// fadd
st[stack_ptr] = st0 + m16;
break;
case 1:
// fmul
st[stack_ptr] = st0 * m16;
break;
case 2:
// fcom
fcom(m16);
break;
case 3:
// fcomp
fcom(m16);
pop();
break;
case 4:
// fsub
st[stack_ptr] = st0 - m16;
break;
case 5:
// fsubr
st[stack_ptr] = m16 - st0;
break;
case 6:
// fdiv
st[stack_ptr] = st0 / m16;
break;
case 7:
// fdivr
st[stack_ptr] = m16 / st0;
break;
default:
dbg_log(mod);
fpu_unimpl();
}
};
this.op_DF_reg = function(imm8)
{
dbg_log_fpu_op(0xDF, imm8);
var mod = imm8 >> 3 & 7,
low = imm8 & 7;
switch(mod)
{
case 4:
if(imm8 === 0xE0)
{
// fnstsw
reg16[reg_ax] = load_status_word();
}
else
{
dbg_log(imm8);
fpu_unimpl();
}
break;
case 5:
// fucomip
fucomi(get_sti(low));
pop();
break;
default:
dbg_log(mod);
fpu_unimpl();
}
};
this.op_DF_mem = function(imm8, addr)
{
dbg_log_fpu_op(0xDF, imm8);
var mod = imm8 >> 3 & 7;
switch(mod)
{
case 0:
var m16 = safe_read16s(addr);
push(m16);
break;
case 2:
// fist
var st0 = get_st0();
if(st0 <= 0x7FFF && st0 >= -0x8000)
{
safe_write16(addr, integer_round(st0));
}
else
{
invalid_arithmatic();
safe_write16(addr, 0x8000);
}
break;
case 3:
// fistp
var st0 = get_st0();
if(st0 <= 0x7FFF && st0 >= -0x8000)
{
safe_write16(addr, integer_round(st0));
}
else
{
invalid_arithmatic();
safe_write16(addr, 0x8000);
}
pop();
break;
case 5:
// fild
var low = safe_read32(addr);
var high = safe_read32(addr + 4);
var m64 = low + 0x100000000 * high;
if(high >> 31)
{
m64 -= 0x10000000000000000;
}
push(m64);
break;
case 7:
// fistp
var st0 = integer_round(get_st0());
if(!(st0 <= 0x7FFFFFFFFFFFFFFF && st0 >= -0x8000000000000000))
{
st0 = 0x8000000000000000;
invalid_arithmatic();
}
pop();
safe_write32(addr, st0);
st0 /= 0x100000000;
if(st0 < 0 && st0 > -1)
st0 = -1;
safe_write32(addr + 4, st0);
break;
default:
dbg_log(mod);
fpu_unimpl();
}
};
}