mirror of
https://github.com/torvalds/linux.git
synced 2024-11-01 17:51:43 +00:00
da957e111b
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
148 lines
3.5 KiB
ArmAsm
148 lines
3.5 KiB
ArmAsm
/*---------------------------------------------------------------------------+
|
|
| reg_norm.S |
|
|
| |
|
|
| Copyright (C) 1992,1993,1994,1995,1997 |
|
|
| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
|
|
| Australia. E-mail billm@suburbia.net |
|
|
| |
|
|
| Normalize the value in a FPU_REG. |
|
|
| |
|
|
| Call from C as: |
|
|
| int FPU_normalize(FPU_REG *n) |
|
|
| |
|
|
| int FPU_normalize_nuo(FPU_REG *n) |
|
|
| |
|
|
| Return value is the tag of the answer, or-ed with FPU_Exception if |
|
|
| one was raised, or -1 on internal error. |
|
|
| |
|
|
+---------------------------------------------------------------------------*/
|
|
|
|
#include "fpu_emu.h"
|
|
|
|
|
|
.text
|
|
ENTRY(FPU_normalize)
|
|
pushl %ebp
|
|
movl %esp,%ebp
|
|
pushl %ebx
|
|
|
|
movl PARAM1,%ebx
|
|
|
|
movl SIGH(%ebx),%edx
|
|
movl SIGL(%ebx),%eax
|
|
|
|
orl %edx,%edx /* ms bits */
|
|
js L_done /* Already normalized */
|
|
jnz L_shift_1 /* Shift left 1 - 31 bits */
|
|
|
|
orl %eax,%eax
|
|
jz L_zero /* The contents are zero */
|
|
|
|
movl %eax,%edx
|
|
xorl %eax,%eax
|
|
subw $32,EXP(%ebx) /* This can cause an underflow */
|
|
|
|
/* We need to shift left by 1 - 31 bits */
|
|
L_shift_1:
|
|
bsrl %edx,%ecx /* get the required shift in %ecx */
|
|
subl $31,%ecx
|
|
negl %ecx
|
|
shld %cl,%eax,%edx
|
|
shl %cl,%eax
|
|
subw %cx,EXP(%ebx) /* This can cause an underflow */
|
|
|
|
movl %edx,SIGH(%ebx)
|
|
movl %eax,SIGL(%ebx)
|
|
|
|
L_done:
|
|
cmpw EXP_OVER,EXP(%ebx)
|
|
jge L_overflow
|
|
|
|
cmpw EXP_UNDER,EXP(%ebx)
|
|
jle L_underflow
|
|
|
|
L_exit_valid:
|
|
movl TAG_Valid,%eax
|
|
|
|
/* Convert the exponent to 80x87 form. */
|
|
addw EXTENDED_Ebias,EXP(%ebx)
|
|
andw $0x7fff,EXP(%ebx)
|
|
|
|
L_exit:
|
|
popl %ebx
|
|
leave
|
|
ret
|
|
|
|
|
|
L_zero:
|
|
movw $0,EXP(%ebx)
|
|
movl TAG_Zero,%eax
|
|
jmp L_exit
|
|
|
|
L_underflow:
|
|
/* Convert the exponent to 80x87 form. */
|
|
addw EXTENDED_Ebias,EXP(%ebx)
|
|
push %ebx
|
|
call arith_underflow
|
|
pop %ebx
|
|
jmp L_exit
|
|
|
|
L_overflow:
|
|
/* Convert the exponent to 80x87 form. */
|
|
addw EXTENDED_Ebias,EXP(%ebx)
|
|
push %ebx
|
|
call arith_overflow
|
|
pop %ebx
|
|
jmp L_exit
|
|
|
|
|
|
|
|
/* Normalise without reporting underflow or overflow */
|
|
ENTRY(FPU_normalize_nuo)
|
|
pushl %ebp
|
|
movl %esp,%ebp
|
|
pushl %ebx
|
|
|
|
movl PARAM1,%ebx
|
|
|
|
movl SIGH(%ebx),%edx
|
|
movl SIGL(%ebx),%eax
|
|
|
|
orl %edx,%edx /* ms bits */
|
|
js L_exit_nuo_valid /* Already normalized */
|
|
jnz L_nuo_shift_1 /* Shift left 1 - 31 bits */
|
|
|
|
orl %eax,%eax
|
|
jz L_exit_nuo_zero /* The contents are zero */
|
|
|
|
movl %eax,%edx
|
|
xorl %eax,%eax
|
|
subw $32,EXP(%ebx) /* This can cause an underflow */
|
|
|
|
/* We need to shift left by 1 - 31 bits */
|
|
L_nuo_shift_1:
|
|
bsrl %edx,%ecx /* get the required shift in %ecx */
|
|
subl $31,%ecx
|
|
negl %ecx
|
|
shld %cl,%eax,%edx
|
|
shl %cl,%eax
|
|
subw %cx,EXP(%ebx) /* This can cause an underflow */
|
|
|
|
movl %edx,SIGH(%ebx)
|
|
movl %eax,SIGL(%ebx)
|
|
|
|
L_exit_nuo_valid:
|
|
movl TAG_Valid,%eax
|
|
|
|
popl %ebx
|
|
leave
|
|
ret
|
|
|
|
L_exit_nuo_zero:
|
|
movl TAG_Zero,%eax
|
|
movw EXP_UNDER,EXP(%ebx)
|
|
|
|
popl %ebx
|
|
leave
|
|
ret
|