;
; Copyright (c) Microsoft Corporation.  All rights reserved.
;
;
; Use of this source code is subject to the terms of your Microsoft Windows CE
; Source Alliance Program license form.  If you did not accept the terms of
; such a license, you are not authorized to use this source code.
;
;rshi64.asm - perform __int64 right shift operation
;

; r0 - loword of __int64 value
; r1 - hiword of __int64 value
; r2 - amount to right shift value

#include "kxarm.h"

    TEXTAREA

    LEAF_ENTRY __rt_srsh

    CMP     r2, #0
    BXEQ    lr

    CMP     r2, #32                     ; Check for < 32 bit shift
    BLT     shift31

    CMP     r2, #64                     ; Check for < 64 bit shift
    BLT     shift63

    MOV     r1, r1, ASR #32             ; shift >= 64, value = 0
    MOV     r0, r1
    BX      lr

shift63                                 ; 32 <= shift < 64
    AND     r2, r2, #31
    MOV     r0, r1, ASR r2
    MOV     r1, r1, ASR #32
    BX      lr

shift31                                 ; shift < 32
    MOV     r0, r0, LSR r2              ; Shift right loword
    RSB     r3, r2, #32                 ; figure shift for hi to low ORR
    MOV     r3, r1, LSL r3              ; or in bits from hiword
    ORR     r0, r0, r3                  ; or in bits from hiword
    MOV     r1, r1, ASR r2              ; Shift hiword
    BX      lr

    LEAF_END __rt_rsh

    END