36 lines
650 B
C
36 lines
650 B
C
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/*
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* C library strlen routine
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*
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* This routine has been optimized for the CPU32+.
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* It should run on all 68k machines.
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*
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* W. Eric Norum
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* Saskatchewan Accelerator Laboratory
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* University of Saskatchewan
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* Saskatoon, Saskatchewan, CANADA
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* eric@skatter.usask.ca
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*/
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#include <string.h>
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/*
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* Test bytes using CPU32+ loop mode if possible.
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*/
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size_t
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strlen (const char *str)
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{
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unsigned int n = ~0;
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const char *cp = str;
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asm volatile ("1:\n"
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"\ttst.b (%0)+\n"
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#if defined(__mcpu32__)
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"\tdbeq %1,1b\n"
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#endif
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"\tbne.b 1b\n" :
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"=a" (cp), "=d" (n) :
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"0" (cp), "1" (n) :
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"cc");
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return (cp - str) - 1;
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}
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