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author | Minkyu Kang <mk7.kang@samsung.com> | 2010-04-19 10:26:18 +0900 |
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committer | Minkyu Kang <mk7.kang@samsung.com> | 2010-04-19 10:26:18 +0900 |
commit | 83653121d7382fccfe329cb732f77f116341ef1d (patch) | |
tree | 0b1ce6764252af15dfb2614372de98a44a7ec61f /arch/arm/lib/_modsi3.S | |
parent | 0f1f21a345e02a68ec16f7ab9e7dc687f9276089 (diff) | |
parent | 07739bcef5da07cc4a4edef8b91014ccc332eda3 (diff) | |
download | u-boot-imx-83653121d7382fccfe329cb732f77f116341ef1d.zip u-boot-imx-83653121d7382fccfe329cb732f77f116341ef1d.tar.gz u-boot-imx-83653121d7382fccfe329cb732f77f116341ef1d.tar.bz2 |
Merge branch 'master' of git://git.denx.de/u-boot-arm
Conflicts:
cpu/arm1176/cpu.c
cpu/arm1176/start.S
cpu/arm_cortexa8/s5pc1xx/Makefile
cpu/arm_cortexa8/s5pc1xx/clock.c
drivers/serial/serial_s5p.c
include/asm-arm/arch-s5pc1xx/clk.h
include/asm-arm/arch-s5pc1xx/gpio.h
include/asm-arm/arch-s5pc1xx/uart.h
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
Diffstat (limited to 'arch/arm/lib/_modsi3.S')
-rw-r--r-- | arch/arm/lib/_modsi3.S | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/arch/arm/lib/_modsi3.S b/arch/arm/lib/_modsi3.S new file mode 100644 index 0000000..539c584 --- /dev/null +++ b/arch/arm/lib/_modsi3.S @@ -0,0 +1,99 @@ + +.macro ARM_MOD_BODY dividend, divisor, order, spare + +#if __LINUX_ARM_ARCH__ >= 5 + + clz \order, \divisor + clz \spare, \dividend + sub \order, \order, \spare + mov \divisor, \divisor, lsl \order + +#else + + mov \order, #0 + + @ 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. +1: cmp \divisor, #0x10000000 + cmplo \divisor, \dividend + movlo \divisor, \divisor, lsl #4 + addlo \order, \order, #4 + blo 1b + + @ For very big divisors, we must shift it a bit at a time, or + @ we will be in danger of overflowing. +1: cmp \divisor, #0x80000000 + cmplo \divisor, \dividend + movlo \divisor, \divisor, lsl #1 + addlo \order, \order, #1 + blo 1b + +#endif + + @ Perform all needed substractions to keep only the reminder. + @ Do comparisons in batch of 4 first. + subs \order, \order, #3 @ yes, 3 is intended here + blt 2f + +1: cmp \dividend, \divisor + subhs \dividend, \dividend, \divisor + cmp \dividend, \divisor, lsr #1 + subhs \dividend, \dividend, \divisor, lsr #1 + cmp \dividend, \divisor, lsr #2 + subhs \dividend, \dividend, \divisor, lsr #2 + cmp \dividend, \divisor, lsr #3 + subhs \dividend, \dividend, \divisor, lsr #3 + cmp \dividend, #1 + mov \divisor, \divisor, lsr #4 + subges \order, \order, #4 + bge 1b + + tst \order, #3 + teqne \dividend, #0 + beq 5f + + @ Either 1, 2 or 3 comparison/substractions are left. +2: cmn \order, #2 + blt 4f + beq 3f + cmp \dividend, \divisor + subhs \dividend, \dividend, \divisor + mov \divisor, \divisor, lsr #1 +3: cmp \dividend, \divisor + subhs \dividend, \dividend, \divisor + mov \divisor, \divisor, lsr #1 +4: cmp \dividend, \divisor + subhs \dividend, \dividend, \divisor +5: +.endm + + .align 5 +.globl __modsi3 +__modsi3: + cmp r1, #0 + beq Ldiv0 + rsbmi r1, r1, #0 @ loops below use unsigned. + movs ip, r0 @ preserve sign of dividend + rsbmi r0, r0, #0 @ if negative make positive + subs r2, r1, #1 @ compare divisor with 1 + cmpne r0, r1 @ compare dividend with divisor + moveq r0, #0 + tsthi r1, r2 @ see if divisor is power of 2 + andeq r0, r0, r2 + bls 10f + + ARM_MOD_BODY r0, r1, r2, r3 + +10: cmp ip, #0 + rsbmi r0, r0, #0 + mov pc, lr + + +Ldiv0: + + str lr, [sp, #-4]! + bl __div0 + mov r0, #0 @ About as wrong as it could be. + ldr pc, [sp], #4 |