Clear Array using indexing
static int Array[10] ={1,2,3,4,5,6,7,8,9,-1};
int main()
{
int size = 10;
ClearUsingIndex( Array, size);
// or you can use this ClearUsingIndex( &Array[0], size);
// call function that Clears static Array
}
// Clears array using indexing.
void ClearUsingIndex(int Array[], int size)
{
int i;
for (i = 0; i < size; i +=1)
Array[i] = 0;
}
Clear Array Using Pointers
void ClearUsingPointers(int *, int);
static int Array[10] ={1,2,3,4,5,6,7,8,9,-1};
int main()
{
ClearUsingPointers( &Array[0], SIZE);
// call function that Clears static Array
}
// Clears array using pointers.
void ClearUsingPointers(int *Array, int size)
{
int *p;
for (p = &Array[0]; p < &Array[size]; p = p+1)
*p= 0;
};
Clear Array Function in ASM as generated
By MS Compiler from C-code (using indexing)
; Copyright (C) 2000 Microsoft Corporation. All rights reserved.
.386
.model flat, c
; Custom Build Step, including a listing file placed in intermediate directory
; but without Source Browser information
; debug:
; ml -c -Zi "-Fl$(IntDir)\$(InputName).lst" "-Fo$(IntDir)\$(InputName).obj" "$(InputPath)"
; release:
; ml -c "-Fl$(IntDir)\$(InputName).lst" "-Fo$(IntDir)\$(InputName).obj" "$(InputPath)"
; outputs:
; $(IntDir)\$(InputName).obj
; Custom Build Step, including a listing file placed in intermediate directory
; and Source Browser information also placed in intermediate directory
; debug:
; ml -c -Zi "-Fl$(IntDir)\$(InputName).lst" "-FR$(IntDir)\$(InputName).sbr" "-Fo$(IntDir)\$(InputName).obj" "$(InputPath)"
; release:
; ml -c "-Fl$(IntDir)\$(InputName).lst" "-FR$(IntDir)\$(InputName).sbr" "-Fo$(IntDir)\$(InputName).obj" "$(InputPath)"
; outputs:
; $(IntDir)\$(InputName).obj
; $(IntDir)\$(InputName).sbr
.code
; Clear array using index as compiler generated.
;
; x:SDWORD - signed double word ( 4 bytes)
_TEXT SEGMENT
_i$ = -8
_Array$ = 8
_size$ = 12
ClearUsingIndex PROC NEAR ; ClearUsingIndex, COMDAT
; Line 14
00000 55 push ebp
00001 8b ec mov ebp, esp
00003 81 ec cc 00 00
00 sub esp, 204 ; 000000ccH
00009 53 push ebx
0000a 56 push esi
0000b 57 push edi
0000c 8d bd 34 ff ff
ff lea edi, DWORD PTR [ebp-204]
00012 b9 33 00 00 00 mov ecx, 51 ; 00000033H
00017 b8 cc cc cc cc mov eax, -858993460 ; ccccccccH
0001c f3 ab rep stosd
; Line 16
0001e c7 45 f8 00 00
00 00 mov DWORD PTR _i$[ebp], 0
00025 eb 09 jmp SHORT $L281
$L282:
00027 8b 45 f8 mov eax, DWORD PTR _i$[ebp]
0002a 83 c0 01 add eax, 1
0002d 89 45 f8 mov DWORD PTR _i$[ebp], eax
$L281:
00030 8b 45 f8 mov eax, DWORD PTR _i$[ebp]
00033 3b 45 0c cmp eax, DWORD PTR _size$[ebp]
00036 7d 0f jge SHORT $L279
; Line 17
00038 8b 45 f8 mov eax, DWORD PTR _i$[ebp]
0003b 8b 4d 08 mov ecx, DWORD PTR _Array$[ebp]
0003e c7 04 81 00 00
00 00 mov DWORD PTR [ecx+eax*4], 0
00045 eb e0 jmp SHORT $L282
$L279:
; Line 18
00047 5f pop edi
00048 5e pop esi
00049 5b pop ebx
0004a 8b e5 mov esp, ebp
0004c 5d pop ebp
0004d c3 ret 0
ClearUsingIndex ENDP ; ClearUsingIndex
_TEXT ENDS
END
end
Clear Array using Pointers as
generated By MS Compiler
.386
.model flat, c
; Custom Build Step, including a listing file placed in intermediate directory
; but without Source Browser information
; debug:
; ml -c -Zi "-Fl$(IntDir)\$(InputName).lst" "-Fo$(IntDir)\$(InputName).obj" "$(InputPath)"
; release:
; ml -c "-Fl$(IntDir)\$(InputName).lst" "-Fo$(IntDir)\$(InputName).obj" "$(InputPath)"
; outputs:
; $(IntDir)\$(InputName).obj
; Custom Build Step, including a listing file placed in intermediate directory
; and Source Browser information also placed in intermediate directory
; debug:
; ml -c -Zi "-Fl$(IntDir)\$(InputName).lst" "-FR$(IntDir)\$(InputName).sbr" "-Fo$(IntDir)\$(InputName).obj" "$(InputPath)"
; release:
; ml -c "-Fl$(IntDir)\$(InputName).lst" "-FR$(IntDir)\$(InputName).sbr" "-Fo$(IntDir)\$(InputName).obj" "$(InputPath)"
; outputs:
; $(IntDir)\$(InputName).obj
; $(IntDir)\$(InputName).sbr
.code
_TEXT SEGMENT
_p$ = -8
_Array$ = 8
_size$ = 12
ClearUsingPointers PROC NEAR ; ClearUsingPointers, COMDAT
; Line 15
push ebp
mov ebp, esp
sub esp, 204 ; 000000ccH
push ebx
push esi
push edi
lea edi, DWORD PTR [ebp-204]
mov ecx, 51 ; 00000033H
mov eax, -858993460 ; ccccccccH
rep stosd
; Line 17
mov eax, DWORD PTR _Array$[ebp]
mov DWORD PTR _p$[ebp], eax
jmp SHORT $L280
$L281:
mov eax, DWORD PTR _p$[ebp]
add eax, 4
mov DWORD PTR _p$[ebp], eax
$L280:
mov eax, DWORD PTR _size$[ebp]
mov ecx, DWORD PTR _Array$[ebp]
lea edx, DWORD PTR [ecx+eax*4]
cmp DWORD PTR _p$[ebp], edx
jae SHORT $L278
; Line 18
mov eax, DWORD PTR _p$[ebp]
mov DWORD PTR [eax], 0
jmp SHORT $L281
$L278:
; Line 19
pop edi
pop esi
pop ebx
mov esp, ebp
pop ebp
ret 0
ClearUsingPointers ENDP ; ClearUsingPointers
_TEXT ENDS
END
Optimized ASM using indexes
snapshot INDX after 6 Iterations
snapshot of Optimized INDX after 3 Iterations
Optimized ASM using pointers
snapshot using POINTERS after 7 iteratios
snapshot OPTIMZED using POINTERS after 7 iterations
Review the above points for SPARC and MIPS (SPIM) processors. Your home work assignments is
Home Assignment
Tutorial on how to run a program in DEBUG mode on a SPARC processor.
