Re: final i386.floating.record.patch

Hui Zhu
2009-08-17T06:36:50Z

Get some error with this patch.
cat fp.c
#include <stdio.h>
#include <math.h>
#include <stdlib.h>

/* the test intends to test following insns.
flds faddp fstps fstpl fldl fxch fabs fdivrp fmulp fsubrp fucomp fnstsw fsqrt
fchs f2xm1 fyl2x fxtract fprem1 fld fdecstp fld1 fldl2t fldl2e FLDPI
FLDLG2 FLDLN2
FLDZ fincstp ffree fptan fpatan fincstp fsincos frndint fscale fsin fcos fcmovb
fcmovbe fcmove fcmovu fcmovnb fcmovnbe fsave frstor fstsw
*/

float no1,no2,no3,no4,no5,no6,no7;
double x = 100.345, y = 25.7789;
long double ldx = 88888888888888888888.88, ldy = 9999999999999999999.99;
float result,resultd,resultld;
float *float_memory;

/* initialization of floats */
void init_floats()
{
no1 = 10.45;
no2 = 20.77;
no3 = 156.89874646;
no4 = 14.56;
no5 = 11.11;
no6 = 66.77;
no7 = 88.88;
float_memory = malloc(sizeof(float) * 4);
*float_memory = 256.256;
*(float_memory + 1) = 356.356;
*(float_memory + 2) = 456.456;
*(float_memory + 3) = 556.556;
}

/* marks FPU stack as empty */
void empty_fpu_stack()
{
asm ("ffree %st(1) \n\t"
"ffree %st(2) \n\t"
"ffree %st(3) \n\t"
"ffree %st(4) \n\t"
"ffree %st(5) \n\t"
"ffree %st(6) \n\t"
"ffree %st(7)");
}

/* tests floating point arithmatic */
void test_arith_floats()
{
result = no1 + no2 + no3 + no4 + no5 + no6 + no7;
printf("result is %f\n",result);

result = fmodf(no2,no1);
printf("result is %f\n",result);

resultd = fmod(x,y);
printf("result is %f\n",resultd);

resultld = fmodl(ldy,ldy);
printf("result is %f\n",resultld);

result = fabsf(no1);
printf("result is %f\n",result);

result = no3 / no4;
printf("result is %f\n",result);

result = no1 * no2 * no3 * no4;
printf("result is %f\n",result);

result = no1 - no2 - no3 - no4;
printf("result is %f\n",result);

asm ("fld %0" : :"m"(*float_memory));
asm ("fchs");

/* test for f2xm1 */
asm ("fld %0" : :"m"(*float_memory));
asm ("f2xm1");

asm ("fyl2x");

asm ("fld %0" : :"m"(*float_memory));
asm ("fxtract");

asm ("fld %0" : :"m"(*float_memory));
asm ("fprem1");

/* decrement fpu stack pointer only status register should get affected */
asm ("fld %0" : :"m"(*float_memory));

empty_fpu_stack();

asm ("fld1");
asm ("fldl2t");
asm ("fldl2e");
asm ("fldpi");
asm ("fldlg2");
asm ("fldln2");
asm ("fldz");

empty_fpu_stack();
/* finishing emptying the stack */

result = sqrt(no3);
printf("result is %f\n",result);
}

void test_log_exp_floats()
{
result = log10(no3);
printf("result is %f\n",result);

result = log(no3);
printf("result is %f\n",result);

result = exp10(no3);
printf("result is %f\n",result);

result = exp(no3);
printf("result is %f\n",result);
}

void test_trigo_floats()
{
result = sin(30);
printf("result is %f\n",result);

result = cos(30);
printf("result is %f\n",result);

result = tan(30);
printf("result is %f\n",result);

result = atan(30);
printf("result is %f\n",result);

asm ("fld %0" : :"m"(*float_memory));
asm ("fptan");

/* changes st1 and popping register stack */
asm ("fpatan");

asm("fincstp");
asm ("fld %0" : :"m"(float_memory));
asm ("fsincos");

asm ("fld %0" : :"m"(*float_memory));
asm ("frndint");

asm ("fld %0" : :"m"(*float_memory));
asm ("fld %0" : :"m"(*(float_memory+1)));
asm ("fscale");

empty_fpu_stack();

asm ("fld %0" : :"m"(*float_memory));
asm ("fsin");
asm ("fcos");

/* currently we assume condition likely and always record the registers
code could be optimized only if the flag is set then record */
asm ("fld %0" : :"m"(*float_memory));
asm ("fld %0" : :"m"(*(float_memory+1)));
asm ("fcmovb %st(1), %st");
asm ("fcmovbe %st(1), %st");
asm ("fcmove %st(1), %st");
asm ("fcmovu %st(1), %st");
asm ("fcmovnb %st(1), %st");
asm ("fcmovnbe %st(1), %st");

empty_fpu_stack();
/* finished emtyping the stack */
}

void test_compare_floats()
{
ldy = 88888888888888888888.88;
if (ldx == ldy)
ldy = 7777777777777777777777777777.777;
else
ldy = 666666666666666666666666666.666;
}

/* test loading and saving of FPU environment */
void test_fpu_env()
{
asm ("fsave %0" : "=m"(*float_memory) : );
asm ("frstor %0" : : "m"(*float_memory));
asm ("fstsw %ax");
}

int main()
{
init_floats();
test_arith_floats();
test_log_exp_floats();
test_trigo_floats();
test_compare_floats();
test_fpu_env();
}

./gdb ./a.out
GNU gdb (GDB) 6.8.50.20090817-cvs
Copyright (C) 2009 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "i686-pc-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Setting up the environment for debugging gdb.
Function "internal_error" not defined.
Make breakpoint pending on future shared library load? (y or [n])
[answered N; input not from terminal]
Function "info_command" not defined.
Make breakpoint pending on future shared library load? (y or [n])
[answered N; input not from terminal]
/home/teawater/gdb/bgdbno/gdb/.gdbinit:8: Error in sourced command file:
No breakpoint number 0.
(gdb) start
During symbol reading, DW_AT_name missing from DW_TAG_base_type.
Temporary breakpoint 1 at 0x8048c74: file fp.c, line 196.
Starting program: /home/teawater/gdb/bgdbno/gdb/a.out

Temporary breakpoint 1, main () at fp.c:196
196 init_floats();
(gdb) record
(gdb) c
Continuing.
../../src/gdb/utils.c:1200: internal-error: virtual memory exhausted.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n) n
../../src/gdb/utils.c:1200: internal-error: virtual memory exhausted.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Create a core file of GDB? (y or n) n

Program received signal SIGTRAP, Trace/breakpoint trap.
0xb7eba9bc in memcpy () from /lib/tls/i686/cmov/libc.so.6
(gdb) quit
A debugging session is active.

Inferior 1 [process 15657] will be killed.

Quit anyway? (y or n) y

Thanks,
Hui

On Mon, Aug 17, 2009 at 05:16, Michael Snyder<msnyder@vmware.com> wrote:
> paawan oza wrote:
>>
>> Hi Hui & Michael,
>> Now we revert status registers also.
>> please find the patch attached.
>> I am sorry, if I am not pasting the patch in email-body due to tabs&spaces
>> problem faced by Michael last time.
>> Regards,
>> Oza.
>
> Looking good!
>
> There were some conflicts between your changes and a check-in that
> happened after your submission  --  I've taken the liberty of merging
> your changes with the cvs head, fixing up the conflicts.  Hope you
> don't mind  --  merged patch attached.
>
> I'll review your tests next.
>
> Can you write up a change log entry for this patch?
>
> Hui, Mark, any more comments?
>
> Cheers,
> Michael
>
>
>
>
>