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Last change
on this file since 444 was
444,
checked in by satin@…, 6 years ago
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add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc
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File size:
668 bytes
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| Line | |
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| 1 | .file "strlen.S" |
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| 2 | |
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| 3 | .section .text |
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| 4 | |
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| 5 | .global _strlen |
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| 6 | .type _strlen,@function |
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| 7 | _strlen: |
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| 8 | #ifdef __RX_DISALLOW_STRING_INSNS__ |
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| 9 | mov r1, r4 |
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| 10 | |
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| 11 | 1: mov.b [r1+], r5 |
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| 12 | cmp #0, r5 |
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| 13 | bne 1b |
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| 14 | |
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| 15 | sub #1, r1 |
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| 16 | sub r4, r1 |
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| 17 | rts |
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| 18 | #else |
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| 19 | add #0, r1, r4 ; Save a copy of the string start address and set the condition flags. |
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| 20 | beq null_string ; Test for a NULL pointer. |
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| 21 | mov #-1, r3 ; Set a limit on the number of bytes examined. |
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| 22 | mov #0, r2 ; Stop searching when we find a NUL byte. |
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| 23 | suntil.b ; Search until *r1 == r2 |
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| 24 | sub #1, r1 ; suntil.b leaves r1 pointing to the byte beyond the match. |
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| 25 | null_string: |
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| 26 | sub r4, r1 ; Compute the length. |
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| 27 | rts |
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| 28 | #endif |
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| 29 | .size _strlen, . - _strlen |
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