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

157 lines
3.9 KiB
ArmAsm

#------------------------------------------------------------------------------
#
# Copyright (c) 2011, ARM. All rights reserved.<BR>
#
# This program and the accompanying materials
# are licensed and made available under the terms and conditions of the BSD License
# which accompanies this distribution. The full text of the license may be found at
# http://opensource.org/licenses/bsd-license.php
#
# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
#
#------------------------------------------------------------------------------
.text
.align 2
GCC_ASM_EXPORT(__aeabi_uidiv)
GCC_ASM_EXPORT(__aeabi_uidivmod)
GCC_ASM_EXPORT(__aeabi_idiv)
GCC_ASM_EXPORT(__aeabi_idivmod)
# AREA Math, CODE, READONLY
#
#UINT32
#EFIAPI
#__aeabi_uidivmode (
# IN UINT32 Dividen
# IN UINT32 Divisor
# );
#
ASM_PFX(__aeabi_uidiv):
ASM_PFX(__aeabi_uidivmod):
RSBS r12, r1, r0, LSR #4
MOV r2, #0
BCC ASM_PFX(__arm_div4)
RSBS r12, r1, r0, LSR #8
BCC ASM_PFX(__arm_div8)
MOV r3, #0
B ASM_PFX(__arm_div_large)
#
#INT32
#EFIAPI
#__aeabi_idivmode (
# IN INT32 Dividen
# IN INT32 Divisor
# );
#
ASM_PFX(__aeabi_idiv):
ASM_PFX(__aeabi_idivmod):
ORRS r12, r0, r1
BMI ASM_PFX(__arm_div_negative)
RSBS r12, r1, r0, LSR #1
MOV r2, #0
BCC ASM_PFX(__arm_div1)
RSBS r12, r1, r0, LSR #4
BCC ASM_PFX(__arm_div4)
RSBS r12, r1, r0, LSR #8
BCC ASM_PFX(__arm_div8)
MOV r3, #0
B ASM_PFX(__arm_div_large)
ASM_PFX(__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
ASM_PFX(__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
ASM_PFX(__arm_div1):
SUBS r1, r0, r1
MOVCC r1, r0
ADC r0, r2, r2
BX r14
ASM_PFX(__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
ASM_PFX(__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 ASM_PFX(__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.
ASM_PFX(__aeabi_idiv0):
BX r14
.end