| Line 110... |
Line 110... |
.globl __aeabi_idiv
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.globl __aeabi_idiv
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__aeabi_idiv:
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__aeabi_idiv:
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_div:
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_div:
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stmdb sp!, {r4, lr}
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stmdb sp!, {r4, lr}
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@ set r4 to 1 if one of the two inputs is negative
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and r2, r0, #0x80000000
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and r3, r1, #0x80000000
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eor r4, r2, r3
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@ Invert negative numbers
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tst r0, #0x80000000
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mvnne r0, r0
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addne r0, r0, #1
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tst r1, #0x80000000
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mvnne r1, r1
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addne r1, r1, #1
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@ divide r1 by r2, also use registers r0 and r4
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@ divide r1 by r2, also use registers r0 and r4
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mov r2, r1
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mov r2, r1
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mov r1, r0
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mov r1, r0
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cmp r2, #0
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cmp r2, #0
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| Line 172... |
Line 186... |
movcc r2,r2,lsr #1 @ and if bit 0 of r3 was zero, also
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movcc r2,r2,lsr #1 @ and if bit 0 of r3 was zero, also
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@ shift r2 right
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@ shift r2 right
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bcc 2b @ If carry not clear, r3 has shifted
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bcc 2b @ If carry not clear, r3 has shifted
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@ back to where it started, and we
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@ back to where it started, and we
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@ can end
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@ can end
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@ if one of the inputs is negetive then return a negative result
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tst r4, #0x80000000
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mvnne r0, r0
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addne r0, r0, #1
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3: ldmia sp!, {r4, pc}^
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3: ldmia sp!, {r4, pc}^
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/* strcpy: String copy function
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/* strcpy: String copy function
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char * strcpy ( char * destination, const char * source );
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char * strcpy ( char * destination, const char * source );
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| Line 184... |
Line 203... |
@ r0 points to destination
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@ r0 points to destination
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@ r1 points to source string which terminates with a 0
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@ r1 points to source string which terminates with a 0
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.globl strcpy
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.globl strcpy
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strcpy:
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strcpy:
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stmdb sp!, {r4-r7, lr}
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stmdb sp!, {r4-r7, lr}
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@ Use r6 to process the destination pointer.
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@ At the end of the function, r0 is returned, so need to preserve it
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mov r6, r0
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mov r6, r0
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@ get relative alignment of strings
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and r2, r6, #3
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and r3, r1, #3
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@ only if both strings are zero-aligned use the fast 'aligned' algorithm
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@ only if both strings are zero-aligned use the fast 'aligned' algorithm
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orrs r2, r3
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orr r2, r6, r1
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ands r2, r2, #3
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bne strcpy_slow
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bne strcpy_slow
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strcpy_fast:
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strcpy_fast:
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@ process strings 12 bytes at a time
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@ process strings 12 bytes at a time
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ldmia r1!, {r2-r5}
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ldmia r1!, {r2-r5}
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| Line 447... |
Line 466... |
add r0, r0, #0x10000
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add r0, r0, #0x10000
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str r0, [r1]
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str r0, [r1]
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mov pc, lr
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mov pc, lr
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.globl times
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times:
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@ TODO
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mov r0, #0
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mov pc, lr
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/* strncpy: String copy function */
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/* strncpy: String copy function */
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@ r0 points to destination
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@ r0 points to destination
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@ r1 points to source string
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@ r1 points to source string
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@ r2 is the number of bytes to copy
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@ r2 is the number of bytes to copy
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.globl strncpy
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.globl strncpy
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strncpy:
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strncpy:
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stmdb sp!, {r4, lr}
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stmdb sp!, {r4, lr}
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cmp r2, #0
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cmp r2, #0
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beq 2f
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beq 2f
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mov r4, #0
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add r4, r0, r2 @ set r4 to the address of the last byte copied
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1: ldrb r3, [r1], #1
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1: ldrb r3, [r1], #1
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strb r3, [r0], #1
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strb r3, [r0], #1
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add r4, r4, #1
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cmp r2, r4
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cmp r2, r4
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beq 2f
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bne 1b
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b 1b
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2: ldmia sp!, {r4, pc}^
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2: ldmia sp!, {r4, pc}^
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/* strncpy: String compare function */
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/* strncpy: String compare function */
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@ return the difference if the strings don't match
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@ return the difference if the strings don't match
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