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| Rev 39 |
Rev 56 |
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Line 8... |
! r6: byte count
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! r6: byte count
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!
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!
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! Exit: r0-r3: trashed
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! Exit: r0-r3: trashed
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!
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!
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! This assumes that the first four bytes of the address space (0..3) are
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! reserved - usually by the linker script. Otherwise, we would had to check
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! for the case of objects of the size 12..15 at address 0..3 .
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#include "asm.h"
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#include "asm.h"
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ENTRY(memset)
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ENTRY(memset)
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mov r4,r3 ! Save return value
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mov r6,r0 ! Check explicitly for zero
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cmp/eq #0,r0
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bt L_exit
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mov #12,r0 ! Check for small number of bytes
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mov #12,r0 ! Check for small number of bytes
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cmp/gt r6,r0
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cmp/gt r6,r0
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bt L_store_byte_loop
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mov r4,r0
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SL(bt, L_store_byte_loop_check0, add r4,r6)
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neg r4,r0 ! Align destination
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tst #3,r0 ! Align destination
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add #4,r0
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SL(bt, L_dup_bytes, extu.b r5,r5)
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and #3,r0
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tst r0,r0
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bt L_dup_bytes
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.balignw 4,0x0009
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.balignw 4,0x0009
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L_align_loop:
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L_align_loop:
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mov.b r5,@r4
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mov.b r5,@r0
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add #-1,r6
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add #1,r0
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add #1,r4
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tst #3,r0
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dt r0
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bf L_align_loop
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bf L_align_loop
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L_dup_bytes:
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L_dup_bytes:
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extu.b r5,r5 ! Duplicate bytes across longword
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swap.b r5,r2 ! Duplicate bytes across longword
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swap.b r5,r0
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or r2,r5
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or r0,r5
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swap.w r5,r2
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swap.w r5,r0
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or r2,r5
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or r0,r5
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add #-16,r6
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mov r6,r2 ! Calculate number of double longwords
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shlr2 r2
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shlr r2
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.balignw 4,0x0009
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.balignw 4,0x0009
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L_store_long_loop:
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L_store_long_loop:
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mov.l r5,@r4 ! Store double longs to memory
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mov.l r5,@r0 ! Store double longs to memory
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dt r2
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cmp/hs r6,r0
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mov.l r5,@(4,r4)
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mov.l r5,@(4,r0)
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add #8,r4
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SL(bf, L_store_long_loop, add #8,r0)
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bf L_store_long_loop
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add #16,r6
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mov #7,r0
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and r0,r6
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L_store_byte_loop_check0:
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tst r6,r6
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cmp/eq r6,r0
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bt L_exit
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bt L_exit
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.balignw 4,0x0009
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.balignw 4,0x0009
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L_store_byte_loop:
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L_store_byte_loop:
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mov.b r5,@r4 ! Store bytes to memory
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mov.b r5,@r0 ! Store bytes to memory
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add #1,r4
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add #1,r0
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dt r6
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cmp/eq r6,r0
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bf L_store_byte_loop
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bf L_store_byte_loop
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L_exit:
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L_exit:
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rts
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rts
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mov r3,r0
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mov r4,r0
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