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sort16.htm
ShellSort

This OS-independent macrolibrary can be included to 32bit programs written in EuroAssembler.

The library contains macroinstructions which sort data in memory.

sort16 HEAD

ShellSort TablePtr, NrOfRecords, RecordSize, CallbackProc

This macro can sort a table of records of the same size using the [ShellSort] algorithm. The entire table must be loaded in memory and it will be sorted in situ.

Input

DS is segment which containts the Table.
CS is segment which contains the CallbackProc.
TablePtr is pointer to the 1st record.
NrOfRecords is number of records in the table.
RecordSize is the size of one record in bytes. Table size = NrOfRecords * RecordSize.
CallbackProc is pointer to the callback procedure which sorts two records.

CallbackProc

is called with register calling convention.
It is expected to compare two records and return CF=0 if they are in proper order.
Otherwise it must swap the contents of these records and return CF=1.

Input

DS:SI is pointer to the first record to compare,
DS:DI is pointer to the second record to compare.

Output

CF=0 if both records were in desired order, or
CF=1 if both records were in wrong order, but they were swapped now.
BX,CX,BP,DS must be preserved by CallbackProc. Other GPR may be destroyed.

Output

None, all registers are preserved.

Example

MyTable DW 5,1,7,6,3,4,2 ; Unsorted WORD data. ShellSort MyTable, SIZE# MyTable/2, 2, MyCmpProc MyCmpProc PROC1 MOV AX,[SI] MOV DX,[DI] CMP DX,AX JNC .Done: ; Jump if both records are in order. MOV [SI],DX ; Otherwise swap them and return CF. MOV [DI],AX .Done: RET ENDP1 MyCmpProc

Tested by

tmac16.htm

ShellSort %MACRO TablePtr,NrOfRecords,RecordSize,CallbackProc
     PUSHW %CallbackProc,%RecordSize,%NrOfRecords,%NrOfRecords,%TablePtr
     CALL ShellSort16@RT::
ShellSort16@RT:: PROC1
      PUSHAW
      MOV BP,SP
%ShellSortTablePtr     %SET BP+18
%ShellSortNrOfRecords  %SET BP+20
%ShellSortRecordNr     %SET BP+22
%ShellSortRecordSize   %SET BP+24
%ShellSortCallbackProc %SET BP+26
 .10: SARW [%ShellSortNrOfRecords],1
      JNG .90:
      MOV CX,[%ShellSortRecordNr]
      SUB CX,[%ShellSortNrOfRecords]
      MOV BX,1
 .20: MOV SI,BX
 .30: MOV DI,SI
      ADD DI,[%ShellSortNrOfRecords]
      PUSH SI,DI
       MOV AX,SI
       DEC AX
       MULW [%ShellSortRecordSize]
       ADD AX,[%ShellSortTablePtr]
       MOV SI,AX
       MOV AX,DI
       DEC AX
       MULW [%ShellSortRecordSize]
       ADD AX,[%ShellSortTablePtr]
       MOV DI,AX
       CALL [%ShellSortCallbackProc]
      POP DI,SI
      JNC .40:
      SUB SI,[%ShellSortNrOfRecords]
      JA .30:
 .40: INC BX
      CMP BX,CX
      JNA .20:
      JMP .10:
 .90: POPAW
      RET 5*2
    ENDPROC1 ShellSort16@RT::
 %ENDMACRO ShellSort

   ENDHEAD sort16