mirror of https://gitee.com/openkylin/linux.git
149 lines
3.6 KiB
ArmAsm
149 lines
3.6 KiB
ArmAsm
.file "reg_u_mul.S"
|
|
/*---------------------------------------------------------------------------+
|
|
| reg_u_mul.S |
|
|
| |
|
|
| Core multiplication routine |
|
|
| |
|
|
| Copyright (C) 1992,1993,1995,1997 |
|
|
| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
|
|
| E-mail billm@suburbia.net |
|
|
| |
|
|
| |
|
|
+---------------------------------------------------------------------------*/
|
|
|
|
/*---------------------------------------------------------------------------+
|
|
| Basic multiplication routine. |
|
|
| Does not check the resulting exponent for overflow/underflow |
|
|
| |
|
|
| FPU_u_mul(FPU_REG *a, FPU_REG *b, FPU_REG *c, unsigned int cw); |
|
|
| |
|
|
| Internal working is at approx 128 bits. |
|
|
| Result is rounded to nearest 53 or 64 bits, using "nearest or even". |
|
|
+---------------------------------------------------------------------------*/
|
|
|
|
#include "exception.h"
|
|
#include "fpu_emu.h"
|
|
#include "control_w.h"
|
|
|
|
|
|
|
|
#ifndef NON_REENTRANT_FPU
|
|
/* Local storage on the stack: */
|
|
#define FPU_accum_0 -4(%ebp) /* ms word */
|
|
#define FPU_accum_1 -8(%ebp)
|
|
|
|
#else
|
|
/* Local storage in a static area: */
|
|
.data
|
|
.align 4,0
|
|
FPU_accum_0:
|
|
.long 0
|
|
FPU_accum_1:
|
|
.long 0
|
|
#endif /* NON_REENTRANT_FPU */
|
|
|
|
|
|
.text
|
|
ENTRY(FPU_u_mul)
|
|
pushl %ebp
|
|
movl %esp,%ebp
|
|
#ifndef NON_REENTRANT_FPU
|
|
subl $8,%esp
|
|
#endif /* NON_REENTRANT_FPU */
|
|
|
|
pushl %esi
|
|
pushl %edi
|
|
pushl %ebx
|
|
|
|
movl PARAM1,%esi
|
|
movl PARAM2,%edi
|
|
|
|
#ifdef PARANOID
|
|
testl $0x80000000,SIGH(%esi)
|
|
jz L_bugged
|
|
testl $0x80000000,SIGH(%edi)
|
|
jz L_bugged
|
|
#endif /* PARANOID */
|
|
|
|
xorl %ecx,%ecx
|
|
xorl %ebx,%ebx
|
|
|
|
movl SIGL(%esi),%eax
|
|
mull SIGL(%edi)
|
|
movl %eax,FPU_accum_0
|
|
movl %edx,FPU_accum_1
|
|
|
|
movl SIGL(%esi),%eax
|
|
mull SIGH(%edi)
|
|
addl %eax,FPU_accum_1
|
|
adcl %edx,%ebx
|
|
/* adcl $0,%ecx // overflow here is not possible */
|
|
|
|
movl SIGH(%esi),%eax
|
|
mull SIGL(%edi)
|
|
addl %eax,FPU_accum_1
|
|
adcl %edx,%ebx
|
|
adcl $0,%ecx
|
|
|
|
movl SIGH(%esi),%eax
|
|
mull SIGH(%edi)
|
|
addl %eax,%ebx
|
|
adcl %edx,%ecx
|
|
|
|
/* Get the sum of the exponents. */
|
|
movl PARAM6,%eax
|
|
subl EXP_BIAS-1,%eax
|
|
|
|
/* Two denormals can cause an exponent underflow */
|
|
cmpl EXP_WAY_UNDER,%eax
|
|
jg Exp_not_underflow
|
|
|
|
/* Set to a really low value allow correct handling */
|
|
movl EXP_WAY_UNDER,%eax
|
|
|
|
Exp_not_underflow:
|
|
|
|
/* Have now finished with the sources */
|
|
movl PARAM3,%edi /* Point to the destination */
|
|
movw %ax,EXP(%edi)
|
|
|
|
/* Now make sure that the result is normalized */
|
|
testl $0x80000000,%ecx
|
|
jnz LResult_Normalised
|
|
|
|
/* Normalize by shifting left one bit */
|
|
shll $1,FPU_accum_0
|
|
rcll $1,FPU_accum_1
|
|
rcll $1,%ebx
|
|
rcll $1,%ecx
|
|
decw EXP(%edi)
|
|
|
|
LResult_Normalised:
|
|
movl FPU_accum_0,%eax
|
|
movl FPU_accum_1,%edx
|
|
orl %eax,%eax
|
|
jz L_extent_zero
|
|
|
|
orl $1,%edx
|
|
|
|
L_extent_zero:
|
|
movl %ecx,%eax
|
|
jmp fpu_reg_round
|
|
|
|
|
|
#ifdef PARANOID
|
|
L_bugged:
|
|
pushl EX_INTERNAL|0x205
|
|
call EXCEPTION
|
|
pop %ebx
|
|
jmp L_exit
|
|
|
|
L_exit:
|
|
popl %ebx
|
|
popl %edi
|
|
popl %esi
|
|
leave
|
|
ret
|
|
#endif /* PARANOID */
|
|
|