da957e111b
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
167 lines
3.9 KiB
ArmAsm
167 lines
3.9 KiB
ArmAsm
.file "reg_u_add.S"
|
|
/*---------------------------------------------------------------------------+
|
|
| reg_u_add.S |
|
|
| |
|
|
| Add two valid (TAG_Valid) FPU_REG numbers, of the same sign, and put the |
|
|
| result in a destination FPU_REG. |
|
|
| |
|
|
| Copyright (C) 1992,1993,1995,1997 |
|
|
| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
|
|
| E-mail billm@suburbia.net |
|
|
| |
|
|
| Call from C as: |
|
|
| int FPU_u_add(FPU_REG *arg1, FPU_REG *arg2, FPU_REG *answ, |
|
|
| int control_w) |
|
|
| Return value is the tag of the answer, or-ed with FPU_Exception if |
|
|
| one was raised, or -1 on internal error. |
|
|
| |
|
|
+---------------------------------------------------------------------------*/
|
|
|
|
/*
|
|
| Kernel addition routine FPU_u_add(reg *arg1, reg *arg2, reg *answ).
|
|
| Takes two valid reg f.p. numbers (TAG_Valid), which are
|
|
| treated as unsigned numbers,
|
|
| and returns their sum as a TAG_Valid or TAG_Special f.p. number.
|
|
| The returned number is normalized.
|
|
| Basic checks are performed if PARANOID is defined.
|
|
*/
|
|
|
|
#include "exception.h"
|
|
#include "fpu_emu.h"
|
|
#include "control_w.h"
|
|
|
|
.text
|
|
ENTRY(FPU_u_add)
|
|
pushl %ebp
|
|
movl %esp,%ebp
|
|
pushl %esi
|
|
pushl %edi
|
|
pushl %ebx
|
|
|
|
movl PARAM1,%esi /* source 1 */
|
|
movl PARAM2,%edi /* source 2 */
|
|
|
|
movl PARAM6,%ecx
|
|
movl %ecx,%edx
|
|
subl PARAM7,%ecx /* exp1 - exp2 */
|
|
jge L_arg1_larger
|
|
|
|
/* num1 is smaller */
|
|
movl SIGL(%esi),%ebx
|
|
movl SIGH(%esi),%eax
|
|
|
|
movl %edi,%esi
|
|
movl PARAM7,%edx
|
|
negw %cx
|
|
jmp L_accum_loaded
|
|
|
|
L_arg1_larger:
|
|
/* num1 has larger or equal exponent */
|
|
movl SIGL(%edi),%ebx
|
|
movl SIGH(%edi),%eax
|
|
|
|
L_accum_loaded:
|
|
movl PARAM3,%edi /* destination */
|
|
movw %dx,EXP(%edi) /* Copy exponent to destination */
|
|
|
|
xorl %edx,%edx /* clear the extension */
|
|
|
|
#ifdef PARANOID
|
|
testl $0x80000000,%eax
|
|
je L_bugged
|
|
|
|
testl $0x80000000,SIGH(%esi)
|
|
je L_bugged
|
|
#endif /* PARANOID */
|
|
|
|
/* The number to be shifted is in %eax:%ebx:%edx */
|
|
cmpw $32,%cx /* shrd only works for 0..31 bits */
|
|
jnc L_more_than_31
|
|
|
|
/* less than 32 bits */
|
|
shrd %cl,%ebx,%edx
|
|
shrd %cl,%eax,%ebx
|
|
shr %cl,%eax
|
|
jmp L_shift_done
|
|
|
|
L_more_than_31:
|
|
cmpw $64,%cx
|
|
jnc L_more_than_63
|
|
|
|
subb $32,%cl
|
|
jz L_exactly_32
|
|
|
|
shrd %cl,%eax,%edx
|
|
shr %cl,%eax
|
|
orl %ebx,%ebx
|
|
jz L_more_31_no_low /* none of the lowest bits is set */
|
|
|
|
orl $1,%edx /* record the fact in the extension */
|
|
|
|
L_more_31_no_low:
|
|
movl %eax,%ebx
|
|
xorl %eax,%eax
|
|
jmp L_shift_done
|
|
|
|
L_exactly_32:
|
|
movl %ebx,%edx
|
|
movl %eax,%ebx
|
|
xorl %eax,%eax
|
|
jmp L_shift_done
|
|
|
|
L_more_than_63:
|
|
cmpw $65,%cx
|
|
jnc L_more_than_64
|
|
|
|
movl %eax,%edx
|
|
orl %ebx,%ebx
|
|
jz L_more_63_no_low
|
|
|
|
orl $1,%edx
|
|
jmp L_more_63_no_low
|
|
|
|
L_more_than_64:
|
|
movl $1,%edx /* The shifted nr always at least one '1' */
|
|
|
|
L_more_63_no_low:
|
|
xorl %ebx,%ebx
|
|
xorl %eax,%eax
|
|
|
|
L_shift_done:
|
|
/* Now do the addition */
|
|
addl SIGL(%esi),%ebx
|
|
adcl SIGH(%esi),%eax
|
|
jnc L_round_the_result
|
|
|
|
/* Overflow, adjust the result */
|
|
rcrl $1,%eax
|
|
rcrl $1,%ebx
|
|
rcrl $1,%edx
|
|
jnc L_no_bit_lost
|
|
|
|
orl $1,%edx
|
|
|
|
L_no_bit_lost:
|
|
incw EXP(%edi)
|
|
|
|
L_round_the_result:
|
|
jmp fpu_reg_round /* Round the result */
|
|
|
|
|
|
|
|
#ifdef PARANOID
|
|
/* If we ever get here then we have problems! */
|
|
L_bugged:
|
|
pushl EX_INTERNAL|0x201
|
|
call EXCEPTION
|
|
pop %ebx
|
|
movl $-1,%eax
|
|
jmp L_exit
|
|
|
|
L_exit:
|
|
popl %ebx
|
|
popl %edi
|
|
popl %esi
|
|
leave
|
|
ret
|
|
#endif /* PARANOID */
|