| Line 202... |
Line 202... |
*/
|
*/
|
@ r0 points to destination
|
@ r0 points to destination
|
@ r1 points to source string which terminates with a 0
|
@ r1 points to source string which terminates with a 0
|
.globl strcpy
|
.globl strcpy
|
strcpy:
|
strcpy:
|
stmdb sp!, {r4-r7, lr}
|
stmdb sp!, {r4-r6, lr}
|
@ Use r6 to process the destination pointer.
|
@ Use r6 to process the destination pointer.
|
@ At the end of the function, r0 is returned, so need to preserve it
|
@ At the end of the function, r0 is returned, so need to preserve it
|
mov r6, r0
|
mov r6, r0
|
@ only if both strings are zero-aligned use the fast 'aligned' algorithm
|
@ only if both strings are zero-aligned use the fast 'aligned' algorithm
|
orr r2, r6, r1
|
orr r2, r6, r1
|
ands r2, r2, #3
|
tst r2, #3
|
bne strcpy_slow
|
bne strcpy_slow
|
|
|
strcpy_fast:
|
strcpy_fast:
|
@ process strings 12 bytes at a time
|
@ process strings 12 bytes at a time
|
ldmia r1!, {r2-r5}
|
ldmia r1!, {r2-r5}
|
|
|
@ check for a zero byte
|
@ check for a zero byte
|
@ only need to examine one of the strings because
|
@ only need to examine one of the strings because
|
@ they are equal up to this point!
|
@ they are equal up to this point!
|
ands r7, r2, #0xff
|
tst r2, #0xff
|
andnes r7, r2, #0xff00
|
tstne r2, #0xff00
|
andnes r7, r2, #0xff0000
|
tstne r2, #0xff0000
|
andnes r7, r2, #0xff000000
|
tstne r2, #0xff000000
|
strne r2, [r6], #4
|
strne r2, [r6], #4
|
subeq r1, r1, #4
|
subeq r1, r1, #4
|
|
|
andnes r7, r3, #0xff
|
tstne r3, #0xff
|
andnes r7, r3, #0xff00
|
tstne r3, #0xff00
|
andnes r7, r3, #0xff0000
|
tstne r3, #0xff0000
|
andnes r7, r3, #0xff000000
|
tstne r3, #0xff000000
|
strne r3, [r6], #4
|
strne r3, [r6], #4
|
subeq r1, r1, #4
|
subeq r1, r1, #4
|
|
|
andnes r7, r4, #0xff
|
tstne r4, #0xff
|
andnes r7, r4, #0xff00
|
tstne r4, #0xff00
|
andnes r7, r4, #0xff0000
|
tstne r4, #0xff0000
|
andnes r7, r4, #0xff000000
|
tstne r4, #0xff000000
|
strne r4, [r6], #4
|
strne r4, [r6], #4
|
subeq r1, r1, #4
|
subeq r1, r1, #4
|
|
|
andnes r7, r5, #0xff
|
tstne r5, #0xff
|
andnes r7, r5, #0xff00
|
tstne r5, #0xff00
|
andnes r7, r5, #0xff0000
|
tstne r5, #0xff0000
|
andnes r7, r5, #0xff000000
|
tstne r5, #0xff000000
|
strne r5, [r6], #4
|
strne r5, [r6], #4
|
subeq r1, r1, #4
|
subeq r1, r1, #4
|
|
|
@ loop back to look at next 12 bytes
|
@ loop back to look at next 12 bytes
|
bne strcpy_fast
|
bne strcpy_fast
|
|
|
@ the source string contains a zero character
|
@ the source string contains a zero character
|
|
|
|
|
|
strcpy_aligned_slow:
|
|
@ unroll the loop 4 times
|
|
ldr r3, [r1], #4
|
|
strb r3, [r6], #1
|
|
ands r4, r3, #0xff
|
|
ldmeqia sp!, {r4-r6, pc}^
|
|
|
|
lsr r3, r3, #8
|
|
strb r3, [r6], #1
|
|
ands r4, r3, #0xff
|
|
ldmeqia sp!, {r4-r6, pc}^
|
|
|
|
lsr r3, r3, #8
|
|
strb r3, [r6], #1
|
|
ands r4, r3, #0xff
|
|
ldmeqia sp!, {r4-r6, pc}^
|
|
|
|
lsr r3, r3, #8
|
|
strb r3, [r6], #1
|
|
ands r4, r3, #0xff
|
|
ldmeqia sp!, {r4-r6, pc}^
|
|
|
|
b strcpy_aligned_slow
|
|
|
|
|
strcpy_slow:
|
strcpy_slow:
|
@ unroll the loop 4 times
|
@ unroll the loop 4 times
|
ldrb r3, [r1], #1
|
ldrb r3, [r1], #1
|
strb r3, [r6], #1
|
strb r3, [r6], #1
|
cmp r3, #0
|
cmp r3, #0
|
ldmeqia sp!, {r4-r7, pc}^
|
ldmeqia sp!, {r4-r6, pc}^
|
|
|
ldrb r3, [r1], #1
|
ldrb r3, [r1], #1
|
strb r3, [r6], #1
|
strb r3, [r6], #1
|
cmp r3, #0
|
cmp r3, #0
|
ldmeqia sp!, {r4-r7, pc}^
|
ldmeqia sp!, {r4-r6, pc}^
|
|
|
ldrb r3, [r1], #1
|
ldrb r3, [r1], #1
|
strb r3, [r6], #1
|
strb r3, [r6], #1
|
cmp r3, #0
|
cmp r3, #0
|
ldmeqia sp!, {r4-r7, pc}^
|
ldmeqia sp!, {r4-r6, pc}^
|
|
|
ldrb r3, [r1], #1
|
ldrb r3, [r1], #1
|
strb r3, [r6], #1
|
strb r3, [r6], #1
|
cmp r3, #0
|
cmp r3, #0
|
ldmeqia sp!, {r4-r7, pc}^
|
ldmeqia sp!, {r4-r6, pc}^
|
|
|
b strcpy_slow
|
b strcpy_slow
|
|
|
|
|
/* int strcmp ( const char * str1, const char * str2 );
|
/* int strcmp ( const char * str1, const char * str2 );
|
| Line 287... |
Line 313... |
strcmp:
|
strcmp:
|
stmdb sp!, {r4-r8, lr}
|
stmdb sp!, {r4-r8, lr}
|
|
|
@ only if both strings are zero-aligned use the fast 'aligned' algorithm
|
@ only if both strings are zero-aligned use the fast 'aligned' algorithm
|
orr r2, r0, r1
|
orr r2, r0, r1
|
ands r2, r2, #3
|
tst r2, #3
|
bne strcmp_slow
|
bne strcmp_slow
|
|
|
strcmp_fast:
|
strcmp_fast:
|
@ process strings 12 bytes at a time
|
@ process strings 12 bytes at a time
|
ldmia r0!, {r2-r4}
|
ldmia r0!, {r2-r4}
|
| Line 304... |
Line 330... |
bne 3f
|
bne 3f
|
|
|
@ strings are equal - find a zero byte
|
@ strings are equal - find a zero byte
|
@ only need to examine one of the strings because
|
@ only need to examine one of the strings because
|
@ they are equal up to this point!
|
@ they are equal up to this point!
|
ands r8, r2, #0xff
|
tst r2, #0xff
|
andnes r8, r2, #0xff00
|
tstne r2, #0xff00
|
andnes r8, r2, #0xff0000
|
tstne r2, #0xff0000
|
andnes r8, r2, #0xff000000
|
tstne r2, #0xff000000
|
|
|
andnes r8, r3, #0xff
|
tstne r3, #0xff
|
andnes r8, r3, #0xff00
|
tstne r3, #0xff00
|
andnes r8, r3, #0xff0000
|
tstne r3, #0xff0000
|
andnes r8, r3, #0xff000000
|
tstne r3, #0xff000000
|
|
|
andnes r8, r4, #0xff
|
tstne r4, #0xff
|
andnes r8, r4, #0xff00
|
tstne r4, #0xff00
|
andnes r8, r4, #0xff0000
|
tstne r4, #0xff0000
|
andnes r8, r4, #0xff000000
|
tstne r4, #0xff000000
|
|
|
@ loop back to look at next 12 bytes
|
@ loop back to look at next 12 bytes
|
bne strcmp_fast
|
bne strcmp_fast
|
|
|
@ the first string contains a zero character
|
@ the first string contains a zero character
|
| Line 365... |
Line 391... |
|
|
|
|
|
|
@ Skipping first 4 bytes so just check they
|
@ Skipping first 4 bytes so just check they
|
@ don't contain an end of string 0 character
|
@ don't contain an end of string 0 character
|
2: ands r8, r2, #0xff
|
2: tst r2, #0xff
|
andnes r8, r2, #0xff00
|
tstne r2, #0xff00
|
andnes r8, r2, #0xff0000
|
tstne r2, #0xff0000
|
andnes r8, r2, #0xff000000
|
tstne r2, #0xff000000
|
beq bytes_zero
|
beq bytes_zero
|
|
|
@ start looking at 5th byte
|
@ start looking at 5th byte
|
sub r0, r0, #8
|
sub r0, r0, #8
|
sub r1, r1, #8
|
sub r1, r1, #8
|
| Line 404... |
Line 430... |
|
|
bne strcmp_slow
|
bne strcmp_slow
|
|
|
@ Skipping first 8 bytes so just check they
|
@ Skipping first 8 bytes so just check they
|
@ don't contain an end of string 0 character
|
@ don't contain an end of string 0 character
|
3: ands r8, r2, #0xff
|
3: tst r2, #0xff
|
andnes r8, r2, #0xff00
|
tstne r2, #0xff00
|
andnes r8, r2, #0xff0000
|
tstne r2, #0xff0000
|
andnes r8, r2, #0xff000000
|
tstne r2, #0xff000000
|
|
|
andnes r8, r3, #0xff
|
tstne r3, #0xff
|
andnes r8, r3, #0xff00
|
tstne r3, #0xff00
|
andnes r8, r3, #0xff0000
|
tstne r3, #0xff0000
|
andnes r8, r3, #0xff000000
|
tstne r3, #0xff000000
|
beq bytes_zero
|
beq bytes_zero
|
|
|
sub r0, r0, #4
|
sub r0, r0, #4
|
sub r1, r1, #4
|
sub r1, r1, #4
|
ldrb r2, [r0], #1
|
ldrb r2, [r0], #1
|
