39 lines
747 B
ArmAsm
39 lines
747 B
ArmAsm
#
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.sect .text; .sect .rom; .sect .data; .sect .bss
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/*
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* Create singleton set.
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* Stack: ( bitnumber size -- set )
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*/
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.sect .text
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.define .set
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.set:
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lw r4, 0(sp) ! r4 = size
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lw r5, 4(sp) ! r5 = bit number
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addiu sp, sp, 8
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srl r4, r4, 2 ! r4 = word count
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! Create an empty set by pushing zeros.
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1:
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addiu sp, sp, -4
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sw zero, 0(sp)
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addiu r4, r4, -1
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bne r4, zero, 1b
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nop
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! sp now points at the set.
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andi r6, r5, ~31 ! r6 = bit offset of base of word in set
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srl r6,r6, 3 ! r6 = byte offset of word in set
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addu r6, sp, r6 ! r6 = address of word in set
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andi r7, r5, 31 ! r7 = bit number within word
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li r8, 1
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sllv r8, r8, r7 ! r8 = word with 1 set
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sw r8, 0(r6) ! write to set
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jr ra
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nop
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