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This commit was manufactured by cvs2svn to create tag 'FreeBSD-release/1.0'.
[unix-history] / sys / i386 / i386 / math_emulate.c
/*
* linux/kernel/math/math_emulate.c
*
* (C) 1991 Linus Torvalds
*
* [expediant "port" of linux 8087 emulator to 386BSD, with apologies -wfj]
*
* from: 386BSD 0.1
* $Id$
*/
/*
* Limited emulation 27.12.91 - mostly loads/stores, which gcc wants
* even for soft-float, unless you use bruce evans' patches. The patches
* are great, but they have to be re-applied for every version, and the
* library is different for soft-float and 80387. So emulation is more
* practical, even though it's slower.
*
* 28.12.91 - loads/stores work, even BCD. I'll have to start thinking
* about add/sub/mul/div. Urgel. I should find some good source, but I'll
* just fake up something.
*
* 30.12.91 - add/sub/mul/div/com seem to work mostly. I should really
* test every possible combination.
*/
/*
* This file is full of ugly macros etc: one problem was that gcc simply
* didn't want to make the structures as they should be: it has to try to
* align them. Sickening code, but at least I've hidden the ugly things
* in this one file: the other files don't need to know about these things.
*
* The other files also don't care about ST(x) etc - they just get addresses
* to 80-bit temporary reals, and do with them as they please. I wanted to
* hide most of the 387-specific things here.
*
*/
#include "machine/cpu.h"
#include "machine/psl.h"
#include "machine/reg.h"
#include "param.h"
#include "systm.h"
#include "proc.h"
#include "user.h"
#include "acct.h"
#include "kernel.h"
#include "signal.h"
#define __ALIGNED_TEMP_REAL 1
#include "i386/i386/math_emu.h"
#define bswapw(x) __asm__("xchgb %%al,%%ah":"=a" (x):"0" ((short)x))
#define ST(x) (*__st((x)))
#define PST(x) ((const temp_real *) __st((x)))
#define math_abort(tfp, signo) tfp->tf_eip = oldeip; return (signo);
/*
* We don't want these inlined - it gets too messy in the machine-code.
*/
static void fpop(void);
static void fpush(void);
static void fxchg(temp_real_unaligned * a, temp_real_unaligned * b);
static temp_real_unaligned * __st(int i);
unsigned char get_fs_byte(char *adr) { return(fubyte(adr)); }
unsigned short get_fs_word(unsigned short *adr) { return(fuword(adr)); }
unsigned long get_fs_long(unsigned long *adr) { return(fuword(adr)); }
put_fs_byte(unsigned char val, char *adr) { (void)subyte(adr,val); }
put_fs_word(unsigned short val, short *adr) { (void)susword(adr,val); }
put_fs_long(unsigned long val, unsigned long *adr) { (void)suword(adr,val); }
math_emulate(struct trapframe * info)
{
unsigned short code;
temp_real tmp;
char * address;
u_long oldeip;
/* ever used fp? */
if ((((struct pcb *)curproc->p_addr)->pcb_flags & FP_SOFTFP) == 0) {
((struct pcb *)curproc->p_addr)->pcb_flags |= FP_SOFTFP;
I387.cwd = 0x037f;
I387.swd = 0x0000;
I387.twd = 0x0000;
}
if (I387.cwd & I387.swd & 0x3f)
I387.swd |= 0x8000;
else
I387.swd &= 0x7fff;
oldeip = info->tf_eip;
/* 0x001f means user code space */
if ((u_short)info->tf_cs != 0x001F) {
printf("math_emulate: %04x:%08x\n\r", (u_short)info->tf_cs,
oldeip);
panic("?Math emulation needed in kernel?");
}
code = get_fs_word((unsigned short *) oldeip);
bswapw(code);
code &= 0x7ff;
I387.fip = oldeip;
*(unsigned short *) &I387.fcs = (u_short) info->tf_cs;
*(1+(unsigned short *) &I387.fcs) = code;
info->tf_eip += 2;
switch (code) {
case 0x1d0: /* fnop */
return(0);
case 0x1d1: case 0x1d2: case 0x1d3:
case 0x1d4: case 0x1d5: case 0x1d6: case 0x1d7:
math_abort(info,SIGILL);
case 0x1e0:
ST(0).exponent ^= 0x8000;
return(0);
case 0x1e1:
ST(0).exponent &= 0x7fff;
return(0);
case 0x1e2: case 0x1e3:
math_abort(info,SIGILL);
case 0x1e4:
ftst(PST(0));
return(0);
case 0x1e5:
printf("fxam not implemented\n\r");
math_abort(info,SIGILL);
case 0x1e6: case 0x1e7:
math_abort(info,SIGILL);
case 0x1e8:
fpush();
ST(0) = CONST1;
return(0);
case 0x1e9:
fpush();
ST(0) = CONSTL2T;
return(0);
case 0x1ea:
fpush();
ST(0) = CONSTL2E;
return(0);
case 0x1eb:
fpush();
ST(0) = CONSTPI;
return(0);
case 0x1ec:
fpush();
ST(0) = CONSTLG2;
return(0);
case 0x1ed:
fpush();
ST(0) = CONSTLN2;
return(0);
case 0x1ee:
fpush();
ST(0) = CONSTZ;
return(0);
case 0x1ef:
math_abort(info,SIGILL);
case 0x1f0: case 0x1f1: case 0x1f2: case 0x1f3:
case 0x1f4: case 0x1f5: case 0x1f6: case 0x1f7:
case 0x1f8: case 0x1f9: case 0x1fa: case 0x1fb:
case 0x1fe: case 0x1ff:
uprintf(
"math_emulate: instruction %04x not implemented\n",
code + 0xd800);
math_abort(info,SIGILL);
case 0x1fd:
/* incomplete and totally inadequate -wfj */
Fscale(PST(0), PST(1), &tmp);
real_to_real(&tmp,&ST(0));
return(0); /* 19 Sep 92*/
case 0x1fc:
frndint(PST(0),&tmp);
real_to_real(&tmp,&ST(0));
return(0);
case 0x2e9:
fucom(PST(1),PST(0));
fpop(); fpop();
return(0);
case 0x3d0: case 0x3d1:
return(0);
case 0x3e2:
I387.swd &= 0x7f00;
return(0);
case 0x3e3:
I387.cwd = 0x037f;
I387.swd = 0x0000;
I387.twd = 0x0000;
return(0);
case 0x3e4:
return(0);
case 0x6d9:
fcom(PST(1),PST(0));
fpop(); fpop();
return(0);
case 0x7e0:
*(short *) &info->tf_eax = I387.swd;
return(0);
}
switch (code >> 3) {
case 0x18:
fadd(PST(0),PST(code & 7),&tmp);
real_to_real(&tmp,&ST(0));
return(0);
case 0x19:
fmul(PST(0),PST(code & 7),&tmp);
real_to_real(&tmp,&ST(0));
return(0);
case 0x1a:
fcom(PST(code & 7),&tmp);
real_to_real(&tmp,&ST(0));
return(0);
case 0x1b:
fcom(PST(code & 7),&tmp);
real_to_real(&tmp,&ST(0));
fpop();
return(0);
case 0x1c:
real_to_real(&ST(code & 7),&tmp);
tmp.exponent ^= 0x8000;
fadd(PST(0),&tmp,&tmp);
real_to_real(&tmp,&ST(0));
return(0);
case 0x1d:
ST(0).exponent ^= 0x8000;
fadd(PST(0),PST(code & 7),&tmp);
real_to_real(&tmp,&ST(0));
return(0);
case 0x1e:
fdiv(PST(0),PST(code & 7),&tmp);
real_to_real(&tmp,&ST(0));
return(0);
case 0x1f:
fdiv(PST(code & 7),PST(0),&tmp);
real_to_real(&tmp,&ST(0));
return(0);
case 0x38:
fpush();
ST(0) = ST((code & 7)+1);
return(0);
case 0x39:
fxchg(&ST(0),&ST(code & 7));
return(0);
case 0x3b:
ST(code & 7) = ST(0);
fpop();
return(0);
case 0x98:
fadd(PST(0),PST(code & 7),&tmp);
real_to_real(&tmp,&ST(code & 7));
return(0);
case 0x99:
fmul(PST(0),PST(code & 7),&tmp);
real_to_real(&tmp,&ST(code & 7));
return(0);
case 0x9a:
fcom(PST(code & 7),PST(0));
return(0);
case 0x9b:
fcom(PST(code & 7),PST(0));
fpop();
return(0);
case 0x9c:
ST(code & 7).exponent ^= 0x8000;
fadd(PST(0),PST(code & 7),&tmp);
real_to_real(&tmp,&ST(code & 7));
return(0);
case 0x9d:
real_to_real(&ST(0),&tmp);
tmp.exponent ^= 0x8000;
fadd(PST(code & 7),&tmp,&tmp);
real_to_real(&tmp,&ST(code & 7));
return(0);
case 0x9e:
fdiv(PST(0),PST(code & 7),&tmp);
real_to_real(&tmp,&ST(code & 7));
return(0);
case 0x9f:
fdiv(PST(code & 7),PST(0),&tmp);
real_to_real(&tmp,&ST(code & 7));
return(0);
case 0xb8:
printf("ffree not implemented\n\r");
math_abort(info,SIGILL);
case 0xb9:
fxchg(&ST(0),&ST(code & 7));
return(0);
case 0xba:
ST(code & 7) = ST(0);
return(0);
case 0xbb:
ST(code & 7) = ST(0);
fpop();
return(0);
case 0xbc:
fucom(PST(code & 7),PST(0));
return(0);
case 0xbd:
fucom(PST(code & 7),PST(0));
fpop();
return(0);
case 0xd8:
fadd(PST(code & 7),PST(0),&tmp);
real_to_real(&tmp,&ST(code & 7));
fpop();
return(0);
case 0xd9:
fmul(PST(code & 7),PST(0),&tmp);
real_to_real(&tmp,&ST(code & 7));
fpop();
return(0);
case 0xda:
fcom(PST(code & 7),PST(0));
fpop();
return(0);
case 0xdc:
ST(code & 7).exponent ^= 0x8000;
fadd(PST(0),PST(code & 7),&tmp);
real_to_real(&tmp,&ST(code & 7));
fpop();
return(0);
case 0xdd:
real_to_real(&ST(0),&tmp);
tmp.exponent ^= 0x8000;
fadd(PST(code & 7),&tmp,&tmp);
real_to_real(&tmp,&ST(code & 7));
fpop();
return(0);
case 0xde:
fdiv(PST(0),PST(code & 7),&tmp);
real_to_real(&tmp,&ST(code & 7));
fpop();
return(0);
case 0xdf:
fdiv(PST(code & 7),PST(0),&tmp);
real_to_real(&tmp,&ST(code & 7));
fpop();
return(0);
case 0xf8:
printf("ffree not implemented\n\r");
math_abort(info,SIGILL);
fpop();
return(0);
case 0xf9:
fxchg(&ST(0),&ST(code & 7));
return(0);
case 0xfa:
case 0xfb:
ST(code & 7) = ST(0);
fpop();
return(0);
}
switch ((code>>3) & 0xe7) {
case 0x22:
put_short_real(PST(0),info,code);
return(0);
case 0x23:
put_short_real(PST(0),info,code);
fpop();
return(0);
case 0x24:
address = ea(info,code);
for (code = 0 ; code < 7 ; code++) {
((long *) & I387)[code] =
get_fs_long((unsigned long *) address);
address += 4;
}
return(0);
case 0x25:
address = ea(info,code);
*(unsigned short *) &I387.cwd =
get_fs_word((unsigned short *) address);
return(0);
case 0x26:
address = ea(info,code);
/*verify_area(address,28);*/
for (code = 0 ; code < 7 ; code++) {
put_fs_long( ((long *) & I387)[code],
(unsigned long *) address);
address += 4;
}
return(0);
case 0x27:
address = ea(info,code);
/*verify_area(address,2);*/
put_fs_word(I387.cwd,(short *) address);
return(0);
case 0x62:
put_long_int(PST(0),info,code);
return(0);
case 0x63:
put_long_int(PST(0),info,code);
fpop();
return(0);
case 0x65:
fpush();
get_temp_real(&tmp,info,code);
real_to_real(&tmp,&ST(0));
return(0);
case 0x67:
put_temp_real(PST(0),info,code);
fpop();
return(0);
case 0xa2:
put_long_real(PST(0),info,code);
return(0);
case 0xa3:
put_long_real(PST(0),info,code);
fpop();
return(0);
case 0xa4:
address = ea(info,code);
for (code = 0 ; code < 27 ; code++) {
((long *) & I387)[code] =
get_fs_long((unsigned long *) address);
address += 4;
}
return(0);
case 0xa6:
address = ea(info,code);
/*verify_area(address,108);*/
for (code = 0 ; code < 27 ; code++) {
put_fs_long( ((long *) & I387)[code],
(unsigned long *) address);
address += 4;
}
I387.cwd = 0x037f;
I387.swd = 0x0000;
I387.twd = 0x0000;
return(0);
case 0xa7:
address = ea(info,code);
/*verify_area(address,2);*/
put_fs_word(I387.swd,(short *) address);
return(0);
case 0xe2:
put_short_int(PST(0),info,code);
return(0);
case 0xe3:
put_short_int(PST(0),info,code);
fpop();
return(0);
case 0xe4:
fpush();
get_BCD(&tmp,info,code);
real_to_real(&tmp,&ST(0));
return(0);
case 0xe5:
fpush();
get_longlong_int(&tmp,info,code);
real_to_real(&tmp,&ST(0));
return(0);
case 0xe6:
put_BCD(PST(0),info,code);
fpop();
return(0);
case 0xe7:
put_longlong_int(PST(0),info,code);
fpop();
return(0);
}
switch (code >> 9) {
case 0:
get_short_real(&tmp,info,code);
break;
case 1:
get_long_int(&tmp,info,code);
break;
case 2:
get_long_real(&tmp,info,code);
break;
case 4:
get_short_int(&tmp,info,code);
}
switch ((code>>3) & 0x27) {
case 0:
fadd(&tmp,PST(0),&tmp);
real_to_real(&tmp,&ST(0));
return(0);
case 1:
fmul(&tmp,PST(0),&tmp);
real_to_real(&tmp,&ST(0));
return(0);
case 2:
fcom(&tmp,PST(0));
return(0);
case 3:
fcom(&tmp,PST(0));
fpop();
return(0);
case 4:
tmp.exponent ^= 0x8000;
fadd(&tmp,PST(0),&tmp);
real_to_real(&tmp,&ST(0));
return(0);
case 5:
ST(0).exponent ^= 0x8000;
fadd(&tmp,PST(0),&tmp);
real_to_real(&tmp,&ST(0));
return(0);
case 6:
fdiv(PST(0),&tmp,&tmp);
real_to_real(&tmp,&ST(0));
return(0);
case 7:
fdiv(&tmp,PST(0),&tmp);
real_to_real(&tmp,&ST(0));
return(0);
}
if ((code & 0x138) == 0x100) {
fpush();
real_to_real(&tmp,&ST(0));
return(0);
}
printf("Unknown math-insns: %04x:%08x %04x\n\r",(u_short)info->tf_cs,
info->tf_eip,code);
math_abort(info,SIGFPE);
}
static void fpop(void)
{
unsigned long tmp;
tmp = I387.swd & 0xffffc7ff;
I387.swd += 0x00000800;
I387.swd &= 0x00003800;
I387.swd |= tmp;
}
static void fpush(void)
{
unsigned long tmp;
tmp = I387.swd & 0xffffc7ff;
I387.swd += 0x00003800;
I387.swd &= 0x00003800;
I387.swd |= tmp;
}
static void fxchg(temp_real_unaligned * a, temp_real_unaligned * b)
{
temp_real_unaligned c;
c = *a;
*a = *b;
*b = c;
}
static temp_real_unaligned * __st(int i)
{
i += I387.swd >> 11;
i &= 7;
return (temp_real_unaligned *) (i*10 + (char *)(I387.st_space));
}
/*
* linux/kernel/math/ea.c
*
* (C) 1991 Linus Torvalds
*/
/*
* Calculate the effective address.
*/
static int __regoffset[] = {
tEAX, tECX, tEDX, tEBX, tESP, tEBP, tESI, tEDI
};
#define REG(x) (curproc->p_regs[__regoffset[(x)]])
static char * sib(struct trapframe * info, int mod)
{
unsigned char ss,index,base;
long offset = 0;
base = get_fs_byte((char *) info->tf_eip);
info->tf_eip++;
ss = base >> 6;
index = (base >> 3) & 7;
base &= 7;
if (index == 4)
offset = 0;
else
offset = REG(index);
offset <<= ss;
if (mod || base != 5)
offset += REG(base);
if (mod == 1) {
offset += (signed char) get_fs_byte((char *) info->tf_eip);
info->tf_eip++;
} else if (mod == 2 || base == 5) {
offset += (signed) get_fs_long((unsigned long *) info->tf_eip);
info->tf_eip += 4;
}
I387.foo = offset;
I387.fos = 0x17;
return (char *) offset;
}
char * ea(struct trapframe * info, unsigned short code)
{
unsigned char mod,rm;
long * tmp;
int offset = 0;
mod = (code >> 6) & 3;
rm = code & 7;
if (rm == 4 && mod != 3)
return sib(info,mod);
if (rm == 5 && !mod) {
offset = get_fs_long((unsigned long *) info->tf_eip);
info->tf_eip += 4;
I387.foo = offset;
I387.fos = 0x17;
return (char *) offset;
}
tmp = (long *) &REG(rm);
switch (mod) {
case 0: offset = 0; break;
case 1:
offset = (signed char) get_fs_byte((char *) info->tf_eip);
info->tf_eip++;
break;
case 2:
offset = (signed) get_fs_long((unsigned long *) info->tf_eip);
info->tf_eip += 4;
break;
#ifdef notyet
case 3:
math_abort(info,1<<(SIGILL-1));
#endif
}
I387.foo = offset;
I387.fos = 0x17;
return offset + (char *) *tmp;
}
/*
* linux/kernel/math/get_put.c
*
* (C) 1991 Linus Torvalds
*/
/*
* This file handles all accesses to user memory: getting and putting
* ints/reals/BCD etc. This is the only part that concerns itself with
* other than temporary real format. All other cals are strictly temp_real.
*/
void get_short_real(temp_real * tmp,
struct trapframe * info, unsigned short code)
{
char * addr;
short_real sr;
addr = ea(info,code);
sr = get_fs_long((unsigned long *) addr);
short_to_temp(&sr,tmp);
}
void get_long_real(temp_real * tmp,
struct trapframe * info, unsigned short code)
{
char * addr;
long_real lr;
addr = ea(info,code);
lr.a = get_fs_long((unsigned long *) addr);
lr.b = get_fs_long(1 + (unsigned long *) addr);
long_to_temp(&lr,tmp);
}
void get_temp_real(temp_real * tmp,
struct trapframe * info, unsigned short code)
{
char * addr;
addr = ea(info,code);
tmp->a = get_fs_long((unsigned long *) addr);
tmp->b = get_fs_long(1 + (unsigned long *) addr);
tmp->exponent = get_fs_word(4 + (unsigned short *) addr);
}
void get_short_int(temp_real * tmp,
struct trapframe * info, unsigned short code)
{
char * addr;
temp_int ti;
addr = ea(info,code);
ti.a = (signed short) get_fs_word((unsigned short *) addr);
ti.b = 0;
if (ti.sign = (ti.a < 0))
ti.a = - ti.a;
int_to_real(&ti,tmp);
}
void get_long_int(temp_real * tmp,
struct trapframe * info, unsigned short code)
{
char * addr;
temp_int ti;
addr = ea(info,code);
ti.a = get_fs_long((unsigned long *) addr);
ti.b = 0;
if (ti.sign = (ti.a < 0))
ti.a = - ti.a;
int_to_real(&ti,tmp);
}
void get_longlong_int(temp_real * tmp,
struct trapframe * info, unsigned short code)
{
char * addr;
temp_int ti;
addr = ea(info,code);
ti.a = get_fs_long((unsigned long *) addr);
ti.b = get_fs_long(1 + (unsigned long *) addr);
if (ti.sign = (ti.b < 0))
__asm__("notl %0 ; notl %1\n\t"
"addl $1,%0 ; adcl $0,%1"
:"=r" (ti.a),"=r" (ti.b)
:"0" (ti.a),"1" (ti.b));
int_to_real(&ti,tmp);
}
#define MUL10(low,high) \
__asm__("addl %0,%0 ; adcl %1,%1\n\t" \
"movl %0,%%ecx ; movl %1,%%ebx\n\t" \
"addl %0,%0 ; adcl %1,%1\n\t" \
"addl %0,%0 ; adcl %1,%1\n\t" \
"addl %%ecx,%0 ; adcl %%ebx,%1" \
:"=a" (low),"=d" (high) \
:"0" (low),"1" (high):"cx","bx")
#define ADD64(val,low,high) \
__asm__("addl %4,%0 ; adcl $0,%1":"=r" (low),"=r" (high) \
:"0" (low),"1" (high),"r" ((unsigned long) (val)))
void get_BCD(temp_real * tmp, struct trapframe * info, unsigned short code)
{
int k;
char * addr;
temp_int i;
unsigned char c;
addr = ea(info,code);
addr += 9;
i.sign = 0x80 & get_fs_byte(addr--);
i.a = i.b = 0;
for (k = 0; k < 9; k++) {
c = get_fs_byte(addr--);
MUL10(i.a, i.b);
ADD64((c>>4), i.a, i.b);
MUL10(i.a, i.b);
ADD64((c&0xf), i.a, i.b);
}
int_to_real(&i,tmp);
}
void put_short_real(const temp_real * tmp,
struct trapframe * info, unsigned short code)
{
char * addr;
short_real sr;
addr = ea(info,code);
/*verify_area(addr,4);*/
temp_to_short(tmp,&sr);
put_fs_long(sr,(unsigned long *) addr);
}
void put_long_real(const temp_real * tmp,
struct trapframe * info, unsigned short code)
{
char * addr;
long_real lr;
addr = ea(info,code);
/*verify_area(addr,8);*/
temp_to_long(tmp,&lr);
put_fs_long(lr.a, (unsigned long *) addr);
put_fs_long(lr.b, 1 + (unsigned long *) addr);
}
void put_temp_real(const temp_real * tmp,
struct trapframe * info, unsigned short code)
{
char * addr;
addr = ea(info,code);
/*verify_area(addr,10);*/
put_fs_long(tmp->a, (unsigned long *) addr);
put_fs_long(tmp->b, 1 + (unsigned long *) addr);
put_fs_word(tmp->exponent, 4 + (short *) addr);
}
void put_short_int(const temp_real * tmp,
struct trapframe * info, unsigned short code)
{
char * addr;
temp_int ti;
addr = ea(info,code);
real_to_int(tmp,&ti);
/*verify_area(addr,2);*/
if (ti.sign)
ti.a = -ti.a;
put_fs_word(ti.a,(short *) addr);
}
void put_long_int(const temp_real * tmp,
struct trapframe * info, unsigned short code)
{
char * addr;
temp_int ti;
addr = ea(info,code);
real_to_int(tmp,&ti);
/*verify_area(addr,4);*/
if (ti.sign)
ti.a = -ti.a;
put_fs_long(ti.a,(unsigned long *) addr);
}
void put_longlong_int(const temp_real * tmp,
struct trapframe * info, unsigned short code)
{
char * addr;
temp_int ti;
addr = ea(info,code);
real_to_int(tmp,&ti);
/*verify_area(addr,8);*/
if (ti.sign)
__asm__("notl %0 ; notl %1\n\t"
"addl $1,%0 ; adcl $0,%1"
:"=r" (ti.a),"=r" (ti.b)
:"0" (ti.a),"1" (ti.b));
put_fs_long(ti.a,(unsigned long *) addr);
put_fs_long(ti.b,1 + (unsigned long *) addr);
}
#define DIV10(low,high,rem) \
__asm__("divl %6 ; xchgl %1,%2 ; divl %6" \
:"=d" (rem),"=a" (low),"=r" (high) \
:"0" (0),"1" (high),"2" (low),"c" (10))
void put_BCD(const temp_real * tmp,struct trapframe * info, unsigned short code)
{
int k,rem;
char * addr;
temp_int i;
unsigned char c;
addr = ea(info,code);
/*verify_area(addr,10);*/
real_to_int(tmp,&i);
if (i.sign)
put_fs_byte(0x80, addr+9);
else
put_fs_byte(0, addr+9);
for (k = 0; k < 9; k++) {
DIV10(i.a,i.b,rem);
c = rem;
DIV10(i.a,i.b,rem);
c += rem<<4;
put_fs_byte(c,addr++);
}
}
/*
* linux/kernel/math/mul.c
*
* (C) 1991 Linus Torvalds
*/
/*
* temporary real multiplication routine.
*/
static void shift(int * c)
{
__asm__("movl (%0),%%eax ; addl %%eax,(%0)\n\t"
"movl 4(%0),%%eax ; adcl %%eax,4(%0)\n\t"
"movl 8(%0),%%eax ; adcl %%eax,8(%0)\n\t"
"movl 12(%0),%%eax ; adcl %%eax,12(%0)"
::"r" ((long) c):"ax");
}
static void mul64(const temp_real * a, const temp_real * b, int * c)
{
__asm__("movl (%0),%%eax\n\t"
"mull (%1)\n\t"
"movl %%eax,(%2)\n\t"
"movl %%edx,4(%2)\n\t"
"movl 4(%0),%%eax\n\t"
"mull 4(%1)\n\t"
"movl %%eax,8(%2)\n\t"
"movl %%edx,12(%2)\n\t"
"movl (%0),%%eax\n\t"
"mull 4(%1)\n\t"
"addl %%eax,4(%2)\n\t"
"adcl %%edx,8(%2)\n\t"
"adcl $0,12(%2)\n\t"
"movl 4(%0),%%eax\n\t"
"mull (%1)\n\t"
"addl %%eax,4(%2)\n\t"
"adcl %%edx,8(%2)\n\t"
"adcl $0,12(%2)"
::"S" ((long) a),"c" ((long) b),"D" ((long) c)
:"ax","dx");
}
void fmul(const temp_real * src1, const temp_real * src2, temp_real * result)
{
int i,sign;
int tmp[4] = {0,0,0,0};
sign = (src1->exponent ^ src2->exponent) & 0x8000;
i = (src1->exponent & 0x7fff) + (src2->exponent & 0x7fff) - 16383 + 1;
if (i<0) {
result->exponent = sign;
result->a = result->b = 0;
return;
}
if (i>0x7fff) {
set_OE();
return;
}
mul64(src1,src2,tmp);
if (tmp[0] || tmp[1] || tmp[2] || tmp[3])
while (i && tmp[3] >= 0) {
i--;
shift(tmp);
}
else
i = 0;
result->exponent = i | sign;
result->a = tmp[2];
result->b = tmp[3];
}
/*
* linux/kernel/math/div.c
*
* (C) 1991 Linus Torvalds
*/
/*
* temporary real division routine.
*/
static void shift_left(int * c)
{
__asm__ __volatile__("movl (%0),%%eax ; addl %%eax,(%0)\n\t"
"movl 4(%0),%%eax ; adcl %%eax,4(%0)\n\t"
"movl 8(%0),%%eax ; adcl %%eax,8(%0)\n\t"
"movl 12(%0),%%eax ; adcl %%eax,12(%0)"
::"r" ((long) c):"ax");
}
static void shift_right(int * c)
{
__asm__("shrl $1,12(%0) ; rcrl $1,8(%0) ; rcrl $1,4(%0) ; rcrl $1,(%0)"
::"r" ((long) c));
}
static int try_sub(int * a, int * b)
{
char ok;
__asm__ __volatile__("movl (%1),%%eax ; subl %%eax,(%2)\n\t"
"movl 4(%1),%%eax ; sbbl %%eax,4(%2)\n\t"
"movl 8(%1),%%eax ; sbbl %%eax,8(%2)\n\t"
"movl 12(%1),%%eax ; sbbl %%eax,12(%2)\n\t"
"setae %%al":"=a" (ok):"c" ((long) a),"d" ((long) b));
return ok;
}
static void div64(int * a, int * b, int * c)
{
int tmp[4];
int i;
unsigned int mask = 0;
c += 4;
for (i = 0 ; i<64 ; i++) {
if (!(mask >>= 1)) {
c--;
mask = 0x80000000;
}
tmp[0] = a[0]; tmp[1] = a[1];
tmp[2] = a[2]; tmp[3] = a[3];
if (try_sub(b,tmp)) {
*c |= mask;
a[0] = tmp[0]; a[1] = tmp[1];
a[2] = tmp[2]; a[3] = tmp[3];
}
shift_right(b);
}
}
void fdiv(const temp_real * src1, const temp_real * src2, temp_real * result)
{
int i,sign;
int a[4],b[4],tmp[4] = {0,0,0,0};
sign = (src1->exponent ^ src2->exponent) & 0x8000;
if (!(src2->a || src2->b)) {
set_ZE();
return;
}
i = (src1->exponent & 0x7fff) - (src2->exponent & 0x7fff) + 16383;
if (i<0) {
set_UE();
result->exponent = sign;
result->a = result->b = 0;
return;
}
a[0] = a[1] = 0;
a[2] = src1->a;
a[3] = src1->b;
b[0] = b[1] = 0;
b[2] = src2->a;
b[3] = src2->b;
while (b[3] >= 0) {
i++;
shift_left(b);
}
div64(a,b,tmp);
if (tmp[0] || tmp[1] || tmp[2] || tmp[3]) {
while (i && tmp[3] >= 0) {
i--;
shift_left(tmp);
}
if (tmp[3] >= 0)
set_DE();
} else
i = 0;
if (i>0x7fff) {
set_OE();
return;
}
if (tmp[0] || tmp[1])
set_PE();
result->exponent = i | sign;
result->a = tmp[2];
result->b = tmp[3];
}
/*
* linux/kernel/math/add.c
*
* (C) 1991 Linus Torvalds
*/
/*
* temporary real addition routine.
*
* NOTE! These aren't exact: they are only 62 bits wide, and don't do
* correct rounding. Fast hack. The reason is that we shift right the
* values by two, in order not to have overflow (1 bit), and to be able
* to move the sign into the mantissa (1 bit). Much simpler algorithms,
* and 62 bits (61 really - no rounding) accuracy is usually enough. The
* only time you should notice anything weird is when adding 64-bit
* integers together. When using doubles (52 bits accuracy), the
* 61-bit accuracy never shows at all.
*/
#define NEGINT(a) \
__asm__("notl %0 ; notl %1 ; addl $1,%0 ; adcl $0,%1" \
:"=r" (a->a),"=r" (a->b) \
:"0" (a->a),"1" (a->b))
static void signify(temp_real * a)
{
a->exponent += 2;
__asm__("shrdl $2,%1,%0 ; shrl $2,%1"
:"=r" (a->a),"=r" (a->b)
:"0" (a->a),"1" (a->b));
if (a->exponent < 0)
NEGINT(a);
a->exponent &= 0x7fff;
}
static void unsignify(temp_real * a)
{
if (!(a->a || a->b)) {
a->exponent = 0;
return;
}
a->exponent &= 0x7fff;
if (a->b < 0) {
NEGINT(a);
a->exponent |= 0x8000;
}
while (a->b >= 0) {
a->exponent--;
__asm__("addl %0,%0 ; adcl %1,%1"
:"=r" (a->a),"=r" (a->b)
:"0" (a->a),"1" (a->b));
}
}
void fadd(const temp_real * src1, const temp_real * src2, temp_real * result)
{
temp_real a,b;
int x1,x2,shift;
x1 = src1->exponent & 0x7fff;
x2 = src2->exponent & 0x7fff;
if (x1 > x2) {
a = *src1;
b = *src2;
shift = x1-x2;
} else {
a = *src2;
b = *src1;
shift = x2-x1;
}
if (shift >= 64) {
*result = a;
return;
}
if (shift >= 32) {
b.a = b.b;
b.b = 0;
shift -= 32;
}
__asm__("shrdl %4,%1,%0 ; shrl %4,%1"
:"=r" (b.a),"=r" (b.b)
:"0" (b.a),"1" (b.b),"c" ((char) shift));
signify(&a);
signify(&b);
__asm__("addl %4,%0 ; adcl %5,%1"
:"=r" (a.a),"=r" (a.b)
:"0" (a.a),"1" (a.b),"g" (b.a),"g" (b.b));
unsignify(&a);
*result = a;
}
/*
* linux/kernel/math/compare.c
*
* (C) 1991 Linus Torvalds
*/
/*
* temporary real comparison routines
*/
#define clear_Cx() (I387.swd &= ~0x4500)
static void normalize(temp_real * a)
{
int i = a->exponent & 0x7fff;
int sign = a->exponent & 0x8000;
if (!(a->a || a->b)) {
a->exponent = 0;
return;
}
while (i && a->b >= 0) {
i--;
__asm__("addl %0,%0 ; adcl %1,%1"
:"=r" (a->a),"=r" (a->b)
:"0" (a->a),"1" (a->b));
}
a->exponent = i | sign;
}
void ftst(const temp_real * a)
{
temp_real b;
clear_Cx();
b = *a;
normalize(&b);
if (b.a || b.b || b.exponent) {
if (b.exponent < 0)
set_C0();
} else
set_C3();
}
void fcom(const temp_real * src1, const temp_real * src2)
{
temp_real a;
a = *src1;
a.exponent ^= 0x8000;
fadd(&a,src2,&a);
ftst(&a);
}
void fucom(const temp_real * src1, const temp_real * src2)
{
fcom(src1,src2);
}
/*
* linux/kernel/math/convert.c
*
* (C) 1991 Linus Torvalds
*/
/*
* NOTE!!! There is some "non-obvious" optimisations in the temp_to_long
* and temp_to_short conversion routines: don't touch them if you don't
* know what's going on. They are the adding of one in the rounding: the
* overflow bit is also used for adding one into the exponent. Thus it
* looks like the overflow would be incorrectly handled, but due to the
* way the IEEE numbers work, things are correct.
*
* There is no checking for total overflow in the conversions, though (ie
* if the temp-real number simply won't fit in a short- or long-real.)
*/
void short_to_temp(const short_real * a, temp_real * b)
{
if (!(*a & 0x7fffffff)) {
b->a = b->b = 0;
if (*a)
b->exponent = 0x8000;
else
b->exponent = 0;
return;
}
b->exponent = ((*a>>23) & 0xff)-127+16383;
if (*a<0)
b->exponent |= 0x8000;
b->b = (*a<<8) | 0x80000000;
b->a = 0;
}
void long_to_temp(const long_real * a, temp_real * b)
{
if (!a->a && !(a->b & 0x7fffffff)) {
b->a = b->b = 0;
if (a->b)
b->exponent = 0x8000;
else
b->exponent = 0;
return;
}
b->exponent = ((a->b >> 20) & 0x7ff)-1023+16383;
if (a->b<0)
b->exponent |= 0x8000;
b->b = 0x80000000 | (a->b<<11) | (((unsigned long)a->a)>>21);
b->a = a->a<<11;
}
void temp_to_short(const temp_real * a, short_real * b)
{
if (!(a->exponent & 0x7fff)) {
*b = (a->exponent)?0x80000000:0;
return;
}
*b = ((((long) a->exponent)-16383+127) << 23) & 0x7f800000;
if (a->exponent < 0)
*b |= 0x80000000;
*b |= (a->b >> 8) & 0x007fffff;
switch (ROUNDING) {
case ROUND_NEAREST:
if ((a->b & 0xff) > 0x80)
++*b;
break;
case ROUND_DOWN:
if ((a->exponent & 0x8000) && (a->b & 0xff))
++*b;
break;
case ROUND_UP:
if (!(a->exponent & 0x8000) && (a->b & 0xff))
++*b;
break;
}
}
void temp_to_long(const temp_real * a, long_real * b)
{
if (!(a->exponent & 0x7fff)) {
b->a = 0;
b->b = (a->exponent)?0x80000000:0;
return;
}
b->b = (((0x7fff & (long) a->exponent)-16383+1023) << 20) & 0x7ff00000;
if (a->exponent < 0)
b->b |= 0x80000000;
b->b |= (a->b >> 11) & 0x000fffff;
b->a = a->b << 21;
b->a |= (a->a >> 11) & 0x001fffff;
switch (ROUNDING) {
case ROUND_NEAREST:
if ((a->a & 0x7ff) > 0x400)
__asm__("addl $1,%0 ; adcl $0,%1"
:"=r" (b->a),"=r" (b->b)
:"0" (b->a),"1" (b->b));
break;
case ROUND_DOWN:
if ((a->exponent & 0x8000) && (a->b & 0xff))
__asm__("addl $1,%0 ; adcl $0,%1"
:"=r" (b->a),"=r" (b->b)
:"0" (b->a),"1" (b->b));
break;
case ROUND_UP:
if (!(a->exponent & 0x8000) && (a->b & 0xff))
__asm__("addl $1,%0 ; adcl $0,%1"
:"=r" (b->a),"=r" (b->b)
:"0" (b->a),"1" (b->b));
break;
}
}
void frndint(const temp_real * a, temp_real * b)
{
int shift = 16383 + 63 - (a->exponent & 0x7fff);
unsigned long underflow;
if ((shift < 0) || (shift == 16383+63)) {
*b = *a;
return;
}
b->a = b->b = underflow = 0;
b->exponent = a->exponent;
if (shift < 32) {
b->b = a->b; b->a = a->a;
} else if (shift < 64) {
b->a = a->b; underflow = a->a;
shift -= 32;
b->exponent += 32;
} else if (shift < 96) {
underflow = a->b;
shift -= 64;
b->exponent += 64;
} else {
underflow = 1;
shift = 0;
}
b->exponent += shift;
__asm__("shrdl %2,%1,%0"
:"=r" (underflow),"=r" (b->a)
:"c" ((char) shift),"0" (underflow),"1" (b->a));
__asm__("shrdl %2,%1,%0"
:"=r" (b->a),"=r" (b->b)
:"c" ((char) shift),"0" (b->a),"1" (b->b));
__asm__("shrl %1,%0"
:"=r" (b->b)
:"c" ((char) shift),"0" (b->b));
switch (ROUNDING) {
case ROUND_NEAREST:
__asm__("addl %4,%5 ; adcl $0,%0 ; adcl $0,%1"
:"=r" (b->a),"=r" (b->b)
:"0" (b->a),"1" (b->b)
,"r" (0x7fffffff + (b->a & 1))
,"m" (*&underflow));
break;
case ROUND_UP:
if ((b->exponent >= 0) && underflow)
__asm__("addl $1,%0 ; adcl $0,%1"
:"=r" (b->a),"=r" (b->b)
:"0" (b->a),"1" (b->b));
break;
case ROUND_DOWN:
if ((b->exponent < 0) && underflow)
__asm__("addl $1,%0 ; adcl $0,%1"
:"=r" (b->a),"=r" (b->b)
:"0" (b->a),"1" (b->b));
break;
}
if (b->a || b->b)
while (b->b >= 0) {
b->exponent--;
__asm__("addl %0,%0 ; adcl %1,%1"
:"=r" (b->a),"=r" (b->b)
:"0" (b->a),"1" (b->b));
}
else
b->exponent = 0;
}
void Fscale(const temp_real *a, const temp_real *b, temp_real *c)
{
temp_int ti;
*c = *a;
if(!c->a && !c->b) { /* 19 Sep 92*/
c->exponent = 0;
return;
}
real_to_int(b, &ti);
if(ti.sign)
c->exponent -= ti.a;
else
c->exponent += ti.a;
}
void real_to_int(const temp_real * a, temp_int * b)
{
int shift = 16383 + 63 - (a->exponent & 0x7fff);
unsigned long underflow;
b->a = b->b = underflow = 0;
b->sign = (a->exponent < 0);
if (shift < 0) {
set_OE();
return;
}
if (shift < 32) {
b->b = a->b; b->a = a->a;
} else if (shift < 64) {
b->a = a->b; underflow = a->a;
shift -= 32;
} else if (shift < 96) {
underflow = a->b;
shift -= 64;
} else {
underflow = 1;
shift = 0;
}
__asm__("shrdl %2,%1,%0"
:"=r" (underflow),"=r" (b->a)
:"c" ((char) shift),"0" (underflow),"1" (b->a));
__asm__("shrdl %2,%1,%0"
:"=r" (b->a),"=r" (b->b)
:"c" ((char) shift),"0" (b->a),"1" (b->b));
__asm__("shrl %1,%0"
:"=r" (b->b)
:"c" ((char) shift),"0" (b->b));
switch (ROUNDING) {
case ROUND_NEAREST:
__asm__("addl %4,%5 ; adcl $0,%0 ; adcl $0,%1"
:"=r" (b->a),"=r" (b->b)
:"0" (b->a),"1" (b->b)
,"r" (0x7fffffff + (b->a & 1))
,"m" (*&underflow));
break;
case ROUND_UP:
if (!b->sign && underflow)
__asm__("addl $1,%0 ; adcl $0,%1"
:"=r" (b->a),"=r" (b->b)
:"0" (b->a),"1" (b->b));
break;
case ROUND_DOWN:
if (b->sign && underflow)
__asm__("addl $1,%0 ; adcl $0,%1"
:"=r" (b->a),"=r" (b->b)
:"0" (b->a),"1" (b->b));
break;
}
}
void int_to_real(const temp_int * a, temp_real * b)
{
b->a = a->a;
b->b = a->b;
if (b->a || b->b)
b->exponent = 16383 + 63 + (a->sign? 0x8000:0);
else {
b->exponent = 0;
return;
}
while (b->b >= 0) {
b->exponent--;
__asm__("addl %0,%0 ; adcl %1,%1"
:"=r" (b->a),"=r" (b->b)
:"0" (b->a),"1" (b->b));
}
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.