74 lines
2 KiB
ArmAsm
74 lines
2 KiB
ArmAsm
/*
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* Creation Date: <2002/10/20 15:54:50 samuel>
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* Time-stamp: <2002/10/20 15:57:21 samuel>
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*
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* <misc.S>
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*
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* Low-level stuff
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*
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* Copyright (C) 2002, 2003 Samuel Rydh (samuel@ibrium.se)
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*
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* Based upon misc.S from the the linux kernel with the following
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* copyrights:
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*
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* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org),
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* Cort Dougan (cort@cs.nmt.edu), Paul Mackerras
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation
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*
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*/
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#include "asm/asmdefs.h"
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#include "asm/processor.h"
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/*
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* Extended precision shifts.
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*
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* Updated to be valid for shift counts from 0 to 63 inclusive.
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* -- Gabriel
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*
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* R3/R4 has 64 bit value
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* R5 has shift count
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* result in R3/R4
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*
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* ashrdi3: arithmetic right shift (sign propagation)
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* lshrdi3: logical right shift
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* ashldi3: left shift
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*/
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GLOBL(__ashrdi3):
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subfic r6,r5,32
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srw r4,r4,r5 # LSW = count > 31 ? 0 : LSW >> count
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addi r7,r5,32 # could be xori, or addi with -32
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slw r6,r3,r6 # t1 = count > 31 ? 0 : MSW << (32-count)
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rlwinm r8,r7,0,32 # t3 = (count < 32) ? 32 : 0
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sraw r7,r3,r7 # t2 = MSW >> (count-32)
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or r4,r4,r6 # LSW |= t1
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slw r7,r7,r8 # t2 = (count < 32) ? 0 : t2
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sraw r3,r3,r5 # MSW = MSW >> count
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or r4,r4,r7 # LSW |= t2
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blr
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GLOBL(__ashldi3):
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subfic r6,r5,32
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slw r3,r3,r5 # MSW = count > 31 ? 0 : MSW << count
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addi r7,r5,32 # could be xori, or addi with -32
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srw r6,r4,r6 # t1 = count > 31 ? 0 : LSW >> (32-count)
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slw r7,r4,r7 # t2 = count < 32 ? 0 : LSW << (count-32)
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or r3,r3,r6 # MSW |= t1
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slw r4,r4,r5 # LSW = LSW << count
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or r3,r3,r7 # MSW |= t2
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blr
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GLOBL(__lshrdi3):
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subfic r6,r5,32
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srw r4,r4,r5 # LSW = count > 31 ? 0 : LSW >> count
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addi r7,r5,32 # could be xori, or addi with -32
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slw r6,r3,r6 # t1 = count > 31 ? 0 : MSW << (32-count)
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srw r7,r3,r7 # t2 = count < 32 ? 0 : MSW >> (count-32)
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or r4,r4,r6 # LSW |= t1
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srw r3,r3,r5 # MSW = MSW >> count
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or r4,r4,r7 # LSW |= t2
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blr
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