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112 lines
2.1 KiB
ArmAsm
112 lines
2.1 KiB
ArmAsm
/*
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* Generic memory routines.
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* (C) notaz, 2007-2008
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*
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* This work is licensed under the terms of MAME license.
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* See COPYING file in the top-level directory.
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*/
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@ 0x12345678 -> 0x34127856
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@ r4=temp, lr=0x00ff00ff
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.macro bswap reg
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and r4, \reg, lr
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and \reg, lr, \reg, lsr #8
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orr \reg, \reg, r4, lsl #8
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.endm
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@ dest must be halfword aligned, src can be unaligned
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.global memcpy16bswap @ unsigned short *dest, void *src, int count
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memcpy16bswap:
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tst r1, #1
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bne mcp16bs_cant_align2
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eor r3, r0, r1
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tst r3, #2
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bne mcp16bs_cant_align
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tst r0, #2
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beq mcp16bs_aligned
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ldrh r3, [r1], #2
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sub r2, r2, #1
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orr r3, r3, r3, lsl #16
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mov r3, r3, lsr #8
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strh r3, [r0], #2
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mcp16bs_aligned:
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stmfd sp!, {r4,lr}
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mov lr, #0xff
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orr lr, lr, lr, lsl #16
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subs r2, r2, #4
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bmi mcp16bs_fin4
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mcp16bs_loop:
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ldmia r1!, {r3,r12}
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subs r2, r2, #4
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bswap r3
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bswap r12
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stmia r0!, {r3,r12}
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bpl mcp16bs_loop
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mcp16bs_fin4:
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tst r2, #2
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beq mcp16bs_fin2
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ldr r3, [r1], #4
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bswap r3
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str r3, [r0], #4
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mcp16bs_fin2:
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ldmfd sp!, {r4,lr}
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ands r2, r2, #1
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bxeq lr
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mcp16bs_cant_align:
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ldrh r3, [r1], #2
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subs r2, r2, #1
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orr r3, r3, r3, lsl #16
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mov r3, r3, lsr #8
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strh r3, [r0], #2
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bne mcp16bs_cant_align
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bx lr
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@ worst case
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mcp16bs_cant_align2:
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ldrb r3, [r1], #1
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ldrb r12,[r1], #1
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subs r2, r2, #1
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mov r3, r3, lsl #8
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orr r3, r3, r12
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strh r3, [r0], #2
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bne mcp16bs_cant_align2
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bx lr
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.global memset32 @ int *dest, int c, int count
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memset32:
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stmfd sp!, {lr}
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mov r3, r1
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subs r2, r2, #4
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bmi mst32_fin
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mov r12,r1
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mov lr, r1
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mst32_loop:
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subs r2, r2, #4
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stmia r0!, {r1,r3,r12,lr}
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bpl mst32_loop
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mst32_fin:
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tst r2, #1
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strne r1, [r0], #4
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tst r2, #2
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stmneia r0!, {r1,r3}
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ldmfd sp!, {lr}
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bx lr
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@ vim:filetype=armasm
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