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Merge "Fix assembler errors in generic arm strlen.c."

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Christopher Ferris 2013-07-17 00:19:42 +00:00 committed by Gerrit Code Review
commit f63c28f033
1 changed files with 13 additions and 4 deletions
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17
libc/arch-arm/generic/bionic/strlen.c
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@ -33,16 +33,16 @@ size_t strlen(const char *s)
{
__builtin_prefetch(s);
__builtin_prefetch(s+32);
union {
const char *b;
const uint32_t *w;
uintptr_t i;
} u;
// these are some scratch variables for the asm code below
uint32_t v, t;
// initialize the string length to zero
size_t l = 0;
@ -69,42 +69,50 @@ size_t strlen(const char *s)
"sub %[t], %[v], %[mask], lsr #7\n"
"and %[t], %[t], %[mask] \n"
"bics %[t], %[t], %[v] \n"
"it eq \n"
"ldreq %[v], [%[s]], #4 \n"
#if !defined(__OPTIMIZE_SIZE__)
"bne 1f \n"
"sub %[t], %[v], %[mask], lsr #7\n"
"and %[t], %[t], %[mask] \n"
"bics %[t], %[t], %[v] \n"
"it eq \n"
"ldreq %[v], [%[s]], #4 \n"
"bne 1f \n"
"sub %[t], %[v], %[mask], lsr #7\n"
"and %[t], %[t], %[mask] \n"
"bics %[t], %[t], %[v] \n"
"it eq \n"
"ldreq %[v], [%[s]], #4 \n"
"bne 1f \n"
"sub %[t], %[v], %[mask], lsr #7\n"
"and %[t], %[t], %[mask] \n"
"bics %[t], %[t], %[v] \n"
"it eq \n"
"ldreq %[v], [%[s]], #4 \n"
"bne 1f \n"
"sub %[t], %[v], %[mask], lsr #7\n"
"and %[t], %[t], %[mask] \n"
"bics %[t], %[t], %[v] \n"
"it eq \n"
"ldreq %[v], [%[s]], #4 \n"
"bne 1f \n"
"sub %[t], %[v], %[mask], lsr #7\n"
"and %[t], %[t], %[mask] \n"
"bics %[t], %[t], %[v] \n"
"it eq \n"
"ldreq %[v], [%[s]], #4 \n"
"bne 1f \n"
"sub %[t], %[v], %[mask], lsr #7\n"
"and %[t], %[t], %[mask] \n"
"bics %[t], %[t], %[v] \n"
"it eq \n"
"ldreq %[v], [%[s]], #4 \n"
"bne 1f \n"
"sub %[t], %[v], %[mask], lsr #7\n"
"and %[t], %[t], %[mask] \n"
"bics %[t], %[t], %[v] \n"
"it eq \n"
"ldreq %[v], [%[s]], #4 \n"
#endif
"beq 0b \n"
@ -117,13 +125,14 @@ size_t strlen(const char *s)
"beq 2f \n"
"add %[l], %[l], #1 \n"
"tst %[v], #0xFF0000 \n"
"it ne \n"
"addne %[l], %[l], #1 \n"
"2: \n"
: [l]"=&r"(l), [v]"=&r"(v), [t]"=&r"(t), [s]"=&r"(u.b)
: "%[l]"(l), "%[s]"(u.b), [mask]"r"(0x80808080UL)
: "cc"
);
done:
return l;
}