Re: Inline assembler syntax error in Delphi 2006

Menaka wrote:
When I tried your first solution , I get Operand type mismatch error.
Please do help me on this.
Can you tell me what is the difference b/w xor eax, DWORD [cCRC32Table][EBX*4] // Result:=eax xor Table[ebx]
and xor eax, DWORD [cCRC32Table][EBX] // Result:=eax xor TByteArray(Table)
and your second solution(xor eax, dword ptr [cCRC32Table + ebx * 4]) denotes // Result:=eax xor Table[ebx] Please explian

What exactly is your array? Array of integer? Array of Longword? Array of byte? Assuming that it is an array of 32-bit quantities.

xor eax, DWORD [cCRC32Table][EBX*4]

This is bizarre syntax. If Delphi knows that you are trying to access array elements, then this is trying to XOR with the element of the array at index EBX*4.

xor eax, DWORD [cCRC32Table][EBX]

This is trying to xor with the element with index EBX. This is probably what you want, but the syntax is odd.

xor eax, dword ptr [cCRC32Table + ebx * 4]

This XORs with the element with index EBX, if the array cCRC32Table is an array of 32-bit (ie. 4 byte) quantities. This is probably what you want. (All the CRC32 tables I have come across are arrays of 4-byte quantities, IIRC).

Cheers,
Nicholas Sherlock

--
http://www.sherlocksoftware.org
.

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