u-boot/lib_arm/_udivsi3.S
Wolfgang Denk 53677ef18e Big white-space cleanup.
This commit gets rid of a huge amount of silly white-space issues.
Especially, all sequences of SPACEs followed by TAB characters get
removed (unless they appear in print statements).

Also remove all embedded "vim:" and "vi:" statements which hide
indentation problems.

Signed-off-by: Wolfgang Denk <wd@denx.de>
2008-05-21 00:14:08 +02:00

78 lines
2.2 KiB
ArmAsm

/* # 1 "libgcc1.S" */
@ libgcc1 routines for ARM cpu.
@ Division routines, written by Richard Earnshaw, (rearnsha@armltd.co.uk)
dividend .req r0
divisor .req r1
result .req r2
curbit .req r3
/* ip .req r12 */
/* sp .req r13 */
/* lr .req r14 */
/* pc .req r15 */
.text
.globl __udivsi3
.type __udivsi3 ,function
.align 0
__udivsi3 :
cmp divisor, #0
beq Ldiv0
mov curbit, #1
mov result, #0
cmp dividend, divisor
bcc Lgot_result
Loop1:
@ Unless the divisor is very big, shift it up in multiples of
@ four bits, since this is the amount of unwinding in the main
@ division loop. Continue shifting until the divisor is
@ larger than the dividend.
cmp divisor, #0x10000000
cmpcc divisor, dividend
movcc divisor, divisor, lsl #4
movcc curbit, curbit, lsl #4
bcc Loop1
Lbignum:
@ For very big divisors, we must shift it a bit at a time, or
@ we will be in danger of overflowing.
cmp divisor, #0x80000000
cmpcc divisor, dividend
movcc divisor, divisor, lsl #1
movcc curbit, curbit, lsl #1
bcc Lbignum
Loop3:
@ Test for possible subtractions, and note which bits
@ are done in the result. On the final pass, this may subtract
@ too much from the dividend, but the result will be ok, since the
@ "bit" will have been shifted out at the bottom.
cmp dividend, divisor
subcs dividend, dividend, divisor
orrcs result, result, curbit
cmp dividend, divisor, lsr #1
subcs dividend, dividend, divisor, lsr #1
orrcs result, result, curbit, lsr #1
cmp dividend, divisor, lsr #2
subcs dividend, dividend, divisor, lsr #2
orrcs result, result, curbit, lsr #2
cmp dividend, divisor, lsr #3
subcs dividend, dividend, divisor, lsr #3
orrcs result, result, curbit, lsr #3
cmp dividend, #0 @ Early termination?
movnes curbit, curbit, lsr #4 @ No, any more bits to do?
movne divisor, divisor, lsr #4
bne Loop3
Lgot_result:
mov r0, result
mov pc, lr
Ldiv0:
str lr, [sp, #-4]!
bl __div0 (PLT)
mov r0, #0 @ about as wrong as it could be
ldmia sp!, {pc}
.size __udivsi3 , . - __udivsi3
/* # 235 "libgcc1.S" */
/* # 320 "libgcc1.S" */
/* # 421 "libgcc1.S" */
/* # 433 "libgcc1.S" */
/* # 456 "libgcc1.S" */
/* # 500 "libgcc1.S" */
/* # 580 "libgcc1.S" */