FreeCalypso > hg > freecalypso-tools
annotate target-utils/libc/strlen.S @ 407:19e5a3e2f9c0
fcup-settime: moved time() retrieval a little closer to the output
A fundamental problem with all simple time transfer tools is that there is
always some delay between the time retrieval on the source system and that
transmitted time being set on the destination, and the resulting time
on the destination system is off by that delay amount. This delay cannot
be fully eliminated when working in a simple environment like ours,
but we should make our best effort to minimize it. In the present case,
moving the atinterf_init() call before the time() retrieval should make
a teensy-tiny improvement.
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Sat, 11 Aug 2018 21:52:17 +0000 |
parents | 3670e7768ab6 |
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95
3670e7768ab6
target-utils/libc: strlen optimized assembly implementation added
Mychaela Falconia <falcon@freecalypso.org>
parents:
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1 .text |
3670e7768ab6
target-utils/libc: strlen optimized assembly implementation added
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
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2 .code 32 |
3670e7768ab6
target-utils/libc: strlen optimized assembly implementation added
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
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3 .globl strlen |
3670e7768ab6
target-utils/libc: strlen optimized assembly implementation added
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
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4 strlen: |
3670e7768ab6
target-utils/libc: strlen optimized assembly implementation added
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
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5 mov r1, r0 |
3670e7768ab6
target-utils/libc: strlen optimized assembly implementation added
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
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6 1: ldrb r2, [r0], #1 |
3670e7768ab6
target-utils/libc: strlen optimized assembly implementation added
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
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7 cmn r2, #0 |
3670e7768ab6
target-utils/libc: strlen optimized assembly implementation added
Mychaela Falconia <falcon@freecalypso.org>
parents:
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8 bne 1b |
3670e7768ab6
target-utils/libc: strlen optimized assembly implementation added
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
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9 sbc r0, r0, r1 |
3670e7768ab6
target-utils/libc: strlen optimized assembly implementation added
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
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10 bx lr |