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Adem · Guest

This is from fastCode project. It's fast.

Could it also be turned into using WideStrings, please.

function PosEx_EWC_IA32_2_b(const ASearchString, AText: String; AOffset:
Integer = 1): Integer;
//Pattern = edi
//Source = esi
//SourceOffset/LoopVar = ecx
//PatternLength = edx
//Result = eax
asm
test eax, eax
jz @NotFound

test edx, edx
jz @NotFound

cmp ecx, 0
jle @NotFound

push esi
push edi
mov edi,eax

sub ecx, 1 //Make AOffset relative to zero
lea esi,[edx+ecx] //Load esi with starting addr of source String

mov eax,[edx-$04] //Get String Source Length
push eax
mov edx,[edi-$04] //Get String Pattern Length

test eax, eax
jz @NotFoundPop
test edx, edx
jz @NotFoundPop

//Calculate Number of Loops to execute
sub eax,ecx // Subtract the AOffset from the Length of the String
sub eax,edx // Backoff the Length of the Pattern
lea ecx,[eax+1] // Add 1 and move the result to the LoopVar

test ecx,ecx //If Pattern is longer than the remaining Source
jle @NotFoundPop // Pattern was not found.

mov al,[edi] //Get Pattern Character
jmp @BeginLoop

@NextSourceChar:
lea esi, [esi+1] //Advance to next Source character

@BeginLoop:
cmp al,[esi] //Compare to Source Character
jnz @NextSource //If no match, Break loop

@BeginPattern:
push edx //Save Pattern Length

@PatternLoop:
sub edx, 1 //Make Pattern Count an AOffset/Dec Loop Counter
jle @Found //If end of Pattern then must be found
mov ah, [edi+edx] //Get Pattern TNanoXMLChar
cmp ah, [esi+edx] //Compare to Source TNanoXMLChar
je @PatternLoop //if Pattern TNanoXMLChar Matches

pop edx //Restore Pattern Count if not found

@NextSource:
sub ecx, 1
jnz @NextSourceChar

@NotFoundPop:
pop eax
pop edi
pop esi
@NotFound:
xor eax, eax
jmp @Done

@Found:
pop edx
pop eax //Length of Source String
pop edi
pop esi

sub eax, ecx //Subtract Number of Iterations Left
sub eax, edx //Add the Length of the Pattern
lea eax,[eax+2]

@Done:
end;