audk/ArmPkg/Library/CompilerIntrinsicsLib/Arm/div.asm

181 lines
4.0 KiB
NASM

//------------------------------------------------------------------------------
//
// Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
// Copyright (c) 2018, Pete Batard. All rights reserved.<BR>
//
// SPDX-License-Identifier: BSD-2-Clause-Patent
//
//------------------------------------------------------------------------------
EXPORT __aeabi_uidiv
EXPORT __aeabi_uidivmod
EXPORT __aeabi_idiv
EXPORT __aeabi_idivmod
EXPORT __rt_udiv
EXPORT __rt_sdiv
AREA Math, CODE, READONLY
;
;UINT32
;EFIAPI
;__aeabi_uidivmod (
; IN UINT32 Dividend
; IN UINT32 Divisor
; );
;
__aeabi_uidiv
__aeabi_uidivmod
RSBS r12, r1, r0, LSR #4
MOV r2, #0
BCC __arm_div4
RSBS r12, r1, r0, LSR #8
BCC __arm_div8
MOV r3, #0
B __arm_div_large
;
;UINT64
;EFIAPI
;__rt_udiv (
; IN UINT32 Divisor,
; IN UINT32 Dividend
; );
;
__rt_udiv
; Swap R0 and R1
MOV r12, r0
MOV r0, r1
MOV r1, r12
B __aeabi_uidivmod
;
;UINT64
;EFIAPI
;__rt_sdiv (
; IN INT32 Divisor,
; IN INT32 Dividend
; );
;
__rt_sdiv
; Swap R0 and R1
MOV r12, r0
MOV r0, r1
MOV r1, r12
B __aeabi_idivmod
;
;INT32
;EFIAPI
;__aeabi_idivmod (
; IN INT32 Dividend
; IN INT32 Divisor
; );
;
__aeabi_idiv
__aeabi_idivmod
ORRS r12, r0, r1
BMI __arm_div_negative
RSBS r12, r1, r0, LSR #1
MOV r2, #0
BCC __arm_div1
RSBS r12, r1, r0, LSR #4
BCC __arm_div4
RSBS r12, r1, r0, LSR #8
BCC __arm_div8
MOV r3, #0
B __arm_div_large
__arm_div8
RSBS r12, r1, r0, LSR #7
SUBCS r0, r0, r1, LSL #7
ADC r2, r2, r2
RSBS r12, r1, r0,LSR #6
SUBCS r0, r0, r1, LSL #6
ADC r2, r2, r2
RSBS r12, r1, r0, LSR #5
SUBCS r0, r0, r1, LSL #5
ADC r2, r2, r2
RSBS r12, r1, r0, LSR #4
SUBCS r0, r0, r1, LSL #4
ADC r2, r2, r2
__arm_div4
RSBS r12, r1, r0, LSR #3
SUBCS r0, r0, r1, LSL #3
ADC r2, r2, r2
RSBS r12, r1, r0, LSR #2
SUBCS r0, r0, r1, LSL #2
ADCS r2, r2, r2
RSBS r12, r1, r0, LSR #1
SUBCS r0, r0, r1, LSL #1
ADC r2, r2, r2
__arm_div1
SUBS r1, r0, r1
MOVCC r1, r0
ADC r0, r2, r2
BX r14
__arm_div_negative
ANDS r2, r1, #0x80000000
RSBMI r1, r1, #0
EORS r3, r2, r0, ASR #32
RSBCS r0, r0, #0
RSBS r12, r1, r0, LSR #4
BCC label1
RSBS r12, r1, r0, LSR #8
BCC label2
__arm_div_large
LSL r1, r1, #6
RSBS r12, r1, r0, LSR #8
ORR r2, r2, #0xfc000000
BCC label2
LSL r1, r1, #6
RSBS r12, r1, r0, LSR #8
ORR r2, r2, #0x3f00000
BCC label2
LSL r1, r1, #6
RSBS r12, r1, r0, LSR #8
ORR r2, r2, #0xfc000
ORRCS r2, r2, #0x3f00
LSLCS r1, r1, #6
RSBS r12, r1, #0
BCS __aeabi_idiv0
label3
LSRCS r1, r1, #6
label2
RSBS r12, r1, r0, LSR #7
SUBCS r0, r0, r1, LSL #7
ADC r2, r2, r2
RSBS r12, r1, r0, LSR #6
SUBCS r0, r0, r1, LSL #6
ADC r2, r2, r2
RSBS r12, r1, r0, LSR #5
SUBCS r0, r0, r1, LSL #5
ADC r2, r2, r2
RSBS r12, r1, r0, LSR #4
SUBCS r0, r0, r1, LSL #4
ADC r2, r2, r2
label1
RSBS r12, r1, r0, LSR #3
SUBCS r0, r0, r1, LSL #3
ADC r2, r2, r2
RSBS r12, r1, r0, LSR #2
SUBCS r0, r0, r1, LSL #2
ADCS r2, r2, r2
BCS label3
RSBS r12, r1, r0, LSR #1
SUBCS r0, r0, r1, LSL #1
ADC r2, r2, r2
SUBS r1, r0, r1
MOVCC r1, r0
ADC r0, r2, r2
ASRS r3, r3, #31
RSBMI r0, r0, #0
RSBCS r1, r1, #0
BX r14
; What to do about division by zero? For now, just return.
__aeabi_idiv0
BX r14
END