f6a1e08218
My i386 code from 893df4b gave the wrong sign to some 8-byte
remainders. Fix by splitting .dvi8 and .rmi8 so each has its own code
to pick the sign. They and .dvu8 and .rmu8 share a private sub
.divrem8 for unsigned division.
Improve the i386 code by using instructions like _bsr_ and _shrd_.
Change the helpers to yield a quotient in ebx:eax or a remainder in
ecx:edx; this seems more convenient, because _div_ puts its quotient
in eax and remainder in edx.
21 lines
351 B
ArmAsm
21 lines
351 B
ArmAsm
.sect .text; .sect .rom; .sect .data; .sect .bss
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.sect .text
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.define .dvu8, .rmu8
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yl=4
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yh=8
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xl=12
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xh=16
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! .dvu8 yields ebx:eax = quotient from x / y
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! .rmu8 yields ecx:edx = remainder from x / y
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.dvu8:
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.rmu8:
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mov edx,yh(esp)
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test edx,edx
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mov eax,xh(esp) ! prepare for .divrem8
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push ebp ! move esp
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call .divrem8
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pop ebp ! move esp
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ret 16
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