140 lines
2.6 KiB
NASM
140 lines
2.6 KiB
NASM
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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;;;
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;;; Microsoft Research Singularity
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;;;
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;;; Copyright (c) Microsoft Corporation. All rights reserved.
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;;;
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;;; This file contains ARM-specific assembly code.
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;;;
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; Signed divide of r1 by r0
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; Return:
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; r0 - quotient
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; r1 - remainder
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OPT 2 ; disable listing
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INCLUDE kxarm.inc
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OPT 1 ; reenable listing
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IMPORT __rt_div0
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IF Thumbing
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AREA |.text|, CODE, READONLY, THUMB
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ELSE
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AREA |.text|, CODE, READONLY
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ENDIF
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EXPORT |__rt_sdiv| [FUNC]
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|__rt_sdiv|
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IF Thumbing
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; Switch from Thumb mode to ARM mode
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DCW 0x4778 ; bx pc
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DCW 0x46C0 ; nop
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ENDIF
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ANDS a4, r0, #&80000000
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RSBMI r0, r0, #0
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EORS ip, a4, r1, ASR #32
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RSBCS r1, r1, #0
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MOVS a3, r0
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BEQ DivideByZero
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while
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CMP a3, r1, LSR #8
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MOVLS a3, a3, LSL #8
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BLO while
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CMP a3, r1, LSR #1
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BHI goto7
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CMP a3, r1, LSR #2
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BHI goto6
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CMP a3, r1, LSR #3
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BHI goto5
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CMP a3, r1, LSR #4
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BHI goto4
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CMP a3, r1, LSR #5
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BHI goto3
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CMP a3, r1, LSR #6
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BHI goto2
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CMP a3, r1, LSR #7
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BHI goto1
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loop
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MOVHI a3, a3, LSR #8
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CMP r1, a3, LSL #7
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ADC a4, a4, a4
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SUBCS r1, r1, a3, LSL #7
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CMP r1, a3, LSL #6
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goto1
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ADC a4, a4, a4
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SUBCS r1, r1, a3, LSL #6
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CMP r1, a3, LSL #5
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goto2
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ADC a4, a4, a4
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SUBCS r1, r1, a3, LSL #5
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CMP r1, a3, LSL #4
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goto3
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ADC a4, a4, a4
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SUBCS r1, r1, a3, LSL #4
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CMP r1, a3, LSL #3
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goto4
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ADC a4, a4, a4
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SUBCS r1, r1, a3, LSL #3
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CMP r1, a3, LSL #2
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goto5
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ADC a4, a4, a4
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SUBCS r1, r1, a3, LSL #2
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CMP r1, a3, LSL #1
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goto6
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ADC a4, a4, a4
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SUBCS r1, r1, a3, LSL #1
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goto7
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CMP r1, a3
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ADC a4, a4, a4
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SUBCS r1, r1, a3
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CMP a3, r0
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BNE loop
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MOV r0, a4
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MOVS ip, ip, ASL #1
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RSBCS r0, r0, #0
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RSBMI r1, r1, #0
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end
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IF Interworking :LOR: Thumbing
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BX lr
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ELSE
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MOV pc, lr
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ENDIF
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;
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; Divide by zero has occurred. Raise an exception
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; call RaiseException(STATUS_INTEGER_DIVIDE_BY_ZERO, 0, 0, NULL)
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;
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DivideByZero
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ldr r12, =__rt_div0
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ldr r0, =0xC0000094
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mov r1, #0
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mov r2, #0
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mov r3, #0
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IF Thumbing
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bx r12
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ELSE
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mov pc, r12
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ENDIF
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END
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